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Topic: Audibility of "typical" Digital Filters in a Hi-Fi Playback  (Read 367766 times) previous topic - next topic
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Audibility of "typical" Digital Filters in a Hi-Fi Playback

Reply #50
Such as non-representative pathological samples?

And those were what?

Quote
...or use rectangular dither, knowing that it could have a stronger influence over the outcome?

What type of dither did Meyer and Moran use?  Whatever was in the A/D and D/A converters of the CD-ROM recorder, right?  Here is Stuart on his latest test:

This [playback] level was
chosen for comfort, and because it was high enough
for details to be audible but also low enough that 16-
bit RPDF dither would be inaudible at the listening
position [30].


And

We chose to use undithered quantization as
a probe and | although we would normally rec-
ommend TPDF dither for best practice -- we con-
sidered rectangular dither to be more representative
of the non-ideal dither or error-feedback processing
found in some commercial A/D and D/A filters.


Seems reasonable to me.  After all, who knows what dither if any was used in the music that people are shipping to us in 16/44.1?  It is not like they know what you and I know about dither types.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #51
And those were what?

I don't know, hence my use of a question mark.  Why don't you tell us?

This [playback] level was chosen for comfort, and because it was high enough for details to be audible but also low enough that 16- bit RPDF dither would be inaudible at the listening position [30].

I'm not buying it.

We chose to use undithered quantization as a probe and although we would normally recommend TPDF dither for best practice -- we considered rectangular dither to be more representative of the non-ideal dither or error-feedback processing found in some commercial A/D and D/A filters.

This doesn't pass the smell test either.

After all, who knows what dither if any was used in the music that people are shipping to us in 16/44.1?

...or what was the true noise floor and dynamic range.

These are all poor excuses not to employ best practices, if you ask me.

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

Reply #52
What type of dither did Meyer and Moran use?

Red Herring dither. Now stick to what BS used in his landmark tests, the only relevant one, remember?

Here is Stuart on his latest test:
This [playback] level was
chosen for comfort, and because it was high enough
for details to be audible but also low enough that 16-
bit RPDF dither would be inaudible at the listening
position [30].

Very vague. What was the measured levels? One more time Amir, did BS's test adhere to ITU-BS1116 or BS.1534-2?
What hidden reference anchor was used?
I actually like to measure the ABX/HR box also. Such boxes are used in all of these tests we hang our hat on yet none of us have any measurements or objective evaluations of them.

We chose to use undithered quantization as
a probe and | although we would normally rec-
ommend TPDF dither for best practice -- we con-
sidered rectangular dither to be more representative
of the non-ideal dither or error-feedback processing
found in some commercial A/D and D/A filters.

Ah, so he cherry picked. Nice. 
So this has nothing to do with whether 16/44 is transparent as a playback method, but more about cherry picking a pathological case.
Yes, I can really see this flipping JJ's position....

cheers,

AJ
Loudspeaker manufacturer

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

Reply #53
And those were what?

I don't know, hence my use of a question mark.  Why don't you tell us?

???  You said: Such as non-representative pathological samples?  I am asking what was non-representative and pathological.  If you don't know what was used why characterize it that way?

Quote
This [playback] level was chosen for comfort, and because it was high enough for details to be audible but also low enough that 16- bit RPDF dither would be inaudible at the listening position [30].

I'm not buying it.

Fine. He is not selling it either. 

Quote
We chose to use undithered quantization as a probe and although we would normally recommend TPDF dither for best practice -- we considered rectangular dither to be more representative of the non-ideal dither or error-feedback processing found in some commercial A/D and D/A filters.

This doesn't pass the smell test either.

It was a listening test, not cooking. 

Quote
After all, who knows what dither if any was used in the music that people are shipping to us in 16/44.1?

...or what was the true noise floor and dynamic range.

These are all poor excuses not to employ best practices, if you ask me.

I guess I need to get calibrated on member points of view.  What is your position on Meyer and Moran since we both have the report in hand.  Followed best practices? 
Amir
Retired Technology Insider
Founder, AudioScienceReview.com


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

Reply #55
What type of dither did Meyer and Moran use?

Red Herring dither. Now stick to what BS used in his landmark tests, the only relevant one, remember?

The thread name is "follow-up to Meyer and Moran."  What plot are you following AJ?  We are comparing the two reports to see which one is valid seeing how they contradict themselves.

