Cabling, testing, and sound quality

[markw]

http://www.apiguide.net/04actu/04musik/AES-cableInteractions.pdf

An interesting read.

markw,

As I said earlier, I would prefer to measure output and compare differences to known tested thresholds rather than measure nothing directly and ask people to tell me what they think they heard. Does anyone here disagree that human perception is of dubious accuracy? Specifically with a multi-varient metric?

Is it reasonable to assume that any difference above the threshold is potentially audible? I think it is. So, the "human" factor is considered by using hearing thresholds to determine if a difference is potential audible.

There is no "potentially" audiable. It either is, or ir isn't.

If you are dealing with measurements, you're not dealing with audiablity.

Shouldn't you be doing this in private?

 

[mojidooji]

There is no "potentially" audiable. It either is, or ir isn't.

What are you saying here? Every difference that can be perceived is perceived every time? People can be trained to hear differences they could not previously hear - prior to training, the difference is potentially audible; after training, it is actually audible.

http://www.tc.umn.edu/~cmicheyl/Micheyl_HearRes_Musicians_2006.pdf

If you are dealing with measurements, you're not dealing with audiablity.

The two are not mutually exclusive.

Shouldn't you be doing this in private?

Why the hostility? If you have something to add that is substantive, I welcome it, but so far you seem to be putting words into my mouth and then attacking them. Others are participating in this discussion and adding value - someone here is trolling, indeed.

 

[markw]

What are you saying here? Every difference that can be perceived is perceived every time? People can be trained to hear differences they could not previously hear - prior to training, the difference is potentially audible; after training, it is actually audible.

See? You don't need instruments to test this, do you? Thanks for making my point for me.

The two are not mutually exclusive.

Well, your previous paragraph sure give my statement more credence, didn't it?

Why the hostility? If you have something to add that is substantive, I welcome it, but so far you seem to be putting words into my mouth and then attacking them. Others are participating in this discussion and adding value - someone here is trolling, indeed.

No hostility here. I actually enjoy calling a spade a spade. If anything, you 're the one that seems to be putting words in my mouth. I relish brevity and clarity in my posts while you, OTOH, seem to use a surfeit of words to hide your obfuscation.

If you haven't picked up on it yet, those "others" are pointing out the ffallicy of your postulations. The act that you continue to press your issue simply reinforces my troll postulation

 

[mojidooji]

See? You don't need instruments to test this, do you? Thanks for making my point for me.

markw,

I'm not sure I understand your point. In this case, differences must be known to exist in order to train someone to detect them. Instrumentation is far more accurate and reliable than humans. So while instrumentation is not needed, a reference is; and instrumentation is a better reference because it is more accurate. There are also psychological and psychoacoustic considerations which make certain conditions in testing particularly unreliable and I think we can come up with a more accurate method. That's it.

If I'm wrong, I will find out at some point, but I'm not going to take your word for it. Like I said, if you have something substantive, please post it.

If you haven't picked up on it yet, those "others" are pointing out the ffallicy of your postulations.

Please tell me which fallacy I've committed. Are the "others" not real others? Is it one person? Why did you put that word in quotes?

 

[Pyrrho]

There is no "potentially" audiable. It either is, or ir isn't.

What are you saying here? Every difference that can be perceived is perceived every time? People can be trained to hear differences they could not previously hear - prior to training, the difference is potentially audible; after training, it is actually audible. ...

"Audible" means capable of being heard, not that it is always heard. So a difference is either audible or it isn't. Both before and after the training you mention, the thing in question, if actually heard ever, is audible.

If you are dealing with measurements, you're not dealing with audiablity.

The two are not mutually exclusive.


...

A measurement of a difference that is not audible is irrelevant. So if you measure a difference, whether it matters or not is a different issue from simply being able to measure the difference. To find out if something is audible, you either use people listening in carefully conducted double blind tests, or you compare the measurements you have taken with past tests of such things. You cannot find an audible difference without reference to people actually being tested to find out if they can hear that sort of thing or not.

If you compare wires, of normal lengths of the same gauge, you will typically find that you need very good equipment to be able to measure the differences that there will be in frequency response, etc., and the difference will be so slight that it will be less than the least variation ever demonstrated to be audible.

