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Meyer and Moran debunked by Meridian's Robert Stuart


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I recently found out that the oft-cited and notorious Meyer and Moran paper on high-res audibility was debunked in a new paper delivered at this month's 137th AES (Audio Engineering Society) Convention in LA by no less an authority on digital audio than Robert J. Stuart of Meridian. I have been unable to find the paper posted online, but I do have this capsule description that was posted by Mark Waldrep, the head of AIX Records, who attended:

"I finished the afternoon by attending a few paper sessions. The first was titled, “The Audibility of Typical Digital Audio Filters in a High-Fidelity Playback System”. Although it may not be obvious from the title of the paper, this is the first AES publication that refutes the Meyer/Moran research that has been so often quoted as “proof” that CD specification PCM audio is enough for music reproduction (Meyer and Moran’s research has been widely discredited including by myself because of the lack of real high-resolution content used during the study).

Robert Stuart and his colleagues conclude: “first there exist audible signals that cannot be encoded transparently by a standard CD; and second, an audio chain used for such experiments must be capable of high-fidelity reproduction.” In other words, CDs aren’t good enough. This paper was given the top award by the AES organization. This is a very important finding."

If anyone here has access to this paper, or more information on it, please post it as this is critical to a number of strongly held beliefs. Chief among which, is that hi-resolution audio is a high-end marketing gimmick that adds no "real" value to recorded music, and also that there is no difference between DACs, and that one can encode/decode digital audio multiple times with no perceptible change in SQ.

George

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I recently found out that the oft-cited and notorious Meyer and Moran paper on high-res audibility was debunked in a new paper delivered at this month's 137th AES (Audio Engineering Society) Convention in LA by no less an authority on digital audio than Robert J. Stuart of Meridian. I have been unable to find the paper posted online, but I do have this capsule description that was posted by Mark Waldrep, the head of AIX Records, who attended:

"I finished the afternoon by attending a few paper sessions. The first was titled, “The Audibility of Typical Digital Audio Filters in a High-Fidelity Playback System”. Although it may not be obvious from the title of the paper, this is the first AES publication that refutes the Meyer/Moran research that has been so often quoted as “proof” that CD specification PCM audio is enough for music reproduction (Meyer and Moran’s research has been widely discredited including by myself because of the lack of real high-resolution content used during the study).

Robert Stuart and his colleagues conclude: “first there exist audible signals that cannot be encoded transparently by a standard CD; and second, an audio chain used for such experiments must be capable of high-fidelity reproduction.” In other words, CDs aren’t good enough. This paper was given the top award by the AES organization. This is a very important finding."

If anyone here has access to this paper, or more information on it, please post it as this is critical to a number of strongly held beliefs. Chief among which, is that hi-resolution audio is a high-end marketing gimmick that adds no "real" value to recorded music, and also that there is no difference between DACs, and that one can encode/decode digital audio multiple times with no perceptible change in SQ.

 

If you check the AES website, there doesn't seem to be a preprint of this presentation. Also missing is any mention of a "top award". Without reading the paper, there's no way to tell if the interpretation of their conclusion is true. Of course the paper may just be a fancy white paper to sell equipment.

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So are we to conclude M&M were in error because they didn't include the head bob count with each track? :)

And always keep in mind: Cognitive biases, like seeing optical illusions are a sign of a normally functioning brain. We all have them, it’s nothing to be ashamed about, but it is something that affects our objective evaluation of reality. 

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CD might not be 'good enough' but in many cases it's all we've got and for some of my music I dont even have that - I have a 256K AAC file downloaded from iTunes. As the song says, love the one you're with ;)

 

Doesnt mean I dont want to hear that same music at the highest possible fidelity - simply that I look at the hi-res catalogs and despair. Even if I was restricted to classical and jazz, I want Puccini and Jeff Beck not Chopin and an obscure trio from New Jersey - I'm sorry if that sounds defeatist but I'm talking about music I'm prepared to pay money for. I completely get that recording in DSD is an expensive and time-consuming process - its not a trivial exercise if you're going to do it properly - but I'd love to see more 24-bit remasters of the music I grew up with and that means the record companies have to get involved. The final slap in the face for me was HDTracks - surely it's fraud to create 'hi-res' music from a Redbook CD ?

