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Topic: Audibility of "typical" Digital Filters in a Hi-Fi Playback  (Read 367775 times) previous topic - next topic
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Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #450
Stuart has written papers that show that 52 kHz / 11 bits are the absolute minimum PCM channel using noise shaping, "capable of replicating the information received by the ear". 14 bits "ought to be adequate" to offer enough headroom. That would be 18.2 bits for a rectangular channel (TPDF, no noise shaping).

"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #451
Tell me again why you guys are arguing.
Again?! Isn't 18 pages of it sufficient?

I would think so and I am looking at ending my participation.  It is a shame though that I can't get people to agree with the simple business principal that high resolution downloads are happening.  And by downloading such bits I am free of worrying whether downgrading them is audible or not.

I have answered this to my satisfaction, if not yours, already.

There are any number of inaudible objective improvements one could make to the recording and reproduction process. Most could fall into the "they can't make it worse so why not" category. Add them together, and you have spent all your money and all your life chasing numerical improvements with little or no audible benefit. Meanwhile the real improvements have passed you by. That is why we have to let the inaudible improvements pass us by, and go and chase audible improvements instead.

(The "you" in that statement is "you" the hi-res audio proponent or "you" the hi-res audio industry.)

So, why should we care about THIS inaudible imrovement? On what basis do you spend money and time on this one, but not 100 others?

Cheers,
David.

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #452
And by downloading such bits I am free of worrying whether downgrading them is audible or not.
There is some logic in there. There is also some logic in capturing the microphone output as losslessly as possible, even if we can't hear it. DXD looks like a safe format for that, since most microphones don't have a bandwidth of more than 100 kHz. Higher-res downloads are more expensive and the claim is that the higher the bitrate, the better the sound quality. From older papers I got the impression that Bob Stuart seems to think that audible differences disappear above 24/96. Besides the satisfaction of "having the studio quality", what would be the point of buying higher formats ?

Some prices for an album in euro, from 2L.no , the provider of the samples of this paper:

stereo:
mp3      09.00
16/44.1   15.00
24/96   21.00
24/192      23.00
DSD64      28.00
DSD128    33.00
DXD          37.00
multichannel:
24/96        25.00
DSD64      33.00

(sorry, can't get tabs to work)

Noting, once again, that they won't sell you the DXD 5.1 "master".

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #453
I wouldn't be surprised if amir was running now, after being unable to answer simple questions, demonstrating a lack of knowledge in even the basics and me asking him if he would do a test where he couldn't cheat as easily (of course he never answered this either).
"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #454
And by downloading such bits I am free of worrying whether downgrading them is audible or not.
There is some logic in there. There is also some logic in capturing the microphone output as losslessly as possible, even if we can't hear it. DXD looks like a safe format for that, since most microphones don't have a bandwidth of more than 100 kHz. Higher-res downloads are more expensive and the claim is that the higher the bitrate, the better the sound quality. From older papers I got the impression that Bob Stuart seems to think that audible differences disappear above 24/96.

Hi Kees.  Give it to you to see the reasonable argument.  As to Stuart, no.  He actually has far lower limits.  Without noise shaping, and a rectangular channel, he advocates 20 bits at 56 Khz.  Since 56 Khz doesn't exist, he says pick the next step up which would be 88 or 96 Khz.

Quote
Besides the satisfaction of "having the studio quality", what would be the point of buying higher formats ?

If it is higher than how the music was recorded/produced, then I have no use for it.  If higher is what is recorded and mixed, then I like to get my hands no those bits as I don't trust anyone to do the right things in the chain to bring it down to something lower.

Some prices for an album in euro, from 2L.no , the provider of the samples of this paper:

Quote
stereo:
mp3      09.00
16/44.1   15.00
24/96   21.00
24/192      23.00
DSD64      28.00
DSD128    33.00
DXD          37.00
multichannel:
24/96        25.00
DSD64      33.00

(sorry, can't get tabs to work)

Yup.  Everyone has a choice of what bits to get.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #455
Tell me again why you guys are arguing.
Again?! Isn't 18 pages of it sufficient?