Quote
Here is Stuart on his latest test:
This [playback] level was
chosen for comfort, and because it was high enough
for details to be audible but also low enough that 16-
bit RPDF dither would be inaudible at the listening
position [30].

Very vague. What was the measured levels?

It is in the report.

Quote
One more time Amir, did BS's test adhere to ITU-BS1116 or BS.1534-2?

The only BS test I know is the Meyer and Moran where they had not even heard of BS116 it seems.  If you mean Stuart's, yes, the followed good bit of it.  They deviated in some areas such as using non-expert listeners as to not get accused of results only being valid for that population.

Quote
What hidden reference anchor was used?

If something is hidden, you wouldn't be able to see it, right?    Part of the answer was in my post.

Quote
I actually like to measure the ABX/HR box also. Such boxes are used in all of these tests we hang our hat on yet none of us have any measurements or objective evaluations of them.

When did you learn to measure stuff AJ?  You didn't go and learn something about audio in the last year or two, did you? 

But no, they did not use a "box" to have measurements as such.  As the line in the movie Fifth Element goes, the switching mechanism was "perfect." 

Quote
We chose to use undithered quantization as
a probe and | although we would normally rec-
ommend TPDF dither for best practice -- we con-
sidered rectangular dither to be more representative
of the non-ideal dither or error-feedback processing
found in some commercial A/D and D/A filters.

Ah, so he cherry picked. Nice. 

He was trying to please you AJ.  Don't say he didn't do anything for you.

Quote
So this has nothing to do with whether 16/44 is transparent as a playback method, but more about cherry picking a pathological case.

I think the only thing pathological is interactions between you and I on forums!   

Are you going to offer anything informative AJ or just keep being yourself?
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #56
I can see that you clearly aren't worth my time or effort, amirm.

I am sorry I made you feel that way.  I didn't see anything constructive in your reply to me.  If you say something is pathological I like to see what you mean by that.  When I provide actual quotes from the paper, you dismiss them out of hand with not passing smell tests and such. What am I supposed to do with that reply?  There is nothing technical there.  So when you ask me to quote more from the paper, I am not inclined to do so and get the same dismissal.  Instead of being direct and telling you all of this, I resorted to a bit of sarcasm and humor.  Would you have preferred this version of my reply instead?  If so, well, you have both now .
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #57
Such as non-representative pathological samples?

And those were what?

Quote
...or use rectangular dither, knowing that it could have a stronger influence over the outcome?

What type of dither did Meyer and Moran use?  Whatever was in the A/D and D/A converters of the CD-ROM recorder, right?  Here is Stuart on his latest test:

This [playback] level was
chosen for comfort, and because it was high enough
for details to be audible but also low enough that 16-
bit RPDF dither would be inaudible at the listening
position [30].


And

We chose to use undithered quantization as
a probe and | although we would normally rec-
ommend TPDF dither for best practice -- we con-
sidered rectangular dither to be more representative
of the non-ideal dither or error-feedback processing
found in some commercial A/D and D/A filters.


Seems reasonable to me.  After all, who knows what dither if any was used in the music that people are shipping to us in 16/44.1?  It is not like they know what you and I know about dither types.


If someone were an advocate of so-called high resolution recordings then of course they would like to see the CD format hobbled by suboptimal dither and suboptimal noise shaping.

Furthermore highly atypical recordings were used: "The recording was of _very_ large dynamic range, roughly 16 bits worth."

I've made recordings of live performances using every trick I could except gain riding, and 15 bits was about as far as I could get. 

A typical live recording made in a concert hall has dynamic range on the order of 12-13 bits.

A commercial recording with 12 bit dynamic range is actually quite exceptional, even before the days of hypercompression.

So to summarize, hobble the 16/44 recording, and use excluded middle recordings, and you just might be able to get positive results.

So what is known about the monitoring system and room used for playback?  I'll bet it wasn't your typical listening room with a 40 dB SPL noise floor...

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

Reply #58
What plot are you following AJ?

The HA one where we discuss the topic of BS's "follow up" AES paper, not Amirs Red Herrings, Ad Hominems and other assorted dives into the rabbit hole, like on AVS and WTF??? forums.
You do know this is HA, not Kansas?

If something is hidden, you wouldn't be able to see it, right?    Part of the answer was in my post.

