Audio Science: Does it explain everything about how something sounds?

Status
Not open for further replies.
Going back to the practical issues about audio science - a very good post from Jason Stoddard (he of Schitt fame) about measurements used, what they mean (or not), what the equipment costs, etc.

A nice bit at the end he calls "measuring the unexpected" about multi-tone tests "one of the measurements we do that is off the beaten path. This measurement appears to correlate at least loosely to subjective impressions, and it unearths some surprising problems in gear that otherwise measures very well."

I like his story about "The Perfect DAC"


I know people will say that this DAC was broken but here's the dilemma - when is something broken? - when we hear a problem? - when a measurement reveals this? - what if the revealing measurement isn't performed, & we hear a problem, is it still broken ? - What if measurements show no problem, a dubious blind test shows no problem but sighted listening does? I know many that would argue that they have evidence on their side that there is no problem!! As my sig says "The greatest obstacle to discovery is not ignorance – it is the illusion of knowledge."
It's a bit of the one hand clapping in the forest sorta thing.

How many broken audio devices are in circulation simply because the measurement to reveal their brokenness hasn't been done?

This is the problem with measurements - where do you stop - there's thousands of possible measurements that can be done.

And, btw, multi-tone testing is not a new test - it has a long history in telephony, apparently but has been dropped from the stock suite of audio measurements for whatever reason. Some argue that IMD results can be extrapolated to multi-tone results - in a non-linear system, I would like to see them defend that. But the hint that something was wrong above did show up in the IMD test so that somewhat proves the efficacy of the stock testing? But what about the engineers who released this DAC - did they not notice the IMD hints given in their testing?

The problem, to my mind, with a lot of talk about audio science & measurements is that it is spoken of in absolute, infallible terms - not taking account of the real-world issues that surround any application of science

Very interesting this, thanks for posting. It just confirms what I always thought, that the 'usual' measurements really only give a very limited indication of the component's performance on music, which is a far more demand signal than just test tones. But the 'objectivists' somehow do not want this to be true.

Amir's objections, while they may something about the manufacturer, have no bearing on the observations highlighted by this engineer.
 
Very interesting this, thanks for posting. It just confirms what I always thought, that the 'usual' measurements really only give a very limited indication of the component's performance on music, which is a far more demand signal than just test tones. But the 'objectivists' somehow do not want this to be true.

Amir's objections, while they may something about the manufacturer, have no bearing on the observations highlighted by this engineer.

The goal post has moved several yards now. Now we're discussing the validity of Usual or standad measurements.

The portion of your post I highlighted is IMO a caricature of "Objecivists" position. The point maintained by many and that includes me, is that Science can explain what we hear. There is nothing that we can hear that will magically escape Science. We may well be not measuring what is important , a view that I share but measuring we can and/or shall once and if the phenomenon exist in the physical realm ...
 
The point maintained by many and that includes me, is that Science can explain what we hear. There is nothing that we can hear that will magically escape Science. We may well be not measuring what is important , a view that I share but measuring we can and/or shall once and if the phenomenon exist in the physical realm ...

I find little to disagree here, and don't see how this contradicts my previous post. Yes, we should be able to measure everything once we know how to measure. For example palpability of sound staging or timbral/spatial instrument separation within the soundstage must be measurable since what is deciding are the sound waves reaching our ears, which is a physical/measurable phenomenon, but I have yet to see one engineer being able to do it. The problem is that we know a lot about sound waves, but very little about human aural perception of them. The crucial question is: how do you measure all that is important, and not just a few limited aspects of it?

The portion of your post I highlighted is IMO a caricature of "Objecivists" position.

Alas I am not so certain that this is the case.
 
The goal post has moved several yards now. Now we're discussing the validity of Usual or standad measurements.

The portion of your post I highlighted is IMO a caricature of "Objecivists" position. The point maintained by many and that includes me, is that Science can explain what we hear. There is nothing that we can hear that will magically escape Science. We may well be not measuring what is important , a view that I share but measuring we can and/or shall once and if the phenomenon exist in the physical realm ...

Frantz, it's all very well talking in futuristics & hypotheticals - "There is nothing that we can hear that will magically escape Science" The question is can science lay out a fully formed model for what we hear & as a consequence define the measurements from that model & predict new findings based on that model & experiments to explore these predictions? I think the answer, at the moment, is no. Without this, science cannot be said to be able to explain what we hear.

And there's no point is your prediction that it WILL be explained in the future - nobody disagrees with that.