I would think so and I am looking at ending my participation.  It is a shame though that I can't get people to agree with the simple business principal that high resolution downloads are happening.  And by downloading such bits I am free of worrying whether downgrading them is audible or not.

I have answered this to my satisfaction, if not yours, already.

There are any number of inaudible objective improvements one could make to the recording and reproduction process. Most could fall into the "they can't make it worse so why not" category. Add them together, and you have spent all your money and all your life chasing numerical improvements with little or no audible benefit. Meanwhile the real improvements have passed you by. That is why we have to let the inaudible improvements pass us by, and go and chase audible improvements instead.

You mean I can't do both?  How come? 

And who is to say it is inaudible?  MP3 artifacts are inaudible to many but I assume not to you and certainly not to me.  What standard do we use for that?

Quote
So, why should we care about THIS inaudible imrovement?

I am not asking at all that you care.  I am asking why people here and other forums go crazy, absolutely crazy at the idea that someone goes and downloads higher resolution bits.  Why?  How is bothering them?  Read Krab's posts.  Or AJ's.  Or Arny's.  Or Xnor.  Or even our moderator.  These are not logical reactions to me going buying high resolution audio.  I know all of their arguments yet they keep repeating them.  As you do here .  Do they think I or others haven't hear them?  Why keep repeating it and of all people tell me about it?

Can you answer the psychology of this?  I mean I have this new guy Xnor in my life who is determined to say I have cheated.  Cheated!  How on earth did he decide it is appropriate to wake up one morning and decide his mission in life is to demonstrate that.  And to what effect?  What is driving him?  You know him better than I.  Culturally it is pretty far over the line to go there.  I would think he would do that if he thought I had done him some personal harm.  But to advocate getting the bits prior to conversion to 16/44.1?  That is all it took for him to write 12-quote replies now?  How did that become a priority for him?

Have people lost all sensibility? 

I mean isn't it stupid of all people to take me on?  I take double blind tests.  I have built a career based objective science.  I am an engineer.  I talk about science and technology of audio.  And this is the person that Krab says is going to put on "ignore" list?  What is left to read then if it is not what I just explained.

On what basis do you spend money and time on this one, but not 100 others?

You are but one of a few reasonable people I have seen here.  Can you explain to me?  If not them, can you explain how you stand next to them?

Now I enjoy the banter so not saying this stuff to have you help me in that regard.  But the whole affair is the most illogical thing there is.  Let folks consume high resolution audio in peace.  No harm will come to any of you.  I promise.  You will suffer less in life waking up to read my posts .
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #456
From such price lists the hi-re$ agenda is painfully obvious.
"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #457
Good morning amir,

Good evening AJ. Today is your birthday. You get to go and celebrate with a good dinner?  What?  It is not your birthday?  Well, it must be some cause for celebration since I decided to answer one your posts! 

Quote
Something about this little story has been bugging me a bit, perhaps you could enlighten us. 

Something is bugging me too and is along the lines of what I just wrote David.  Why do you come here AJ?  What all these posts?  Why the anger and frustrations over someone buying high resolution audio?  Can you think through your motivations and answer in your reply?

The rest of your answer in part 2.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #458
I am asking why people here and other forums go crazy, absolutely crazy at the idea that someone goes and downloads higher resolution bits.  Why?  How is bothering them?  Read Krab's posts.  Or AJ's.  Or Arny's.  Or Xnor.  Or even our moderator.  These are not logical reactions to me going buying high resolution audio.  I know all of their arguments yet they keep repeating them.  As you do here .  Do they think I or others haven't hear them?  Why keep repeating it and of all people tell me about it?


I am not going crazy, in fact, I couldn't care less what files you download. You are also in no position to judge what is logical, given your previous posts.
You know all arguments, yeah right, but are unable to answer even simple questions?