IOW, no, BS didn't use MUSHRA. We know you "like" statements such as standard ABX is "fatally flawed". Hopefully this BS test wasn't.

But no, they did not use a "box" to have measurements as such.  As the line in the movie Fifth Element goes, the switching mechanism was "perfect." 

IOW, no measurements or objective evaluations of the switching apparatus to hang our credentialed hats on. Very amateurish.

He was trying to please you AJ.

Right. BS tests are for daydream believers and shysters who have pecuniary interests. Thus cherry picking and pathological methods becomes a necessity.

Are you going to offer anything informative AJ or just keep being yourself?

Both.

cheers,

AJ
Loudspeaker manufacturer

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

Reply #59
Seems reasonable to me.  After all, who knows what dither if any was used in the music that people are shipping to us in 16/44.1?  It is not like they know what you and I know about dither types.


It is true that the choice of dither is up to the people producing the recording.  Over the years various producers have advertised that they were using high performance dithering techniques.

An example of such a product could be JVC XRCDs.

Sony's Super Bit mapping seems to specifically claim the use of special noise shaping.

Anybody with better-than-average converters in their production facility can do this with off-the-shelf software such as Audition.

Just make the recording with good 24 bit ADCs with > 106-116 dB dynamic range (readily available off-the-shelf) and do the 24->16 bit conversion in software where the required dithering algorithms are readily available. 

The tricky part is actually making a recording with enough dynamic range of its own for these steps to yield audible improvements. Doing that in a studio or concert hall is not easy, and is in fact unlikely unless very special care is taken with the choice of recording venue, the performance, micing and mixing techniques.  As I've said I've done it and it implies a number of artificial constraints.

Or, the production staff can cheat and process the live recording with a dynamics expander, or simply ride the gains during mixing.


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

Reply #60
Furthermore highly atypical recordings were used

What? Nothing as 16/44-insufficient and highly demanding as Neil freaking Young? No Floyd either?? Say it aint so.

The type of the music the VAST majority of audio show going "Hi Rez" advocates listen to and "hear" benefits for?
Hmmm.
Loudspeaker manufacturer

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

Reply #61
...
Would you care to explain how the corrupt/gameable/non-proctored online amateur AVS files "test" adhered to ITU-BS1116...or BS.1534-2?
They did not and thus the results must be dismissed as ad-hoc garbage, per a highly reputable source. ...


I have followed the execution and discussion of several comparative tests recently, starting with Arnie's keys. All of the tests proved to have samples that were defective. I believe this is the issue that needs to be discussed, not the results of the tests. GI = GO.
Regards,
   Don Hills
"People hear what they see." - Doris Day

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

Reply #62
A typical live recording made in a concert hall has dynamic range on the order of 12-13 bits.

Your computation there is psychoacoustically blind Arny as we have discussed.  You cannot use a single digit SPL number for your room noise.  You must look at its spectrum and see how much noise you have relative to threshold of hearing as I show in my article, building on Fieldler's work: http://www.madronadigital.com/Library/RoomDynamicRange.html:

.
Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #63
IOW, no, BS didn't use MUSHRA.

And?

Quote
We know you "like" statements such as standard ABX is "fatally flawed". Hopefully this BS test wasn't.

There is no such statement or position in Bob's paper.  Nor does it reflect mine. 

You are however reflecting the common but mistaken assumption among hobbyists that the term "ABX" brings with it assurance of good results.  Folks are blinded by those three letters thinking a gift from above is being handed to them.  This is not true at all.  The quality of the test determines whether the results are reliable.  Not what it is called.  You can stick an ABX box in a test, make a mistake of having both A and B be the same input and your results would be totally garbage.  And this is what is wrong with people who carry the Meyer and Moran test as their bible to every thread and forum.

Quote
But no, they did not use a "box" to have measurements as such.  As the line in the movie Fifth Element goes, the switching mechanism was "perfect." 

IOW, no measurements or objective evaluations of the switching apparatus to hang our credentialed hats on. Very amateurish.

I am afraid the plot is lost AJ.  I mentioned why the question is moot but your myopic view of how these tests can be performed is causing to run into a ditch.  Here is another try: do you need to measure or perform objective evaluation if someone used Foobar's ABX comparator? 



Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #64
What? Nothing as 16/44-insufficient and highly demanding as Neil freaking Young? No Floyd either?? Say it aint so.