 

Sorry, guys - as one cynic put it, in many cases we are talking crap music beautifully recorded and the only people I know prepared to endure that kind of ripoff are audiophiles. This isnt new - how many of us bought SACDs only to find they didnt sound any better than the CD version of the same album ? Per the other thread, in some cases that's exactly what they were - HDTracks would be proud.

Just one more headphone and I know I can kick this nasty little habit !

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CD might not be 'good enough' but in many cases it's all we've got and for some of my music I dont even have that - I have a 256K AAC file downloaded from iTunes. As the song says, love the one you're with ;)

 

Doesnt mean I dont want to hear that same music at the highest possible fidelity - simply that I look at the hi-res catalogs and despair. Even if I was restricted to classical and jazz, I want Puccini and Jeff Beck not Chopin and an obscure trio from New Jersey - I'm sorry if that sounds defeatist but I'm talking about music I'm prepared to pay money for. I completely get that recording in DSD is an expensive and time-consuming process - its not a trivial exercise if you're going to do it properly - but I'd love to see more 24-bit remasters of the music I grew up with and that means the record companies have to get involved. The final slap in the face for me was HDTracks - surely it's fraud to create 'hi-res' music from a Redbook CD ?

 

Sorry, guys - as one cynic put it, in many cases we are talking crap music beautifully recorded and the only people I know prepared to endure that kind of ripoff are audiophiles. This isnt new - how many of us bought SACDs only to find they didnt sound any better than the CD version of the same album ? Per the other thread, in some cases that's exactly what they were - HDTracks would be proud.

 

 

Your last paragraph reminds of Holt's first law of recordings: "The quality of a recording is inversely proportional to the quality of the music and/or the performance of said music"

George

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...this is critical to a number of strongly held beliefs. Chief among which, is that hi-resolution audio is a high-end marketing gimmick that adds no "real" value to recorded music, and also that there is no difference between DACs, and that one can encode/decode digital audio multiple times with no perceptible change in SQ.

 

All of the above are "true" for people who either have impaired hearing or whose negative expectation bias has convinced them that hi res audio or better engineered DACs do not offer the potential for better than CD sound quality. Will such a paper persuade these 'objectivists' to change their minds or, at least, approach the issue afresh? I expect not.

"Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall

"Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron

 

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I must have missed something here because I saw nothing on that forum page that mentions either Meyer and Moran, Robert J. Stuart, “The Audibility of Typical Digital Audio Filters in a High-Fidelity Playback System”, or Meridian.

 

Me neither, but here it is. I'm not going to order the preprint, I'll let the folks at DIYAudio chew over it for a while. It's the 137th Convention, paper # 9174. From:

 

AES Los Angeles 2014 » Paper Session P14: Perception: Part 2

 

To order convention papers:

 

AES Convention Papers

 

"P14-3 The Audibility of Typical Digital Audio Filters in a High-Fidelity Playback System—Helen M. Jackson, Meridian Audio Ltd. - Huntingdon, UK; Michael D. Capp, Meridian Audio Ltd. - Huntingdon, UK; J. Robert Stuart, Meridian Audio Ltd. - Huntingdon, UK

This paper describes listening tests investigating the audibility of various filters applied in high-resolution wideband digital playback systems. Discrimination between filtered and unfiltered signals was compared directly in the same subjects using a double-blind psychophysical test. Filter responses tested were representative of anti-alias filters used in A/D (analog-to-digital) converters or mastering processes. Further tests probed the audibility of 16-bit quantization with or without a rectangular dither. Results suggest that listeners are sensitive to the small signal alterations introduced by these filters and quantization. Two main conclusions are offered: first, there exist audible signals that cannot be encoded transparently by a standard CD; and second, an audio chain used for such experiments must be capable of high-fidelity reproduction.