Can you answer the psychology of this?  I mean I have this new guy Xnor in my life who is determined to say I have cheated.  Cheated!  How on earth did he decide it is appropriate to wake up one morning and decide his mission in life is to demonstrate that.  And to what effect?  What is driving him?  You know him better than I.

amir, for once try to stop being stupid.
I said that your own posting made it even more likely that you cheated. And your constant evasion of simple questions related to those tests support that assumption.

What is driving me? I already told you amirm. ... something you don't seem to be interested in.


Culturally it is pretty far over the line to go there.  I would think he would do that if he thought I had done him some personal harm.  But to advocate getting the bits prior to conversion to 16/44.1?  That is all it took for him to write 12-quote replies now?  How did that become a priority for him?

What are you even talking about? You are talking absolute rubbish.

I asked simple questions. You demonstrably evaded and went at length in your replies just to contradict me. You admitted to stereotyping. What is wrong with you, amirm?


I mean isn't it stupid of all people to take me on?  I take double blind tests.  I have built a career based objective science.  I am an engineer.  I talk about science and technology of audio.  And this is the person that Krab says is going to put on "ignore" list?  What is left to read then if it is not what I just explained.

But you demonstrably lack knowledge about basic science, logic, statistics and fail to make replies that are not riddled with fallacies, or evasion maneuvers.


You talk down on me, but take a look at the mirror. As someone has PM'd me: "he has no interest in intellectual honesty or scientific rigor". Well, I couldn't agree more and everyone can see it. (Although, given previous posts, I tend to think it is ignorance and an agenda rather than simply "no interest".)
"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #459
And by downloading such bits I am free of worrying whether downgrading them is audible or not.

There is some logic in there.

Sorry Kees, don't see it. Amirlogic perhaps, not "logic" logic.
It may be audiophile logic to buy Clarity Cap MR for "worry free", non-"downgraded" audio, whether non-boutique caps are audible or not (the drum up some doubt method). Why? Because Clarity fabricated a singing cap themselves, which was, surprise, surprise, audible using blind tests in a University study. IOW, contrive a scenario that does not exist in real life, sell "worry free" widget to audiophiles based on this. Method sound familiar?

Some prices for an album in euro, from 2L.no , the provider of the samples of this paper:

stereo:
16/44.1   15.00
24/96   21.00

Yep, with no evidence the 24/96k version can be distinguished, since the 16/44 version must be RPDF dither doctored, heard in an iso-ward, with questionable system transparency, etc, etc, etc....

Not seeing the logic there at all.

cheers,

AJ

Loudspeaker manufacturer

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #460
Is there any record anywhere, of you demonstrating this elite aural athleticism, at say, the fully documented listening Olympics, supervised, to your peers?

I imagine you have done special things in your work that are not public and can be verified this way, right? 

But yes, there are hundreds of people at Microsoft that know about my listening abilities many of them first hand. Vast majority of them are not active on forums though.

I didn't think there would have been a need years later to prove that on some forum.  I would have gotten notarized statements from witnesses otherwise.

This being the Internet, I trust you accept Internet type evidence.  I did a search on AVS and quickly landed on a post by Ben Waggoner.  Ben is quite a famous compressionist.  You can google his name to find more.  Anyway, he worked in my group and said this on AVS unprompted: http://www.avsforum.com/forum/114-hdtv-sof...ml#post13633874

Quote from: Ben Waggoner on AVS link=msg=0 date=
Quote from: Steve Burke link=msg=0 date=


Even Amirm has said that he cannot make this claim:

Surely you wouldn't imply that 640k tracks are indistinguishable from TrueHD, would you?

Amirm: "No I wouldn't"


Amir is also a golden-ears audio compression expert.

Transparency can be achieved by any of the right compression, content, and audience .

Digital Media Technology Insider with Microsoft

My compression blog
[/color]


Quote
Or is the very first demo to the world earlier this year (2014), when you the ex-MS exec, sat at your Windows pc (possibly with your occasionally barking dog as the sole witness) and "passed" Arnie's corrupt ABX windows computer file ABX online test? And all similar subsequent ones of course.
Just curious, is all. Thanks.

