Hi-Res - Does it matter? Blind Test by Mark Waldrep

[Ajax]

Hi Everyone,

Following is an invitation to participate in a study being performed by Mark Waldrep to determine whether or not we can actually hear differences between various formats? I know this is an old and tired argument but one in my opinion that really needs to be put to bed and I encourage you to participate. Too may of us are being ripped off by manufactures' marketing hype, and too many potential audiophiles are staying away because we have overcomplicated things by looking for solutions to problems that simply don't exist. It takes courage to participate in these types of tests because you may have to face your biases and long held beliefs. 

Prior to reading the study please read the introduction to my previous thread on this subject "Some Commonsense" and in particular to John Siau of Benchmark Media's thoughts - it's all about the maths.

 

 

The HD-Audio Challenge II
Dr. AIX

I spent the weekend gearing up for the second round of the HD-Audio challenge. Some of you may remember the first iteration of this study (click here). The music industry seems intent on continuing to push their claims that "hi-res audio" is a tremendous advance in the evolution of music reproduction. After being involved with real high-resolution audio for almost 20 years, I'm not so sure it matters. I'd love to demonstrate that hi-res music and hi-res audio are delivering a "better" experience, but the studies I've read have left me unconvinced.

I believe that I can contribute to the debate by offering up a catalog of real high-resolution tracks in a variety of formats. You — my readers and fellow audiophiles — can download the tracks and play them to your heart's content. I only ask that you not analyze them to determine which is which. What's the point of cheating?

I've selected 20 tracks from a variety of genres and took into consideration suggestions from many of you. I've included solos, small and large ensembles, acoustic and electric, and vocal vs. instrumental http://www.realhd-audio.com/?p=6197.The tracks that will be available are listed below:

The HD-Audio Challenge II - Track List

These are full length tracks not merely samples.

I spent all weekend converting the tracks using Sonic Studio's professional software tool PROCESS to do the conversions. I took the native 96 kHz/24-bit PCM masters and downconverted them to 96 kHz/16-bit, 44.1 kHz/24-bits, and 44.1 kHz/16-bits (CD "Redbook" spec). I will also create constant bitrate MP3 versions at 320 and 256 kbps for those interested in compressed formats. Then I converted all of downconversions back to 96 kHz/24-bits so that all of them are precisely the same size. I have been very careful to ensure that they are the same volume.

I have uploaded all of the files to a folder in my premium Dropbox account and will "Share" the contents with those interested in participating in the study. The files are randomly named and should provide a rich opportunity for those willing to download them and do some serious listening. The goal is to discover if bona fide high-resolution audio recordings can be distinguished from lower resolution formats.

A Preview

I will be doing a thorough analysis of each file and providing the spectra and dynamic analysis to participants. I've already done that for a test file by The Latin Jazz Trio. Here's the spectra of all of the formats:

The Spectra of "Memories of Rio" in all six formats

Sign Up

The more audio enthusiasts that participate in this study, the more raw data I'll have and the more valid the results will be. I'm prepared to be criticized for the casual nature of this experiment. Some will insist that using my own catalog is too limiting, others will insist that it be done in a state-of-the-art studio, or with mega buck equipment. I don't believe that any of those things matter. We all have different rooms, systems of differing values, and varying abilities to listen...exactly the diversity that is required to establish whether the marketing claims made by the industry are true.

If you want to sign up, you'll have to visit the post on my site and use the form at the bottom of the page by clicking here.

This should be fun. I'll leave the files up for a couple of months. I have to report back to my university sometime in early 2020, so you'll have lots of time. Thanks!

 

[sandyk]

Yet more flogging of a dead horse by those who wish to take away the pleasure that others get from 24/192 recordings from Barry Diament, and the recent DSD releases from Cookie Marenco and others .

It's bad enough having crappy MQA dumped on us  without concerted efforts to try and dumb down what we already have available from HD Tracks etc. by way of biased Uni results.