Hush you. Hi rez is what matters.  As long as it's hi rez, it's better than Redbook...and not just better, but 'even my wife can hear it ' better. 

That's the audiophile program.

Get with it.  Amirm is.

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

Reply #65
After all, who knows what dither if any was used in the music that people are shipping to us in 16/44.1?
That has been demonstrated by the AIX samples in the AVS test. Note that this is no different for hi-res content, where the end user has no idea what happened in the production path.

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

Reply #66
We chose to use undithered quantization as
a probe and | although we would normally rec-
ommend TPDF dither for best practice -- we con-
sidered rectangular dither to be more representative
of the non-ideal dither or error-feedback processing
found in some commercial A/D and D/A filters.
This paragraph is talking about the downconversion to 16/44.1, and yet includes this strange statement. It makes no sense. No one is making native 16/44.1 recordings, so no modern recording uses an A/D running at 16/44.1. 20/48 was ubiquitous more than a decade ago, 24/96 A/D is consumer (even commodity!) level now. Hence talking about "non-ideal dither or error-feedback processing found in some commercial A/D filters" in respect of 16/44.1 is a complete red herring.

D/As don't run at 16-bits or 44.1kHz either.


Coming from a 24/96 master, what matters in this respect is the downconversion...
Quote
After all, who knows what dither if any was used in the music that people are shipping to us in 16/44.1?  It is not like they know what you and I know about dither types.
You can detect what was used on many CDs by analysing the digital bits on them. Even in the venerable Cool Edit, you have an accurate waveform view, a highly configurable spectral view, the ability to zoom/cut/amplify/speed-change as you wish, and your own ears. Noise shaped dither is easily detectable. Rectangular dither (or basically sub-optimal dither) during fades to silence is detectable. With a little MATLAB script I can plot the distribution of sample values - that can reveal some strange practicies.

It's a while since I've found a problem with the final conversion to 16/44.1. It's typically gentle noise-shaped dither.

Such audio forensics often reveal problems further up the chain. Samples, tracks, or entire albums re-mastered from a previous generation 16/44.1 (or worse) version, lossy coding, and the many symptoms of the loudness war.


If you want to enjoy the worst that's found on CDs (and hi-res), throw all those things in. If you want to understand what restriction "CD quality" places on a decent master, downconvert it properly. We've known rectangular PDF dither was the wrong way to do it for 30 years.

I wouldn't normally claim that the difference between the right dither and the wrong dither would be or even could be audible, but it seems possible that this test has been so carefully set up that it just might be.

Cheers,
David.

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

Reply #67
A typical live recording made in a concert hall has dynamic range on the order of 12-13 bits.

Your computation there is psychoacoustically blind Arny as we have discussed.


There was no discussion, just excluded-middle assertions.

Quote
You cannot use a single digit SPL number for your room noise.


I didn't. I gave the room noise number in terms of bits.  Obviously, I'm responding to a post that appears to come from someone with severe perceptual difficulties - someone who quotes "bits" and responds to "dB SPL"

Who doesn't know the difference between bits and dB SPL?  Are they credible?

Quote
You must look at its spectrum and see how much noise you have relative to threshold of hearing as I show in my article, building on Fieldler's work: http://www.madronadigital.com/Library/RoomDynamicRange.html:


Fielder makes some poorly-documented measurements under unrealistic circumstances in some SOTA venues. Who is stupid enough to use them to characterize actual performances and recordings made typical performance spaces?

One obvious flaw with these measurements is that they don't appear to include the presence of living, moving, breathing musicians.  A symphony orchestra often has 100 or more of them. They contribute nothing to the noise floor? GMAB!


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

Reply #68
And?

Problem is, they (M&M) missed the next level of understanding. Let me quote International Telecommunication Union (ITU) document that is the bible of testing for small impairments in BS1116

According to one self assessed expert, non-adherence to BS1116 is a problem. The BS test failed to adhere, no cherry picking about "some" adherence can remedy that.

I am afraid the plot is lost AJ.