Arny's corrupt ABX?  I will let him address you on that. 

I tell you what AJ.  I will make a deal with you. I will fly to Florida to see you.  You pay half of my expenses and I pay the other half.  I will bring just my laptop and headphones and repeat the same tests I have post here.  If I pass, you pay the other half of my expenses plus another $1,000 I give to charity.  If I lose, I will do the reverse and you can decide what to do with the extra $1,000.  What say you?

Alternatively you fly to Seattle and I take the test here in front of you and we only wager the $1,000.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #461
Amir's, position as I understand it in all of this is as follows.

When he wants to buy music, he wants to buy the masters of the recording. If they only exist in 44.1, then fine. If it's 96 or 112 then fine. He doesn't want anything that's been up or down converted. If you think about it, that's his preference and as far as preferences go, it's whatever floats your boat.

How we each justify our preferences is an individual matter. There are rational, irrational, and any number of reasons why we choose things. A problem generally arises when we vocalize our reasonings to others. After all, not everything we say is going to make sense to the other person or there may even be errors in our thinking.

Amir has demonstrated to his satisfaction that he can key in on certain aspects of the conversion process with great success. That may well play apart in his internal justification process. He's aware that hi-res, even compressed, takes up more room and it costs more. Significantly in my opinion but to him that's irrelevant so long as what he bought is the master. It may well be that the master still suffers from loudness issues or even poor recording or mastering. But if it's the original then that's what matters.

The rest of what transpires are matters of verbal jousting. For me, the pity is that the complaints the public has had with the recordings are not going to go away. Look at those links I posted earlier and IMO, it's not about doing a better job with recording. Studios are going to put out what sells and in whatever format, moving the sliders around until they get something the customer approves. A crappy picture at 800x600 is still going to be crappy at mega resolutions.


Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #462
Why do you come here AJ?

You mean why have I been here since '09? To discuss audio, one of my interests. Like this BS test.
Why did I bait you into coming here? I thoroughly enjoy our conversations, because your lack of answers, two-stepping, etc. do provide answers. 
What do I also enjoy? Turning the tables on the elitists, bullies, illogical condescending snobs and highly self deluded "audiophiles" that permeate my audio hobby . Giving them healthy doses of their own medicine.
Nothing you could be cognizant of, figure out, much less worry about.
Now, about this highly contrived BS paper....

Oh and BTW, the thread is about the BS test, not "What Amir Bolt wants with audio files".

cheers,

AJ
Loudspeaker manufacturer

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #463
FYI, I passed all of my double blind ABX tests using my laptop and headphones.
You probably think you're getting a hard time here, but you should take it as a compliment that no one has challenged you on this. The assumption must be that, given your employment history, you must know what you're doing. Anyone else who arrived on HA and made this claim would get a really hard time, due to a long history of drivers, sound cards, and transducers that don't take kindly to ultrasonic content. ABXing hi-res vs 16/44.1 on such crappy equipment is easy, and it's not because hi-res is audibly better.

Cheers,
David.


Are there some details on the system amir used? Which operating system/version, which headphones, which soundcard, which sound API, which DirectSound common sampling rate was configured (if applicable) ... ?

You spoke too soon David.  As you see Xnor and AJ are on full bore inquisition with no regards to my prior experience.

I didn't answer you xnor because all of this has been hashed out on AVS Forum.  And mzil gave you part of it.  I know you haven't seen them but I thought you would at least pay attention to what David said.

So that you know what he is referring to, my team at Microsoft was responsible for entire Audio/Videos tack in Windows including DS, mixing and resampling pipeline, etc.  I championed ditching the horrible one in XP and creating a proper one.  I hired JJ to head that activity and the results were a major step up from XP.

