MQA creator Bob Stuart answers questions.

[Wombat]

660 posts and no confirmable result in sight. Yawn. Ah, the joy of audio forums.

 

[Krunok]

My intent is not to prove anything. Rather, to illustrate why I believe that the hi-res vs CD perception depends a lot on the music genre, on how a particular music piece was captured and mixed, on the listener, and on many other parameters.

To illustrate the illustration of the point. A puzzle by Lewis Carrol (paraphrasing):

- You need to walk to a train station to catch a train departing in 2 hours.
- The distance to the train station is 5 miles.
- You walk with the speed of 3 miles per hour.
- Will you catch the train?

The straightforward answer is: "Yes."
Lewis Carrol retorts: "But what if on the way to the station, a mad bull starts chasing you?"
Morale of the story: the correct answer is "I don't know".

So, the correct answer to the "Is there an audible difference between ... ?", being hotly debated on the forums like this one, is, in most cases, "I don't know", as it has many important parameters under-specified.

Once you concretize the question with the music, equipment, person, and person't physiological condition, then you may get to a more concrete answer. Averaging these answers over many variations of music, equipment, person, and trials, will get you a general answer. If that's what you are after, great. If you are interested in the answer regarding concretely your music and your equipment - you'd need to experiment on yourself.

I don't mean to be rude, but you are struggling here on 32+ pages of posts to prove something that nobody proved to hear. Let me quote @JJB70 's post again as IMHO that one hits the spot perfectly:

"My honest opinion is that if differences are so marginal that there is a debate over whether they are audible and even if real can only be discerned by a trained listener under controlled conditions (even there with less than a 100% success rate in DBT) then that tells its own story. That story being that it is all meaningless in the real world of using hifi and carrier media to just enjoy music. "

 

[Krunok]

There are two major uses of splines in audio time domain processing I know of:
(A) Extrapolating between samples during upsampling.
(B) Using them as basis functions for sampling and reconstruction of analog signal.

(A) is not actually the best interpolation approach. It is fast computationally, and produces nice smooth upsampled graphs pleasing the eye, yet it introduces distortions that the sinc-based interpolation and Fourier-based upsampling don't.

(B) is theoretically attractive because it allows to vary between the most accurate representation of the resulting analog output in frequency domain and its most accurate representation in the time domain, by changing the spline order parameter, while getting rid of the infinite character of sinc-based reconstruction.

So, I could imagine using different spline orders for recording an opera singer solo vs a death metal concert. However, (B) is computationally challenging, and requires either using a proprietary end-to-end system (thus interest of MQA creators I guess) or a new set of open standards. IMHO, the latter is not going to happen any time soon - PCM is very convenient and too entrenched.

I really can't see how spline can perform good in B scenario (reconstruction of analog signal) but fail to do so in A scenario (interpolation when upsampling).

 

[March Audio]

This appears to be the case, for me, in the context of the audio systems I had access to, and genres of music I ever cared about. 192/24 is 100% for me, to the best of my knowledge, as of today.


I'd think so too, if all the tracks I cared about, including Gamelan and Prog Rock (I think I could survive without Mariachi for a while ), were available in 192/24. But they aren't Perhaps that's why I'm so passionate about this whole Hi-Res thing: I want more music in 192/24!

You still haven't grasped the simple fact that microphones used in 99.999999999999999999999999999999999999999999999999999999999% of recordings simply don't capture anything any where near 96 kHz bandwidth. Specialised mics are required to do this. Your speakers can't reproduce up to 96kHz bandwidth. You can't hear 96kHz bandwidth .

As has already been pointed out timing is not dependant on sample rate.

As Amir pointed out "transient" doesn't mean infinitely high frequency content is in the signal.

So you have no basis to conclude 192kHz sample rate is beneficial. Simple fact is that you have never heard any overall recording/replay chain that has this capability.

Where do you think you are going with this?

 

[Sergei]

I don't mean to be rude, but you are struggling here on 32+ pages of posts to prove something that nobody proved to hear. Let me quote @JJB70 's post again as IMHO that one hits the spot perfectly:

You made a statement without reading all the pages. The proofs were provided.

