Losing Audible Information.

[ItemAudio]

In my experience of the ABX, once a limitation threshold has been reached, no further improvement can avoid being made. It is therefore impossible for Shannon to demonstrate any further gain in resolution achievable without fundamental restructuring algorithm filtration of the signal. This applies to DSD equally or more than 16/44.1 and is a function of the known.

Once more, you're entitled to own your facts, but not an opinion.

 

[Werner]

Yep Julf. Picked the 16/44 every single time. And I have witnesses

Interesting. Could you provide more detail? What exactly was compared and how? How were the 44.1k/16b data generated? Which components were used? Etc.

 

[Julf]

Yep Julf. Picked the 16/44 every single time. And I have witnesses

I am not doubting you - I actually do find it very interesting.

Just as Werner, I would love more details. ABX logs? Test setup? Etc etc.

 

[adamdea]

And for anyone who has not read it before or recently Meyer and Moran
http://www.drewdaniels.com/audible.pdf

It has been argued that this piece is flawed because the Hi rez might not have been hirez, but since there were many subjects and they were asked to bring their favourite recordings on hi rez (PCM and dsd), it seems unlikely that this could have been the case for all of them.

Oh and I suggest also reading this less well known paper comparing dsd with 24/176 using over 100 highly trained listeners eg professional musicians, tonmeisters and students of the same. I think we can all guess where this is going....
http://ebookbrowsee.net/1-pdf-d327431005

 

[TwoSeventy]

And for anyone who has not read it before or recently Meyer and Moran
http://www.drewdaniels.com/audible.pdf

It has been argued that this piece is flawed because the Hi rez might not have been hirez, but since there were many subjects and they were asked to bring their favourite recordings on hi rez (PCM and dsd), it seems unlikely that this could have been the case for all of them.

Oh and I suggest also reading this less well known paper comparing dsd with 24/176 using over 100 highly trained listeners eg professional musicians, tonmeisters and students of the same. I think we can all guess where this is going....
http://ebookbrowsee.net/1-pdf-d327431005

One of the interesting things is that the HHB recorder they used in the loop for the 44.1khz/16bit "bottleneck" in the Meyer and Moran tests is not a particularly expensive bit of kit around £500 IIRC. I must add they were very good recorders IME.

 

[adamdea]

One of the interesting things is that the HHB recorder they used in the loop for the 44.1khz/16bit "bottleneck" in the Meyer and Moran tests is not a particularly expensive bit of kit around £500 IIRC. I must add they were very good recorders IME.

Yes that is interesting.

It is consistent also with the point that the Boston audio society achieved test results suggesting transparency of the 16/44 loop with vinyl 30 years ago. They used a Sony PCM-F1 which I believe contained the same dac chip as the first sony cd player.

Unicorn repellent anyone?

 

[darrenyeats]

One could argue that amp/speaker technology has improved since then, making the transparency test more difficult.

One could also argue that ADC/DAC technology has improved since then.

At the end of the day, it's the last large-scale evidence collected on this particular point. It's hardly a scientific priority for the human race. I base my opinions on my own subjective perceptions, blind tests etc.

 

[Werner]

Meyer and Moran
http://www.drewdaniels.com/audible.pdf

It has been argued that this piece is flawed

Although the paper is not explicit on it, I think it may be flawed for a totally different reason:

Most of the tests were done using a pair of highly regarded,
smooth-measuring full-range loudspeakers in a rural
listening room

The picture being painted is that a significant number of the 60 test people did a significant portion of their listening in one particular room with one particular system.
Pertinent questions are: how acquainted were the listeners with this room and system, and how well rested were their ears after having traveled to this rural place?

Habituation is a strong force in perception, and for instance a clear and stable stereo can generally only be perceived when the listener knows the system and room very well, or when the latter are of a very very very high standard.

So, given that the differences between hi-res and well-done CD-res are never more than subtle, isn't there a chance that a sizeable portion of the tests were marred by the participants being not receptive to small differences for the above reason? This would seriously skew the outcome.

 

[merlin]

Most of the tests were done using a pair of highly regarded,
smooth-measuring full-range loudspeakers in a rural
listening room

And they are going to show exactly how much of any claimed/potential benefits from a hires signal?

 

[Plutox]

So, given that the differences between hi-res and well-done CD-res are never more than subtle, isn't there a chance that a sizeable portion of the tests were marred by the participants being not receptive to small differences for the above reason [habituation]?

One of the beauties of this type of test is that test subjects are merely required to detect a difference between the two options, a simple yes/no position. While habituation is highly relevant when forming wider-ranging and deeper-meaning subjective judgements, it's relevance to a simple "is there or is there not a difference" style test, is questionable. I would assume that if the journey to the test site entailed any significant noise-stress to the test subjects, sufficient rest time would be built into the program to allow for aural recovery – typically no more than an hour-ish unless serious noise levels are encountered.

Clearly, those who question the entire validity of instant tests will question this entire research program. All I can say is that, in 40 years of serious listening experience, instant tests have always revealed a difference where there is one. I have never been subjected to that syndrome of a REAL difference only becoming apparent after extended listening. The instant YES/NO test is probably the best weapon we have to determine the concept of audio transparency.

Without wishing to labour the point, an awful lot of amateur audiophiles do not appear to understand the concepts behind a test regime in which the only question is "can you hear a difference" and the only possible answers are YES or NO.

 

[merlin]

But Paul, it would be really helpful if the equipment was capable of reproducing the potential differences in the first place.

 

[Paul R]

There is some supplemental information on systems and rooms here, http://www.bostonaudiosociety.org/explanation.htm

Paul

 

[Werner]

One of the beauties of this type of test is that test subjects are merely required to detect a difference between the two options, a simple yes/no position.

Yes, I know. And I would agree ... if it were not for the observation that when I come to meet an alien system in an alien room, both very unlike my own, I need several hours before I 'get' stereo and before I can accept the new tonal balance. In these initial hours subtleties would be entirely lost on me, even with rapid switching.

I state this only to point out that a rigorous test, to be accepted by a majority of involved individuals, constitutes a very large effort.

 

[merlin]

I see they also used Quads

I, for one, would wonder why you would test a system with extended HF response with loudspeakers that clearly roll off early.

 

[Werner]

One of the beauties of this type of test is that test subjects are merely required to detect a difference between the two options, a simple yes/no position.

Yes, I know. And I would agree ... if it were not for the observation that when I come to meet an alien system in an alien room, both very unlike my own, I need several hours before I 'get' stereo and before I can accept the new tonal balance. In these initial hours subtleties would be entirely lost on me, even with rapid switching.

I state this only to point out that a rigorous test, to be accepted by a majority of involved individuals, constitutes a very large effort.

 

[adamdea]

Although the paper is not explicit on it, I think it may be flawed for a totally different reason:

Most of the tests were done using a pair of highly regarded,
smooth-measuring full-range loudspeakers in a rural
listening room

The picture being painted is that a significant number of the 60 test people did a significant portion of their listening in one particular room with one particular system.
Pertinent questions are: how acquainted were the listeners with this room and system, and how well rested were their ears after having traveled to this rural place?

Habituation is a strong force in perception, and for instance a clear and stable stereo can generally only be perceived when the listener knows the system and room very well, or when the latter are of a very very very high standard.

So, given that the differences between hi-res and well-done CD-res are never more than subtle, isn't there a chance that a sizeable portion of the tests were marred by the participants being not receptive to small differences for the above reason? This would seriously skew the outcome.

I guess. But

"Furthermore, none of the more elaborate and expensive playback systems (for which the subjects were all dedicated
amateur audiophiles, active students in a professional
recording program, and/or experienced working
professionals) revealed detectable differences on music,
again at levels as defined previously."

It does appear that the results were analysed for each venue. see also http://www.bostonaudiosociety.org/explanation.htm under venue 3. Can we assume the students were familiar with the listening room at the unversity? You'd hope so. Not sure how many subjects were in that part of the test.

I accept that what you have raised might merit further investigation, but it does seem conjectural. In the other test, with high rate pcm vs dsd they used headphones for quite a lot of the test. Mind you who could be surprised by that result ? (except quite a lot of audiophiles obviously)

 

[adamdea]

I see they also used Quads

I, for one, would wonder why you would test a system with extended HF response with loudspeakers that clearly roll off early.

wan't that only in system 4? It seems sensible to use a range of different devices, and anyway how is that worse than using people who have limited HF response?

 

[merlin]

wan't that only in system 4? It seems sensible to use a range of different devices, and anyway how is that worse than using people who have limited HF response?

I've produced the measurements for the half of the speakers that I can find them for. So at least 50% of the tests were carried out with a curtailed top octave and zero output above that.

If there are audible differences it will either be because of those top octaves or because Kunchur was right.

If you are going to carry out tests, surely the first thing is to choose equipment that can accurately replay the source material?

 

[Paul R]

And they are going to show exactly how much of any claimed/potential benefits from a hires signal?

Is your contention that the only advantage of 'hires' is ultrasonics?

In which case hires is redundant in the majority of cases because there is nothing in the recording above 20k.

FWIW do you have access to distortion measurements of speakers above 20kHz? I suspect that quite often any output up there is somewhat accidental and bears little resemblance to the source.

Paul

 

[adamdea]

I've produced the measurements for the half of the speakers that I can find them for. So at least 50% of the tests were carried out with a curtailed top octave and zero output above that.

If there are audible differences it will either be because of those top octaves or because Kunchur was right.

If you are going to carry out tests, surely the first thing is to choose equipment that can accurately replay the source material?

Probably. I guess they were trying to see whether people could hear the difference in practice.

if you were wanting to check whether it was possible at all you'd defintely want to make sure there was somehtign to hear.

Mind you the predominant theory now seems to be about the alleged filtering not the actual frequency range. So maybe it's moot.

There was a point when speakers where being marketed on the basis that they had a higher frequency extension necessary to use hi rez. Don't hear so much about that nowadays.

Thing is have you ever heard anyone say DSD sounds so much better, except when I play it through my quads, when I can't hear the difference because of the droopy top octave extension?

And how come people had to use spectrum analysers to show which hi rez disks weren't just upsampled 16/44? Why didn't all the people who can hear the difference just say "this doesn't have that unmistakable dsd sound". And is there any real hf information on many of those old analog recordings that sound so much better in hi rez?