It seems that objectivists now fall in a spectrum as regards time - on the one hand we have those that state all that audio science finished 50 years ago & the other end of the spectrum that it will all be sorted out eventually in the future.

I believe subjectivists generally deal with the here & now & what they perceive.

What we are talking about is thepresent - can audio science explain everything that we hear i.e how something sounds?

Answer: NO!!

"The goal post has moved several yards now. Now we're discussing the validity of Usual or standad measurements."
If you can show other measurements being routinely done by other manufacturers then what are we to assume? The conclusion is that these sets of measurements define & decide the pool of audio devices from which we can select - all are circumscribed by these measurements.
 
The point maintained by many and that includes me, is that Science can explain what we hear.

In other words, YES.

jkeny said:
What we are talking about is the present - can audio science explain everything that we hear i.e how something sounds?

Answer: NO!!

In other words, NO.

There seems to be a lack of consensus on this issue. I am curious as to why.
 
Last edited:
(...) The point maintained by many and that includes me, is that Science can explain what we hear. There is nothing that we can hear that will magically escape Science. We may well be not measuring what is important , a view that I share but measuring we can and/or shall once and if the phenomenon exist in the physical realm ...

Current science is the existing knowledge, not future knowledge. What we now call "magic" is probably future science - perhaps some day we will have a better understanding of what we hear.
 
Out of curiosity, what was the data path from the computer to the DAC, expecially digital interconnect type, protocol and clocking that produced those ugly plots?
They were different configurations. I think the one with high jitter sidebands was with Toslink. S/PDIF did not show that problem. The playback issues I think was through USB connection.

Original issue was that my son could here his computer activities bleed through this DAC. He had upgraded to it specifically to get rid of that problem based on my recommendation of what I had read about the company online. The instrumentation showed that system activity did bleed into it despite talk of isolation and good performance on their site.
 
Irrespective of the above, his post is a good outline of stock suite of measurements that are generally used by audio manufacturers & his comments & observations are worthwhile. I'm not holding him up as a bastion of anything - just as a good summary of the stock application of audio science!
I had read that post before and it is a good explanation of different measurements from perspective of equipment designer. In that regard, it is worth a read. There is one mistake in there though: he emphasizes clock jitter as the oscillator source to the DAC. This is what is important to a designer. To a user, that is the wrong emphasis. The DAC filters incoming jitter and therefore what we care about, is what finally appears in the analog output of the DAC. That is the measurements I shared and others do just the same.

For that write up to be about audio science, it needs to incorporate psychoacoustics and there is none of that in there. For example, he talks about picoseconds jitter not realizing that depending on spectrum of jitter, 1000 times higher levels could very well be inaudible due to masking. This type of analysis is what I consider audio science. Saying 60 db or higher this and that distortion could be audible, is not.


To give you some idea of what I consider audio science, let's take the notion of audibility of speed variation in a turntable/reel-to-reel tape deck. Research into audibility of that shows our highest sensitivity at 4 Hz:

i-T9VC8Jk-X2.png


The explanation is at the bottom. The peak at 4 Hz interferes with typical cadence in human speech. So naturally intelligibility suffers the most at that frequency. As we climb higher and lower, the audibility thresholds increase rapidly. Now let's compare that result to the IEC weighting for measurement of Wow and Flutter:

400px-Lindos9_Flutter.svg.png


What do you know? The peak emphasis is around 4 Hz just the same!!! Wow and Flutter at lower and higher frequencies are de-emphasized. So this type of measurement is actually psychoacoustically aware.

Now this is audio science. We analyze and bring understanding to the topic based on listening tests and explanation that ties everything together. There is no such talk or analysis in that post and hence my reluctance to call it application of audio science.

BTW, the above graph is from bible of psychoacoustics by Fastl and Zwicker: "Psychoacoustics, Facts and Models." http://www.amazon.com/Psychoacousti...-1&keywords=Psychoacoustics,+Facts+and+Models.
 
You raise good points, Amir but how many measurements are used by audio designers or consumer focussed measurements (such as Paul Miller's or Atkinson's) that are psychoacoustically aware? I know Stereophile tried to implement some multi-tone measurements years ago (as they were considered more psychoacoustically aware) but dropped them a while later - I think they didn't find a correlation between their measurements & subjective impressions. This doesn't necessarily mean that multitone testing is irrelevant - it may have been their particular multitone format was not very representative of the musical structure?

BTW, I wouldn't agree with you that what we care about, is what finally appears in the analog output of the DAC - there are many techniques used in DACs which remove the traces of jitter from the analogue output but change it into other forms of noise.