 If those with above average gear, and not having closed minds on this subject wish for more immediate results, then try these examples provided by FrederickV several months back, despite FrederickV insisting that most participants previously failed the test , I had NO problem originally deciding which file was which, and which is the original high res version, and posted the differences that I heard at the time.

Even a few minutes ago when I checked to see if they are still available, I had no problems readily hearing the differences within several seconds.. 

 I feel sorry for those who are unable to appreciate recent genuine high resolution material, and I am 80 years old with industrial type  hearing damage. 

However, I use Class A , NOT Class D amplification. .

 

Do not cheat by looking at the files first !!!

http://klinktbeter.be/hushhush/x.wav

http://klinktbeter.be/hushhush/y.wav

[Ajax]

Hi Alex,

 

Didn't take long - I wish it was that easy to catch something fishing.

 

FWIW I do enjoy your contributions - takes two to tango!

 

All the best,

 

Ajax

[sandyk]

Hi Ajax

 I wish we weren't so far apart these days, as I am now up in the Lower Hunter area not that far from Audiophile Neuroscience.

 I wouldn't mind betting that I could easily convert you. The problem with most gear is that the typical Xtal Oscillators used in most gear just aren't low enough noise and as high a stability as needed for best reproduction of 24/192 material.

 I use a .1PPM 24.576 MHZ TCXO in my highly modified X-DAC V3 for the P.C and the improvement over a typical 50PPM type was quite obvious.

 Barry D. also obtained worthwhile improvements with his Metric Halo ULN8 used for recording after he upgraded it's clocking earlier this year.

 Have you tried listening to any  of Barry' recent 24/192 recordings such as Kay Sa  ?

Unfortunately, his Comparison page doesn't do the provided samples justice. I have also heard all of Barry's other 5 high res recordings after he changed to a different S/W for conversion from the original .aiff to .wav, and sent them to me to compare with the original .wav files. These things do matter too.

 

Regards

Alex

[MetalNuts]

I believe the results will be inconclusive even allowing a sufficient no. of participants taking part.  I can only see that every participant is using different gear and the only constant factor is not there to test the variables unless we believe that different gear should sound the same.

[Rexp]

2 hours ago, sandyk said:

Yet more flogging of a dead horse by those who wish to take away the pleasure that others get from 24/192 recordings from Barry Diament, and the recent DSD releases from Cookie Marenco and others .

It's bad enough having crappy MQA dumped on us  without concerted efforts to try and dumb down what we already have available from HD Tracks etc. by way of biased Uni results.

 If those with above average gear, and not having closed minds on this subject wish for more immediate results, then try these examples provided by FrederickV several months back, despite FrederickV insisting that most participants previously failed the test , I had NO problem originally deciding which file was which, and which is the original high res version, and posted the differences that I heard at the time.

Even a few minutes ago when I checked to see if they are still available, I had no problems readily hearing the differences within several seconds.. 

 I feel sorry for those who are unable to appreciate recent genuine high resolution material, and I am 80 years old with industrial type  hearing damage. 

However, I use Class A , NOT Class D amplification. .

 

Do not cheat by looking at the files first !!!

http://klinktbeter.be/hushhush/x.wav

http://klinktbeter.be/hushhush/y.wav

Y sounds good, x sounds distorted. Do you agree? 

[sandyk]

3 minutes ago, Rexp said:

Y sounds good, x sounds distorted. Do you agree? 

 I will reply via PM so as not to prejudice results

[esldude]

3 hours ago, sandyk said:

Yet more flogging of a dead horse by those who wish to take away the pleasure that others get from 24/192 recordings from Barry Diament, and the recent DSD releases from Cookie Marenco and others .

It's bad enough having crappy MQA dumped on us  without concerted efforts to try and dumb down what we already have available from HD Tracks etc. by way of biased Uni results.

 If those with above average gear, and not having closed minds on this subject wish for more immediate results, then try these examples provided by FrederickV several months back, despite FrederickV insisting that most participants previously failed the test , I had NO problem originally deciding which file was which, and which is the original high res version, and posted the differences that I heard at the time.

Even a few minutes ago when I checked to see if they are still available, I had no problems readily hearing the differences within several seconds.. 

 I feel sorry for those who are unable to appreciate recent genuine high resolution material, and I am 80 years old with industrial type  hearing damage. 

However, I use Class A , NOT Class D amplification. .

 

Do not cheat by looking at the files first !!!

http://klinktbeter.be/hushhush/x.wav

http://klinktbeter.be/hushhush/y.wav

I assume you'll not be taking part in the listening tests despite your ability to hear such resolutions once Again.  Even worse your response is to offer your own files for people to listen to.  Wouldn't be a problem normally, but to refuse participation as futile in other's online test files while offering up your own is a bit rich.  

 

I also think you have Mark Waldrep all wrong.  He has been a career long supporter of the idea that high resolution is beneficial.  Making all his recordings in 96 khz form.  So how you can try to characterize him as "flogging of a dead horse by those who wish to take away the pleasure that others get from 24/192 recordings from Barry Diament, and the recent DSD releases from Cookie Marenco and others "?  This makes no sense.  He doesn't wish to take away anyone's pleasure of high resolution. He has believed in it. 

 

Now he has been surprised that others don't hear benefits of his high resolution recordings.  So he is making yet another attempt to see if the wider public can hear them at greater than chance levels.   In other words he is submitting his beliefs to the scrutiny of the cold hard world of reality.  Something that should be applauded and pursued by more people.  

 

He has steadfastly said he thinks hearing recordings in their native format is best, and that 96 khz 24 bits is worthwhile.  Now he is trying to see if that is so or if lesser bits or lesser sample rates are effectively just as good.  

[sandyk]

Dennis

 It will be an exercise in futility with those most interested in participating ,  people like yourself trying to reinforce their own views that High Res is Snake Oil. Ajax has already made it  perfectly clear what he thinks of high res, both in his initial post and the thread he linked to which he started.

 

Quote

This following article reinforces my own personal experience being that I cannot "hear" the difference between CD (redbook 16/44.1) and high res (24/96 and 192) when played back through my Benchmark Media DAC 1 HDR or Devialet 200 systems. 

It's just more flogging of a dead horse as far as I am concerned .

 High Res LPCM and DSD are here to stay, whether people like yourself like it or not.

Quote

 Even worse your response is to offer your own files for people to listen to. 

 

They aren't my files, they were posted in this forum by FrederickV who virtually dragged me into listening to them, even though I said I wasn't interested. They are a good example of 16/44.1 vs. 24/96 , and there is nothing stopping others from first trying these before registering at a different web site.

Alex

 

 P.S.

 I may be wrong, but it also gives the impression of a little promotion for his own recordings, drawing people's attention to them, which certainly wouldn't hurt his company's bottom line.

[STC]

I am proud to admit I don't hear a difference in Hi Rez. I also admit I hear difference in them in my system when I run hundreds of DSPs and for that reason alone I use 24/96 and if possible I want 192 sampling for more accuracy in the processing.

[Miska]

6 hours ago, Ajax said:

I will be doing a thorough analysis of each file and providing the spectra and dynamic analysis to participants. I've already done that for a test file by The Latin Jazz Trio. Here's the spectra of all of the formats:

The Spectra of "Memories of Rio" in all six formats

 

One of the spectrum plots where there is clearly something wrong. Spectrum goes straight to the Nyquist of 96k sample rate. I guess yet another ADC that has got digital decimation filters wrong.

 

Have to download and see how many of these contain some actual content in the higher frequencies.

 

 

P.S. Never mind, doesn't seem to be actually available for download.

 

[kirkmc]

This test should include AAC at 256 kbps as well. And having two different MP3 resolutions isn't very useful. 

 

Also, the fact that the 256 kbps MP3 has higher frequencies than the Redbook is a bit odd. Something wrong with the measurements? 

[Miska]

4 minutes ago, kirkmc said:

Also, the fact that the 256 kbps MP3 has higher frequencies than the Redbook is a bit odd. Something wrong with the measurements? 

 

I think it is 48 kHz sample rate MP3.

 

Rest of course depends on the particular MP3 encoder. Not all the encoders sound or work the same.

 

5 minutes ago, kirkmc said:

This test should include AAC at 256 kbps as well.

 

Yes, that is interesting too. To me personally, AAC sounds better than MP3, and I think I know the technical reason for that too. Of course in that case too, a bit depending on the particular encoder implementation.

 

[kirkmc]

If it's 48 kHz - which would make sense - then why is the 320 kbps file not also 48 kHz? And, as you say, there can be a big difference between the results of MP3 encoders. 

 

Yes, AAC generally does sound better than MP3, and because of that I think it would make sense to include it, even at 256 kbps.

[Ajax]

6 hours ago, sandyk said:

Hi Ajax

 I wish we weren't so far apart these days, as I am now up in the Lower Hunter area not that far from Audiophile Neuroscience.

 I wouldn't mind betting that I could easily convert you. The problem with most gear is that the typical Xtal Oscillators used in most gear just aren't low enough noise and as high a stability as needed for best reproduction of 24/192 material.

 I use a .1PPM 24.576 MHZ TCXO in my highly modified X-DAC V3 for the P.C and the improvement over a typical 50PPM type was quite obvious.

 Barry D. also obtained worthwhile improvements with his Metric Halo ULN8 used for recording after he upgraded it's clocking earlier this year.

 Have you tried listening to any  of Barry' recent 24/192 recordings such as Kay Sa  ?

Unfortunately, his Comparison page doesn't do the provided samples justice. I have also heard all of Barry's other 5 high res recordings after he changed to a different S/W for conversion from the original .aiff to .wav, and sent them to me to compare with the original .wav files. These things do matter too.

 

Regards

Alex

Hi Alex,

 

You don't need to convert me as I don't hold a firm position, however, I am very sceptical of the benefits touted about Hi Res. My personal experience is that well mastered 16/44.1 sounds very very good. About 4 years ago I purchased a Devialet 220 with OTHM G1 speakers, marketed as a  complete system (Ensemble). I bought the demo system from a HiFi show in Melbourne where all the dealers were demonstrating using Hi Res and vinyl (Michael Fremer was presenting), except Devialet, who were using 16/44.1 .... and it sounded so much better. I asked the demonstrator why he wasn't using Hi Res material and he just nodded knowingly and basically told me it wasn't necessary. Surely you would use the best available material if you were selling a product? At that time 95% of my music was of CD quality, and the best streaming available was also CD quality, so it just made sense for me to purchase a system that played 16/44.1 well.

 

I have a second system in my office, a Benchmark Media DAC / Preamp into Adam A7 active speakers. I am a great admirer of Benchmark, not only for it's technical excellence and service but also it's no bullshit approach, which is why I quoted John Siau (Director of Engineering) in my previous "Common Sense" thread. His position is very clear - it's just maths. Having said that the best sound I have ever heard (through any system using any format) was from Peter Gabriel's Society of Sound in 24/48 in my office. Was that due to the 24 bit rate and slightly higher sample rate, my room acoustics, or the location and quality of the microphones and excellent mastering? I don't know, but it was incredibly life like and natural sounding.

 

I have degree in Engineering (Civil) although I have spent most of my life running small businesses. One thing that has always stuck in my mind from my time at University was to always strive to do more with less. i.e. don't waste materials for both commercial and ecological reasons. IF we can produce great sound with only 16/44.1 then it just makes sense to me not to burden our Broadband, LANs and hard drives with huge data files.

 

Finally, I spent good deal of time corresponding with Barry Diament, when he was a regular contributor here. A terrific fellow and a thorough gentleman and obviously a very capable and experienced mastering engineer. Barry encouraged me to download his files in 16/44.1, 24/96 & 24/ 192. He was adamant that there were vast difference between each format. I spent a whole day listening but couldn't hear a difference between any of them. This could be due to my poor hearing from rock concerts and blasting my ears with headphones or simply old age (now 63) or there is no perceivable difference. That is why I am encouraging everyone to participate in Mark's study. The bigger the sample base the more reliable the results.

 

All the best

 

Ajax

[marce]

7 hours ago, sandyk said:

Yet more flogging of a dead horse by those who wish to take away the pleasure that others get from 24/192 recordings from Barry Diament, and the recent DSD releases from Cookie Marenco and others .

It's bad enough having crappy MQA dumped on us  without concerted efforts to try and dumb down what we already have available from HD Tracks etc. by way of biased Uni results.

 If those with above average gear, and not having closed minds on this subject wish for more immediate results, then try these examples provided by FrederickV several months back, despite FrederickV insisting that most participants previously failed the test , I had NO problem originally deciding which file was which, and which is the original high res version, and posted the differences that I heard at the time.

Even a few minutes ago when I checked to see if they are still available, I had no problems readily hearing the differences within several seconds.. 

 I feel sorry for those who are unable to appreciate recent genuine high resolution material, and I am 80 years old with industrial type  hearing damage. 

However, I use Class A , NOT Class D amplification. .

 

Do not cheat by looking at the files first !!!

http://klinktbeter.be/hushhush/x.wav

http://klinktbeter.be/hushhush/y.wav

Your posts are a prime example of posts from someone with a closed mind, they all follow the same pattern, ridicule any science or objective testing and throw in a quick advert for "insert name here" or "insert thread name here"...

Why not try out the test instead of just jumping in and dissing it. A recent discussion was similarly derailed when some science based facts were introduced.  It is trolling behaviour and one of the main reasons I can't be bothered to post here anymore...

[sandyk]

1 hour ago, Ajax said:

Finally, I spent good deal of time corresponding with Barry Diament, when he was a regular contributor here. A terrific fellow and a thorough gentleman and obviously a very capable and experienced mastering engineer. Barry encouraged me to download his files in 16/44.1, 24/96 & 24/ 192. He was adamant that there were vast difference between each format. I spent a whole day listening but couldn't hear a difference between any of them

 Hi Ajax

 Barry is a good online friend of mine, and I was involved with Barry in the selection of the best sounding S/W out of 4 different versions for the conversion from the original .aiff files to .wav for his new Kay Sa album. We both agreed on  the selected version with Barry saying it seemed to get more out of the way IIRC.

 Unfortunately, to my ears at least, Barry's comparison page that is hosted doesn't do justice to the 24/192 versions.

 If you would like me to UL a snippet from Kay Sa please let me know. You can then compare it against the 16/44.1 version on the comparison pages.

 Kind Regards

Alex

[sandyk]

1 hour ago, marce said:

It is trolling behaviour and one of the main reasons I can't be bothered to post here anymore...

 That's good news.

 Ever considered the possibility that your "Science" is flawed or incomplete ?

Unlike you,  I am able to demonstrate most of the things that I report, and they have now been verified by quite a few members , as well as the others I have previously mentioned.

The fact remains that both high res LPCM and DSD , unlike hopefully MQA, are here  to stay and there is nothing that these tests will ever do to change that. All they are likely to do is increase sales of some the albums from which the test material is sourced for Mark Waldrep .

 

 Just because you are unable to explain why high res can sound better than 16/44.1 does not mean it doesn't isn't .

 There are a large number of members of this forum that are able to appreciate the differences even if you are unable to do so.

[botrytis]

17 minutes ago, sandyk said:

 Hi Ajax

 Barry is a good online friend of mine, and I was involved with Barry in the selection of the best sounding S/W out of 4 different versions for the conversion from the original .aiff files to .wav for his new Kay Sa album. We both agreed on  the selected version with Barry saying it seemed to get more out of the way IIRC.

 Unfortunately, to my ears at least, Barry's comparison page that is hosted doesn't do justice to the 24/192 versions.

 If you would like me to UL a snippet from Kay Sa please let me know. You can then compare it against the 16/44.1 version on the comparison pages.

 Kind Regards

Alex

 

You see, you have already biased your listening form the outset.

 

We are talking about Mark Waldrep, not you. If you want to do YOUR own listening, then start another thread, please.

[Miska]

1 hour ago, Ajax said:

That is why I am encouraging everyone to participate in Mark's study. The bigger the sample base the more reliable the results.

 

I guess it is quite hard to get enough diversity in participants that it would be statistically valid for entire earth's population.

 

I rather take safe approach that recording should capture everything that can be captured of the performance, in terms of dynamic range and frequency spectrum. This also includes microphones, thus using mics like the Sanken's 100 kHz bandwidth one. And then ADC should record it all without removing anything. Regarding audio, this is not a problem at all with current network bandwidths and storage capacities. My 60 fps 4K video recordings are much more resource hogs in all shape and form, and soon things will move over to 8K and probably 120 fps.

 

[sandyk]

1 minute ago, botrytis said:

You see, you have already biased your listening form the outset.

 

I already know the differences that I am able to hear between the various formats, and whether the recordings come from Barry Diament, Cookie Marenco or Mark Waldrep doesn't matter as long as they are well recorded. 

 I f you wish to participate in a pile of tests that ultimately prove or change nothing, by all means do so.

[bobbmd]

@Ajax nice article it's my feeling for a while to me everything sounds pristine 16/44 and up to 24/192

BUT BTW that site you referred to says its NOT A SECURE SITE would be wary

[kumakuma]

@sandyk

 

I understand that you have strong opinions in this area but I don't understand why you felt the need to shit all over this thread.

 

@Ajax

 

I suggest that you ask Chris for moderation rights and delete the off topic posts.

[gmgraves]

13 hours ago, Ajax said:

Hi Everyone,

Following is an invitation to participate in a study being performed by Mark Waldrep to determine whether or not we can actually hear differences between various formats? I know this is an old and tired argument but one in my opinion that really needs to be put to bed and I encourage you to participate. Too may of us are being ripped off by manufactures' marketing hype, and too many potential audiophiles are staying away because we have overcomplicated things by looking for solutions to problems that simply don't exist. It takes courage to participate in these types of tests because you may have to face your biases and long held beliefs. 

Prior to reading the study please read the introduction to my previous thread on this subject "Some Commonsense" and in particular to John Siau of Benchmark Media's thoughts - it's all about the maths.

 

 

The HD-Audio Challenge II
Dr. AIX

I spent the weekend gearing up for the second round of the HD-Audio challenge. Some of you may remember the first iteration of this study (click here). The music industry seems intent on continuing to push their claims that "hi-res audio" is a tremendous advance in the evolution of music reproduction. After being involved with real high-resolution audio for almost 20 years, I'm not so sure it matters. I'd love to demonstrate that hi-res music and hi-res audio are delivering a "better" experience, but the studies I've read have left me unconvinced.

I believe that I can contribute to the debate by offering up a catalog of real high-resolution tracks in a variety of formats. You — my readers and fellow audiophiles — can download the tracks and play them to your heart's content. I only ask that you not analyze them to determine which is which. What's the point of cheating?

I've selected 20 tracks from a variety of genres and took into consideration suggestions from many of you. I've included solos, small and large ensembles, acoustic and electric, and vocal vs. instrumental http://www.realhd-audio.com/?p=6197.The tracks that will be available are listed below:

The HD-Audio Challenge II - Track List

These are full length tracks not merely samples.

I spent all weekend converting the tracks using Sonic Studio's professional software tool PROCESS to do the conversions. I took the native 96 kHz/24-bit PCM masters and downconverted them to 96 kHz/16-bit, 44.1 kHz/24-bits, and 44.1 kHz/16-bits (CD "Redbook" spec). I will also create constant bitrate MP3 versions at 320 and 256 kbps for those interested in compressed formats. Then I converted all of downconversions back to 96 kHz/24-bits so that all of them are precisely the same size. I have been very careful to ensure that they are the same volume.

I have uploaded all of the files to a folder in my premium Dropbox account and will "Share" the contents with those interested in participating in the study. The files are randomly named and should provide a rich opportunity for those willing to download them and do some serious listening. The goal is to discover if bona fide high-resolution audio recordings can be distinguished from lower resolution formats.

A Preview

I will be doing a thorough analysis of each file and providing the spectra and dynamic analysis to participants. I've already done that for a test file by The Latin Jazz Trio. Here's the spectra of all of the formats:

The Spectra of "Memories of Rio" in all six formats

Sign Up

The more audio enthusiasts that participate in this study, the more raw data I'll have and the more valid the results will be. I'm prepared to be criticized for the casual nature of this experiment. Some will insist that using my own catalog is too limiting, others will insist that it be done in a state-of-the-art studio, or with mega buck equipment. I don't believe that any of those things matter. We all have different rooms, systems of differing values, and varying abilities to listen...exactly the diversity that is required to establish whether the marketing claims made by the industry are true.

If you want to sign up, you'll have to visit the post on my site and use the form at the bottom of the page by clicking here.

This should be fun. I'll leave the files up for a couple of months. I have to report back to my university sometime in early 2020, so you'll have lots of time. Thanks!

 

To me, hi-res audio has two real advantages: 1) the high sampling rate moves the cut-off frequency high above the pass band, obviating the need for steep filters above 22 KHz. 2) 24-bits gives the recordist a larger dynamic range allowing him to keep low passages out of the mud where only a couple of bits are in use and a lower overall record level can be used to make sure that sudden changes in the music’s volume doesn’t overmodulate the digital recording (a strict no-no in digital audio). Now, as to whether or not these result in noticeable improvements in SQ, depends, as usual, on all the other parameters of the recoding procedure.

[John Dyson]

13 minutes ago, gmgraves said:

To me, hi-res audio has two real advantages: 1) the high sampling rate moves the cut-off frequency high above the pass band, obviating the need for steep filters above 22 KHz. 2) 24-bits gives the recordist a larger dynamic range allowing him to keep low passages out of the mud where only a couple of bits are in use and a lower overall record level can be used to make sure that sudden changes in the music’s volume doesn’t overmodulate the digital recording (a strict no-no in digital audio). Now, as to whether or not these result in noticeable improvements in SQ, depends, as usual, on all the other parameters of the recoding procedure.

 

Since the mention of 'recordist', I'll also bring in signal processing advantage of high rates -- any time there is a nonlinear operation on the audio.   To inform non-DSP people, there are nonlinear math operations that happen other than just a static nonlinear gain curve.

 

The higher rates allow for fewer problems with nonlinear operations on recordings -- even compressor/limiter/expander gain control with moderately fast attack/release create cause sidebands that can wrap the Nyquist rate.   Keeping the rate high all of the time avoids the samplerate upconversions/downconversions/etc.  44.1k is a bit narrow (22.05kHz Nyquist) to give room for fast gain control sidebands...   Even 48k can be troublesome without very advanced management of the gain control sidebands...  In the past (before the super aggressive gain control management), 44.1k could give a metallic sound with some older fast gain control code -- the problem is resolved with tricky hilbert transform stuff.  That doesn't happen anymore in my code, but the tradeoff of complexity might not be worth it in normal compressors/limiters -- just keep the rate high, accept a quality hit, or tolerate slower attack/release.

 

From my recent experience and test results, the nonstandard rate of 64k is a good compromise rate for gain control signal processing (I haven't heard artifacts at 56k either, but probably measureable without using tricky math to avoid problems.)    With the fully debugged advanced gain control code in my project -- I have pondered explict specification of 44.1k sample rates for essentially full quality, but recording pros don't really care much about 44.1k anyway, so I am leaving 44.1k as a 'lower quality' mode.

 

John