Convention Paper 9174"

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If anyone here has access to this paper, or more information on it, please post it as this is critical to a number of strongly held beliefs. Chief among which, is that hi-resolution audio is a high-end marketing gimmick that adds no "real" value to recorded music, and also that there is no difference between DACs, and that one can encode/decode digital audio multiple times with no perceptible change in SQ.

 

The percentage of classical releases by world class artists from major labels available in hi-resolution is vanishingly small. To me, this says that those record executives and artists see hi-resolution as marketing gimmick that they don't need.

 

On the other hand, the labels that make a big deal the fact their releases are available in hi-resolution have artist rosters that prove the old joke "What's the difference between a pizza and a musician, a pizza can feed a family of four". For them, its an obvious marketing gimmick to help promote otherwise unsellable releases.

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All of the above are "true" for people who either have impaired hearing or whose negative expectation bias has convinced them that hi res audio or better engineered DACs do not offer the potential for better than CD sound quality. Will such a paper persuade these 'objectivists' to change their minds or, at least, approach the issue afresh? I expect not.

 

All of the above are true for people who are sane or who are not extremely ignorant, so no, it will not.

FLAC -> JDS Labs ODAC/O2 -> Sennheiser HD 650

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All of the above are true for people who are sane or who are not extremely ignorant, so no, it will not.

 

Normally, I would welcome a new member to the Forum. Unfortunately, with this type of confrontational first post, I find myself somewhat reluctant to do so.

"Relax, it's only hi-fi. There's never been a hi-fi emergency." - Roy Hall

"Not everything that can be counted counts, and not everything that counts can be counted." - William Bruce Cameron

 

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Me neither, but here it is. I'm not going to order the preprint, I'll let the folks at DIYAudio chew over it for a while. It's the 137th Convention, paper # 9174. From:

 

AES Los Angeles 2014 » Paper Session P14: Perception: Part 2

 

To order convention papers:

 

AES Convention Papers

 

"P14-3 The Audibility of Typical Digital Audio Filters in a High-Fidelity Playback System—Helen M. Jackson, Meridian Audio Ltd. - Huntingdon, UK; Michael D. Capp, Meridian Audio Ltd. - Huntingdon, UK; J. Robert Stuart, Meridian Audio Ltd. - Huntingdon, UK

This paper describes listening tests investigating the audibility of various filters applied in high-resolution wideband digital playback systems. Discrimination between filtered and unfiltered signals was compared directly in the same subjects using a double-blind psychophysical test. Filter responses tested were representative of anti-alias filters used in A/D (analog-to-digital) converters or mastering processes. Further tests probed the audibility of 16-bit quantization with or without a rectangular dither. Results suggest that listeners are sensitive to the small signal alterations introduced by these filters and quantization. Two main conclusions are offered: first, there exist audible signals that cannot be encoded transparently by a standard CD; and second, an audio chain used for such experiments must be capable of high-fidelity reproduction.

Convention Paper 9174"

 

 

I was kind of hoping that Meridian would reprint the paper on their web-site, but they haven't. I suspect that once a paper is given or published by the AES, it becomes their property. This seems logical, but I don't know that for sure.

George

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All of the above are true for people who are sane or who are not extremely ignorant, so no, it will not.

 

 

So, you are saying that deaf = sane or ignorant? You seem to be agreeing with Meyer and Moran. If so, why are you even interested in posting to this forum? We have all types here and generally tolerate all viewpoints. But some viewpoints seem to me to be antithetical to the goals of digital music reproduction. Specifically, and to wit: All DACs do sound different, so-called high-resolution audio can sound significantly better than 16-bit/44.1 KHz CD quality audio, and every time you decode a digital audio signal to analog, and then re-digitize it, the SQ degrades, contrary to the findings of the Meyer/Moran "study".

George

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All of the above are true for people who are sane or who are not extremely ignorant, so no, it will not.