But even if we just take your example of 4Hz fluctuations as being our most sensitive frequency for wow & flutter - how often is this close in jitter examined in a jitter plot? A slight spread at the base of the fundamental is how this would appear in a plot, right? Have you seen anybody examine or comment on the 4Hz jitter figure in an analogue jitter plot?
 
For example palpability of sound staging or timbral/spatial instrument separation within the soundstage must be measurable since what is deciding are the sound waves reaching our ears, which is a physical/measurable phenomenon, but I have yet to see one engineer being able to do it. The problem is that we know a lot about sound waves, but very little about human aural perception of them. The crucial question is: how do you measure all that is important, and not just a few limited aspects of it?

Hello Al M

That is a tuff nut. The room and speaker positioning has quite a lot to do with soundstage perception as well as your position in the room. Not to mention what's going on in your head as your brain processes what you hear. That is not something you can measure using simple measurements like frequency response. It really is a red herring to expect measurements to do that. Everything has limitations and understanding them may at least get you on right road or get you thinking of what it might be.

Rob:)
 
Soundstage and imaging have to be related to phase and volume differences between channels, but I've never seen anything correlating specific phase relationships to perceived soundstage and imaging. Perhaps others have?
 
In other words, YES. In other words, NO.

There seems to be a lack of consensus on this issue. I am curious as to why.

Peter, you didn’t exactly ask a direct question but I’m going to take a stab and see if I can satisfy your curiosity a bit. But I don't suspect I'll get any browny points for doing so.

The problems the high-end audio industry faces are multi-dimensional and therefore perhaps impossible to rectify. Why?

1. It’s a hearing / interpretation (trained ear) thing.
It’s a given that nearly the entire world can hear and see to some extent. High-end audio isn’t just about hearing because even a toddler can hear. In a simple sense, high-end audio is a bit like appreciating fine paintings. But just like the toddler can listen to Mozart and not appreciate what they hear, that toddler could also gaze at a Van Gohg painting and not appreciate its viewing qualities.

The toddler turns 21 and is gifted a very well-thought-out playback system and a Van Gogh painting. He may listen to and view his gifts but without any training in either area, he lacks the ability to interpret what he hears and sees. Advance his age another 30 years and still without training, at the age of 51 his ability to discern what he hears and views are not much better than when he was 21, which in turn were not much better than when he was a toddler.

But that’s where the similarities between listening and viewing the finer arts ends and discernable listening becomes far more nebulous.

For example,

- When viewing the stationary painting, he’s able to focus on any part of the painting he so desires and could even use a magnifying glass or microscope to assist him.

- When listening, the music is traveling at the speed of sound and there’s very few if any apparatus to allow him to better discern the music in real time. And no matter how you slice it, it is extremely difficult to sufficiently evaluate a fast moving target.

2. It’s a lack of performance thing.
You won’t find many examples, which in itself should be a testament, but every so often you’ll hear an “expert” exclaim something like what Jonathan Valin said around 2008, “We are lucky if even our very best playback systems can capture even 15% of the magic of the live performance.” I know a few who’ve said that even Valin’s 15% is being optimistic. BTW, I interpret Valin’s use of “magic” as “believability”. Not 15% of the overall music presentation. IME, Valin’s statement is not far off the mark. And yes, I’m well aware there are many who claim many playback systems are capable of sounding very much like live music.

3. It’s a much raised noise floor induced by severe distortions thing.
When viewing the painting, he has the ability to capture 100% of all the detail within the canvas. But when listening, he is not privy to all the music info embedded in the recording, in fact far from it. Hence all of the detail captured at the canvas is far greater than the music traveling at the speed of sound has been greatly diminished. Think of this deficiency as him having lost half of his hearing ability. Moreover, when one has the ability to study an object (like a painting) at its full potential, the opportunity to grow in knowledge and understanding is far greater than attempting to study an object (music output) that is exhibited at far less that its full potential.

4. It’s a bling-bling and keeping up with the Jones thing.
It’s no secret that many enthusiasts too often mistake aesthetically pleasing or cool looking gear for performance. As such, many automatically assume if a product or system is financially out of their reach, then it must be superior to their own. To compound the issue, many who possess expensive playback systems also assume because their system costs more, it must be a superior performer to less costly systems. How many times do you see somebody comment on somebody else’s system saying, “Wow, I’ll bet it sounds awesome.”? Sure some of that is just flattery, but more times than not I suspect with what appears genuine excitement and infatuation, they really mean it.

5. It’s a lack of leadership thing.
Everything listed herein generally applies equally to reviewers and so-called “experts” as it does enthusiasts.