No, I'm quite clear on the "plot".
The BS test is a complete farce and fabrication of results in a desperate attempt to justify $$$ales of "Hi Rez" which of course nosed dived once people realized the scam, confirmed by M&Ms AES peer reviewed tests of actual audiophools, their hardware and purported "Hi Rez" media, the EXACT conditions they and the scam industry claimed to be able to "hear" differences.
The scam industry does not require the audiophool be "trained", the "Hi Rez" equipment/system to be certified, the room to have a specific noise floor, or the music content be cherry picked and doctored as in the BS test.
Believers and shysters will latch on to this BS test (despite most of them abhorring and utterly rejecting Delusion Blocked Testing as a listening valid method -see JAs latest Stereophile edition).
The audio fashion jewelry industry will continue it's death spiral, rejecting real audio advances like PSR et al, while craving "more resolution" from the 10% 2channels of info, because they know the audiomoron has long ago ended any pretense of desire for the "real thing".

cheers,

AJ
Loudspeaker manufacturer

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

Reply #69
...
Would you care to explain how the corrupt/gameable/non-proctored online amateur AVS files "test" adhered to ITU-BS1116...or BS.1534-2?
They did not and thus the results must be dismissed as ad-hoc garbage, per a highly reputable source. ...


I have followed the execution and discussion of several comparative tests recently, starting with Arnie's keys. All of the tests proved to have samples that were defective. I believe this is the issue that needs to be discussed, not the results of the tests. GI = GO.



Since there is a lack of agreement, without a clear detailed statement of what constitutes a defective sample, the above post is GI=GO. 

Even if there is a clear statement but it requires compliance with  some arbitrary standard that is well  below perceptual limits, it is  still GI=GO.

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

Reply #70
.


Apparently misleading answers is the order of the day. I see no information related to the AES paper being discussed, just some very old AES papers that are fully discredited at this point.

On-topic responses would appear to need to relate to the recent AES Conference paper titled:  "Audibility of Typical Digital Filters in a Hi-Fi Playback System".

The conferencing system tries to help those of us who are literate by putting that information on the title line...

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

Reply #71
I wouldn't normally claim that the difference between the right dither and the wrong dither would be or even could be audible, but it seems possible that this test has been so carefully set up that it just might be.

Cheers,
David.

This staged test reminds me a lot of the infamous Clarity Cap white toilet paper farce across the pond, where they "proved" capacitor sound, using ITU-BS1116 of course, all dressed up in "University research". It was long ago pulled from their website but still exists in cyberspace.
Did they simply test some cheapo caps vs their magic ones? Nope. They fabricated a "singing" cap themselves, then compared to their own non-singing boutique cap.
Audiophools do like their doctored blind tests....when the results satiate the disorder.

cheers,

AJ
Loudspeaker manufacturer

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

Reply #72
Good morning Arny.
Quote
You cannot use a single digit SPL number for your room noise.


I didn't. I gave the room noise number in terms of bits. 

What is this then Arny:

Quote from:  link=msg=880335 date=0

So what is known about the monitoring system and room used for playback? I'll bet it wasn't your typical listening room with a 40 dB SPL noise floor...

The 40 db number without any kind of spectrum analysis is psychoacoustically blind.  Isn't it? 

Quote
Obviously, I'm responding to a post that appears to come from someone with severe perceptual difficulties - someone who quotes "bits" and responds to "dB SPL"

I responded to both having had the same argument with you on AVS where you keep subtracting 40 db type numbers from your peak to arrive at your dynamic range and then bits.

Amir
Retired Technology Insider
Founder, AudioScienceReview.com

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

Reply #73
I get the feeling that "Arnold B. Krueger", "ajinfla", and "amirm" know each other - maybe in the real world, and certainly in cyberspace.

For the benefit of the rest of us, and maybe to prevent history from being re-run here on HA, can you guys(?) explain very briefly who you are, what you've done, and what baggage you're bringing to this discussion.

I know it's OT - maybe start a new thread if you like - but I think it would be very helpful for the rest of us.

(While people are of course free to hide behind a single username here on HA, I'm guessing that you guys are very far from anonymous and know full well who you are, so it would help if the rest of us knew too. You don't have to answer, but I'm asking nicely: please do :-) I bet you've all got websites with resumes on anyway, so just a link will be fine...)

Cheers,
David.

 

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

Reply #74
I get the feeling that "Arnold B. Krueger", "ajinfla", and "amirm" know each other - maybe in the real world, and certainly in cyberspace.

It is off topic, but if you must know, Amir and I grew up together and Arnie is our godfather.
Btw David, user profiles contain info towards who/what, as does mine.

And now back to our regular programming, "Audibility of Atypical Digital Filters in a Hi-Fi Playback System"....

cheers,

AJ
Loudspeaker manufacturer