Most of my testing was done on my rather new HP Zbook 14.  I take these tests casually in our family room with TV on and such (hence the dogs barking).  I like to use my Etymotic headphones because they seal so well.  I was challenged on that so I repeated the test with my Shure IEM.  To really put that argument to bed, I also ran a test with my uncomfortable Paradigm IEM.  I have a stock audio stack in my laptop and have Foobar running in default configuration.  Since all of the tests have been at 24-bit/96 Khz, I have set that as the audio property of the sound card.  There is still dither added on the way in/out of the kernel stack but seeing how I had positive results, I didn't need to go with WASAPI or ASIO to eliminate that.

I have run Arny's Ultrasonic IM test and passed that (I post that in one of the threads here).

New version of Foobar ABX spits out the audio stack selection so here is David's test I ran:

foo_abx 2.0 beta 4 report
foobar2000 v1.3.5
2014-11-13 09:16:06

File A: limehouse_maximum_phase_100.wav
SHA1: 722dc26db8d4ce666dc03875b2c8d4570d22b521
File B: limehouse_reference.wav
SHA1: e8ad96830d23cad4bba5bf822ce875ae452b9e7c

Output:
DS : Primary Sound Driver

09:16:06 : Test started.
09:16:48 : 01/01
09:16:56 : 02/02
09:17:04 : 03/03
09:17:14 : 04/04
09:17:21 : 05/05
09:17:29 : 06/06
09:17:38 : 07/07
09:17:45 : 08/08
09:17:52 : 09/09
09:18:02 : 10/10
09:18:08 : 11/11
09:18:14 : 12/12
09:18:20 : 13/13
09:18:28 : 14/14
09:18:36 : 15/15
09:18:42 : 16/16
09:18:42 : Test finished.

----------
Total: 16/16
Probability that you were guessing: 0.0%

-- signature --
5b42b06c414b6ba77a3998695bf119a2d57663c0

Edit: Forgot to mention the OS.  It is Windows 7 Pro.

BTW, you asked me what test to run.  Start with the above.  It is in the parallel link.  Please post your answer here.  AJ, same to you.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #464
Is there any record anywhere, of you demonstrating this elite aural athleticism, at say, the fully documented listening Olympics, supervised, to your peers?

I imagine you have done special things in your work that are not public and can be verified this way, right? 
But yes, there are hundreds of people at Microsoft that know about my listening abilities many of them first hand. Vast majority of them are not active on forums though.
I didn't think there would have been a need years later to prove that on some forum.  I would have gotten notarized statements from witnesses otherwise.

This being the Internet, I trust you accept Internet type evidence.  I did a search on AVS and quickly landed on a post by Ben Waggoner.  Ben is quite a famous compressionist.  You can google his name to find more.  Anyway.....

Unfortunately Amir, those aren't the droids we're looking for again.
So I'll answer for you: No, you have zero evidence of demonstrating any such ability. Ever. Particularly for 16/44.

I tell you what AJ.  I will make a deal with you. I will fly to Florida to see you.  You pay half of my expenses and I pay the other half.  I will bring just my laptop and headphones and repeat the same tests I have post here.  If I pass, you pay the other half of my expenses plus another $1,000 I give to charity.  If I lose, I will do the reverse and you can decide what to do with the extra $1,000.  What say you?
Alternatively you fly to Seattle and I take the test here in front of you and we only wager the $1,000.

Unfortunately Amir, those aren't the droids we're looking for either. 
Certainly wouldn't pass ITU-R BS.1116-2, or be submittable to AES. We wouldn't want to fall into that Hobbyist trap, right?
However, you are still welcome to accept my multiple invites to attend an audio show I exhibit at, have a beer with some banter. With your laptop. 

cheers,

AJ
Loudspeaker manufacturer

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #465
I didn't answer you xnor because all of this has been hashed out on AVS Forum.  And mzil gave you part of it.

mzil gave me part of what? Your system, system configuration, what you precisely hear and when ...?
Are you confused again? If all of this information is available then why didn't you post a simple link to that particular post instead of posting pages of evasion and nonsense?

So that you know what he is referring to, my team at Microsoft was responsible for entire Audio/Videos tack in Windows including DS, mixing and resampling pipeline, etc.  I championed ditching the horrible one in XP and creating a proper one.  I hired JJ to head that activity and the results were a major step up from XP.