 

[mojidooji]

I think you're missing the point. Research similar to what I am proposing has already been done many times, so I am not attempting to reinvent the wheel, but neither am I seeking to defend the relevence of this research based on unreferenced (and unsubstantiated) claims. I will continue to monitor this thread, however, in case useful input is given.

So, I'd like to thank those who have contributed answers to my questions and especially to mtrycrafts: psychoacoustics is extremely relevent to this work.

 

[Alex2507]

... surfeit of words to hide your obfuscation.

Mark, I want you to stop using word I don't understand.

OP, although I'm not sure what your 'question' is exactly it seems to me like your answer may lie with Sean Olive. He has his own site on which he talks about a bunch of stuff that I don't get in the same way I don't get your question or purpose. My obfuscation is completely surfeit now. This is cosmic.

 

[mtrycrafts]

So, I'd like to thank those who have contributed answers to my questions and especially to mtrycrafts: psychoacoustics is extremely relevent to this work.

I didn't follow up as I am not sure if I totally understand what you are after.
A sufficient measuring methodology that would show audibility without actually testing for audibility?

Then you brought up several measuring types like FFT? I think it was mentioned that you may be looking for something more complicated than is actually needed.

Perhaps existing research into various parameters for audibility like a level JND, distortion JND, etc is what you are after? If so, measuring techniques for them already exists.

As to wire audibility, not many parameters of it is needed. It was brought up that resistance is a major indicator. A delta between the reference and the test wire/component can be established nicely.
Then, the application of wire/cable also matters. Speaker wire and interconnects have different parameters that would indicate a possible audibility factor. Interconnect application is affected by cable capacitance while speaker wire is not but and amp can be affected by cable capacitance by going into oscillation and self destructing but that is not what you are after, I am pretty sure.

Also, since psychoacousics is so important, would you be after the person who has the most sensitive detecting capability and that would be your reference data point while most all other subject would never come close to the reference? I ask because some JND studies, if not all good ones use special signals to detect the JND levels, not music or real signals that one would be listening to. This too would alter things.

 

[mojidooji]

mtrycrafts,

Thanks for your response. The way I'm looking at the problem has changed some now that I have read some of the earlier work on it, but the essence - investigating the boundary between JND and audible difference - has not changed.

My interest in TFFT is as a method to quantify the theoretical differences in component characteristics with respect to measurable differences in sound; but, this is just one way to potentially accomplish this. I am familiar with the arguments you make regarding cable characteristics' theoritical effects (or lack thereof) and would like to see some additional certainty on the subject. Again, with respect to audibility, as well.

While I am a cable minimalist (decent, short cables and stable connections), I am not closed to other's claims, some of which I have had some positive experimental results. I have not encountered theory that directly contradicts some of the claims, so this is another area where additional certainty would be helpful. Lastly, given some difference between a set of components, a simple method for comparison (even if no difference can be detected) would be handy, since several components in a chain beneath the audibility threshold, may constitute an audible difference. This can also put to rest (or verify) claims regarding "loading output stages", microphonics, and similar sorts of claims.

 

[highfigh]

mtrycrafts,

Thanks for your response. The way I'm looking at the problem has changed some now that I have read some of the earlier work on it, but the essence - investigating the boundary between JND and audible difference - has not changed.

My interest in TFFT is as a method to quantify the theoretical differences in component characteristics with respect to measurable differences in sound; but, this is just one way to potentially accomplish this. I am familiar with the arguments you make regarding cable characteristics' theoritical effects (or lack thereof) and would like to see some additional certainty on the subject. Again, with respect to audibility, as well.

While I am a cable minimalist (decent, short cables and stable connections), I am not closed to other's claims, some of which I have had some positive experimental results. I have not encountered theory that directly contradicts some of the claims, so this is another area where additional certainty would be helpful. Lastly, given some difference between a set of components, a simple method for comparison (even if no difference can be detected) would be handy, since several components in a chain beneath the audibility threshold, may constitute an audible difference. This can also put to rest (or verify) claims regarding "loading output stages", microphonics, and similar sorts of claims.

