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Hydrogenaudio Forum => General Audio => Topic started by: Kohlrabi on 27 March, 2012, 04:12:16 AM

Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 27 March, 2012, 04:12:16 AM
Just found this article (http://trustmeimascientist.com/2012/03/03/ace-engineers-share-tips-and-secrets-of-mastering-for-itunes) via twitter, circled among mastering "engineers" (in fact Heba Kadry (https://twitter.com/#!/hebakadryy) reposted it, the girl who mastered the latest Mars Volta album, which reaches -12.79 dB on my RG scans, and is generally mastered in a horrible fashion).

This further backs my impression that most of them don't have a single clue of what they are doing. The section about the mastering practices of Rubin and Meller are especially eye-opening to me. Masterdisk "engineers" also apparently are now out to rape the Rush back catalogue. Further down they cite phase-reverse tests to prove AAC files are different from the original (wow, REALLY?).

The good thing is, I can use this article to decide which releases to avoid in the future. But I'm really at a loss what we can do beside that. I'm really fed up with mastering "engineers" destroying music releases.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: evereux on 27 March, 2012, 04:26:56 AM
Quote
Apple’s 256 kbps AAC files are supposed to sound pretty close to CD-quality and they routinely fool listeners in double-blind listening tests. But when record-producer/living-legend Rick Rubin heard the iTunes version of his new Red Hot Chili Peppers production I’m With You, he was reportedly appalled by how its sound changed during the conversion process.

“He was horrified,” Grammy-winning mastering engineer Vlado Meller told me when I visited him at Masterdisk.

“It was as if they had notched out certain frequencies in order to compress the file. The highs were missing and the lows were missing. The mids and the high-mids sounded like they were filtered out. When we did the A/B test with the original and the iTunes release it was like it was two different masters. If it wasn’t for [Rubin] making a stink and putting his weight behind it, we wouldn’t have this today. He deserves the credit for that.”


This makes me so sad. 
Title: Big-label mastering engineers don’t understand lossy formats
Post by: skamp on 27 March, 2012, 04:32:30 AM
They obviously think what they do is teh shit. Normal people think it sounds great. I remember when I first listened to Californication during New Year's Eve 1999-2000: loved the album, didn't complain about how it sounded. I developed the tastes I have now over several years, and I think it would be fair for others to qualify me as being anal.

What we have here is a mix of different tastes, a bunch of misconceptions, a certain lack of education, and perhaps straight up incompetence in certain cases. What can we do?

Fortunately, some albums still come out sounding great.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 27 March, 2012, 04:35:47 AM
I think you're being a little harsh on the article.

One thing amazed me though...
Quote
Bob Ludwig of Gateway Mastering, who is known for his objectivity and diligence, said "…[Another] important addition is the realization that the act of AAC encoding can cause clipping where there was none on the original PCM .wav or .aiff file"
This is news to a diligent mastering engineer? Has he just stepped out of a time machine from 1996?!


I haven't looked into "mastered for iTunes" - it seems strange to "need" to EQ a track to compensate for the effects of an AAC encoder running at 256kbps.

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 27 March, 2012, 04:44:10 AM
I think you're being a little harsh on the article.

I'm a little anxious right now, because I tried to listen to "Noctourniquet" by The Mars Volta and got all angry. 

I haven't looked into "mastered for iTunes" - it seems strange to "need" to EQ a track to compensate for the effects of an AAC encoder running at 256kbps.

Please understand how these people roll. They don't understand perceptual encoding. They don't understand that AAC encodes merely are intended to sound like the original. I guess they sit in front of their mastering software and see that the waveforms differ, and then start to fiddle with the stream they send into the encoder until the waveforms match better. I have no definitive proof of that, but the phase-inversion comparison gives me the strong impression that this is the case.

Just to make it clear, I don't intend to give disrespect to mastering engineers or engineers in general, just to the breed which completely abandoned, or never acquired, understanding of digital audio, and still sprout their bullshit all over the internet, and keep destroying legit good music. They are a disgrace to the engineering community.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: KMD on 27 March, 2012, 05:14:57 AM
Thats  round the wrong way,  the article said the waveform shapes were not the relevant factor it was the person skeptical of mastered for itunes that was looking at the sum of  two file with one inverted.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Nessuno on 27 March, 2012, 05:55:25 AM
Just to make it clear, I don't intend to give disrespect to mastering engineers or engineers in general
[...]
They are a disgrace to the engineering community.


Actually, americans have a rather imaginative way to use the word "engineer"... 
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Porcus on 27 March, 2012, 06:15:50 AM
I bet the people behind Monkey's Audio will want to bomb a certain kohlrabi with rotten bananas over this comparison.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: DonP on 27 March, 2012, 07:38:10 AM
Just to make it clear, I don't intend to give disrespect to mastering engineers or engineers in general
[...]
They are a disgrace to the engineering community.


Actually, americans have a rather imaginative way to use the word "engineer"... 


There are several senses of it.

1) a guy who drives a train

2) Someone who puts science into practice.  Generally considered as needing at least a BS/BE degree in the field and for some disciplines, a license.

3) Someone looking to dignify his job, like a janitor calling himself a sanitation engineer.  In fact, sanitation engineers design things like sewage and water treatment plants.


As I understand, in Britain machinists are called engineers, but not in the US.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: dhromed on 27 March, 2012, 09:10:53 AM
I'm a little anxious right now, because I tried to listen to "Noctourniquet" by The Mars Volta and got all angry.


I don't consider the new album (and the one previous to that) to be as harsh as the earlier ones, but subjectively I find it less interesting. It's just a shame that the earlier albums break one's ear drums, because on purely musical terms, I think they're very good. That is what saddens me. It's like putting on a light show but you shine all the spotlights directly in people's faces.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: RobWansbeck on 27 March, 2012, 11:11:53 AM
Vlado Meller  is reported as saying :

“  The highs were missing and the lows were missing. The mids and the high-mids sounded like they were filtered out.  “

Seems like everything was missing.  Perhaps he forgot to turn the volume up!
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 27 March, 2012, 11:14:19 AM
http://www.hydrogenaudio.org/forums/index....st&p=787986 (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=93628&view=findpost&p=787986)
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Arnold B. Krueger on 27 March, 2012, 12:15:23 PM
Thats  round the wrong way,  the article said the waveform shapes were not the relevant factor it was the person skeptical of mastered for itunes that was looking at the sum of  two file with one inverted.


That is very sad as well.

That goes back to knowing what a perceptual coder does.

The one question that really matters is whether or not they've done reliable listening tests. The expected answer is "No".

BTW, Bob Ludwig is probably about my age.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 28 March, 2012, 06:39:18 PM
I think you're being a little harsh on the article.


Thats  round the wrong way,  the article said the waveform shapes were not the relevant factor it was the person skeptical of mastered for itunes that was looking at the sum of  two file with one inverted.


From the Author

Thanks for sharing the article, Kohlrabi. If you have another read of it sometime, I think you'll find it's pretty even-handed.

I get the sense that you disagree with the claims made by the mastering engineers, and not with the article itself, which tries to take a neutral stance.

Since this was piece of reportage, rather than opinion, I wanted to accurately deliver the news, present both the commentary and the criticism, and to offer some dispassionate analysis of both stances. The article tries to remain skeptical of the magnitude of the claims, but I also stand by the fact that it's unfair to dismiss them entirely without proper tests.

If you do want to read an opinion piece, you'll probably find that my own feelings about blind listening are pretty congruent with the philosophy here at Hydrogen Audio. I'm a big supporter of this site and of ABX tests in general, and I even wrote a supportive opinion piece about blind listening tests in the very same issue you cited! (You can read that here):

"Can You Hear What I Hear? A Guide to Listening Blind (http://trustmeimascientist.com/2012/03/03/can-you-hear-what-i-hear-an-mp3-test-and-a-guide-to-listening-blind/)"

I will have to disagree with the extreme stance that mastering engineers are generally snake-oil salesmen (I've never had an experience that would lead me to believe that) or that Mr. Ludwig or Ms. Kadry are incompetent (I know both, and they're definitely not).

However, as a matter of personal opinion, I would agree that Rick Rubin overstates the audible differences normally found between high-res AAC files and their original WAV masters. I'd also agree that at least one of Meller's comments was probably more figurative and expressive than it was literal.

With that said, the engineers I interviewed told me that in "Mastered for iTunes", Apple also fixed an actual issue they had in the past with creating AAC files from high-resolution masters. To be fair, even Bob Ludwig agrees that 256kbps files won't necessarily sound any worse than traditional CD files - Just so long as they're created properly, and the engineer can verify there were no issues with the transfer. (He says that this is something that they're now able to do.)

The other real development appears to be that MEs can now easily and effectively hear the differences between their original master and the file that the iTunes store's proprietary encoder will create. (I'm told that, for better or worse, it's not the same encoder used in the consumer version of iTunes.)

Who knows? Even if the AACs sound identical in 95% of cases, this new ability to actually listen and check can't be a bad thing

Personally, I think the new tools are a good idea, but I'm not about to replace my music library with new "Mastered for iTunes" versions anytime soon. 

I definitely appreciate the healthy dose of skepticism here on Hydrogen Audio, and would agree that people who have a service or product to sell sometimes dramatize their claims... But show me a salesman who doesn't, and I'll show you a salesman who's out of a job!

Thanks again for the share and the comments. Keep doing what you guys do!

Very best,

Justin Colletti
Recordist, Journalist
http://justincolletti.com (http://justincolletti.com)
http://trustmeimascientist.com (http://trustmeimascientist.com)
http://sonicscoop.com (http://sonicscoop.com)
Title: Big-label mastering engineers don’t understand lossy formats
Post by: ExUser on 28 March, 2012, 10:12:59 PM
show me a salesman who doesn't, and I'll show you a salesman who's out of a job
If that's the case, I fully support sales staff unemployment.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 28 March, 2012, 11:29:31 PM
I get the sense that you disagree with the claims made by the mastering engineers, and not with the article itself, which tries to take a neutral stance.

Since this was piece of reportage, rather than opinion, I wanted to accurately deliver the news, present both the commentary and the criticism, and to offer some dispassionate analysis of both stances.


Yes, clearly people are mostly annoyed by how clueless some of the people doing the mastering are.  That Bob Ludwig quote where he seemingly does not understand what audio encoding is or why it might cause clipping is particularly galling from someone doing any sort of audio work.  Particularly to people like me who consider the huge amount of clipping accidentally introduced by incompetent engineers to be one of the worst aspects of modern music.

The article tries to remain skeptical of the magnitude of the claims, but I also stand by the fact that it's unfair to dismiss them entirely without proper tests.


Yes of course, however some of the stuff you say is just ... odd.  For instance:

Quote
First is that Sheperd’s sample size of one song is far too small to be conclusive — especially with a manual process like mastering for iTunes.

Second is that Sheperd’s methodology is flawed. He takes a song that was mastered in August, before the new protocols were in place, and then uses both a lower bit-depth source-file and a different AAC encoder than was used to create the “Mastered for iTunes” version.

With all that in mind, it would be no surprise if Shepherd’s results are different. He then continues to compare his own custom file to a down-sampled CD version rather than the original high-resolution master. In his test, Shepherd also neglects to run either a blind ABX test or an objective frequency analyzer to verify which version of the file could be shown to sound more similar to the original during normal playback.

Even if Shepherd fixes his methodology, there’s still a third argument that could call his analysis into question: Since the Mastered for iTunes process uses a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process, it’s plausible to suggest that the phase-shift inherent in all non-linear EQs could cause his phase-based null test to report additional cancellation differences — even if the EQ was successful in restoring the original frequency balance.


No, first everything that clown says is irrelevant since you can't show that one encoding is closer to CD by subtraction.    Its not that his sample size is too small its that his test is meaningless.  Its not that he took a song mastered at the wrong time, its that he doesn't know what hes doing.  Why are you talking about EQ when nothing he says could possibly make sense?  Actually, why are you even addressing this guy aside from to say "no I'm sorry, thats not how audio works"?

I will have to disagree with the extreme stance that mastering engineers are generally snake-oil salesmen (I've never had an experience that would lead me to believe that) or that Mr. Ludwig or Ms. Kadry are incompetent (I know both, and they're definitely not).


That part where Ludwig discovers that very loud digital files can easily clip when you do any sort of lossy processing, was that taken out of context?  Because by implying that hes unfamiliar with digital processing you make him sound utterly incompetent . . .
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Fandango on 28 March, 2012, 11:34:15 PM
show me a salesman who doesn't, and I'll show you a salesman who's out of a job
If that's the case, I fully support sales staff unemployment.

Me too.

The main characteristic of snake oil is that the one who sells it claims it can do stuff, it in reality cannot. Another not so well known characteristic is that snake oil might actually do stuff that the salesman is either unaware of or if he is he is silent about it...

With that said, the engineers I interviewed told me that in "Mastered for iTunes", Apple also fixed an actual issue they had in the past with creating AAC files from high-resolution masters. To be fair, even Bob Ludwig agrees that 256kbps files won't necessarily sound any worse than traditional CD files - Just so long as they're created properly, and the engineer can verify there were no issues with the transfer. (He says that this is something that they're now able to do.)

The other real development appears to be that MEs can now easily and effectively hear the differences between their original master and the file that the iTunes store's proprietary encoder will create. (I'm told that, for better or worse, it's not the same encoder used in the consumer version of iTunes.)

So they're telling you that they have basically added a signal that they can audibly perceive later on when playing the AAC? And Apple even uses a special version of their encoder to ensure the signal is not extenuated? For what? To ensure the encoding process didn't "damage" the music too much? I've never heard of a more ridiculous process. "Mastered for iTunes" is a sound degrading watermark, really?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 28 March, 2012, 11:46:44 PM
Quote
the Mastered for iTunes process uses a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process

Citation please!
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Fandango on 29 March, 2012, 12:14:31 AM
@greynol: Oh, here it is explained by a guy named Bob Ludwig, he says some funny things along the way but I think the concept behind "Mastered for iTunes" should be somewhat clearer now. Whether it's the only processing "Matered for iTunes" is capable of remains unclear, I guess.