I gotta laugh because the resampler of Vista, 7 had absolutely horrible performance, such as when recording approaching an ENOB of ~8 bits. Also there have been so many reports about problems with the whole new audio stack (I've had absurd bugs as well) that it's not even funny anymore.
It took Microsoft roughly ~5 years to fix the most annoying problems and bad performance.

Most of my testing was done on my rather new HP Zbook 14.  I take these tests casually in our family room with TV on and such (hence the dogs barking).  I like to use my Etymotic headphones because they seal so well.  I was challenged on that so I repeated the test with my Shure IEM.  To really put that argument to bed, I also ran a test with my uncomfortable Paradigm IEM.  I have a stock audio stack in my laptop and have Foobar running in default configuration.  Since all of the tests have been at 24-bit/96 Khz, I have set that as the audio property of the sound card.  There is still dither added on the way in/out of the kernel stack but seeing how I had positive results, I didn't need to go with WASAPI or ASIO to eliminate that.
[...]
Edit: Forgot to mention the OS.  It is Windows 7 Pro.

Thanks. You haven't specified the IEM models, but most of these models have rolled-off treble (which doesn't matter much anyway since you said your hearing rolls off above 12k and you claim that the filter ringing at 21+ kHz somehow distorts audio below <12 kHz).

Now there is one thing left: what did you specifically hear in these tests?


New version of Foobar ABX spits out the audio stack selection so here is David's test I ran:

"Primary Sound Driver" could be anything, but doesn't matter anyway since, I'm sorry, I'm not trusting these logs for (what should be by now) obvious reasons.

So, anyway, are you up for a test where e.g. a spectrum analyzer running in the background wouldn't help you?
(I'm still waiting for you to finally explain what you specifically hear in these tests. Would make it easier to design a test that specifically targets your super-trained abilities.)
"I hear it when I see it."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #466
What say you?

Contact this guy in WA.
Have him setup/have someone run a valid, robust test. Use his home brewed speakers (the big ones with the ribbon), they are capable of what we need. Save some travel $$/headaches.
Post on Youtube (won't be any need for submitting to AES with the results you get). Or here.
Spend the $1k on CDs or maybe some therapy for these bizarre cravings.

cheers,

AJ
Loudspeaker manufacturer

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #467
No, you are confused. I'm not talking about ripple but ringing. I never even mentioned ripple.

Oh?  Did you not immediately follow up with this post?

Adding to the ringing post above:



The background signal (blue) shows a sweep from 20 kHz to 23 kHz.
The rest show this signal filtered with the following pass band edges:
magenta = 20.5 kHz
cyan = 21.591 kHz
red = 22 kHz

Stop band starts at 22.05 kHz in all cases.

Here the same graph when subtracting the filtered signals from the original:


Here's what happens when you mess up the filtering (see cyan line which doesn't null anymore with the original signal): png


Where would I see "ringing" in those?  You clearly say they are frequency sweeps from 20 to 23 Khz.  Is that how we show the Impulse response and ringing?  With a spectrum display from 20 to 23 Khz?  You are telling us that those visualizations are the same as these I post?



My graph shows ringing in time domain.  Exactly the topic David and I were discussion.  You clearly confused passband ripple in frequency domain with time domain ringing.  It doesn't get any simpler than this.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #468
Why do you come here AJ?

Why did I bait you into coming here? I thoroughly enjoy our conversations, because your lack of answers, two-stepping, etc. do provide answers. 
What do I also enjoy? Turning the tables on the elitists, bullies, illogical condescending snobs and highly self deluded "audiophiles" that permeate my audio hobby . Giving them healthy doses of their own medicine.

There we go.  The truth comes out.  No interest in having a technical discussion about the topic at hand.  A thread is created to discuss an AES paper and your priorities are "condescending snobs and highly self deluded audiophiles?"  Why not go and waste forum bandwidth somewhere else where that is the topic?

Quote
Nothing you could be cognizant of, figure out, much less worry about.

Good that you know why I don't answer most of your posts.  I am not remotely worried about them.  So rant away my good friend.

Quote
Oh and BTW, the thread is about the BS test, not "What Amir Bolt wants with audio files".

Oh?  I thought it was about turning the tables on the elitists, bullies, illogical condescending snobs and highly self deluded "audiophiles" that permeate my audio hobby?  Not so smart as the Oracle said in movie Matrix. 
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #469
What say you?

Contact this guy in WA.

I don't want to wind up on his list of idiots by doing so.  You can contact him though since you have so much passion in this.
Quote
cheers,

AJ

AJ I have been meaning to say this but keep forgetting.  Your picture in your avatar has the wrong aspect ratio.  It is squashed horizontally.  Are you not even aware of such obvious flaws?  Good grief man. I have not even seen the original but I am pretty sure it is wrong.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #470
I don't want to wind up on his list of idiots by doing so.

You're not on it already? Haha, just kidding 
Well, he does seem rather qualified for such endeavors, don't you think? Thought you were friends too.
Ah well. Your side could have finally swooned in victory over the stone deaf party poopers...but alas.
Another null wouldn't have mattered, your side rejects those.

You can contact him though since you have so much passion in this.

Nope, I'll try this again, even though I know you could never get it, but the onus is squarely on you/your camp.
Guess we'll just have to stick with Amir Geller, rather than Amir Bolt. 

AJ I have been meaning to say this but keep forgetting.  Your picture in your avatar has the wrong aspect ratio.  It is squashed horizontally.  Are you not even aware of such obvious flaws?  Good grief man. I have not even seen the original but I am pretty sure it is wrong.

Here's the original but I'm just too lazy to fix the forum one.


Have a nice weekend Amir, now I think I'll go listen to some nice 4ch 16/44 CD. Since PSR at 320 kbps never took off and the MCH Hi-Rez stuff still tends to suck spatially.

cheers,

AJ



Loudspeaker manufacturer

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #471
On page 2 I find two rather conflicting statements and I'm not sure what conclusion the authors draw:
Quote
It has further been suggested [22, 23, 24] that listeners can discriminate timing differences of the order of 5 µs and below, which, if correct, would require a Nyquist frequency of 32 kHz or higher...

And below that:
Quote
However, it can not be assumed that the auditory system cannot extract time differences that are shorter than the periods between successive samples, even when convolved with a sinc function in D/A conversion (assuming a sufficient signal-to-noise ratio).

It is my understanding (references to JJ, David Griesinger e.a.) that "In Physics, the accuracy of timing is not determined by the bandwidth, but roughly by the product of the bandwidth and the signal to noise ratio".
Am I correct that the authors say that the time resolution argument based on sample rate and excluding SNR is not valid ?


A goodly number of the cited references lack reliable substantiation.

For example reference 23 is
M. N. Kunchur. Audibility of temporal smearing and time misalignment of acoustic signals.  Technical Acoustics, 17, 2007.  You can read it here: http://boson.physics.sc.edu/~kunchur/paper...s---Kunchur.pdf .

If I can remember the critiques of it when it first came out, it is actually implicitly criticized in the new Meridian paper by this statement:
"However, it can not be assumed that the auditory
system cannot extract time diff erences that are
shorter than the periods between successive samples,
even when convolved with a sinc function in D/A
conversion (assuming a sufficient signal-to-noise ratio)."

and this relates to the following false claim in Kunchur's paper:

"...use of digital carriers limits the shortest resolvable time interval to about half the sampling interval (which for CD would be 11 ?s);"

One of the problems with the new Meridian paper is that if it is considered to be an AES refereed paper, it adds a number of serious errors (such as overlooking ABX1982 which is after all a refereed JAES paper) and apparent folklore such as:

"Listeners were able to
listen to as many labelled pairs of extracts as they
liked before progressing to the test. The filter used
here was an FIR filter with a frequency transition
band spanning 8-10 Hz. This fi lter was chosen as it
would have been straightforward for most listeners
to identify differences introduced by its application."