 

Hi Grave,

 

I will welcome you to the forum although I sympathise with Allan's reaction to your post.

 

I have been following the CD vs hi-res argument for several years and I maintain an open mind as I am still unsure, and I suspect so are the most knowledgeable amongst us, whether or not CD quality (16/44.1) already does or will match hi res (24/88.2 and above). I believe that digital audio is still in its infancy as demonstrated by the dramatic improvement in sound quality over the past few years alone, particularly 16/44.1.

 

My own understanding is that CD quality is "theoretically" adequate for the production and replaying of music assuming the original recording is at 24/88.2 say and is properly dithered. Also playback is through properly configured software that bypasses the computers OS, such as Audirvana or J River, and that the signal is fed into a suitable DAC whose filters have been specifically designed for red-book so that aliasing, ringing and inter modular distortion are either completely eliminated or moved away from the audio frequency with noise shaping etc.

 

i.e. 16/44.1 will do the job if the source is recorded (captured) and mastered properly and the ADC and DAC playback chain is properly implemented, however, there is little or no room for error and it is very equipment dependent and that is why IMO so many prefer the sound of hi res.

 

My knowledge base is solely from what I have read on this and other forums and my own listening experiences. I don't profess to be an expert and I am here more to learn than espouse my theories, however, as an engineer (civil) I have been trained to always apply a factor of safety to my calculations and that is my understanding why recording engineers prefer to use 24bit .... it gives them additional headroom and a lower noise floor.

 

This make sense to me and it would follow that the recording sample rate should also be set at a "safe" distance from the upper limit of the audio range you are trying to capture (say 20khz being the upper limit of human hearing). Here I digress from what I know to what I think (guess?) and that is a sample rate of around 88.2khz (capturing all audio up to 44.1khz) should therefore be ideal for recording as it will not impair or impact on the audio range being captured.

 

My own hearing cuts out at about 14khz so theoretically I should be happy with a lower sample rate (CD quality?). The ultimate IMO would be to be able to adjust / personalise the filters (in either the software or hardware) to match our own hearing limitations and preferences. In my case when listening to a CD I would adjust my audio listening range down to 16khz placing less demand on the filtering process and giving some level of safety (1/2 of 44.1khz - 16khz = 6khz say).

 

I would much rather see software designers and DAC manufacturers concentrate on improving the playback of CDs (16/44.1), than provide ever increasing PCM sample rates of 192khz and above as well as DSD etc., for no other reason than that it is what the majority of us own. In my case about 90% of my music are CD quality files and after replacing all my vinyl with CDs in the 90's I really don't want to do it again.

 

Interestingly at the recent Melbourne Audio Show a lot of manufacturers were using red-book to demonstrate their gear and common sense tells you they would be looking for the best possible source so it can't (in their opinion) be that far off hi-res.

 

I am on my 20th wedding anniversary and sitting in a cabana on the island of Lembongan off Bali. My wife has gone to a yoga class and I'm waiting for the tide to change so I can go for a surf, and have written this blog to past time .... it therefore may all just be a crock of sh...t!

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Interestingly at the recent Melbourne Audio Show a lot of manufacturers were using red-book to demonstrate their gear and common sense tells you they would be looking for the best possible source so it can't (in their opinion) be that far off hi-res.

 

But how many were doing this via computers? Many C.A. members will tell you that well optimised PC Audio can easily outperform most affordable CD players. My understanding is that Vinyl featured heavily in Melbourne too.

 

How a Digital Audio file sounds, or a Digital Video file looks, is governed to a large extent by the Power Supply area. All that Identical Checksums gives is the possibility of REGENERATING the file to close to that of the original file.

PROFILE UPDATED 13-11-2020

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So, you are saying that deaf = sane or ignorant? You seem to be agreeing with Meyer and Moran. If so, why are you even interested in posting to this forum? We have all types here and generally tolerate all viewpoints. But some viewpoints seem to me to be antithetical to the goals of digital music reproduction. Specifically, and to wit: All DACs do sound different, so-called high-resolution audio can sound significantly better than 16-bit/44.1 KHz CD quality audio, and every time you decode a digital audio signal to analog, and then re-digitize it, the SQ degrades, contrary to the findings of the Meyer/Moran "study".