Quote
4: Speaking of compression, many people believe you cannot get a download to sound good no matter what you do. I disagree, not that I feel the overall dynamics of a download can equal that of an LP (or can they)—but I play a great deal of downloaded music at home through a decent DAC and system, and I'm surprised at how good it can sound. Do you master things differently for iTunes for example?

Bob Ludwig: Apple has begun a new initiative called "Mastered for iTunes" which greatly improves the sound of iTunes AAC encodes without changing a single piece of hardware on the 250,000,000 players in the field. It can be so dramatic you can easily hear the difference between the new and old technology on your little laptop speakers.

Instead of ingesting the music from a CD rip or 16-bit file, the new system uses 24-bit master files for the encode. The AAC encoder can make use of bits 17-24. An important addition is the realization that the act of AAC encoding can cause clipping where there was none on the original PCM .wav or .aiff file. In classical music this encoder induced clipping can occur at the occasional climaxes or in a typical over-compressed pop/rock recording, many times a second. Apple has created tools to log the number, severity and time of each clip so the mastering engineer can lower the level of the 24-bit master by fractions of a dB and the clips and resulting distortion from them is eliminated.

It is a complicated answer, but a 24-bit AAC encoded file can thus sound better and measure better in certain cases than a normal 16-bit Compact Disc, which unfortunately has been regarded as the gold standard for sound in these comparisons.


Well, I'm not that into the matter of lossy encoding, but can't you just make a 16bit master that is not that freaking loud and brick-walled and have the same effect at the end? The whole "Mastered for iTunes" fad is like a cruel joke when the industry is putting out crap like this:

I'm a little anxious right now, because I tried to listen to "Noctourniquet" by The Mars Volta and got all angry.

So you only got a little anxious and angry? Why didn't you scratch your eyes out, poked your eardrums and shredded your skin when listening to this joke of an album?

When I tried listening to it, it sounded as if something was wrong with my speakers, like if a driver was dead. Or as if my amplifier was broken. No kidding. Of course I knew they weren't but...

People see for yourselves, this is one of the worst DR meter results if not the worst, I've seen:

Code: [Select]
foobar2000 1.1.11 / Dynamic Range Meter 1.1.1
log date: 2012-03-29 05:47:45

--------------------------------------------------------------------------------
Analyzed: The Mars Volta / Noctourniquet
--------------------------------------------------------------------------------

DR         Peak         RMS     Duration Track
--------------------------------------------------------------------------------
DR4       -0.20 dB    -6.74 dB      4:49 01-The Whip Hand
DR5        0.00 dB    -6.04 dB      5:11 02-Aegis
DR3        0.00 dB    -3.91 dB      4:22 03-Dyslexicon
DR2        0.00 dB    -4.44 dB      6:43 04-Empty Vessels Make the Loudest Sound
DR3        0.00 dB    -4.90 dB      4:44 05-The Malkin Jewel
DR3        0.00 dB    -4.95 dB      4:16 06-Lapochka
DR4        0.00 dB    -6.11 dB      7:26 07-In Absentia
DR3        0.00 dB    -5.51 dB      3:58 08-Imago
DR3        0.00 dB    -4.53 dB      3:33 09-Molochwalker
DR4        0.00 dB    -7.72 dB      4:25 10-Trinkets Pale of Moon
DR3        0.00 dB    -4.94 dB      3:54 11-Vedamalady
DR4        0.00 dB    -6.38 dB      5:39 12-Noctourniquet
DR3        0.00 dB    -5.75 dB      5:36 13-Zed and Two Naughts
--------------------------------------------------------------------------------

Number of tracks:  13
Official DR value: DR3

Samplerate:        44100 Hz
Channels:          2
Bits per sample:   16
Bitrate:           1003 kbps
Codec:             WavPack
================================================================================

Mastered for iTunes my ass, that's like putting a cherry on top of a pile of shit.

PS: The Dynamic Range Meter results for Ms. Kadry's latest work are worse than Frances the Mute (DR7), Amputechture (DR6) and The Bedlam in Goliath (DR6).
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 12:23:37 AM
I read the paper by Apple back when we first discussed it.  I don't believe it said anything about "a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process," or did it?

To me this sounds like the author doesn't understand even the basics about how lossy compression works.

EDIT: I read the paper again.  It says nothing about additive EQ to restore frequencies that are lost during the AAC conversion process.  Not a big surprise.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Fandango on 29 March, 2012, 12:30:57 AM
Ah, it has been discussed before and Apple actually released a paper about it? I didn't know that. But yes, regarding the article, I got the same impression, you don't even have to be an expert in the matter to notice that he isn't actually explaining how this technique by Apple works. It's not well written and the fact that one mastering engineers is linking to it, let's one believe that she doesn't have a clue of what she is doing.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 12:35:58 AM
I provided a link already.  Go to the first post in that topic for a link to the paper.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Fandango on 29 March, 2012, 12:51:35 AM
I provided a link already.  Go to the first post in that topic for a link to the paper.

Thanks, I'm skimming throught it already...

Quote
You’re being provided with all the tools you’ll need to encode your masters precisely the same way the iTunes Store does so that you can audition exactly what they’ll sound like as iTunes Plus AAC files.

I have the feeling that this will not end well!  The article from the first post here provides proof of that. MEs are tweaking already.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 12:53:15 AM
I think the most damning thing about the mastered for itunes program is the incredible detail Apple felt they needed to go into in order to explain how to correctly master tracks so that they do not clip.  They explain what clipping is, how it happens, and why someone would want to avoid it.  Then they give tools to check for clipping, and urge people to convert their files to lossy first, check for clipping, and then lower the damn volume if it clipped.  Finally, they remind people that Apple products use soundcheck, so trying to make their tracks louder digitally will generally not have the intended effect.

Essentially the entire document assumes that the reader has absolutely no idea how to master a CD, and if left to their own devices, they would screw it up.  It certainly seems to me at least that Apple's engineers have independently come to much of the same conclusions as the people in this thread, and are at least trying to do something about it.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 12:59:01 AM
As I said in the dedicated discussion, Apple is addressing inter-sample overs.  They were very clear that DRC is subject to artistic expression.

Please, let's not have a parallel discussion about this here.

EDIT: Apple is addressing clipping resulting from lossy compression.  I'm brain-dead this evening.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Fandango on 29 March, 2012, 01:04:31 AM
Essentially the entire document assumes that the reader has absolutely no idea how to master a CD, and if left to their own devices, they would screw it up.

Well, they don't have a clue or why else would they do what they do and say what they say since the age the CD arrived? Wasn't Apple too trustful of what the engineers eventually will do with this Mastered for iTunes concept and the provided tools?

From the article by Mr. Coletti it seems some mastering engineers already interpret the concept of Mastering for iTunes their own way and find quite amusing ways to "cheat" the AAC encoder. I'd love to hear what codec developers at Apple have to tell about their cooperation with those guys. But that must remain behind NDA-secured corporate walls, I guess.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 01:12:24 AM
As I said in the dedicated discussion, Apple is addressing inter-sample overs.  They were very clear that DRC is subject to artistic expression.

Please, let's not have a parallel discussion about this here.


Yes of course, and I'm not interested in that argument.  I'm just pointing out their presumed level of reader competence:

Quote
Clipping is a form of audio distortion
and can be caused in many ways. In
general, it is the result of the amplitude
of a signal becoming too great to be
accurately represented by a system.


Can you imagine if FAA flight regulations began like this?

"Plane crashes are a form of impacting the ground at high speed.  Plane crashes can be caused in many ways.  In general, they are the result of the plane descending too fast..."

Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 01:30:11 AM
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 29 March, 2012, 04:36:14 AM
It's what happens when the art-world and science/engineering-world meet head-on. You get arty people operating technical equipment, when their understanding is barely one step up from believing that magic pixies are making it all work.

Actually, some of them probably do believe in the magic pixies.


It would probably be even worse if we only got to hear songs written by artless science types*. Good songs, badly recorded, vs bad songs perfectly recorded?

* - I can upload something I wrote to prove the point.

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 29 March, 2012, 09:24:55 AM
show me a salesman who doesn't, and I'll show you a salesman who's out of a job
If that's the case, I fully support sales staff unemployment.

Haha - Fair enough.

That Bob Ludwig quote where he seemingly does not understand what audio encoding is or why it might cause clipping is particularly galling from someone doing any sort of audio work.  Particularly to people like me who consider the huge amount of clipping accidentally introduced by incompetent engineers to be one of the worst aspects of modern music.


Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are. From what I remember, he's come recommending that masters peak at a maximum of a full -1db below 0dbfs to reduce unintended clipping, which is an idea that was balked at by many of the mastering engineers I spoke with. Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.

First everything that clown (Shepherd) says is irrelevant since you can't show that one encoding is closer to CD by subtraction.  [/b]  Its not that his sample size is too small its that his test is meaningless.  Its not that he took a song mastered at the wrong time, its that he doesn't know what hes doing.  Why are you talking about EQ when nothing he says could possibly make sense?  Actually, why are you even addressing this guy aside from to say "no I'm sorry, thats not how audio works"?


What you seem to take issue with here is that I presented the most damning argument last rather than first (because that's how mounting arguments work!) Otherwise, I think we're on the same page. 

Shepherd's faulty analysis was ranked high in Google and getting a ton of reads, so I felt it was only appropriate to address it in the article. Please remember that not everyone has the same level of understanding, and that a nuanced breakdown is extremely valuable to many readers.


I read the paper by Apple back when we first discussed it.  I don't believe it said anything about "a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process," or did it?
...
EDIT: I read the paper again.  It says nothing about additive EQ to restore frequencies that are lost during the AAC conversion process.  Not a big surprise.


Correct greynol, that fact is not from the Apple paper, but from my interviews with over a half dozen of the busiest M.E.s in New York City.

They say that in practice, they use the new toolset to A/B before-and-after files, and then use additive EQ to compensate for changes in tone if they find it necessary to do so.

In theory, that's not much different than having two slightly different EQ settings so that a cassette and vinyl version sound closer.

Many of you might effectively argue that this process is subjective and open to error (true) or that the sonic differences between a 24-bit WAV and a 256kbps AAC tend to be much slighter than the differences between vinyl and cassette (also true).


PS: The Dynamic Range Meter results for Ms. Kadry's latest work are worse than Frances the Mute (DR7), Amputechture (DR6) and The Bedlam in Goliath (DR6).


To be fair, I believe that's a reflection of taste rather than competence. Making a master that's less hot isn't that difficult, and it doesn't take much advanced training at all.

To argue that Kadry or any other in-demand ME don't know what they're doing misses the point. I believe they know exactly what they're doing: Making very loud masters!

Whether you dig what they're doing is an entirely different question. I just don't think it makes sense to argue about that on a "technical" level.

(Unless you we were citing some scientific double-blind tests that compare specific levels of dynamic range with perceived enjoyment. Now that would be neat! If you know of such a study, I'd be the first to read it.)

I'll admit that I haven't heard the records you've cited here, but in defense of Kadry, it's important to remember that any mastering job can be deemed "good" as long as it's what it was intended to be. We just have to judge it by the creator's criteria.

For instance: I love the sound of a lot of Dave Fridmann's work with the Flaming Lips, which is often clipped-to-death. What's important to remember is that those records aren't clipped because they're loud... they're loud because they're clipped!

That's a world of difference. That style of mixing and mastering is an aesthetic choice, and not some unintended side-effect of ignorance or accident.

The truth is that mastering engineers who get repeat clients aren't making loud records by mistake. You don't have to like their work, but I still think it's important to make a fair argument. Otherwise, we just end up sounding like dimwits who trash on studio reverbs because they don't sound like actual concert halls.

It's also useful to remember that to people younger than us, taste-based arguments against hot, bombastic masters is going to sound a whole lot like "Hey you damn kids, get off of my lawn!"

In reality, that's part of the reason the kids are into those records in the first place! Don't you remember what it's like to be young?    What self-respecting American teenager wants to listen exclusively to music his parents would approve of?

In the end, I think that with the right effort, we can bring healthy dynamic range back into the mainstream. I just don't think we're going to do that by making negative or unprincipled arguments.

It's what happens when the art-world and science/engineering-world meet head-on.
...
It would probably be even worse if we only got to hear songs written by artless science types*. Good songs, badly recorded, vs bad songs perfectly recorded?


Now that, I'd agree with in a heartbeat.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 10:22:45 AM
I read the paper by Apple back when we first discussed it.  I don't believe it said anything about "a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process," or did it?
...
EDIT: I read the paper again.  It says nothing about additive EQ to restore frequencies that are lost during the AAC conversion process.  Not a big surprise.

Correct greynol, that fact is not from the Apple paper, but from my interviews with over a half dozen of the busiest M.E.s in New York City.

Your article states that the Mastered for iTunes process adds EQ to compensate for losses caused by the encoding process.  It should say that some mastering specialists are taking a liberty that is not prescribed by the process.

They say that in practice, they use the new toolset to A/B before-and-after files, and then use additive EQ to compensate for changes in tone if they find it necessary to do so.

So that you understand, Justin, A/B is not ABX.  If these specialists were to actually employ ABX then they would quickly realize that the compression process does not color the tone in the way that they imagine.

In theory, that's not much different than having two slightly different EQ settings so that a cassette and vinyl version sound closer.

It would be if the compression process actually colored the tone.

Many of you might effectively argue that this process is subjective and open to error (true)

Subjective in that some people are more capable of identifying lossy artifacts than others? Yes.  Subjective in that expectation bias cannot be circumvented? No.

that the sonic differences between a 24-bit WAV and a 256kbps AAC tend to be much slighter than the differences between vinyl and cassette (also true).