6. It’s a marketing and revenue thing.
Ever since the “Is it live or is it Memorex?” commercials in the 70’s, the gloves came off when it comes to marketing hype. Don’t believe me? Pick up any high-end audio mag and list all the extreme superlatives used in most every advertisement. Frankly, it’s almost like an industry in a drunken stupor. The fact that some-to-many of us never question this hype should substantiate some of what I’m claiming here.

7. It’s an improper emphasis on the use of measurements thing.
If as a result of unaddressed universal distortions, every sensitive component and playback system’s precision and accuracy is severely crippled, is it not likely that sensitive measuring instruments’ precision and accuracy could likewise be crippled?
Moreover, if our playback systems are so severely crippled (as I would attest), that for the sake of argument let’s say only 50% of all music info embedded in a given recording remains audible at the speaker’s output, what does that say about many of the measurements taken and the “science-minded” types who compile and/or report these findings? Additionally, if during playback our systems’ precision and accuracy are indeed severely crippled, what more would that say about the potentially already compromised measurements if indeed our sensitive measuring instruments likewise are crippled from the same universal distortions?

8. It’s a misunderstanding of the meaning of “expert” thing.
Recently Atkinson (of Stereophile) was quoted in a Vandersteen Model 7A speaker ad saying, “Made the hairs on the back of my neck stand up. …. Musically perfect… across the board.” And if reproduced audio could be “more perfect” than that, I suggest reading Harley’s (of TAS) recent review of Meridian’s MQA high-rez formatted music. It puts Atkinson’s comments about the Vandersteen’s to shame.
Yet, in 2009 both of these editors-in-chief can be found claiming that something catastrophic is occurring that keeps much of the music info from ever reaching the recording in the first place. When PhD’s like Floyd Toole engage and their research is hamstrung by the same deficiencies, what does that really say about their findings and white papers? Going back to 50% of the music info remaining audible at the speakers, assuming it’s anywhere close to true, what does that really say about the supposedly really smart fellers in this industry? To me, it says, they’re not really quite the experts we and they think they are and in the end they are just as lost as the rest of us.

9. For some-to-many, it’s an intellectual thing rather a performance thing.
Frankly, even though many talk performance all the day long, I suspect a good many don’t really care all that much about performance.

10. It’s a lack of focus thing.
Other industries seem to have very clear and observable targets on the wall. But as a result of all the above, it should be apparent that from a performance perspective (the core), the high-end audio industry remain very much in its infancy. What’s even worse is that may well imply perhaps every other aspect of the industry also remains in its infancy.

In summary.
When you add up all or even half of these truths (yes truths), it should become apparent that we’re talking essentially an entire “performance-oriented” industry wandering aimlessly in the desert. Maybe now it becomes easier to see why it seems no two enthusiasts can shoot at the same target or there can be no consensus.
 
Excellent points. I am not so pessimistic, though. You have described the tendencies toward entropy that affect our perception of audio as well as the industry trying to satisfy our musical listening desires. But, in spite of similar constant entropy in nature, sciences like chemistry, physics and others have made major progress in understanding, explaining and applying knowledge to the application of these disciplines for our betterment. In spite of the entropy, audio has quite dramatically improved in the decades I have enjoyed this hobby. I expect that to continue, but slowly because it is difficult.

I do not think that audiophile arguments, reviewer hyperbole or manufacturer claims have been of very much help in that advance. Rather, I think that better science and applied technology that is able to see the forrest beyond the trees of particular playback systems or individual listener opinions leads us on the path forward.
 
(...) Now this is audio science. (...)

Nice to see a reference to the Fraunhofer LBF in Darmstadt, Germany. They are the people behind the very expensive racks for electronics components, using either passive resonators or active piezoelectric systems, eliminating sound influencing vibrations, an effect reported by audiophiles since many decades ago.

Perhaps now that the apparatus has been developed in the installations of a prestigious scientific institution skeptics will believe.

BTW, german high-end manufacturers do not hesitate to write their beleifs. Quoted from the MBL site:

Why are the engineers at MBL so different from others?

Reis: I think the most important thing is we are all open-minded. Of course we all received conscientious scientific training and we are all are obsessed with theory. But I have to admit that, we can’t make things only based on science and theory. Sound is something alive and you just cannot explain it with something dead. You have to listen to it and feel it, or your products may not be able to produce sound that is full of vitality.
 
In other words, YES.

In other words, NO.

There seems to be a lack of consensus on this issue. I am curious as to why.

This a religious question, hence the controversy and degree of heat and flames.