 

So, why is someone who thinks all DACs sound alike less entitled to be here than someone who thinks vinyl is better than computer audio?

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I know I'm being a nit-picky, curmudgeonly grammar-scold here, but the use of terms like "debunk" and "disprove" to describe the effects of research like this on the state of our knowledge realllllly bugs me, because it implies a level of finality that it's unlikely that any of us will see during our lifetimes. "Challenge" is, I think, a superior alternative.

 

OK. Rant over. Now to hopefully find a way to download the paper for reading on the plane on Sunday. Perhaps I'll even understand some of it.

Office: MacBook Pro - Audirvana Plus - Resonessence Concero - Cavailli Liquid Carbon - Sennheiser HD 800.

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Interestingly at the recent Melbourne Audio Show a lot of manufacturers were using red-book to demonstrate their gear and common sense tells you they would be looking for the best possible source so it can't (in their opinion) be that far off hi-res.

 

To establish a level playing field, the organisers may have drawn a line in the sand to say only use CDs or Vinyl for source materials.

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Interestingly at the recent Melbourne Audio Show a lot of manufacturers were using red-book to demonstrate their gear and common sense tells you they would be looking for the best possible source so it can't (in their opinion) be that far off hi-res.

 

Many of the exhibitors at this past year's Capital Audio Fest were using Redbook, and though some of them were doing so as bragging rights I think most of them recognized that the general public wanted to hear equipment playing normal/realistic source music (the kind of music people have been collecting over the past 20 years). This was a welcome change from everything being high res esoteric music that no one had ever heard before. Of course one of the best sounds of the show was United Home Audio's R2R tape deck (sorry - I suppose this is blasphemy on CA).

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Many of the exhibitors at this past year's Capital Audio Fest were using Redbook, and though some of them were doing so as bragging rights I think most of them recognized that the general public wanted to hear equipment playing normal/realistic source music (the kind of music people have been collecting over the past 20 years). This was a welcome change from everything being high res esoteric music that no one had ever heard before. Of course one of the best sounds of the show was United Home Audio's R2R tape deck (sorry - I suppose this is blasphemy on CA).

 

I wouldn't call it never a blasphemy from a listener, we have to respect everyone's taste. But from a dealer I can say it's lack of honesty, because they must demonstrate their gear with all possible formats, this is the only way listeners could compare.

 

What I found from a lot of dealers they rather 'prefer' to sell CD players than DACs. Maybe because a lot of DACs are direct sales from the manufacturer...?

 

From other side a lot of people are under CD players because they are scare of computers, the same to a lot audio dealers.

 

Then this is a marketing issue.

 

Roch

 

PS/ My pa and grandpa are still on LPs, maybe they believe tracking distortion is part of the soundstage?

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To establish a level playing field, the organisers may have drawn a line in the sand to say only use CDs or Vinyl for source materials.

 

But how many were doing this via computers? Many C.A. members will tell you that well optimised PC Audio can easily outperform most affordable CD players. My understanding is that Vinyl featured heavily in Melbourne too.

 

 

Hi Alex and one and a half,

 

There were no limits placed on exhibitors. All sources were present - vinyl, CD players, computers (PC & MACs), streamers, etc..

 

The reason I mentioned the CD source is because this is what was being used to demonstrate IMO the best in show being the Devialet 120 utilising the new SAM technology combined with the ATHOM GT1 SE speakers. The exhibitor was also using hi res but it was Diana Krall rebook file that really blew me away. I highly recommend an audition.

 

I am not convinced one way or the other about the superiority of 24/88.2 over 16/44.1 but IMO redbook played through the Devialet system surpassed all the other systems whether they be using vinyl, hi res or red-book.

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