"My honest opinion is that if differences are so marginal that there is a debate over whether they are audible and even if real can only be discerned by a trained listener under controlled conditions (even there with less than a 100% success rate in DBT) then that tells its own story. That story being that it is all meaningless in the real world of using hifi and carrier media to just enjoy music. "

I don't argue with your opinion. I just said it couple posts ago. However, the trained listeners have other opinions, also worthy of consideration.

 

[Wombat]

You made a statement without reading all the pages. The proofs were provided.


I don't argue with your opinion. I just said it couple posts ago. However, the trained listeners have other opinions, also worthy of consideration.

Proofs? Opinions, opinions, opinions. Only as good as the verified evidence that backs them up. Otherwise they tend to be subjective beliefs, no more, no less.

 

[March Audio]

You made a statement without reading all the pages. The proofs were provided.


I don't argue with your opinion. I just said it couple posts ago. However, the trained listeners have other opinions, also worthy of consideration.

I don't think you have proved anything.

 

[Krunok]

You made a statement without reading all the pages. The proofs were provided.

Well, I must have missed them, do you care to make a short recap?

However, the trained listeners have other opinions, also worthy of consideration.

As English is not my prime language I will quote again:

"You still haven't grasped the simple fact that microphones used in 99.999999999999999999999999999999999999999999999999999999999% of recordings simply don't capture anything any where near 96 kHz bandwidth. Specialised mics are required to do this. Your speakers can't reproduce up to 96kHz bandwidth. You can't hear 96kHz bandwidth ."

So, your trained listeners are from Krypton, special mikes were used to record up to 96kHz and also special speakers that can reproduce all that bandwidth. Did I get it right?

 

[mansr]

44.1/16 PCM would fail to encode correctly some odd-shaped signals in the 11-22kHz range

No, even "odd-shaped" signals are accurately captured at 44.1 kHz if their bandwidth is less than 22 kHz.

 

[Krunok]

No, even "odd-shaped" signals are accurately captured at 44.1 kHz if their bandwidth is less than 22 kHz.

Thanks, I know how that works. When I said "odd-shaped" signals I was referring to signals which harmonics exceed 22kHz.

 

[Blumlein 88]

You have no idea We went as far as recording live performances with three independent sets of ADC boxes: at 48/24, 96/24, and 192/24; and giving the tracks (numbering between 12 and 14) to three different mixing engineers to produce mixes they liked. Also doing downsampling of the resulting mixes from 192/24 to lower resolutions. Also converting them to MP3 and AAC.

The three mixing engineers had quite different preferences for the mixes. One of them would de-emphasize high-frequencies, and in general didn't like transients. Another one liked "crisp" and "punchy" mixes. The third one was somewhere in between. Mixes of the first engineer tended to translate well all the way down to 48/16, as they were "mellow" to start with. MP3 and AAC of these mixes sounded OK too.

Mixes of the second engineer not so much: that's where I could hear the differences between the 192/24 and downsampled 48/24. Interestingly enough, I personally couldn't hear differences of 192/24 vs 96/24 and 96/24 vs 48/24, so it was "two steps down" that would reveal the differences to me. You are right, the differences were small.

And as I mentioned before, for simple music, such as a solo vocalist accompanied by a solo acoustic guitar, there were no differences. The mixes of the three engineers sounded virtually identical, between each other, and at all sampling rates.

3 sound mixers mixed differently. Wow, not exactly surprising. Again, why are all your hints so terribly indirect? If it weren't so small we'd never have to grope about for such flimsy explanations of something really being there. Much more direct and clear differences would be easily found.

 

[Blumlein 88]

Not the beautiful imagery of Louis Carol, but consider this: In perceptual matters you are never going to draw a fine sharp line. Just as an alternative: how much weight can a human dead lift? We know it isn't 5000 lbs. We know it isn't 1000 lbs. Whoops, wait a minute there have been a couple do 1000 pounds. Okay, but an edge case. Seems out of 7,000,000,000 people a couple can do 1000 lbs. Most can't do half that. An average might be 1.5 times body weight for healthy people. Now we have good info on the variability in hearing. It isn't nearly so wide a range as dead lift capability. Maybe someone can somewhat hear 25 khz. Maybe there is a person or two somewhere who can do 27 khz. 99% never can hear beyond 20 khz and only that for a few years.

But as pointed out, microphones, speakers, hearing, conditions of hearing etc etc, the idea you need high, high sample rates is just bonkers for enjoyable music. Instruments that put out way up in the high ultrasonic range are going to have that sound absorbed by air in a few extra meters.

 

[Peter Leyenaar]

It seems from this chart that most frequencies generated by musical instruments fall below 14000 hertz.

 

[Sergei]

Well, I must have missed them, do you care to make a short recap?

Sure. Polite inquiry invites polite answer.

From https://www.audiosciencereview.com/...rt-answers-questions.7623/page-11#post-183344:
"A more comprehensive meta-study (http://www.aes.org/e-lib/browse.cfm?elib=18296), combining 400 participants in over 12,500 trials reveals that there is indeed statistically significant difference, yet it is small, 5% at most."

https://www.audiosciencereview.com/...rt-answers-questions.7623/page-31#post-188788 explains in simple everyday terms why it is possible to hear "a misshaped half of an ultrasonic wave cycle" (otherwise known as "short pulse" or "transient").

As English is not my prime language I will quote again:

"You still haven't grasped the simple fact that microphones used in 99.999999999999999999999999999999999999999999999999999999999% of recordings simply don't capture anything any where near 96 kHz bandwidth. Specialised mics are required to do this. Your speakers can't reproduce up to 96kHz bandwidth. You can't hear 96kHz bandwidth ."

So, your trained listeners are from Krypton, special mikes were used to record up to 96kHz and also special speakers that can reproduce all that bandwidth. Did I get it right?

The simple fact is that a physical event that only lasts 1 microsecond, such as a nuclear bomb explosion, can be heard, because it puts in motion a chain of physical phenomena, which eventually create a sensation of sound. You don't need a hearing frequency range up to 1,000,000 Hz to hear a nuclear explosion, or a sound of lightning, or a supersonic shockwave, or a sharp transient generated by cymbal/xylophone/gamelan.

 

[March Audio]

The simple fact is that a physical event that only lasts 1 microsecond, such as a nuclear bomb explosion, can be heard, because it puts in motion a chain of physical phenomena, which eventually create a sensation of sound. You don't need a hearing frequency range up to 1,000,000 Hz to hear a nuclear explosion, or a sound of lightning, or a supersonic shockwave, or a sharp transient generated by cymbal/xylophone/gamelan.

Sorry but that is utterly idiotic.

Why are you comparing a nuclear bomb explosion to music replay in the home?

The hearing range of humans has been firmly established over decades of scientific research. There is a tiny fraction of the populous that can hear into the mid 20 kHz range and the SPL needs to be huge to do so. There is no credible scientific evidence that contradicts this.

You still haven't grasped the fact that the definition of transient does *NOT* mean there is ultrasonic acoustic content, or that you are perceiving it if there is. This point is easily demonstrable. Record one of these "transients" such as a xylophone, high pass filter it above 30kHz and replay. Let's see what you can hear. You will hear nothing.

If you think you have heard normal music recordings that have bandwidth up to 96kHz then you are wrong. The mics didn't record the sound up to that frequency and your speakers didn't replay it even if it were there.

Sorry but you have diverted this thread from its subject with unsupported waffle. Whatever evidence that is supplied that contradicts your assertions you ignore and keep on waffling.

 

[mansr]

Why are you comparing a nuclear bomb explosion to music replay in the home?

«The Hitchhiker's Guide to the Galaxy notes that Disaster Area, a plutonium rock band from the Gagrakacka Mind Zones, are generally held to be not only the loudest rock band in the Galaxy, but in fact the loudest noise of any kind at all.»
-- Douglas Adams

 

[Sergei]

Not the beautiful imagery of Louis Carol, but consider this: In perceptual matters you are never going to draw a fine sharp line. Just as an alternative: how much weight can a human dead lift? We know it isn't 5000 lbs. We know it isn't 1000 lbs. Whoops, wait a minute there have been a couple do 1000 pounds. Okay, but an edge case. Seems out of 7,000,000,000 people a couple can do 1000 lbs. Most can't do half that. An average might be 1.5 times body weight for healthy people.

Perfect analogy.

Now we have good info on the variability in hearing. It isn't nearly so wide a range as dead lift capability.

Actually, just from the first principles, it ought to be just as wide. I think that the varying parameter is not just the frequency range of individual hearing though. I believe it is music "processing capacity", more accurately described by the information throughput, expressed in bits per second.

Regarding the olympic-class dead-lifters: it turns out that they possess very high percentage of fast-twitch muscle fibers (https://www.active.com/fitness/articles/fast-twitch-vs-slow-twitch-muscles), compared to general population. So, it is not about just strength, it is also about speed.

It all starts with a genetic predisposition. Then some of the people exhibiting this predisposition get selected for specialized training, usually at a young age. Those who achieve high enough level by mid-school start competing, getting up to a very serious level of competition by high school. Those who often win the competitions (or auditions, or job interviews), get to do it professionally, further sharpening the skill.

But as pointed out, microphones, speakers, hearing, conditions of hearing etc etc, the idea you need high, high sample rates is just bonkers for enjoyable music.

My other hobby is volleyball videography. I started taping my daughter's games, long ago, at 1080p 30 fps. Those videos didn't quite look like live games.

When I upped it to 4K 30 fps, there was a huge qualitative change: the resolution became high enough to capture facial expressions, while still keeping the whole court in view. We could now see live, emotional, people playing on the court! To some degree, we could now feel what they feel.

When I upped it to 4K 60 fps, there was yet another qualitative change: the movements became visually smooth. When played frame-by-frame, we could now see details of individual techniques - some of heretofore mysterious secrets of volleyball mastery became plainly obvious.

For instance, it is an accepted notion that no human can produce a gross motor reaction earlier than in 750 milliseconds after the onset of stimuli warranting such reaction. But, lo and behold, the video plainly shows this particular young beach volleyball player managing to move and receive the ball just 400 milliseconds after it was spiked. Over and over again.

Or another player - and this brings us closer to the topic of "unreasonable" resolutions - executes a half-wave with the palm of her hand, significantly changing the trajectory of the ball she is spiking, in the course of just three frames, that is, in just 50 milliseconds!

I got very excited when I saw it for the first time on a frame-by-frame replay, and immediately brought it to the attention of my daughter. "I already know" - she said - "I can see this feint when I'm blocking her".

How's that for a reality check? In real time, I could barely see the gross outline of the technique being used, no matter how closely to the court I stood. My daughter could perceive the fine temporal structure of what's going on, and this in turn helped her to acquire a reputation of a player not to be messed with on a block.

Instruments that put out way up in the high ultrasonic range are going to have that sound absorbed by air in a few extra meters.

Very true. Perhaps one of the reasons I'm able to perceive some of those pulses is because most of the time I'm listening to professional studio monitors in the near field. Or to a chamber live music: indeed, grand piano sounds quite different from 6 meters away vs 18 meters away.

 

[Peter Leyenaar]

If we assume that most people use their stereo systems to listen to music at a quality level of a CD (16 bit 44.1Khz determined by the good people of Phillips and Sony, taking the Nyquist sampling rate in account) it should be clear that 20 Khz is the very upper limit of frequencies one will ever
experience.
I'll include once again the chart showing the frequency range of musical instruments indicating frequencies between 30hz and 14Khz
except perhaps a church organ that can go as low as 18hz (average).
Expecting to hear frequencies in music above say 18Khz is unrealistic.

 

[pkane]

If we assume that most people use their stereo systems to listen to music at a quality level of a CD (16 bit 44.1Khz determined by the good people of Phillips and Sony, taking the Nyquist sampling rate in account) it should be clear that 20 Khz is the very upper limit of frequencies one will ever
experience.
I'll include once again the chart showing the frequency range of musical instruments indicating frequencies between 30hz and 14Khz
except perhaps a church organ that can go as low as 18hz (average).
Expecting to hear frequencies in music above say 18Khz is unrealistic.

How is that in any way related to nuclear explosions or volleyball? Your audio facts are completely irrelevant to this thread

This has turned into a compendium of @Sergei’s anecdotes in every possible field unrelated to the original topic.

 

[Peter Leyenaar]

Mea Culpa, I didn't realize this thread is about listening to nuclear explosions , you go ahead and listen to them,
I'll listen to music.
Any others listening to nuclear explosions ?