Yes, but the type of audible lossy artifacts cannot be corrected through pre-equalization.  To think otherwise is foolhardy.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 10:37:59 AM
Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are. From what I remember, he's come recommending that masters peak at a maximum of a full -1db below 0dbfs to reduce unintended clipping, which is an idea that was balked at by many of the mastering engineers I spoke with. Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.

I don't think Saratoga will mind me speaking to this.  The issue is not peak levels, the issue is audible distortion that is caused by aggressive use of dynamic range compression.  Reducing the volume by a "full" decibel below full-scale does very little to cool a hot master.

For instance: I love the sound of a lot of Dave Fridmann's work with the Flaming Lips, which is often clipped-to-death. What's important to remember is that those records aren't clipped because they're loud... they're loud because they're clipped!

They're loud because they're compressed (and sometimes given mid-range emphasis) and often this compression can cause clipping regardless of whether the final master reaches full-scale.

That's a world of difference.

Yes, especially when you actually focus on the offending mechanism.

You might find this educational:
http://www.hydrogenaudio.org/forums/index....showtopic=91909 (http://www.hydrogenaudio.org/forums/index.php?showtopic=91909)
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 29 March, 2012, 11:45:42 AM
That style of mixing and mastering is an aesthetic choice, and not some unintended side-effect of ignorance or accident.

The truth is that mastering engineers who get repeat clients aren't making loud records by mistake. You don't have to like their work, but I still think it's important to make a fair argument. Otherwise, we just end up sounding like dimwits who trash on studio reverbs because they don't sound like actual concert halls.

It's also useful to remember that to people younger than us, taste-based arguments against hot, bombastic masters is going to sound a whole lot like "Hey you damn kids, get off of my lawn!"

In reality, that's part of the reason the kids are into those records in the first place!
You can have that sound without clipping. What you can't have is that loudness. If you switch Sound Check on, or use ReplayGain, the latter is irrelevant.

Some clipping is inaudible. Some clipping is gratuitously audible, and sounds like ****. Teenagers might like a loud aggressive sound, but when they grow up and try to play their music on something other than a mobile phone, they'll find the clipped bass just sounds poor. Or maybe, as CliveB suggests in that thread greynol just linked to, people will give up trying to play recent pop music on decent stereos because it just sounds so bad. I know I have. I save it for the car/train.


I think there's a big distinction between intentionally changing the sound to make the whole recording sound more dense, and trying to make the master louder while trying not to change the sound too much. Others will disagree, but it's the latter that I think is a disaster. You have a recording, it sounds just how you want it to - but then you wreck it to make it louder. That's pathetic. Whereas taking a recording which doesn't sound how you want it to, and trashing it to make it sound like you want it to is another matter entirely!

Cheers,
David.

EDIT: You can change the sound of something without clipping it at all, or even making it louder. Here's a jazz example...
original:
[attachment=6995:04_Clair...ection_2.mp3]
compressed:
[attachment=6996:04_Clair...Q_16_bit.mp3]
I'm sure someone with access to a proper compressor and some unmastered pop music could prove the point better.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: krabapple on 29 March, 2012, 12:10:15 PM
For instance: I love the sound of a lot of Dave Fridmann's work with the Flaming Lips, which is often clipped-to-death. What's important to remember is that those records aren't clipped because they're loud... they're loud because they're clipped!
.
.
.
It's also useful to remember that to people younger than us, taste-based arguments against hot, bombastic masters is going to sound a whole lot like "Hey you damn kids, get off of my lawn!"



Wayne Coyne is just one year younger than me.  Given the kind of mastering he favors, I've got to wonder how good his hearing is at this point.   


Title: Big-label mastering engineers don’t understand lossy formats
Post by: krabapple on 29 March, 2012, 12:14:48 PM
So that you understand, Justin, A/B is not ABX.  If these specialists were to actually employ ABX then they would quickly realize that the compression process does not color the tone in the way that they imagine.
...

It would be if the compression process actually colored the tone.



You mean 'data compression' (high bitrate lossy encoding in this case) here rather than dynamic range compression, right?  The latter certainly can subjectively 'color the tone'.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: krabapple on 29 March, 2012, 12:17:08 PM
Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are. From what I remember, he's come recommending that masters peak at a maximum of a full -1db below 0dbfs to reduce unintended clipping, which is an idea that was balked at by many of the mastering engineers I spoke with. Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.

I don't think Saratoga will mind me speaking to this.  The issue is not peak levels, the issue is audible distortion that is caused by aggressive use of dynamic range compression.  Reducing the volume by a "full" decibel below full-scale does very little to cool a hot master.


Not to mention that individual tracks of a multitrack can already be made 'hot' early in the production process -- nothing done at the mastering stage can reverse that.

Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 29 March, 2012, 12:18:21 PM
Your article states that the Mastered for iTunes process adds EQ to compensate for losses caused by the encoding process.  It should say that some mastering specialists are taking a liberty that is not prescribed by the process.


As a matter of practice, the engineers I spoke to employ the judicious use of EQ as part of the process. You're entitled to your argument, although I feel it's a semantic one. I still think the way it was expressed in the article gives the clearest picture of what engineers are actually doing. Of course, you don't have to agree!

So that you understand, Justin, A/B is not ABX.  If these specialists were to actually employ ABX then they would quickly realize that the compression process does not color the tone in the way that they imagine.


I'm aware that A/B and ABX are different, and I believe any credible mastering engineer would be as well. The M.E.s I spoke to are arguing that faults in the encoding process have resulted in audible tonal differences in the resulting files in many cases. Whether you believe that claim is another story.

As you already know, listening tests suggest that with proper encodes at a decent rate, this shouldn't be the case for almost any listeners. This fact is also mentioned in the story, complete with a link to an entire article on the importance of blind listening tests (http://trustmeimascientist.com/2012/03/03/can-you-hear-what-i-hear-an-mp3-test-and-a-guide-to-listening-blind/). I felt that was a responsible thing to do.

In theory, that's not much different than having two slightly different EQ settings so that a cassette and vinyl version sound closer.

It would be if the compression process actually colored the tone.


See above.

Many of you might effectively argue that this process is subjective and open to error (true)

Subjective in that some people are more capable of identifying lossy artifacts than others? Yes.  Subjective in that expectation bias cannot be circumvented? No.


Agreed.

that the sonic differences between a 24-bit WAV and a 256kbps AAC tend to be much slighter than the differences between vinyl and cassette (also true).

Yes, but the type of audible lossy artifacts cannot be corrected through pre-equalization.  To think otherwise is foolhardy.


Again, the mastering engineers are claiming that there were tonal differences between the resulting AACs and the 24-bit source file that are separate from what we consider expected lossy artifacts.

They also claimed that creating a different master for the encoder was able to lessen the tonal differences between files, and have stated that the iTunes Store's encoding process has been improved as part of "Mastered for iTunes."

Again, I have no way to prove or disprove these claims. I am only able to present them as consistent statements, and to allow room for skepticism, and suggest further reading to give fuller context. To take a different stance would have been dishonest and biased. The rest is for you guys to test and decide! If you come up with a scientific and newsworthy conclusion, then I can always report on that too.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 29 March, 2012, 12:32:18 PM
Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are. From what I remember, he's come recommending that masters peak at a maximum of a full -1db below 0dbfs to reduce unintended clipping, which is an idea that was balked at by many of the mastering engineers I spoke with. Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.

I don't think Saratoga will mind me speaking to this.  The issue is not peak levels, the issue is audible distortion that is caused by aggressive use of dynamic range compression.  Reducing the volume by a "full" decibel below full-scale does very little to cool a hot master.


I'm sorry greynol, but I think you're confused about Ludwig's point here. From what I understand, he suggests that lowering the peak level reduces the number of additional clipping errors introduced by the AAC encoder itself. According to his argument, and the Apple whitepaper, this is a separate issue from aggressive use of dynamic range compression.

For instance: I love the sound of a lot of Dave Fridmann's work with the Flaming Lips, which is often clipped-to-death. What's important to remember is that those records aren't clipped because they're loud... they're loud because they're clipped!

They're loud because they're compressed (and sometimes given mid-range emphasis) and often this compression can cause clipping regardless of whether the final master reaches full-scale.


Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.

You might find this educational:
http://www.hydrogenaudio.org/forums/index....showtopic=91909 (http://www.hydrogenaudio.org/forums/index.php?showtopic=91909)


I've read Bob Katz's book a couple of times and seen him speak on several occasions. I don't have the time to check out another of his videos at the moment, but maybe later.

If your desire is to school me on the basics of how all this works, there may be better uses of your time. But if you honestly think it's a neat video that adds something new to the conversation, I'd love to check it out in the future!

Have a good one,

Justin
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 12:39:29 PM
As a matter of practice, the engineers I spoke to employ the judicious use of EQ as part of the process. You're entitled to your argument, although I feel it's a semantic one.

Your negligence is appalling!  You are clearly misleading people into believing that judicious use of EQ is part of Apple's process.  It is not.

I'm sorry greynol, but I think you're getting confused about Ludwig's point here. He suggests that lowering the peak level reduces the number of additional clipping errors introduced by the AAC encoder. According to his argument, and the Apple whitepaper, this is a separate issue from aggressive use of dynamic range compression.

Once again, I think you should be concerned with your communication.  It was about Saratoga's point, not your non sequitur reply.

Of course, if you honestly think it's a neat video that adds something new to the conversation, I'd love to check it out!

I do.

I think it should be clear by now that there may be better uses of your time.

This is disappointing as you don't really inspire much confidence if you think compression and clipping are the same thing.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 12:48:48 PM
That Bob Ludwig quote where he seemingly does not understand what audio encoding is or why it might cause clipping is particularly galling from someone doing any sort of audio work.  Particularly to people like me who consider the huge amount of clipping accidentally introduced by incompetent engineers to be one of the worst aspects of modern music.


Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are.


I'm not talking about intentions, I'm talking about competence.  Its great if he dislikes how hot things are mastered and I completely agree with him if so.  My general complaint is that you make it sound like he has no idea why clipping happens

Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.


If by 'handle' you mean 'not clip' then this would be basically impossible.  So either they don't know what they're doing, or they're just leaving clipping in for basically no reason!

Again, the mastering engineers are claiming that there were tonal differences between the resulting AACs and the 24-bit source file that are separate from what we consider expected lossy artifacts.


If someone tells you this, then you ought to know that they are not credible.

Again, I have no way to prove or disprove these claims. I am only able to present them as consistent statements, and to allow room for skepticism, and suggest further reading to give fuller context.


There is actually a lot of research into the artifacts produced by perceptual audio encoding.  Saying you have no way to verify a statement here is incorrect.  You could access the research in question, compare files yourself, or use your knowledge of how perceptual audio encoding works to realize that you're being fed a load of bullshit. 

So saying you have no way to prove or disprove these claims is simply not true.  I think what you mean to say is that you decided not to try and evaluate these claims.  Which is unfortunate, because they are counter to the reality of how AAC encoding works.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 29 March, 2012, 12:49:55 PM
As a matter of practice, the engineers I spoke to employ the judicious use of EQ as part of the process. You're entitled to your argument, although I feel it's a semantic one.

Your negligence is appalling!  You are clearly misleading people into believing that judicious use of EQ is part of Apple's process.  It is not.


I have to disagree.  I believe that yours is an extreme statement, as well as a misinterpretation of the whitepaper.

Apple has released new tools, based on the engineer's requests, that were specifically designed to allow them to A/B the source and encoded material and make adjustments if necessary.

It's true that Apple's documentation does not say "Though Must EQ", but to call a reasonably accurate representation of the practice and the context that surrounding "misleading" or "negligent" is ridiculous.

With that, I'm going to have to bow out of this conversation, as your demeanor is clearly inhospitable, and you're now resorting to knee-jerk ad hominem attacks.

Sorry dude. Not my style. The floor is now yours, and you can use it to be a silly and self-important as you want.

Bye now,

Justin
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 01:00:18 PM
Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are. From what I remember, he's come recommending that masters peak at a maximum of a full -1db below 0dbfs to reduce unintended clipping, which is an idea that was balked at by many of the mastering engineers I spoke with. Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.

I don't think Saratoga will mind me speaking to this.  The issue is not peak levels, the issue is audible distortion that is caused by aggressive use of dynamic range compression.  Reducing the volume by a "full" decibel below full-scale does very little to cool a hot master.


I'm sorry greynol, but I think you're confused about Ludwig's point here. From what I understand, he suggests that lowering the peak level reduces the number of additional clipping errors introduced by the AAC encoder itself.


He "suggests" that taking a signal thats just short of peak normalized and then adding a bunch of additional random signals to it might introduce clipping?  Are you sure he is only suggesting that taking a signal and driving it above peak will introduce clipping? 

Would you "suggest" 1+1=2? 

For instance: I love the sound of a lot of Dave Fridmann's work with the Flaming Lips, which is often clipped-to-death. What's important to remember is that those records aren't clipped because they're loud... they're loud because they're clipped!

They're loud because they're compressed (and sometimes given mid-range emphasis) and often this compression can cause clipping regardless of whether the final master reaches full-scale.


Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.


No this is nonsense.

I have to disagree. I believe that yours is an extreme statement, as well as a misinterpretation of the whitepaper.

Apple has released new tools, based on the engineer's requests, that were specifically designed to allow them to A/B the source and encoded material and make adjustments if necessary.


Yes, but the claims you have made are as far as I can tell, so while his statement may be extreme, it also appears to be correct. 

With that, I'm going to have to bow out of this conversation, as your demeanor is clearly inhospitable, and you're now resorting to knee-jerk ad hominem attacks.


Attacking the false statements you make is not an ad hominem attack.  An ad hominem attack is an argument of the form "you're wrong because you're stupid".  Arguments that begin with "you've made incorrect statements, therefore..." are not ad hominem by definition, even if you feel attacked by them. 


Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 01:02:12 PM
With that, I'm going to have to bow out of this conversation, as your demeanor is clearly inhospitable, and you're now resorting to knee-jerk ad hominem attacks.

Sorry dude. Not my style. The floor is now yours, and you can use it to be a silly and self-important as you want.


Ironically, this IS an ad hominem attack!
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 29 March, 2012, 01:02:44 PM
There is actually a lot of research into the artifacts produced by perceptual audio encoding.
...
So saying you have no way to prove or disprove these claims is simply not true.


That is a fair argument, saratoga. Still, I have to remind you that I don't have access to their before and after files, and therefore it would be patently wrong of me to say that dozens of respected audio professionals are lying without having actual direct evidence.

All I can do is remind readers that there have been a ton of listening tests and studies that suggest it's unlikely any listeners would be able to hear tonal differences between these files, if they do in fact exist.

The article was also supportive of skepticism against these claims, but maintained that those accusations should be made properly. And again, I even wrote and linked to an article supporting blind ABX listening tests that would encourage healthy skepticism.

I think that's due diligence. You're entitled to feel like I should have taken a harder line in support of your position.  However, I believe my job here was to present the news, the process, and the context surrounding it. My job was not to editorialize passionately that it's a foregone conclusion that mastering engineers must be lying dirtbags because related tests raise suspicions on their claims!  So, mission accomplished, I guess.

Again, I see the atmosphere here has become less than welcoming of a nuanced and non-aggressive position like mine, so I'm going to respectfully step aside, and leave you guys to it.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 01:03:41 PM
You mean 'data compression' (high bitrate lossy encoding in this case) here rather than dynamic range compression, right?

Right.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 01:13:03 PM
There is actually a lot of research into the artifacts produced by perceptual audio encoding.
...
So saying you have no way to prove or disprove these claims is simply not true.


That is a fair argument, saratoga. Still, I have to remind you that I don't have access to their before and after files, and therefore it would be patently wrong of me to say that dozens of respected audio professionals are lying without having actual direct evidence.


They're not lying, they're confused.  And no its not wrong of you to figure out whats going on.  You call yourself a journalist right?  Isn't that actually your job, to know whats going on and then report it?  If you just report what someone says without actually figuring out if they understand what they're saying, you're not doing a very good job. 

All I can do is remind readers that there have been a ton of listening tests and studies that suggest it's unlikely any listeners would be able to hear tonal differences between these files, if they do in fact exist.


But you didn't even do that much!

"Since the Mastered for iTunes process uses a healthy dose of additive EQ to restore frequencies that are lost during the AAC conversion process"

You're repeating something that you know isn't true!  Why?

I believe my job here was to present the news, the process, and the context surrounding it.


So how does repeating things that aren't true work towards that end?

Again, I see the atmosphere here has become less than welcoming of a nuanced and non-aggressive position like mine, so I'm going to respectfully step aside, and leave you guys to it.


Heh, I would say lazy and misinformed.  And indeed, people won't be welcoming of that.  But if we're welcoming of you, well that depends.  Are you willing to open your mind and learn something or are you going to get angry and storm off that people don't agree with you?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 01:19:00 PM
Hi Saratoga,

I think you and Ludwig would agree that most masters shouldn't be as hot as they are. From what I remember, he's come recommending that masters peak at a maximum of a full -1db below 0dbfs to reduce unintended clipping, which is an idea that was balked at by many of the mastering engineers I spoke with. Most of them seemed to believe their clients expect peaks at at least -0.5 or -0.4 dbfs, and would continue shooting for those peaks as long as they could verify that the encoder could handle it.


I don't think Saratoga will mind me speaking to this.  The issue is not peak levels, the issue is audible distortion that is caused by aggressive use of dynamic range compression.  Reducing the volume by a "full" decibel below full-scale does very little to cool a hot master.


I think you and I have a different perspective here.  I don't mind high dynamic range compression necessarily.  What drives me nuts is audible clipping. It just ruins the sound to me.  So if someone has a master that sounds good with high compression, I'm ok with that.  But I just ask that, having knocked off all the peaks, they don't then push the entire signal up into distortion!  Its not that hard to set the level first, then apply DRC.  But everyone seems to like to do it the other way and it sounds awful. 

People talking about a fraction of a dB of headroom on a DRCed track is just nuts.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 29 March, 2012, 01:26:34 PM
Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.
Oh for goodness sake - you haven't a clue what you're talking about with this one!

(there's no nicer way of putting it - sorry!).

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 29 March, 2012, 01:52:45 PM
Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.
Oh for goodness sake - you haven't a clue what you're talking about with this one!

(there's no nicer way of putting it - sorry!).

Cheers,
David.


David, care to back that statement up with a widely accepted definition of "clipping" that would exclude an aggressive dynamic-range limiter?

To be honest, I'm really surprised and disappointed by the few posters who are taking extreme positions and resorting to anonymous ad hominem attacks, especially when we already agree on so much. 

Disagreement I'm fine with. The childishness of a few of your peers, not so much.

For the record, I am ethically and legally obligated not to call anyone "a liar" or "incompetent" without direct proof. That would be called "libel".

There are related studies that can be used to suggest the MEs and Apple folks could be overstating their claims. (The article makes direct mention of that - I'm surprised I have to keep mentioning that like it hasn't been said already.) But without direct before-and-after evidence, saying that their claims are conclusively false would not only be illegal and unethical, but factually incorrect.

That's all I have to say on that. I'm sure the vast majority of readers here are smart enough and unbiased enough to understand that. For the few who aren't - I'm sorry to hear that. Good luck and be well. I wish you a long life of yelling at strangers on the interwebs.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: ExUser on 29 March, 2012, 01:58:38 PM
care to back that statement up with a widely accepted definition of "clipping" that would exclude an aggressive dynamic-range limiter?
Urf. You don't need a limiter or anything to clip. f(x)=max(x,min(x,1.0),-1.0) on a signal that exceeds [-1,1] will cause clipping where the signal falls outside that interval. This is conceptually identical to working with samples at a certain word-length and dealing with values that fall outside that word length.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 29 March, 2012, 02:02:01 PM
care to back that statement up with a widely accepted definition of "clipping" that would exclude an aggressive dynamic-range limiter?
Urf. You don't need a limiter or anything to clip. f(x)=max(x,min(x,1.0),-1.0) on a signal that exceeds [-1,1] will cause clipping where the signal falls outside that interval. This is conceptually identical to working with samples at a certain word-length and dealing with values that fall outside that word length.


That's not the question. The question is "Can a dynamic range limiter cause clipping?"

The answer is "Duh."
Title: Big-label mastering engineers don’t understand lossy formats
Post by: drewfx on 29 March, 2012, 02:02:26 PM
Perhaps interviewing someone with a background in lossy compression codec development would be helpful in explaining exactly what sorts of audible changes/artifacts might occur?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 29 March, 2012, 02:04:26 PM
Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.

That's not the question. The question is "Can a dynamic range limiter cause clipping?"

Moving the goal posts just a little?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: ExUser on 29 March, 2012, 02:04:35 PM
care to back that statement up with a widely accepted definition of "clipping" that would exclude an aggressive dynamic-range limiter?
That's not the question.
Glad we cleared that up.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 29 March, 2012, 02:37:03 PM
Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.
Oh for goodness sake - you haven't a clue what you're talking about with this one!

(there's no nicer way of putting it - sorry!).

Cheers,
David.


David, care to back that statement up with a widely accepted definition of "clipping" that would exclude an aggressive dynamic-range limiter?


http://en.wikipedia.org/wiki/Clipping_(aud...igital_clipping (http://en.wikipedia.org/wiki/Clipping_(audio)#Digital_clipping)

Quote
In digital signal processing, clipping occurs when the signal is restricted by the range of a chosen representation. For example in a system using 16-bit signed integers, 32767 is the largest positive value that can be represented, and if during processing the amplitude of the signal is doubled, sample values of, for instance, 32000 should become 64000, but instead they are truncated to the maximum, 32767.


To be honest, I'm really surprised and disappointed by the few posters who are taking extreme positions and resorting to anonymous ad hominem attacks, especially when we already agree on so much.

Disagreement I'm fine with. The childishness of a few of your peers, not so much.


As far as I can tell, you seem to be the primary person launching ad hom attacks.  If you stopped doing that, perhaps this would be less of a problem. 

But without direct before-and-after evidence, saying that their claims are conclusively false would not only be illegal and unethical, but factually incorrect.


This is false for a number of reasons.  Most directly, since you are an American, libel is not actually illegal.

That's all I have to say on that. I'm sure the vast majority of readers here are smart enough and unbiased enough to understand that. For the few who aren't - I'm sorry to hear that. Good luck and be well. I wish you a long life of yelling at strangers on the interwebs.


Heh, so basically you came back to post some personal attacks against people who are trying to help explain things to you.  I wonder what an unbiased person would think of that.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 30 March, 2012, 05:19:45 AM
Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.
Oh for goodness sake - you haven't a clue what you're talking about with this one!

(there's no nicer way of putting it - sorry!).

Cheers,
David.


David, care to back that statement up with a widely accepted definition of "clipping" that would exclude an aggressive dynamic-range limiter?
You are really confused. The whole point of compressing or limiting peaks is to avoid clipping. If you increase the amplitude without squashing the peaks down, they will be clipped once their amplitude exceeds digital full scale. If you "squash" them (e.g. by momentarily reducing the amplitude), you can keep their shape, avoid clipping distortion, raise the overall level of the rest of the signal - and (up to a point) the momentary reduction in amplitude is inaudible. That's exactly what classic peak limiting does. It's almost the opposite of clipping!

It's true that some DRC processors can also introduce clipping. Sometimes clipping is introduced intentionally - good old Orban has used a module called a "clipper" for decades (though FM processing means this acts in a slightly different way to what we're discussing here). Sometimes clipping is introduced as a by-product of poorly chosen settings. Usually you find clipping on CDs because, even after the various stages including multi-band compression and peak limiting, the engineer still wants it louder, and at some point simply clipping the signal sounds less bad that even more peak limiting.

I hope this clears things up.

btw, I don't think the 84260 members of HA count as each other's peers.

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 30 March, 2012, 11:49:53 AM
When I am in a position to improve something of mine I think is important and it is fairly easy, I generally take action and improve it.  Maybe it's too late for Justin Colletti to amend or pull his article, if not then that's unfortunate, IMHO.

I wouldn't present information about the effects of the process of psychoacoustic coding primarily from mastering specialists any more than I would present information about the effects of food on the human body primarily from chefs (if at all!), no matter how reputable they are.

Also, how does reporting that someone has won Grammy awards or has a very successful career have anything to do with their ability to understand the intricate details of something when this knowledge is not necessary to do their job well, let alone at all?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 30 March, 2012, 12:19:22 PM
It's true that some DRC processors can also introduce clipping. Sometimes clipping is introduced intentionally.


Thank you David. That was exactly the point I was trying to make when I wrote that Dave Fridmann's work is 'not clipped because it's loud. It's loud because it's clipped. That's a world of difference.'

The rest of the discussion on the definition of clipping seems a little ego-driven to me. The main point remains that extreme compression and limiting are forms of clipping, and that they are often used in that way today for aesthetic effect.

I don't see why we should be arguing about that, unless our desire is to show off for an audience by battling over semantics and further derailing the conversation.

As far as I can tell, you seem to be the primary person launching ad hom attacks.


Please find a quote where I made an ad hominem attack directed at any specific individual. If I did, I'd be happy to apologize.

I know that I expressed my disappointment with the tone of the discussion after two anonymous ad hominem attacks were made against me. I'm doubtful that any objective reader would construe that as an ad hominem attack on my part.

...since you are an American, libel is not actually illegal.


That's technically correct. Libel is not a criminal offense - Only something you can be sued for. My sincere apologies for the semantic misstep.

Once again, the central point still stands: I am ethically obligated to state that related ABX tests invite skepticism of some mastering engineers' claims. So I did.

I am also ethically obligated to state that no conclusive proof has been presented to show that these particular mastering engineers were unable to hear differences between two similar audio files and adjust accordingly. So I did that too.

If you feel that I failed at expressing these two points clearly, I'll accept that as your personal critique. However, if you feel I have some other obligation that runs contrary to this, or that I made no concerted effort to fulfill both of these obligations, then we'll just have to disagree.

Heh, so basically you came back to post some personal attacks against people who are trying to help explain things to you.  I wonder what an unbiased person would think of that.


Please see above!

Unfortunately, I'm non-anonymous, so it's necessary for me to correct the record when inaccurate portrayals of my positions are made in a public conversation.

At this point, I'd ask that the moderators lock this thread, so I won't have to monitor it for additional inaccurate portrayals like the one you made in the quote above.

I think that all essential points have been presented on both sides of this "conversation", and at this time, any further discussion in this thread is likely to be pretty darn silly.

On a more positive note, a few HA members wrote me personally to express their regret about the direction this conversation took.

I'm very happy about that, so thanks. I'll try not to let the manners and off-topic arguments of a few anonymous posters color my feelings about the site too much.

I'm especially surprised by the comments of the few, because I've already made it clear that I'm a big fan of the philosophy behind HA and of ABX tests in general. As mentioned, I've even sung their praises to thousands upon thousands of readers. I guess I'll just have to accept that some people don't get that alienating your allies is lousy strategy.

To the rest of you, thanks for reading and have a good one,

Justin
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 30 March, 2012, 12:40:36 PM
When I am in a position to improve something of mine I think is important and it is fairly easy, I generally take action and improve it.  Maybe it's too late for Justin Colletti to amend or pull his article, if not then that's unfortunate, IMHO.

I wouldn't present information about the effects of the process of psychoacoustic coding primarily from mastering specialists any more than I would present information about the effects of food on the human body primarily from chefs (if at all!), no matter how reputable they are.

Also, how does reporting that someone has won Grammy awards or has a very successful career have anything to do with their ability to understand the intricate details of something when this knowledge is not necessary to do their job well, let alone at all?


What do you suggest would be good a way to amend the article? When you do so, please bear in mind that:


If you care to make specific recommendation, I'd be happy to hear it. But please be sure to read the article in full before making your critique. I'm certain that you're an intelligent person, and based on your current analysis, it's hard for me to believe that you have done more than skim it. Don't sweat it. It happens to the best of us.

For the future, please also be aware that moderators are generally tasked with helping make forums more civil and their discussions more focused. If you feel you've done a lot to foster a cordial and meaningful conversation in this particular thread, I'll have to respectfully disagree.

At this point, I'd again ask that you to make amends by locking the thread down, and voicing any of your specific critiques to me directly via email - after reading the story in full, of course.

Thanks,

Justin
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 30 March, 2012, 02:06:06 PM
As far as I can tell, you seem to be the primary person launching ad hom attacks.


Please find a quote where I made an ad hominem attack directed at any specific individual. If I did, I'd be happy to apologize.


Perhaps, you missed it, but I pointed an example out before right here:

http://www.hydrogenaudio.org/forums/index....st&p=790942 (http://www.hydrogenaudio.org/forums/index.php?showtopic=94214&view=findpost&p=790942)

Trying to discredit an argument by (falsely) claiming the author is "resorting to knee-jerk ad hominem attacks" is an ad hom attack, because it attempts to discredit the author and not the idea.  Most telling, you then failed to respond to the actual substance of the argument (e.g. that you were negligent in presenting information that was not true), which IMO implies bad faith. 



I know that I expressed my disappointment with the tone of the discussion after two anonymous ad hominem attacks were made against me. I'm doubtful that any objective reader would construe that as an ad hominem attack on my part.


Hmm, it seems to me that you're a little unclear on what an ad hom attack actually is.

Check wikipedia:

An ad hominem (Latin for "to the man" or "to the person"), short for argumentum ad hominem, is an attempt to negate the truth of a claim by pointing out a negative characteristic or belief of the person supporting it.

So as far as I can tell, no one here has done this to you.  Its pretty much just been you doing it to other people (e.g. greynol).

I am also ethically obligated to state that no conclusive proof has been presented to show that these particular mastering engineers were unable to hear differences between two similar audio files and adjust accordingly. So I did that too.

If you feel that I failed at expressing these two points clearly, I'll accept that as your personal critique. However, if you feel I have some other obligation that runs contrary to this, or that I made no concerted effort to fulfill both of these obligations, then we'll just have to disagree.


I see that you have corrected the false statements greynol pointed out, and the incorrect stuff about frequency changes from lossy encoding.  Failing to admit that you had made a mistake and correct those mistakes were my main complaints.  That said, I'm still not impressed with your handling of this, nor that you edited the article without making it clear that you were retracting quite a bit of it. 



On a more positive note, a few HA members wrote me personally to express their regret about the direction this conversation took.


As am I.  However, seeing as you eventually made the edits you needed to, perhaps you could have saved all of us this grief by being more open feedback in the first place. 

I'm especially surprised by the comments of the few, because I've already made it clear that I'm a big fan of the philosophy behind HA and of ABX tests in general. As mentioned, I've even sung their praises to thousands upon thousands of readers. I guess I'll just have to accept that some people don't get that alienating your allies is lousy strategy.


You shouldn't be surprised.  ABX isn't a cult.  We don't worship at it.  The reason we push ABX is that its a good way to avoid being wrong.  Its basically an end to that means.  But the goal is to be correct and avoid spreading misinformation.  If you put up an article implying that AAC encoding involves "notching" out frequencies, people are going to be angry.  Using ABX here would have been great, since it would have prevented someone from mistakenly believing it, but thats not really the point.

Does that make sense to you?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 30 March, 2012, 02:13:59 PM
What do you suggest would be good a way to amend the article? When you do so, please bear in mind that:
  • It already states that related ABX tests invite skepticism of some the mastering engineer's claims.
  • It links to articles on the merits of ABX tests in evaluating audio claims.
  • I've offered to write a follow up if anyone cares to present good evidence that refutes these claims.
  • I'm under an obligation to avoid libel, defamation, or any unproven statements on my part that these particular engineers can't hear the differences between these particular files.
  • And that this is a news article about new procedures and tools being used by mastering engineers - not an article about ABX tests, sample rates, bit rates, perception, bias, the loch ness monster, or anything else.


If you care to make specific recommendation, I'd be happy to hear it. But please be sure to read the article in full before making your critique. I'm certain that you're an intelligent person, and based on your current analysis, it's hard for me to believe that you have done more than skim it. Don't sweat it. It happens to the best of us.


Sorry to double post, but I missed this.  Yes I think your edits so far are very good.  You've removed almost all of the stuff that was misleading or irrelevant.  One minor point I would suggest that in some of the quotes, you've removed clauses and sentences from the original quote that significantly change what the author is implying.  In that case you may wish to add a [...] to make it clear that the quote has been edited to remove stuff the author originally said.  Usually this isn't a big deal, but since the meaning is changed a little its a good idea here.

For the future, please also be aware that moderators are generally tasked with helping make forums more civil and their discussions more focused. If you feel you've done a lot to foster a cordial and meaningful conversation in this particular thread, I'll have to respectfully disagree.


I think the improvements suggested by greynol that you've made to your article are quite an accomplishment.

At this point, I'd again ask that you to make amends by locking the thread down, and voicing any of your specific critiques to me directly via email - after reading the story in full, of course.


I think making them in public makes much more sense, since a much wider range of people will be able to comment on them.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: TrustScience on 30 March, 2012, 03:13:27 PM
That's true. I did make a couple clarifying edits and fixed a typo too.

I took out the part of Mr. Meller's quote where he said that the "highs, lows and mids" were "filtered out completely". Once I realized that some of you took him literally rather than figuratively, I agreed it was a valid critique and felt his statements were clearer without it.

There were also two minor edits for style:

1) I got some good feedback in an email saying that the section about Shepherd's tests and the alternative tests was wordy and confusing in parts. I rephrased a couple of sentences to make it clearer and less verbose. The substance of the points did not change.

2) I acknowledged the criticism that it was unclear whether Apple's whitepaper explicitly recommends the use of equalizers in the mastering process. I still feel that's a semantic distinction, but I decided to add a couple words to make misinterpretation impossible. Again, the substance of the statement remains the same.

I'll take any valid criticisms to heart if they're specific. I also routinely clean up the copy in older articles if I'm alerted to punctuation errors or unclear sentences. If something is factually inaccurate, I'll even issue retractions and do follow-ups in future issues.

Since the above were not factual changes, I have no plans to do that in this case. Of course, I'm always happy to write more on the subject in the future, and I'm always looking for contributing writers with real expertise.

Chances are that I'm not going to look to anonymous axe-grinders to find valuable sources, or to publicly thank curmudgeons for their copy-editing recommendations and spell-checking services. That's just human nature. C'mon, you guys know all about "selection bias"* 

If you have an issue with a specific sentence, statement, or see a typo, feel free to shoot me an email. All that I ask is that you be human about it.

And as I said in the beginning, thanks for reading, and for the feedback.

-Justin

(* Yes, I know what "selection bias" actually means. This is what normal people call a "pun".)
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 30 March, 2012, 03:47:53 PM
I'll try not to make this a long post as I've got a lot of things on my plate at the moment.

First, I'm delighted to see that the author is actively making an effort to improve his article.  I regret that I felt that he needed to be shamed into doing so.  Clearly there are better ways, even when a valid critique has been snubbed.

Regarding the article as a whole (which I've read at least three times in full and had done so at least once before the author joined in on the discussion), I guess I have trouble with its purpose.  It appears as though it's about the new "Mastered for iTunes" process and tools and how they're supposed to make delivering high quality downloads easier.  This is fine.  That the article is divided up to present two opposing viewpoints is fine too.  However, I have trouble with the way the sides are divided.  On the one side there appears to be people who seem to be happy with the tools but clearly don't know how to use them (or exactly why they were even provided in the first place; that Rick Rubin is either taking credit or is being given credit can't be taken seriously).  On the other side is another person who also doesn't understand the point of the tools nor how to use them properly.  I applaud that the author believes in double-blind testing methodology, but it's being presented as if it is for the end-listener and beneath mastering specialists.  It seems as if it's really not much more than an aside; an editorial by the author.

For me the issue here is not whether I'm for or against "Mastered for iTunes", it is about presenting the topic in a meaningful and informative way.  My concerns over which I may have "allies" or "enemies" is not about mastering, delivery formats or even the state of audio in general, it has to do with the presentation of factual information.

A stronger article, more beneficial to the iTunes consumer, would dive into the precise reason for why Mastered for iTunes was created and would present information provided by Apple and those who developed the specific tools or those who develop codecs in general.  It would point out how the tools were intended to be used and whether the benefit of them will be realized based on the way the tools are actually being used.

As it is right now I would title the article, "Mastered for iTunes, a wasted opportunity."  Whether it was intended or not, it points out the very sorry state of how music is produced for digital consumption and that there appears to be little hope that it will get better.  Until Meller and his peers understand that equalizing to prep for lossy conversion is an unnecessary and therefore harmful process, they will continue to polish cars in total darkness.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 30 March, 2012, 04:41:10 PM
At least from my point of view (and as I mentioned i my first post), the real story is just how poorly Apple has managed to communicate the goals of the "Mastered For iTunes" program.  Before I mocked their description for its almost condescending tone to the reader, but really I think even much of what they have tried to explain has been lost.  For example, in the original quote from Muller he attempts to determine what the frequency response of an AAC encoder is:

“I can tell you what doesn’t work,” he said. “One of my initial trial-and-error methods was to take digital fingerprints of both versions of the song, and then try to apply a [compensating EQ] to the CD version and pump that back through the AAC encoder.”

Now this is a perfectly logical thing to do to a speaker or a tube amplifier.  But its just plain insane to expect that to work on a perceptual audio encoder.  No one with the slightest clue of whats going on would expect that to work.  But to someone still living in the pre-digital era, its all they would have to go on.  Now to Muller's credit, he does correctly deduce that a perceptual audio encoder is very, very different from an amplifier through experimental means:

"Well, the problem with that is that input does not equal output. It’s highly program dependent, and you rarely get the same thing twice in a row."

Unfortunately, while he has (thankfully!) given up trying to compensate for perceptual encoding with EQ, he has no idea why AAC encoding works differently then an amplifier.  The notion that its actually analyzing a signal and converting it to a new form in a nonlinear, adaptive manner without actually altering the intensity per frequency is lost on him.  Thus while Apple has given him tools, they have failed to explain to him adequately what it is those tools are meant to do or why he should be using them.  And so he (and most of the people quoted) seem to be grasping the dark trying to relate an ill-explained set of objective handed to them by Apple to (irrelevant) experience using more conventional audio equipment like microphones and amplifiers. 

I suppose that while we have criticized Rubin, Muller, Shepherd and company for not understanding their trade, in some sense this isn't really their fault.  They've been handed a complicated goal by Apple with very little explanation or guidance.  And while yes we would hope they would take the time to learn their tools even without guidance, perhaps given their time constraints. their age, and their other responsibilities this is unrealistic.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 30 March, 2012, 04:52:27 PM
Aside from db1989's point in the next post which I overlooked, I agree with you completely.

Unfortunately articles like these left by themselves will likely not accomplish much good until they focus on presenting the true intention behind the process and whether the goals are being met from a technical (rather than monetary) standpoint.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: db1989 on 30 March, 2012, 04:53:49 PM
And while yes we would hope they would take the time to learn their tools even without guidance, perhaps given their time constraints. their age, and their other responsibilities this is unrealistic.
their age

What does that have to do with it?

Actually, maybe it’s best just to pretend that bit isn’t there. A mud-fest will solve nothing, and I certainly don’t want to be the one to have started it.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: saratoga on 30 March, 2012, 05:23:09 PM
And while yes we would hope they would take the time to learn their tools even without guidance, perhaps given their time constraints. their age, and their other responsibilities this is unrealistic.
their age

What does that have to do with it?


Quite a lot.  Experience is a double edge sword. It is a resource of potential contexts to illuminate a new situation, but it also constrains ones thinking by out-competing new ideas with past experience.  The more one specializes in a specific field, the harder it is to to look at things from a new perspective and the more tempting it is to use ideas that have previously proven successful.  This isn't a dig at someone, its just common sense.  Ideas that have worked before are likely to work again.

This problem is particularly acute in my line of work where we see the graying of scientists and the shutting out of new ideas:  http://online.wsj.com/article/SB1000142405...3334216604.html (http://online.wsj.com/article/SB10001424052748703444804575071573334216604.html)

But its actually a more general trait of human existence.  I actually have never met Meller nor do I know anything about his age.  But given that his goto concept was linear systems, time invariant systems, he almost certainly started his career more then 20 years ago when time variant processing was more difficult to implement (and thus less likely to be a significant factor in a new technique).  This is not to say that a younger person would have done better (and in fact I suspect that the newer generation is in some ways worse than the old...).  However, I don't think its unfair to suggest that someone's experience could (among other factors) guide his or her choice of intellectual tools when confronting a new problem.  Actually, I would be surprised if it did not.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 31 March, 2012, 05:33:19 AM
It's true that some DRC processors can also introduce clipping. Sometimes clipping is introduced intentionally.


Thank you David. That was exactly the point I was trying to make when I wrote that Dave Fridmann's work is 'not clipped because it's loud. It's loud because it's clipped. That's a world of difference.'

The rest of the discussion on the definition of clipping seems a little ego-driven to me. The main point remains that extreme compression and limiting are forms of clipping, and that they are often used in that way today for aesthetic effect.
Ego? No. Just irritated when someone attempts to re-define words that have perfectly good definitions already. Please try to understand: you can have extreme compression and limiting without any clipping at all. Engineers have been over-using compression to get a particular "sound" for decades (at least five of them!). Clipping the mix was (until recently) very rare. Any Time At All mix vs Revolution guitar, if you're a Beatles fan.

Anyway, it's a side point to your article. Sorry to drag the thread off topic.

cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: skamp on 31 March, 2012, 05:59:05 AM
PS: The Dynamic Range Meter results for Ms. Kadry's latest work are worse than Frances the Mute (DR7), Amputechture (DR6) and The Bedlam in Goliath (DR6).


She blames it on the artists: (https://twitter.com/#!/hebakadryy/status/185105490387275777)

Quote
an artist's vision for their album is sometimes not my decision even if it ends up going against what you think is right
Title: Big-label mastering engineers don’t understand lossy formats
Post by: krabapple on 31 March, 2012, 04:59:38 PM
It's true that some DRC processors can also introduce clipping. Sometimes clipping is introduced intentionally.


Thank you David. That was exactly the point I was trying to make when I wrote that Dave Fridmann's work is 'not clipped because it's loud. It's loud because it's clipped. That's a world of difference.'


That may have been the point you were trying to make, but instead you what you actually wrote was this:

Quote
Compression is clipping - In a very strict and literal sense. Whenever a compressor or limiter acts on peaks, it is inducing "clipping" by definition.


...which simply IS NOT THE CASE, and does not make the point you were trying to make.  Compression *may* cause clipping, or it may not.  It's all in how it's applied.  It does not cause clipping by definition as you appear to
say.

How about you just concede that?

As for what induces clipping, when the signal amplitude exceeds the digital 'container' capacity, clipping distortion results.  Alas for Spinal Tap, you can't go 'go to 11' when the format only goes to '10'.  Put another way (and ignroing for a moment the more accurate, psychoacoustic definition of 'loud'),  in digital world a signal gets clipped *because it is too 'loud'* at some point in the production chain.  After that point you can't un-clip it, even if you reduce the peak amplitude.  The clipping distortion remains.

 
Quote
The rest of the discussion on the definition of clipping seems a little ego-driven to me. The main point remains that extreme compression and limiting are forms of clipping, and that they are often used in that way today for aesthetic effect.


Except, they aren't necessarily so.


[EDIT:  I see 2bdecided made much the same point much more succinctly.  Mods, feel free to delete this if it seems too redundant.]
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 31 March, 2012, 05:14:44 PM
Since others are piling on while admittedly not adding to the discussion, I think it's more than appropriate to leave your post since it does make and attempt to add to the discussion.

How about you just concede that?

It might ease the irony in the ego-driven comment.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Axon on 01 April, 2012, 12:26:59 PM
Perhaps TrustScience would have found our reactions more understandable if we just told him up-front how little many of us tend to respect mastering engineers, as a matter of engineering (as opposed to artistic) technical competence. Mastering engineers don't necessarily need a firm grasp of signal processing fundamentals to do their jobs well, yet this topic is probably more about signal processing than it is about artistic or subjective notions of sound quality.

The incorrect statements that appear to be made by respected mastering engineers in the article -- the premise of EQing a master to compensate for encoder coloration, using nulling comparisons as a metric for encoder quality, etc. -- are something a lot of us have come to expect. (cf: widespread professional misconceptions about loudness equalization, the audio properties of vinyl, high-res digital audio formats.....) Stated baldly, that's why a bunch of us non-mastering-engineers seem quite at ease critiquing mastering engineers about how they do their jobs.

In that context, I find TrustScience's situation as a journalist rather unenviable. If he were going to placate us, he would probably need to interview mastering engineers while operating under the premise that he might know more about the topic than they do...
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 01 April, 2012, 01:09:51 PM
In that context, I find TrustScience's situation as a journalist rather unenviable. If he were going to placate us, he would probably need to interview mastering engineers while operating under the premise that he might know more about the topic than they do...

The problem is that some of the "engineers" simply perpetuate FUD about lossy formats/encoders. I guess most have read the article in the OP by now, I found another piece by Scott Hull, the owner of Masterdisk (http://mad.ly/edf762):
Quote
The bottom line is that experienced engineers can -- and do -- make noticeably better sounding AAC files than you get using the standard, automatic encoder.

Warranted, "better sounding" is a loose term. But the point of AAC is not "better sound", but transparency. And regarding that no amount of mastering engineering tricks can improve on AAC, especially not ones by those who don't even understand that digital clipping of CDs at full scale is bad (which isn't an artistic choice, but bad engineering). They probably are talking about creating a new master specifically for AAC encoding. With that they can manage to create a "better sounding" AAC file, but sure as hell the master they derived that from will also "sound better" than the previous master.

It's one thing if you don't understand something and shut up about it. It's far worse to not understand something, but in turn having strong opinions about it, and sprouting your misconceptions out to the public. All the while putting in your weight of apparent knowledge in the field because you mastered some CDs before and have a big sign up front.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: knutinh on 01 April, 2012, 05:06:58 PM
Warranted, "better sounding" is a loose term. But the point of AAC is not "better sound", but transparency. And regarding that no amount of mastering engineering tricks can improve on AAC

If you are the painter and decide what scene and style to paint in, surely your choices can serve to hide flaws in your selection of colors?

-k
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 01 April, 2012, 05:22:26 PM
Warranted, "better sounding" is a loose term. But the point of AAC is not "better sound", but transparency. And regarding that no amount of mastering engineering tricks can improve on AAC

If you are the painter and decide what scene and style to paint in, surely your choices can serve to hide flaws in your selection of colors?

My point is that when master A sounds better than master B when encoded to AAC, A will sound better than B when left lossless too, unless you encounter AAC artifacts, and you are able to defeat them with your new master. You could then also try to diminish that problem by choosing a higher encoding bitrate. I doubt the mastering engineers consistently find AAC artifacts at common bitrates.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: krabapple on 02 April, 2012, 02:17:24 AM
It's possible that calling famous mastering engineers 'monkeys' in the subject might be considered aggressive. 
Title: Big-label mastering engineers don’t understand lossy formats
Post by: knutinh on 02 April, 2012, 04:00:36 AM
My point is that when master A sounds better than master B when encoded to AAC, A will sound better than B when left lossless too, unless you encounter AAC artifacts, and you are able to defeat them with your new master. You could then also try to diminish that problem by choosing a higher encoding bitrate. I doubt the mastering engineers consistently find AAC artifacts at common bitrates.

Yes, audible degradation is necessary for the argument to float. I dont know what bitrates we are talking about, but let us just assume that they are low enough for this to really be an issue (I am sure that much of the talk from producers stem from the lack of blind testing).

My point was that if some piece of classical music sounds bad through a given AAC encoder/bitrate, the extreme artistic possibility would be to use an entirely other piece of music (e.g. Britney Spears) that might or might not sound equally degraded at that bitrate. A mastering technician might do other significant changes to the mix that divert our attention from problems (or avoid problems in the first place). These are artistic choices that an encoder will never have the freedom to do, but I think that the technically savvy people on this site tend to under-appreciate the craftman-ship (or lack thereof) of mastering a song or an album. It is an interesting challenge that require both technical and artistic skill.

Sadly (for many of us), even highly acclaimed mastering engineers seems to lack technical skills that seems basic to us (or at least the ability to describe the technical causes in a meaningful way), and at the same time seem to have an artistic vision that is very far from what many of us prefer.

I believe that it is common in "hand crafts" such as music making and cooking, where knowledge is of a more intuitive, "pass-on-by-example" and training nature (as opposed to the engineering route that is more theoretical and QED-oriented), to perhaps do the right thing (e.g. "keep hot signal levels, but avoid clipping", "fry your steak at hot temperature before adding butter"), but for very wrong reasons (i.e. "the magic sound fairy will bite you in the nose otherwise"). I can see how experience and feedback will (best case) tend to direct such professionals in to doing stuff the right way through some form of natural selection, but since theoretic analysis is seldom needed or celebrated, why would one expect it to accumulate into the most celebrated professionals?

Reference:
"Molecular Gastronomy: Exploring the Science of Flavor", Hervé This

-k
Title: Big-label mastering engineers don’t understand lossy formats
Post by: skamp on 02 April, 2012, 04:15:15 AM
let us just assume that they are low enough for this to really be an issue

iTunes AAC files are encoded at 256 kbps. How many issues are there at that bitrate?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: knutinh on 02 April, 2012, 07:31:14 AM
iTunes AAC files are encoded at 256 kbps. How many issues are there at that bitrate?

I did not know that. My guess: practically none.

-k
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 02 April, 2012, 08:07:08 AM
The notion that mastering engineers who deliberately compress their recordings to 10-12 bits and allow distortion through digital clipping are also among the few human beings able to to consistently identify AAC encodes, and constantly run into problems with iTunes encodes, should not strike only me as odd, to say the least.

It's possible that calling famous mastering engineers 'monkeys' in the subject might be considered aggressive. 

Now that I vented a bit, like skamp aptly said, I also would be in favour of changing that particular wording. Maybe change it to "Mastering engineers don't understand lossy formats" or similar, to be less ad hominem and more about what exactly bothered me.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: db1989 on 02 April, 2012, 08:25:19 AM
I also would be in favour of changing that particular wording. Maybe change it to "Mastering engineers don't understand lossy formats" or similar, to be less ad hominem and more about what exactly bothered me.

How’s that? If you want any other changes, you can request them via the Report button.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 02 April, 2012, 08:48:05 AM
Thank you very much, db1989. That was what I had in mind.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: db1989 on 02 April, 2012, 08:50:37 AM
Great!
Title: Big-label mastering engineers don’t understand lossy formats
Post by: absinthe33 on 02 April, 2012, 10:22:32 AM
Just found this article (http://trustmeimascientist.com/2012/03/03/ace-engineers-share-tips-and-secrets-of-mastering-for-itunes) via twitter, circled among mastering "engineers" (in fact Heba Kadry (https://twitter.com/#!/hebakadryy) reposted it, the girl who mastered the latest Mars Volta album, which reaches -12.79 dB on my RG scans, and is generally mastered in a horrible fashion).

This further backs my impression that most of them don't have a single clue of what they are doing. The section about the mastering practices of Rubin and Meller are especially eye-opening to me. Masterdisk "engineers" also apparently are now out to rape the Rush back catalogue. Further down they cite phase-reverse tests to prove AAC files are different from the original (wow, REALLY?).

The good thing is, I can use this article to decide which releases to avoid in the future. But I'm really at a loss what we can do beside that. I'm really fed up with mastering "engineers" destroying music releases.
On QQ there is a topic where Steven Wilson (Porcupine Tree and other projects, surround mixing for others too, KC, Jethro Tull) answers questions, at one point he says this: "I prefer to provide the mastering engineer with the maximum possible dynamic range and let them judge how much to compress, if any."

brrr... 


Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 02 April, 2012, 10:28:56 AM
Some lossy codecs can introduce audible temporal smearing - and the effect of such smearing (apart from the obvious!) in terms of perceived frequency response is to make the mix sound brighter. EQing the mix to reverse this subjective effect would be possible.

Some lossy codec introduce clipping. If this wasn't being explicitly avoided, then it's easy to believe that certain amounts of clipping in certain mixes would bias the perceived frequency response, stereo effect, density of sound etc in a certain way, and all these changes could be counteracted, to a certain degree, by fiddling with the mix.

So the concept of re-working a mix to counteract the effects of lossy coding seems perfectly reasonable to me.


The problem is, to my ears, it's perfectly reasonable for sub-64kbps encoding today, or circa 1997 128kbps mp3 - but it's an absolute nonsense for 256kbps AAC encoding. I'd love to be proven wrong, but I suspect, like others, it's all down to a lack of rigorous blind testing. Which is hardly surprising. Mastering engineers, as a rule, don't blind test changes to their mix. They just make them.


If they do turn out to be the only people in the world who can routinely ABX 256kbps AAC (and I agree with Kohlrabi (http://www.hydrogenaudio.org/forums/index.php?s=&showtopic=94214&view=findpost&p=791380) on the likelihood of that), then I guess they're "improving" AAC mixes for all the other mastering engineers out there - but if all the people who can hear a difference demand lossless, and all the people who can't hear a different are buying AAC, then they're wasting their time!

Except it's great Emperor's New Clothes marking. Like much of the audio industry.

Cheers,
David.

P.S. I still buy CDs, so I don't care. On the rare (but getting less rare) occasions that I can't get a CD or lossless download, I still feel cheated.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: dhromed on 02 April, 2012, 11:08:23 AM
brrr... 


I don't understand what you're brrring about.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: absinthe33 on 02 April, 2012, 06:04:05 PM
brrr... 


I don't understand what you're brrring about.

Because it seems that in the end it's the mastering engineer that gets to decide how a record sounds, not the artist, not the mixer, not the producer.

Title: Big-label mastering engineers don’t understand lossy formats
Post by: splice on 02 April, 2012, 06:52:54 PM
... Because it seems that in the end it's the mastering engineer that gets to decide how a record sounds, not the artist, not the mixer, not the producer.


They wish.... From my limited contact with mastering engineers, the majority of them would rather produce a clean, unsmashed master. They don't often get the opportunity, though. The artist and producer normally specify the desired result and if they don't get what they asked for, it gets done again.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: skamp on 04 April, 2012, 10:23:51 AM
Heba Kadry again: (https://twitter.com/#!/hebakadryy/status/187213583199911938) "While Im all for setting a dynamic standards for records, people fail to realize that these days mixes are already brickwalled to an extreme"

Honest question: why do we automatically blame the mastering engineers?
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 04 April, 2012, 11:25:12 AM
...which leads back to Justin's latest article...

http://trustmeimascientist.com/2012/04/02/...e-loudness-war/ (http://trustmeimascientist.com/2012/04/02/how-to-win-the-loudness-war/)

...which I think is great.

Though, frankly, the line between "clipped because they want that sound", and "clipped because they were trying to go louder", is a fine one which I doubt many in the industry have the tools, ears, or freedom to call properly.

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 04 April, 2012, 05:29:35 PM
Heba Kadry again: (https://twitter.com/#!/hebakadryy/status/187213583199911938) "While Im all for setting a dynamic standards for records, people fail to realize that these days mixes are already brickwalled to an extreme"

Ted Jensen, who mastered Death Magnetic, claimed the same thing (http://en.wikipedia.org/wiki/Death_Magnetic#Criticism_regarding_production). Then the Guitar Hero 3 version surfaced. As far as I know that version isn't mastered as "hot", and doesn't sport the bad engineering trademark of digital clipping like the CD version (it comically digitally clips below digital fullscale).

Honest question: why do we automatically blame the mastering engineers?

Because, from my understanding, the recording mixes are not digitally clipping. Because they spread FUD about lossy formats.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: splice on 04 April, 2012, 08:33:39 PM
... Ted Jensen, who mastered Death Magnetic, claimed the same thing (http://en.wikipedia.org/wiki/Death_Magnetic#Criticism_regarding_production). Then the Guitar Hero 3 version surfaced. As far as I know that version isn't mastered as "hot", and doesn't sport the bad engineering trademark of digital clipping like the CD version (it comically digitally clips below digital fullscale). ...


The GH3 version doesn't prove that Ted didn't receive a hot version to master. It does prove that the original recorded tracks of the individual instruments weren't overly compressed, and these were what were supplied to the GH3 developers. If Ted is telling the truth, it means they were compressed at the point where they were mixed down to the stereo mix supplied to him. This is a common practice at the mix stage, where the artists and producers try to get the sound as close as possible to their references (other smashed music). The problem is that the mix engineers rarely have the equipment or expertise to do the job properly. Anecdotally, there's also a certain amount of ego involved - to see who can pi** higher up the wall.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 05 April, 2012, 06:24:02 AM
...which leads back to Justin's latest article...

http://trustmeimascientist.com/2012/04/02/...e-loudness-war/ (http://trustmeimascientist.com/2012/04/02/how-to-win-the-loudness-war/)

...which I think is great.
To temper that a little, he does seem to expect (or at least, unfairly imply it's possible for) automatic calculations of dynamic range to tell you things that they cannot. They cannot say anything about the sound quality, microphone placement, mixing technique, use of EQ, overall style etc of a track. Modulated white noise or sine wave can have a huge dynamic range. Picking completely different records, and suggesting that the DR values don't seem to correlate with sound quality is a red herring - it's one factor out of many which make a good record. The fact that other factors can outweigh it doesn't mean it's unimportant. A nice smile does not a beautiful person make - but if they never smile, then I don't think I'd like to spend my life with them. Dynamic range does not a good record make, but if most of it has gone, then I probably don't want to listen to it on a decent stereo for long.

Also, AFAIK, that specific DR rating system doesn't actually flag up clipping, or intentional mix distortion. You can make a track with one or both, but still have a large "dynamic range". DR calculators can measure the range, but can't spot specific faults. It's the specific faults (especially audible track or mix clipping) that really annoy me. Even then, someone might want a square wave applied for an effect - but they probably wouldn't have chosen to turn the three loudest bass hits/peaks in the track into a square wave if it wasn't for the loudness wars. For now, it probably takes a human to judge the difference.


Still, if the world does slowly move to a mostly SoundChecked/ReplayGained future - and at the same time people hear more new music through mediums that don't use radio-style compression - then "that loudness wars sound" will be largely consigned to history, exactly as both Justin and Greg (http://mixonline.com/mixline/reierson_loudness_war_0802/) suggest. It such a future, you can switch the effect on or off for a verse or chorus or line as you wish.

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: stephan_g on 05 April, 2012, 11:30:09 AM
^Agreed. A "decent stereo", btw, includes a DAP and some good headphones these days and probably is more affordable than ever.

He's arguing,
Quote
Somewhere along the way, “loud” has morphed to become more than a level — It’s now an aesthetic choice of its own, and has even transcended perceived volume.

...which I don't think anyone seriously has issues with. (Though one could also argue that younger people's hearing is seriously f'd up.)

But what if, for the same material, there's a CD release with DR6 and a vinyl release with DR10 (or even DR12)? This is not at all uncommon these days. Good for vinylphiles, but not exactly fitting my definition of "unified artistic vision". Plus, I like CDs and I know that they could live up to the promise of "perfect sound forever" nowadays. There certainly is no technical reason to make CDs hotter than LPs.

Normally you would expect the artist to be creating their vision in the studio, when then serves as a reference for whatever media are created.
"The medium is not the message."
Which gets us back to the start of this thread and the unfortunate attempts to compensate for differences in lossy formats that may not even be real. For CDs, this feedback loop seems to be broken in many cases.

Justin again:
Quote
In fact, I had trouble finding many pop albums that should be worth listening to according to the Dynamic Range Database. Any rating in their system under 9DR is marked “bad”, and even Dark Side of the Moon with its album average of 10DR is labeled “transitional”.

Actually "bad" is DR7 and under. (Ahem.) But as with any single-number indicators, keeping the salt shaker handy is not a bad idea. A metal album at DR6 can actually still be quite listenable, while a pop record would be sounding like Cyprinus carpio at this point. (Florence and the Machine's Ceremonials is only DR5. Ugh. Lana Del Rey's debut is no different, but the vinyl is DR11.) It's the guitars that skew the DR reading. Reverb tends to do the same - Enya's Watermark (http://www.dr.loudness-war.info/details.php?id=347) sure sounds a lot more dynamic to these ears than DR12, which would seem to be an average value for a production from the olden days (which are usually DR11-12).

Not sure why DSOTM (overrated, overrated album btw) is only DR10, WYWH is DR12. Old versions of Fleetwood Mac's Rumours are DR14 or DR15, respectively. (Those are pretty "dry".) Most of Chris Rea's '80s albums are DR13-14. The Cars' Heartbeat City is DR14. Same for Peter Gabriel's eponymous 4th a.k.a. "Security" (pre-remastering) - now that, ladies and gentlemen, is how you masterfully use dynamics. The people involved presumably cut their teeth on prog-rock in the '70s and possibly classical before that.

Justin further argues
Quote
I’ll admit that Aja is good for what it is, but if you find an engineer who wants to make your record sound just like it, he probably arrives at the studio wearing a gray, thinning pony-tail and a polyester polo-shirt proudly embroidered with the words “Out-of-Touch”.

(That sort of argument really screams hipster, but that's another story.)
He's got a point in that quality apparently became a matter of fashion. Being the old quality geek that I am, this strikes me as problematic. Sure enough, I've heard plenty of innovative, "bleeding edge" material with dynamics approaching the flatness of a postage stamp. If my ears are any sort of indication, nowadays it is easily possible to make recordings so unnaturally dense that they result in nausea on the part of the listener. (I might be more sensitive to this than most, I don't know. Putting on some classical or whatever, it sure feels nice to listen to music that's not screaming "LISTEN TO ME!11" at the top of its lungs all the time.)

Why don't people in the industry listen to listeners anyway? It's the end user who ultimately has to put up with whatever they're putting out after all. AFAIK, artists commonly are sick and tired of hearing their own stuff at the point it's mastered, so they usually aren't of much help.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: krabapple on 05 April, 2012, 01:04:40 PM
Why don't people in the industry listen to listeners anyway? It's the end user who ultimately has to put up with whatever they're putting out after all. AFAIK, artists commonly are sick and tired of hearing their own stuff at the point it's mastered, so they usually aren't of much help.



They do listen to the listeners -- for example, convening listening panels to compare potential singles.  The problem is that they don't level match, so whatever is louder tends to get rated better.  THAT is why we have the loudness
wars in the first place.

Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 05 April, 2012, 01:43:29 PM
^Agreed. A "decent stereo", btw, includes a DAP and some good headphones these days and probably is more affordable than ever.
Yes - and blatant clipping is more obvious on those than almost any speakers IMO, because there's no room to hide it.

Agree with all the rest too. I'm wondering: didn't we have a "well mastered albums" thread on HA before? A few surprisingly dynamic examples of pop music were posted in that IIRC.

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: stephan_g on 05 April, 2012, 04:56:40 PM
Don't know about that, but I was just browsing a thread over @ SH that lists about a gazillion* high-DR albums:
http://www.stevehoffman.tv/forums/showthread.php?t=243688 (http://www.stevehoffman.tv/forums/showthread.php?t=243688)

*) rough approximation
They do listen to the listeners -- for example, convening listening panels to compare potential singles.  The problem is that they don't level match, so whatever is louder tends to get rated better.  THAT is why we have the loudness
wars in the first place.

Not level matching essentially boils down to neglecting that people have something called a volume control. One would think that they'd noticed that at some point? Or did nobody ever take the time to think about things like these (which would be sad, but not unlikely)? Then again, even if they had, who likes to admit that they've been wrong...
Title: Big-label mastering engineers don’t understand lossy formats
Post by: markanini on 05 April, 2012, 09:01:46 PM
Not level matching essentially boils down to neglecting that people have something called a volume control. One would think that they'd noticed that at some point? Or did nobody ever take the time to think about things like these (which would be sad, but not unlikely)? Then again, even if they had, who likes to admit that they've been wrong...

Interesting point stephan_g, maybe someone should conduct volume-matched blind tests with this in mind. Even better if this could happen where the conclusions would reach lots of people say on the Mythbusters show. The material should be prepared by the same people that work for the big labels, only that in the mastering stage there's one moderate master and one loud master made. For example 9:30-11.20 in this Bob Katz video http://youtu.be/u9Fb3rWNWDA?t=9m30s (http://www.youtube.com/watch?v=u9Fb3rWNWDA)

BTW I listenented to Noctourniquet and liked it, I'd even deem the production values as great overall but I'm hearing lots of pumping and some harshness in the loud parts. I'll go along with the harshness as an aesthetic choice but the pumping just sounds like crap. As an amateur producer I recognize it as a secondary effect of heavy hard limiting, you could achieve similar effects with a saturation effect without the pumping.
As for Rick Rubins false statements sadly it seem it takes a certain kind of assertive person beside talent to have the priveledge of working with major label bands like TMV RHCP, The Strokes etc.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: krabapple on 06 April, 2012, 03:28:13 PM
Not level matching essentially boils down to neglecting that people have something called a volume control. One would think that they'd noticed that at some point? Or did nobody ever take the time to think about things like these (which would be sad, but not unlikely)? Then again, even if they had, who likes to admit that they've been wrong...



Except psychoacoustically, small differences in 'volume' are not necessarily perceived as 'loudness' changes -- they are perceived as quality changes.  That's why the biasing effect of level mismatch is so insidious.

(Yes, at some point as the difference increases it will be recognized as a difference in volume.)
Title: Big-label mastering engineers don’t understand lossy formats
Post by: IgorC on 06 April, 2012, 06:17:37 PM
Who knows? Even if the AACs sound identical in 95% of cases ...

It's not 95%. It's  more than 99% for iTunes Plus 256 kbps.

 
Title: Big-label mastering engineers don’t understand lossy formats
Post by: julf on 07 April, 2012, 03:06:42 AM
Except psychoacoustically, small differences in 'volume' are not necessarily perceived as 'loudness' changes -- they are perceived as quality changes.  That's why the biasing effect of level mismatch is so insidious.


Absolutely. When I did a rudimentary 16-bit vs 24-bit and 44 vs 48 vs 96 k listening test over at CA, one of my references was a file that had been amplified by 1 dB. That was the one consistently picked as "best" despite not being the best sample rate or resolution...
Title: Big-label mastering engineers don’t understand lossy formats
Post by: ErectX on 13 April, 2012, 12:09:07 PM
Engineers really need to go back to the pre-mastered version and use this for a quality lossy encode.

Mastering these days is a euphemism for making the tracks as hot as possible. This means not just using typical analog-style dynamic compression to get it as close to 0dB as possible, they use digital processing on the waveform samples to essentially clip (with rounded edges) every peak to make a CD packed full of maximum level samples. You can see this when viewing the waveform on a ripped CD of something new, you would swear the signal is just clipped from the multiple max samples in a row. Even just decoding the samples back into a analog waveform (with DAC lowpass frequency filtering) will result in levels higher than 0dB. That's how you get a CD that looks like this: http://upload.wikimedia.org/wikipedia/comm...se_waveform.png (http://upload.wikimedia.org/wikipedia/commons/b/b0/Metallica_My_Apocalypse_waveform.png)

Another factor turning 0dB meant-for-CD tracks into a clipped mess is that when encoding lossy, the audio content is filtered into many passbands, and the ones deemed to be inaudible are discarded. Changing the spectral content will result in a 0dB signal going above 0dB too, as frequency components that had previously cancelled each other out are removed. One has to encode and then decode to see the resultant levels above peaks, and then process them into analog VU levels beyond that to avoid DAC clipping of the analog waveform. In other words, encode audio that gets nowhere near 0dB.

Then finally there is the fact that the psychoacoustic model can't work well on audio cranked up way beyond max. Lossy compression works on figuring out what you can't hear and discarding it, in comparison to a reference level. When the RMS level of the signal is +20dB of what an uncompressed and unprocessed version would be, lossy codecs can no longer work well as it will not be played back anything like the codec hearing model unless you like jet-engine volumes.

There is no reason to encode mp3/aac at loudness war levels. The audio is not going to be played on radio and doesn't have to compete with other tracks in the "loudness" war. The problem is that to do a proper "mastering for iTunes", you have to go back to the source before it went through the bit-cranking hard limiters, and it is doubtful that many engineers will be paid to do this. And unfortunately, "mastered for iTunes" more likely means that misguided engineers actually compress the audio more and screw with the equalization, picturing cheap speakers and ipods as the destination.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Thasp on 20 May, 2013, 01:13:41 AM
I think you're being a little harsh on the article.

One thing amazed me though...
Quote
Bob Ludwig of Gateway Mastering, who is known for his objectivity and diligence, said "…[Another] important addition is the realization that the act of AAC encoding can cause clipping where there was none on the original PCM .wav or .aiff file"
This is news to a diligent mastering engineer? Has he just stepped out of a time machine from 1996?!


I haven't looked into "mastered for iTunes" - it seems strange to "need" to EQ a track to compensate for the effects of an AAC encoder running at 256kbps.

Cheers,
David.


He was trying to be informative. Is it really necessary that he denote everything he says with "I already knew this, but just incase YOU didn't.."

When you are trying to get people to listen to you - you should not be condescending. This is a social industry, you get nowhere by giving people the "wow, you didn't already know X? Well, here's what you SHOULD know" attitude.

Most mastering engineers hate what they are forced to do by the labels. They do it because if they don't, someone else with an L2 or Ozone maximizer plugin. Mastering engineers crushing music sucks, but it is 100000x worse when some bozo with a single plugin tries to do the same thing.

It is weird that in 2013 we are still reading threads where people blame the mastering engineers for everything. If mastering dude X doesn't ruin the music, he will be fired and they will give it to mastering guy Y. Considering how few paying jobs there are left in the music industry, you can't expect them to abandon their paying clients to fight a losing battle when the crushing will happen down the hall at another studio anyway.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 20 May, 2013, 03:03:12 AM
Most mastering engineers hate what they are forced to do by the labels. They do it because if they don't, someone else with an L2 or Ozone maximizer plugin. Mastering engineers crushing music sucks, but it is 100000x worse when some bozo with a single plugin tries to do the same thing.
You can make a recording sound hot without showing off your technical inability by letting your signal clip or claiming FUD about AAC. I simply don't buy the "poor mastering engineers" story in these cases. How come that regardless of producer the same engineers always produce the same horrible masters?

It is weird that in 2013 we are still reading threads where people blame the mastering engineers for everything. If mastering dude X doesn't ruin the music, he will be fired and they will give it to mastering guy Y. Considering how few paying jobs there are left in the music industry, you can't expect them to abandon their paying clients to fight a losing battle when the crushing will happen down the hall at another studio anyway.
So, we should all be thankful for the great job Vlado Meller did on the last few RHCP recordings, because someone else might have done a worse job? That's a pretty low standard there.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 20 May, 2013, 05:05:25 AM
He was trying to be informative.
If that's informative, it just shows you how behind the times the audience is.

FWIW some (lesser) mastering engineers absolutely despise discussions like this. Their results aren't shameful to them - they are quite proud of what they do, and are very insulted that anyone should question their "judgement" and "skill". It's the good ones that realise what crap they're pushing out.

We should remember that, even in 2013, there are still whole swathes of the industry that are largely unaffected by these trends - with many wonderful recordings issued every year.

Cheers,
David.

Title: Big-label mastering engineers don’t understand lossy formats
Post by: Kohlrabi on 20 May, 2013, 05:23:07 AM
We should remember that, even in 2013, there are still whole swathes of the industry that are largely unaffected by these trends - with many wonderful recordings issued every year.
Which is problematic if you are into pop, rock or metal music (and derivatives), since the mastering standards in these genres are generally exceptionally low.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: db1989 on 20 May, 2013, 07:24:06 AM
To add to the recent unearthing of this post:
One thing amazed me though...
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Bob Ludwig of Gateway Mastering, who is known for his objectivity and diligence, said "…[Another] important addition is the realization that the act of AAC encoding can cause clipping where there was none on the original PCM .wav or .aiff file"
This is news to a diligent mastering engineer? Has he just stepped out of a time machine from 1996?!
Not to mention that his oversimplified statement implies that such introduced clipping is more likely to be audible/consequential than it is in reality.

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I haven't looked into "mastered for iTunes" - it seems strange to "need" to EQ a track to compensate for the effects of an AAC encoder running at 256kbps.
Indeed. Many of us had the same sentiment in the thread about this, erm, service. Something is fundamentally wrong with the concept. Another amazing innovation from Apple!
Title: Big-label mastering engineers don’t understand lossy formats
Post by: skamp on 20 May, 2013, 09:20:31 AM
Not to mention that his oversimplified statement implies that such introduced clipping is more likely to be audible/consequential than it is in reality.


I recall that you retorted to me in the past, that I jumped the gun by drawing conclusions from certain statements. This time I think it applies to you. Simply saying that some processing can cause clipping doesn't imply anything about audibility, just like it doesn't imply anything about the amount of clipping that will occur. And as a techie who likes to do things Right™, you're probably going to aim for a result that doesn't include any clipping at all, even if SOME of it would be acceptable (inaudible). But then that only implies attenuation (or headroom), in the smallest amount that will do the job.

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Indeed. Many of us had the same sentiment in the thread about this, erm, service. Something is fundamentally wrong with the concept. Another amazing innovation from Apple!


I don't recall Apple's paper saying anything about applying EQing or any other sort of processing prior to encoding. The important part of it was, "please feed our encoder your high resolution master without prior downsampling, as our encoder will do it automatically with optimized settings" (I'm paraphrasing here). The idea that a different master is needed, more likely comes from mastering engineers like Vlado Meller (and producers like Rick Rubin) trying to get more business.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: db1989 on 20 May, 2013, 09:35:39 AM
I recall that you retorted to me in the past, that I jumped the gun by drawing conclusions from certain statements. This time I think it applies to you. Simply saying that some processing can cause clipping doesn't imply anything about audibility, just like it doesn't imply anything about the amount of clipping that will occur.
This is a good point. I should have qualified my statement with the condition that what he said was technically correct. What I meant was that it might be open to being misread by other people. But that is their problem, not his, and it is probably not very feasible to expect people always to bullet-proof their statements against misinterpretation by others.

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And as a techie who likes to do things Right™, you're probably going to aim for a result that doesn't include any clipping at all, even if SOME of it would be acceptable (inaudible).
This is a nice thought, if only it were true for more engineers!

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I don't recall Apple's paper saying anything about applying EQing or any other sort of processing prior to encoding. The important part of it was, "please feed our encoder your high resolution master without prior downsampling, as our encoder will do it automatically with optimized settings" (I'm paraphrasing here). The idea that a different master is needed, more likely comes from mastering engineers like Vlado Meller (and producers like Rick Rubin) trying to get more business.
Good points too. I confess that I remembered little about MfI, and not to blame David, but when I read what he said, I just defaulted to assuming it was definitely correct.

Still, looking at the official PDF about MfI, certainly not all of it is unreasonable, but very near the start, we have this:
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AAC is the new standard for digital music. It only makes sense to create masters specifically for this format.
As the document goes on to explain, albeit without making it crystal-clear and thus avoiding the risk of undermining their pet format, the concepts recommended by Apple during mastering are not format-specific and, indeed, are little more than common sense. Whilst I cannot argue with many of their recommendations on the latter level, I disagree with how they are presented as revelations and points in favour of AAC. Anyway, no doubt this has all been said before.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: smok3 on 20 May, 2013, 03:11:26 PM
From what I observed lately mastering goes all the way from useless to quite ok, however there is that weird feeling when you enjoy youtube-bootleg version better than the final master.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: Thasp on 22 May, 2013, 02:21:16 AM
So, we should all be thankful for the great job Vlado Meller did on the last few RHCP recordings, because someone else might have done a worse job? That's a pretty low standard there.


It's not about Vlado Meller. I'm not saying you should be happy, I'm suggesting you blame the people responsible for the wreckage. You're blaming the soldier instead of Bush, the pilot instead of Truman. Blame the decision makers, not the people who carry out the decisions, and maybe things wil actually change. I wish I had a better analogy, but it is 2 AM here and I'm pretty tired.

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How come that regardless of producer the same engineers always produce the same horrible masters?


It is likely that the engineer who puts out five loud albums probably gets hired by the same label, which probably has the same ignorant staff members who demand that it be loud. Then it creates this mindset in the group members that want it to be loud because the label people want it to be loud, then they force that on the mixers & mastering engineers. Or, the label directly forces that on the mixers & mastering engineers.

Some engineers record Tori Amos today, and Opeth tomorrow. Others are known for what they do,, and get asked to work on those projects.

My favorite mastering engineers during my time intering under them long ago used to ask the artists - do you want to make music people want to turn up, or shit people want to lower? He'd show the common sense, play recordings, and was almost always ignored, and forced to crush nonsense to pacify the talking heads in the room. A lot of good mastering engineers don't really love making crap loud, but have to find ways to do so or lose paying clients. Again, in 1984, maybe they could afford to. In 2013, if someone is paying you to work on music - you hold on for dear life, and say yes sir! Thank you sir!

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FWIW some (lesser) mastering engineers absolutely despise discussions like this. Their results aren't shameful to them - they are quite proud of what they do, and are very insulted that anyone should question their "judgement" and "skill". It's the good ones that realise what crap they're pushing out.


Some consider it a video game. "Well, I'm foced to make this loud, how can I do it while still maintaining some sembleance of musicality. " It's the only way people who hate what they are doing can keep doing it, try to turn it into a game for yourself where you set goals and achieve them. Same as any other job.

Look on forums like the womb forums, prosoundweb, tape op, even the smut that is gearslutz, and you'll get to hear more than one article. You can read thousands of comments from hundreds of real, working professionals. When you do - when you work in the industry, and meet the people, a lot of these generalizations go away. It's easy to keep the disdain for mastering engineers alive as long as we're looking at one article a year, taking 2 or 3 lines of it and bashing it, but it's hard when you get to see the community as a whole & their thoughts on the issue. Check out sites like http://www.turnmeup.org (http://www.turnmeup.org) , where you have legions of these mastering engineers fighting to get the industry(and the public) to care about the problem.

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You can make a recording sound hot without showing off your technical inability by letting your signal clip or claiming FUD about AAC. I simply don't buy the "poor mastering engineers" story in these cases. How come that regardless of producer the same engineers always produce the same horrible masters?


There are a lot of mastering engineers that master to -0.3 or -0.2 dB or so. A lot of mastering engineers will work on these perfect systems with $10,000 lavry converters and finish their work. We can argue all day about whether differences in DACs are audible, but one DAC's -0.2 dB can easily be another DAC's clipping. If you master to a slightly lower volume you avoid a ton of problems when your master leaves your system and goes to another. It is possible that one system's -0.005 dB  is another's clipping.

Making separate masters for AAC is kind of silly, if you make a master that won't clip any DAC, it probably won't clip any lossy codec either. The "big picture" point I think he was trying to make is that a master can clip on one system while it doesn't on another. I would venture to say it's best to strike a balance, because no one is changing the station based on 0.2 dB.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 22 May, 2013, 05:07:13 AM
In that context, you may this quaintly careful...

The BBC wouldn't let its internet streams peak above -6dB FS for fear of inducing clipping during encoding and in crappy consumer sound cards...
http://www.audiomisc.co.uk/BBC/iPlayerRulesOK/Page2.html (http://www.audiomisc.co.uk/BBC/iPlayerRulesOK/Page2.html)

EBU R128 limits the "true peak" (i.e. the oversampled / inter-sample peak) to -1dB FS...
http://tech.ebu.ch/docs/r/r128.pdf (http://tech.ebu.ch/docs/r/r128.pdf)
(item n)


We could discuss the "sound" of clipping due to lossy encoding, and clipping due to inter-sample overs, and clipping due to really crappy old sound cards that can't cope with 0dB FS signals - but some of these are rarely audible - and others, if audible, are far less audible than the dynamic range compression that's been applied to "smashed" masters. So dropping back to -0.2dB FS rather than 0dB FS will almost never solve the problem, and the sound isn't really that much better if the problem is solved.

Whereas at least the BBC's worry (and solution) with Radio 3 is somewhat justified: clipping, in the context of a pure piano or flute note, is easily audible and pretty horrible.

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: greynol on 22 May, 2013, 10:25:09 AM
Depending on the material, 1dB is still not enough to prevent clipping during lossy decoding. This is especially true for squashed masters.

Thanks for talking about actual audibility, David.

More on the point if audibility of different things, we don't "argue all day" unless there is actual proof of the phenomenon in the way of positive ABX results. Unfortunately I read far more crap from mastering engineers about differences in sound than I read any knowledge about ABX. Instead I hear about A/B which is usually not blind, let alone double-blind; nor does it seem to be properly level-matched or have other necessary controls.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: skamp on 22 May, 2013, 10:46:10 AM
Depending on the material, 1dB is still not enough to prevent clipping during lossy decoding. This is especially true for squashed masters.


Peaks of 1.5 (+3.52dB) or more are quite common, so I guess that at least 4dB of headroom would be needed to entirely avoid clipping due to lossy decoding.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: 2Bdecided on 22 May, 2013, 11:01:16 AM
Depending on the material, 1dB is still not enough to prevent clipping during lossy decoding. This is especially true for squashed masters.
In the context of EBU R128 though, a squashed master adjusted to a loudness of -23LUFS couldn't have a peak anywhere near -1dB FS (unless you specially created a test signal to cause this).

If Mastered for iTunes included a reference level of -23LUFS (or even soundcheck's ~ -16.5LUFS, or ReplayGain's 89dB which is ~ -17.3LUFS), then we'd never worry about clipping of smashed masters due to encoding, and we could probably forget about lossy-induced clipping and inter-sample overs for almost all "popular" content (and for almost all "classical" content with a -23LUFS = ~ ReplayGain's 83dB reference level).

Cheers,
David.
Title: Big-label mastering engineers don’t understand lossy formats
Post by: tnargs on 31 July, 2013, 11:09:38 PM
I think the most damning thing about the mastered for itunes program ....Essentially the entire document assumes that the reader has absolutely no idea how to master a CD, and if left to their own devices, they would screw it up.


I get the impression Apple want to speak to the 'small indie' operators, whose clients might even go down to the 'home recording' musicians and bands. The first line of Apple's Technology Brief says "Whether you’re a major label or a small indie,...". If they help some of these operators to get it right(ish), good thing.