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #472
On page 2 I find two rather conflicting statements and I'm not sure what conclusion the authors draw:
Quote
It has further been suggested [22, 23, 24] that listeners can discriminate timing differences of the order of 5 µs and below, which, if correct, would require a Nyquist frequency of 32 kHz or higher...

And below that:
Quote
However, it can not be assumed that the auditory system cannot extract time differences that are shorter than the periods between successive samples, even when convolved with a sinc function in D/A conversion (assuming a sufficient signal-to-noise ratio).

It is my understanding (references to JJ, David Griesinger e.a.) that "In Physics, the accuracy of timing is not determined by the bandwidth, but roughly by the product of the bandwidth and the signal to noise ratio".
Am I correct that the authors say that the time resolution argument based on sample rate and excluding SNR is not valid ?


You may want to read this thread, starting from around the 12th or 13th post or so.
He schools some of the fashion engineer luminaries from amirs camp rather nicely. 

cheers,

AJ
Loudspeaker manufacturer

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #473
You may want to read this thread, starting from around the 12th or 13th post or so.
Thanks for the link. It confirms what I've read elsewhere. It's just sad that it's not common knowledge. Just look at this article from Yamaha Professional Audio:

Quote
To also accurately reproduce changes in a signal’s frequency spectrum with a temporal resolution down to 6 microseconds, the sampling rate of a digital audio system must operate at a minimum of the reciprocal of 6 microseconds = 166 kHz.
...
table 504: Main decision parameters for the selection of a digital audio system’s sample rate

Audio quality issues:  desired temporal resolution 

48 kHz    20 ?S - high quality
96 kHz    10 ?S - very high quality
192 kHz    5 ?S - beyond human threshold

On the topic of filters, can someone explain to me the use of impulse response energy as displayed in Fig.2 ? I know how to interpret amplitude response, but have never seen an energy plot like that.

 

Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #474
For those who have not read the whole of this thread, I'd note that the question of the use of no dither when quantising to 16-bits (test conditions  2 and 5), or rectangular dither when quantising to 16-bits (test conditions 3 and 6) could be regarded as a subsidiary matter. This is because the paper reports that there was a statistically significant correct identification of an audible difference for test condition 1, i.e. filtering to emulate a resampling to 44.1kHz, and without any quantisation to 16 bits. (As for conditon 4, a filtering to emulate resampling to 48kHz,  and without any quantization to 16 bits, "the t-test just failed to reach significance at the 5% level". )

If it is true that a mere filtering at 24-bit depth for the 22.05kHz Nyquisit limit of 44.1kHz sampling was of itself identifiable (in particular for certain "high yield" [easier to spot differences] sections of the music), it becomes a subsidiary matter what effect a subsequent quantisation to 16-bits might have had. The "damage" or "impairment" had already occurred, or so it would appear.

Amirm, a few posts above, raises as a possible explanation the matter of ringing, with emphasis on the time domain aspect (the timing and duration of the ringing), rather than the frequency domain aspect (primarily, the frequency of the oscillation):
OK, finally I get to this technical point:
...

The above is also the reason I say that if CD had picked 48 Khz as the sampling, I would have no beef with it.  We have plenty of room to implement our filter above 20 Khz. But by picking 44.1, it leaves us a small margin forcing sharper filters and more time domain ringing.


I note that had the filtering been performed with non-linear phase, then indeed signal frequencies in the audible range could well have been shifted in phase, and particularly when listening with headphones, such phase changes might have become audible as a subtle change. However the paper indicates that linear phase Finite Impulse Response filters were used. The filter for the notional 44.1kHz sample rate had a transition band from 23500 to 24000Hz.  That suggests that audible frequencies at 20kHz and below would not only have been unaffected in amplitude, but unaffected in phase.

In a separate thread in this forum on the audibility of a 20kHz brickwall filter, the promising ABX results reported have been for maximum phase shift, not linear phase shift.  See: Audibility of 20kHz brick wall filtering, samples provided for ABXing - 24/96 sound card required.