Check this out- it may save some time and effort-
http://www.eetimes.com/electronics-blogs/audio-designline-blog/4033511/Audio-Myths-Workshop-video

 

[mtrycrafts]

mtrycrafts,

Thanks for your response. The way I'm looking at the problem has changed some now that I have read some of the earlier work on it, but the essence - investigating the boundary between JND and audible difference - has not changed.

My interest in TFFT is as a method to quantify the theoretical differences in component characteristics with respect to measurable differences in sound; but, this is just one way to potentially accomplish this. I am familiar with the arguments you make regarding cable characteristics' theoritical effects (or lack thereof) and would like to see some additional certainty on the subject. Again, with respect to audibility, as well.

While I am a cable minimalist (decent, short cables and stable connections), I am not closed to other's claims, some of which I have had some positive experimental results. I have not encountered theory that directly contradicts some of the claims, so this is another area where additional certainty would be helpful. Lastly, given some difference between a set of components, a simple method for comparison (even if no difference can be detected) would be handy, since several components in a chain beneath the audibility threshold, may constitute an audible difference. This can also put to rest (or verify) claims regarding "loading output stages", microphonics, and similar sorts of claims.

Not sure if you are aware of Fred Davis's AES paper.
http://bruce.coppola.name/audio/cableInteractions.pdf

While it may not be perfect, it has some good info in it as to frequency responses of different cables he measured. He did not test for audibility between speaker cables.

Combining that data with known JNDs for at least amplitude level difference detection, one can start putting pieces together. But then, that is just a small part of the whole picture.

Another part is in this AES paper.
http://home.provide.net/~djcarlst/abx_crit.htm

The above paper shows that it gets even more difficult as the bandwidth of level differences also has an effect on detection. Is this level difference over 1/3 octave? Wider? Where in the frequency band is it? In the most sensitive region of detection, around 2kHz-4kHz? Below 80Hz? Above 10kHz?

I would recommend making contact with Sean Olive, mentioned elsewhere in this thread. Spent his career researching credible detection methods and protocols, etc.
http://seanolive.blogspot.com/

You are aware of Dr. Floyd Toole's works you mentioned and perhaps his book as well available through Amazon.

Not sure what else I can help you with. Contact some other credible researchers in the fields? You may need to do some original experimentation and publish in peer journals?

You also mentioned 'other's claims.' My first question to those claimants would be: how was the listening tests conducted? How credible was it? Can it be replicated? Claiming is one thing, demonstrating is another. Just be careful.

 

[chesbak]

Not sure if you are aware of Fred Davis's AES paper.
http://bruce.coppola.name/audio/cableInteractions.pdf

While it may not be perfect, it has some good info in it as to frequency responses of different cables he measured. He did not test for audibility between speaker cables.

Combining that data with known JNDs for at least amplitude level difference detection, one can start putting pieces together. But then, that is just a small part of the whole picture.

Another part is in this AES paper.
http://home.provide.net/~djcarlst/abx_crit.htm

The above paper shows that it gets even more difficult as the bandwidth of level differences also has an effect on detection. Is this level difference over 1/3 octave? Wider? Where in the frequency band is it? In the most sensitive region of detection, around 2kHz-4kHz? Below 80Hz? Above 10kHz?

I would recommend making contact with Sean Olive, mentioned elsewhere in this thread. Spent his career researching credible detection methods and protocols, etc.
http://seanolive.blogspot.com/

You are aware of Dr. Floyd Toole's works you mentioned and perhaps his book as well available through Amazon.

Not sure what else I can help you with. Contact some other credible researchers in the fields? You may need to do some original experimentation and publish in peer journals?

You also mentioned 'other's claims.' My first question to those claimants would be: how was the listening tests conducted? How credible was it? Can it be replicated? Claiming is one thing, demonstrating is another. Just be careful.

Wow... This topic is interesting... I started reading and couldn't stop... I just thought quality cables did the trick.... WOW....

 

[mtrycrafts]

Wow... This topic is interesting... I started reading and couldn't stop... I just thought quality cables did the trick.... WOW....

Glad you find it interesting. This barely scratches the surface though. You may also want to check out the helpful articles at the home page.