• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required as is 20 years of participation in forums (not all true). Come here to have fun, be ready to be teased and not take online life too seriously. We now measure and review equipment for free! Click here for details.

High Resolution Audio: Does It Matter?

TBone

Major Contributor
Joined
Mar 16, 2016
Messages
1,001
Likes
145
#81
Measured 'DR' is affected by EQ choices.

For example if there's more bass, on A vs B, A will read as 'lower DR'.

As always one number rarely tells the whole (audio) story.
Funny how you don't think we know that!

A high order subsonic filter influences DR values, but not nearly enough to tip the DR/SQ scales, same saga.

IME, pre-emphasis & hdcd peak-extended ripped CD -without proper decoding- often cause about a ~2dB DR error. Adding more bass eq here, not there, isn't going to measure nearly as much.
 
Last edited:

Wombat

Major Contributor
Joined
Nov 5, 2017
Messages
2,465
Likes
916
Location
Australia
#82
If hi-res is better than RBCD then its distortion components should be audibly less apparent/more desirable. I am yet to be convinced.
 

andreasmaaan

Major Contributor
Patreon Donor
Joined
Jun 19, 2018
Messages
1,294
Likes
628
#83
Sorry to revive an old thread, @Thomas savage wisely suggested I move my questions off the desirable distortion thread.

@amirm, in your article here you note that: "The paper authors hypothesize that it is the filtering “ringing” in the time domain that may have caused these artifacts. Ringing is an unavoidable manifestation of digital filtering. The sharper the filter has to be, the longer its “tails” (ringing) in time domain. The ear is not a spectrum analyzer but rather "hears" the samples as they arrive. In theory the ringing can be audible and potentially is what was heard."

In the other thread - if I understand @SIY and @DonH56 correctly - it was stated that digital FIR filters are capable of brickwall low pass filtering with flat amplitude and phase response below the cutoff point (the only price being increased latency).

@SIY says that it is therefore possible to confine the ringing to the "transition range", i.e. the range between the cutoff point and the nyquist frequency. In the case of an optimally implemented 44.1Khz LPF, this would mean it is possible to contain the ringing to the range between 20Khz and 22,050Hz.

Assuming this is correct, one would have to conclude one of three things:
  • the participants in the study had useful hearing above 20Khz;
  • the LPF applied to the "low-res" files in the study contained amplitude or phase error below 20Khz (was a sub-optimal filter??);
  • OR something else was going on which was not addressed.
Anyone care to speculate on this?
 
Last edited:

Blumlein 88

Major Contributor
Joined
Feb 23, 2016
Messages
4,049
Likes
2,235
#84
I'm not sure phase error tells you much. Testing done to date shows humans are not much attune to phase as you pass above 1500 hz. In the 10khz and above region we probably don't hear it.

Also there are small numbers of young adults that hear above 20 khz. Maybe 1 or 2%. I think that is why some have suggested an optimum blameless digital system would have sample rates of 60 or 65 khz, flat response to 25 khz and leaving generous room for filtering above 25 khz as a transition region.
 

andreasmaaan

Major Contributor
Patreon Donor
Joined
Jun 19, 2018
Messages
1,294
Likes
628
#85
That all sounds very reasonable @Blumlein 88 and I generally agree concerning phase error sensitivity vs frequency, but unless I’ve misunderstood, it doesn’t get us any closer to understanding the outcome of the study.
 

sergeauckland

Active Member
Joined
Mar 16, 2016
Messages
261
Likes
293
Location
Suffolk UK
#86
Ok, I will quibble a little, Serge. I agree that 44k/16 is a more than adequate distribution medium, although I personally would not describe it as "perfectly" adequate.

I also have trouble with "transparent". To me there are degrees of transparency. It is not a binary, true/false description. We may think something is transparent, until we hear something else we consider more transparent, in which case our standards shift. Personally, this has happened to me frequently in audio, usually with slight degrees of greater apparent transparency over the years, but not so much in recent years. The forward pace in audio has definitely slowed, I believe, except for some schiity backsliding, among other alarming mini trends.

As to your tests, I am unclear on their specifics. But, within whatever limits they may have, I accept them as totally credible, as I do you personally. Except, other very experienced recording engineers have done similar comparisons involving RBCD, hirez PCM or DSD vs. mic feeds, and they reach very different conclusions. Some stake their careers at substantial equipment expenditure upgrade levels in preferring recording and distributiion in hirez because they view it as sounding superior. Some of those guys are also very credible to me.

And, I have my own comparisons along with friends, hopefully all of us with discerning ears, of RBCD vs. various types of hirez at different sampling frequencies/formats from the same digital master. You and I do not agree that RBCD cannot be bettered, albeit slightly, but still noticeably and preferably. Note that native analog or RBCD recordings are not likely to reveal much difference for all the reasons cited in this thread about upsampling.

The 2016 Joshua Reiss meta analysis, carefully read, including looking carefully at the individual tests he summarized, can be looked at in various ways, depending on the reader's established viewpoint. To my mind, it demonstrates that some people, particularly those with prior training in what to listen for, can discern a difference with reasonable statistical significance with hirez, though not a preference which was not normally part of the testing. Others, of course, may read it as indicating such a small overall difference so as not to be worthwhile. And, some individual tests, excluding even the infamous, poorly conducted Meyer-Moran, do not show much discrimination of hirez for whatever reason.

https://secure.aes.org/forum/pubs/journal/?ID=591

Hirez is no panacea, and there is no slam dunk case to be made for it. In the slow evolution of audio, it might be a mere blip at substantial expense and inconvenience to many for not much improvement. But, others of us hear the improvement and value it.
To me, there aren't degrees of adequacy. It's either adequate, in which case no improvement is necessary (note:- doesn't mean that an improvement can't be made), or it isn't. What I accept does vary is what each of us considers 'adequate'. For me, it's adequate if I can not hear any difference, i.e. it's transparent. I don't agree that there are degrees of transparency. That seems to me to be an oxymoron. If something passes a straight-wire bypass test, with different sources and with different listeners, then it's transparent.

The tests were done some years ago, comparing direct microphone feeds, commercial CDs and test signals.

As to commercial Hires releases, Many of them are a total con. Rereleases of classic recordings, done on analogue tape means that there's hardly anything there above 18-20kHz except noise, with a noise floor not much below 70dB, consisting of microphone amplifier noise, tape noise, aircon rumble etc etc. Even the classic microphones so valued by some don't have any response above 18kHz, so what's the point of a 96k/24 bit release?

Even early digital recordings would have been sampled at 48k (50k for the very early ones before standardisation) so again, what's the point?
Only recent recordings done at high resolution could be called Hires releases, if they're not resampled DSD or upsampled 48k material.

Anyway, enough of a rant.
S.
 

Grave

Active Member
Joined
Jun 30, 2018
Messages
280
Likes
93
#87
The answer is no, HRA is a joke. . .
 

sergeauckland

Active Member
Joined
Mar 16, 2016
Messages
261
Likes
293
Location
Suffolk UK
#88
The answer is no, HRA is a joke. . .
Pithy, but to the point!

I posted this on the 'Desireable Distortion' thread, but is probably more appropriate here.

As to commercial Hires releases, Many of them are a total con. Rereleases of classic recordings, done on analogue tape means that there's hardly anything there above 18-20kHz except noise, with a noise floor not much below 70dB, consisting of microphone amplifier noise, tape noise, aircon rumble etc etc. Even the classic microphones so valued by some don't have any response above 18kHz, so what's the point of a 96k/24 bit release?

Even early digital recordings would have been sampled at 48k (50k for the very early ones before standardisation) so again, what's the point?
Only recent recordings done at high resolution could be called Hires releases, if they're not resampled DSD or upsampled 48k material.

S
 

Fitzcaraldo215

Major Contributor
Joined
Mar 4, 2016
Messages
1,417
Likes
474
#90
Just a short comment on «hirez», which is the word, writing you chose.

In my eyes, «hirez» is the fake thing (say 16/44 upsampled and sold at a higher price as 24/xxy), while «hires»/«hi-res» is the real thing.

Just a detail, but I don’t like the word «hirez» when it’s used about high quality productions.

See my point?
No, sorry, I don't. I think they are synonomous. And, I think the distinction far too subtle without there being standardized differentiated definitions of each. However, I agree that there has been shameless fakery by repackaging upsampled material in hirez/hires packages to little, if any, sonic advantage.

I think the descriptions hirez/hires are interchangeably about a file format being > RBCD, regardless of its native recording format. And, even if there were a distinction, which term does one apply to remasters from native analog recordings?

I also don't like "hires" because it is too much like the name of an old root beer brand in the US. I used to drink it as a kid. It is also a common verb, hence easily confused.

So, I will try to stick with "hirez" describing the file format and make a distinction with the native recording format as necessary. :)
 

DonH56

Major Contributor
Technical Expert
Patreon Donor
Joined
Mar 15, 2016
Messages
1,947
Likes
1,343
Location
Monument, CO
#91
High-resolution audio = hi-res, hi-rez, hirez, HRA
Hires = root beer
hires = people you get to work for you

Unless I forget, I use hi-res, though I don't use the term often as I have seen too many variations on what folk consider "hi-res". Anything over CD quality used to be the accepted definition, but I've lost track these days. Not all that important to me.
 

andreasmaaan

Major Contributor
Patreon Donor
Joined
Jun 19, 2018
Messages
1,294
Likes
628
#93
...that is why some have suggested an optimum blameless digital system would have sample rates of 60 or 65 khz, flat response to 25 khz and leaving generous room for filtering above 25 khz as a transition region.
@Blumlein 88, I just re-read your post and thought about it more in the context of the study. Sorry for the second reply.

In the study, the transition range in each case of downsampling was above 20,000Hz (for example, it was 21,500-22,050 in the worst case scenario).

Assuming all amplitude and phase non-linearity (including ringing) was restricted to the transition range, and assuming no test subject had useful hearing above 20,000Hz (or even 21,500Hz) - how then can we explain the results?

And if there was no amplitude or phase error in the audible range for that filter, with its cutoff at 21,500Hz, how and why could increasing the cutoff to say 25,000Hz (or any other higher frequency) make a difference?

@amirm, I know you were able to produce a similar brickwall filter in Matlab - did the filter you produced contain amplitude or phase error (particarly ringing) below 20,000Hz?

I feel there's still something inexplicable going on here. Either:
  1. there was ringing (or some other artefact) in the audible range, which the subjects were able to identify, or
  2. everything in the audible range was amplitude and phase correct, but there was ringing (or some other artefact) in the super-20,000Hz range only, which the subjects were nevertheless able to identify.
The second alternative, if true, would cast a lot of doubt on established theories of human auditory perception.
 

Wombat

Major Contributor
Joined
Nov 5, 2017
Messages
2,465
Likes
916
Location
Australia
#94
It must be ego boosting to profess to have super-critical hearing. I have yet to see conclusive evidence that supports it.

Middle-aged(and beyond) males seem to be the ones who unashamedly make these claims. They are the least credible advocates re hearing acuity. Compensation for advancing decrepitude, maybe. :rolleyes:
 

andreasmaaan

Major Contributor
Patreon Donor
Joined
Jun 19, 2018
Messages
1,294
Likes
628
#95
It must be ego boosting to profess to have super-critical hearing. I have yet to see conclusive evidence that supports it.

Middle-aged(and beyond) males seem to be the ones who unashamedly make these claims. They are the least credible advocates re hearing acuity. Compensation for advancing decrepitude, maybe. :rolleyes:
Hahaha true...but @amirm has actually passed a double blind controlled test that showed he was able to reliably discern between redbook and hi-res (on a particular sample with two particle filters - one very steep and one shallower - IIRC).

And then there are the results of this study.

I think we need to examine the filter used in the study in adequate detail to confirm that it did not contain amplitude or phase non-linearity within the audible band. That would be a good start to making sense of the results.
 

Wombat

Major Contributor
Joined
Nov 5, 2017
Messages
2,465
Likes
916
Location
Australia
#96
Hahaha true...but @amirm has actually passed a double blind controlled test that showed he was able to reliably discern between redbook and hi-res (on a particular sample with two particle filters - one very steep and one shallower - IIRC).

And then there are the results of this study.

I think we need to examine the filter used in the study in adequate detail to confirm that it did not contain amplitude or phase non-linearity within the audible band. That would be a good start to making sense of the results.

I think we need to see that it is repeatable across a wider range of participants.

Also the audio chain and test conditions needs to be free of influence. Mmmmm.

Ultimately how it translates to real-time music listening(masking, et.al.) has to be proved. Amirm may be immune from all of those pesky psychoacoustic influences. I doubt it.
 

andreasmaaan

Major Contributor
Patreon Donor
Joined
Jun 19, 2018
Messages
1,294
Likes
628
#97
@Wombat yes definitely. At the end of the day, I'll be blown over if there wasn't some kind of artefact within the audible spectrum in both cases. I'd just love to be able to pinpoint what it was.... OR to find that there was none - in which case the results become much, much more interesting o_O

What do you speculate the possible influences on the audio chain and test conditions might have been in these cases?

And what do you mean "real-time music listening"? The test conditions in both cases involved real-time listening to music signals IIRC.
 

Wombat

Major Contributor
Joined
Nov 5, 2017
Messages
2,465
Likes
916
Location
Australia
#98
@Wombat yes definitely. At the end of the day, I'll be blown over if there wasn't some kind of artefact within the audible spectrum in both cases. I'd just love to be able to pinpoint what it was.... OR to find that there was none - in which case the results become much, much more interesting o_O

What do you speculate the possible influences on the audio chain and test conditions might have been in these cases?

And what do you mean "real-time music listening"? The test conditions in both cases involved real-time listening to music signals IIRC.
 

Wombat

Major Contributor
Joined
Nov 5, 2017
Messages
2,465
Likes
916
Location
Australia
#99
'Normal' listening to music is not the same as listening under discriminating test conditions. i.e. a more general experience.

Meant real-world rather than real-time. :oops:
 

Blumlein 88

Major Contributor
Joined
Feb 23, 2016
Messages
4,049
Likes
2,235
@j_j would you care to comment on audibility of sample rates, transition bands and filtering. Specifically why you've suggested 60-65 khz sample rates with roll-off starting at 25 to 30 khz.
 
Top Bottom