Those people who are authoritarian followers who believe in the religion of Scientism are religiously following a philosophy of materialism and belief that the scientific method is or will be ultimately capable of answering all questions related to the physical world. They vote YES.

Those people who do not follow this "ism" tend to vote NO. (I say, "tend to" because this group of people is diverse and many try to avoid holding dogmatic beliefs for which there is no evidence.)
 
This a religious question, hence the controversy and degree of heat and flames.

Those people who are authoritarian followers who believe in the religion of Scientism are religiously following a philosophy of materialism and belief that the scientific method is or will be ultimately capable of answering all questions related to the physical world. They vote YES.

Those people who do not follow this "ism" tend to vote NO. (I say, "tend to" because this group of people is diverse and many try to avoid holding dogmatic beliefs for which there is no evidence.)

I love your statement "The authoritarian followers who believe in the religion of Scientism are religiously following a philosophy of materialism". Right on.

Yet Scientism holds that the physical world is all that exists and therefore ultimately all questions are scientific questions. I do not believe that the physical world is all that exists. On the other hand, I do believe that by its very method science may be ultimately capable of answering (almost) all questions related to the physical world. This does not imply Scientism.
 
2. It’s a lack of performance thing.
You won’t find many examples, which in itself should be a testament, but every so often you’ll hear an “expert” exclaim something like what Jonathan Valin said around 2008, “We are lucky if even our very best playback systems can capture even 15% of the magic of the live performance.” I know a few who’ve said that even Valin’s 15% is being optimistic. BTW, I interpret Valin’s use of “magic” as “believability”. Not 15% of the overall music presentation. IME, Valin’s statement is not far off the mark. And yes, I’m well aware there are many who claim many playback systems are capable of sounding very much like live music.

I once asked JV if he could put a percentage on this idea of our best systems capturing the musical event, and he simply told me at the time, "No". I recently heard Suzanne Vega's song, "Tom's Diner" on a CD reproduced on an excellent digital system with mini monitors. That studio recording was extremely believable to me, and if that recording were available on a Direct-to-Disk LP and reproduced on an even better system, it would probably be even more so. However, playing a superb recording of Beethoven's Ninth Symphony on even the best systems available today, I think, is another matter.

I have heard solo instruments and voices sound incredibly convincing on my system, and it is far from being one of the best systems available today. So I think we have come a very long way to being able to reproduce some sounds. But, as we all have experienced, a live performance at Symphony Hall, simply can not be reproduced convincingly in the home. It may sound extremely good in the best settings, but few if any of us would ever be fooled into thinking we were listening to the real thing.

To start to discuss this topic, I think we would have to define what we are trying to reproduce? How complex is the music - a single piano note or a cappella performance , a jazz quartet, or a full symphony? Haven't we all turned around while watching a movie believing the phone was ringing? Is the reproduction somewhat believable, or are we being asked to identify "is it live or a recording" while blindfolded? The former would seem to have a higher percentage than the latter, surely.

Could an objectivist even attempt to measure such a thing? And if so, how close would he/she think that we are, in percentage terms, to reproducing a live musical event on the best audio systems available today, if we define more specifically the type of performance we are measuring?

Perhaps I will start another thread for this topic.
 
(...) To start to discuss this topic, I think we would have to define what we are trying to reproduce? (...)

Peter,

Jordi Savall can help you :

Existing only at the moment when it becomes materialized in the form of sound waves produced by the human voice or instruments, Music is the art of memory per excellence, and it is precisely this temporal constraint which makes it the most human and the most spiritual of the arts.


Quoted from the liner notes of "Du temps & de l'instant", an wonderful recording that proved me that a system can have a soul.
 
You can only to reproduce the file, vinyl, CD you have, there is nothing else.
Keith.

Yes, the recordings are limiting factors. But if recordings (mics, mastering, etc.) are getting better and better at capturing the original sounds, and the systems are getting better and better at capturing what is on the recording, how close is the combination of the recording and system getting to reproducing the original sounds?
 
Yes, the recordings are limiting factors. But if recordings (mics, mastering, etc.) are getting better and better at capturing the original sounds, and the systems are getting better and better at capturing what is on the recording, how close is the combination of the recording and system getting to reproducing the original sounds?

If the recording was a simple 2 mike recording, I do think you can get pretty close to reproducing what was picked up by the microphones, and that will be pretty close to what was heard when played over your better systems. That however is a different animal to saying the recording system is able to reproduce the original event. There are considerable limitations in sampling only two points in space then using the resulting recording to reproduce that sound field in another location.
 
Status
Not open for further replies.

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu