Have these articles been discussed previously?

[Chuck]

This article appeared in the JAES so one assumes that it was properly peer reviewed before publication.

http://bruce.coppola.name/audio/cableInteractions.pdf

The second piece takes a more negative view, but is consistent with the above (note the magnitude of the differences measured in the first paper).

http://bruce.coppola.name/audio/TenAudioLies.pdf

Since both are PDF files it may be easier to download them and read them off-line.

[mtrycraft]

This article appeared in the JAES so one assumes that it was properly peer reviewed before publication.

http://bruce.coppola.name/audio/cableInteractions.pdf

The second piece takes a more negative view, but is consistent with the above (note the magnitude of the differences measured in the first paper).

http://bruce.coppola.name/audio/TenAudioLies.pdf

Since both are PDF files it may be easier to download them and read them off-line.

I do cite the Davis paper when called for. Yes, it is a Journal paper, not a conference paper and was peer reviewed. A great find on line. I am not sure it is leagl though.

The second is cited by others from time to time but now you found that on line as well.

[Chuck]

I do cite the Davis paper when called for. Yes, it is a Journal paper, not a conference paper and was peer reviewed. A great find on line. I am not sure it is leagl though.

The second is cited by others from time to time but now you found that on line as well.

I can't take credit for either find. Both came from GDS.

[pctower]

I can't take credit for either find. Both came from GDS.

Unfortunately, about the only discussion that will occur on this board is cheerleading, as both articles are really just preaching to choir here.

Too bad there isn't a place they could be critically reviewed by knowledgeable people who don't have a particular agenda to advance.

I'm not technically qualified to discuss either article. However, the second one seems to just be a collection of broad generalizations in the form of absolute pronouncements which I don't find particularly helpful. All one needs to do is go over to AA and easily find someone who can shout just as loud in the opposite direction.

I subscribed to Audio Critic back in the days with Mr. Aczel was an unabashed subjectivist. In fact, I followed his suggestion on a turntable and arm and was very satisfied with the result. However, as I recall, it was later discovered that he was favorably reviewing a speaker that he had an undisclosed business interest in.

He shut down Audio Critic, and went into producing speakers full time. As I recall there were still several issues remaining on my subscription for which I never received a refund.

At some point, God paid him a visit and he was magically transformed into his current objective manisfestation.

The foregoing is just my personal opinion and and vague historical recollection, which could be flawed.

BTW, on the first article, as I understand it he did not test complex waveforms and possible distortion, including temporal distortion. Am I correct and do you think such tests should be performed?

[Pat D]

Unfortunately, about the only discussion that will occur on this board is cheerleading, as both articles are really just preaching to choir here.

Too bad there isn't a place they could be critically reviewed by knowledgeable people who don't have a particular agenda to advance.

Can you produce anything better? Didn't think so.

[pctower]

Can you produce anything better? Didn't think so.

Yeah, like I observed over at Prophead recently, this is all about tribes. It just depends on whether you want to hang out in naysayer territory or yeasayer territory. In either case, the objective of the tribe you choose to hang with is to destroy the other tribe.

If you want to delude yourself that this board is a place where there is a good exchange of opposing views and information based on a desire for the truth, and where all claims and "evidence" is subjected to critical analysis, then be my guest.

[mtrycraft]

Too bad there isn't a place they could be critically reviewed by knowledgeable people who don't have a particular agenda to advance.

Well, Davis had a critical review before publishing in a Journal.

However, the second one seems to just be a collection of broad generalizations in the form of absolute pronouncements which I don't find particularly helpful. All one needs to do is go over to AA and easily find someone who can shout just as loud in the opposite direction.


Yes, they can shout without evidence. Peter and Dr.David Rich, his technical person at TAC has been doing DBT from the day he saw the light. That is what converted him, not God.[/b]

At some point, God paid him a visit and he was magically transformed into his current objective manisfestation.

Actuall, it was sanity, reality that transformed him.

.

BTW, on the first article, as I understand it he did not test complex waveforms and possible distortion, including temporal distortion. Am I correct and do you think such tests should be performed?



You think wires will react to complex waveforms differently? I'd like to see the evidence for that. Same for temporal distortion that jneutron is so fond of. Skin effect delays some of the frequency arrival times, in the nano second timescale:
"Amplifier-Loudspeaker Interfacing", Greiner, R.A., JAES vol. 28, no. 5 May 80,
I think he is confusing the ability to spacially locate sound sources that require the same frequency to arrive at the left and right ear at different times and shift in the frequency itself in the same cable. Having two cables in the left and right channel would delay the frequency equally in each cable hence no time difference between the two channels, unless you have 1000s of feet of wire differencesin one channel. But, hey, I have no idea.

If you followed Steve Eddy's wire distortion reports and discussions, there is no measured distortion from wire. Signal complexity in the audio band will not change that.

[pctower]

[QUOTE=mtrycraft]Well, Davis had a critical review before publishing in a Journal.

So why did Chuck ask for discussion if there is absolutely nothing to question?

I've got a serious question for you. Do you universally accept as reliable any test where the results confirm your beliefs? Do you see any value in questioning test results that seem to confirm mainstream beliefs? If your answer to is no to the first question and yes to the second one, I must say that you have never as far as I'm aware demonstrated any behvior on this board that would be consistent with such an answer.

While we are at it, do you claim to be objective on the subject of cables?

[You think wires will react to complex waveforms differently? I'd like to see the evidence for that. Same for temporal distortion that jneutron is so fond of. Skin effect delays some of the frequency arrival times, in the nano second timescale:

How would I know. Chuck asked for some discussion.

[E-Stat]

You think wires will react to complex waveforms differently? I'd like to see the evidence for that.

You've got that bass ackwards. Perhaps you listen to test tones, but I think it is fair to say that most folks enjoy listening to music (aka complex waveforms). It is your camp that begins with the assumption that there will be no difference with tests on simplistic wave forms vs. that which is used in the real world.

The burden of proof is yours to substantiate that assumption. History is not on your side as the value of the time domain has been proven over and over again. Do you recall how worthless THD measurements were rendered once TIM was established? Do you recall how worthless most specifications were on the "perfect sound forever" digital players prior to the understanding of jitter?

rw

[jneutron]

You think wires will react to complex waveforms differently? I'd like to see the evidence for that. Same for temporal distortion that jneutron is so fond of. Skin effect delays some of the frequency arrival times, in the nano second timescale:

yes, I would also like to see evidence for that..I certainly have none at this time..

Skin effect on sines is in the 250nSec regime, from what I recall..not what I hypothesize.
What I am hypothesizing is the change in energy storage, not something as simple as group delays..

Where that stands now? Glad you asked..

I am wrestling with my model, and how it stands w/r to superposition. As in, does my model break down in regard to multiple signals each at different skin values...can the resultant be equally described by the sum of the signals, or does my slew rate model break down...still lots of work to do before I can really test it..

Cheers, John

[Chuck]

BTW, on the first article, as I understand it he did not test complex waveforms and possible distortion, including temporal distortion. Am I correct and do you think such tests should be performed?

The author makes the assertion that the electrical characteristics of the wire, amp, and loudspeaker, will determine the ultimate performance, and then proceeds to measure the electrical characteristics, along with their effects on the performance. If the assertion is true, then his measurements are sufficient. As a result I think your question is actually aimed at his assertion rather than his measurements. Aren't you really asking if there isn't more to cables than just the electrical parameters?

Certainly there are many alternate ways to measure just about anything, and it only makes sense to use the appropriate tool for the job. If we had reason to believe that commonly used speaker wire configurations are distorting the signal in some way not revealed by conventional static measurements then it would make since to investigate further. It is rare to see anything in the complex transfer function of a circuit that isn't predicted by the electrical parameters. When it does happen it just means that we've overlooked some parameter. If you're asking if I'd have done things differently, the answer is a resounding YES. After going to all the trouble to set up the equipment for the test I'd certainly have run and recorded MLS tests for later analysis, and I'd have measured the complex transfer function of every wire/speaker/amp combination. I would not, however, expect any of these tests to show anything that wasn't indicated by relevant electrical parameters. In other words, I think electricity obeys the laws of physics. We sometimes overlook factors in our circuit analysis, so I tend to over-do my own measurements. The author is probably much smarter than myself in this respect.

Phil, did you notice that none of his measurements showed as much as a full dB of loss at 20k, and never enough phase (temporal) shift to be suspect? Do you know of anyone, other than me, who has measured a wire induced anomaly greater in magnitude than what is presented in this JAES paper? I've measured 2dB at 14k, but can you point to ANY other tests of ANY kind that that show greater problems in typical wire configurations? I'm not aware of any, so if they exist I'd appreciate a few links.

What exactly do you think the author (and the AES peer review) overlooked?

[pctower]

The author makes the assertion that the electrical characteristics of the wire, amp, and loudspeaker, will determine the ultimate performance, and then proceeds to measure the electrical characteristics, along with their effects on the performance. If the assertion is true, then his measurements are sufficient. As a result I think your question is actually aimed at his assertion rather than his measurements. Aren't you really asking if there isn't more to cables than just the electrical parameters?

Certainly there are many alternate ways to measure just about anything, and it only makes sense to use the appropriate tool for the job. If we had reason to believe that commonly used speaker wire configurations are distorting the signal in some way not revealed by conventional static measurements then it would make since to investigate further. It is rare to see anything in the complex transfer function of a circuit that isn't predicted by the electrical parameters. When it does happen it just means that we've overlooked some parameter. If you're asking if I'd have done things differently, the answer is a resounding YES. After going to all the trouble to set up the equipment for the test I'd certainly have run and recorded MLS tests for later analysis, and I'd have measured the complex transfer function of every wire/speaker/amp combination. I would not, however, expect any of these tests to show anything that wasn't indicated by relevant electrical parameters. In other words, I think electricity obeys the laws of physics. We sometimes overlook factors in our circuit analysis, so I tend to over-do my own measurements. The author is probably much smarter than myself in this respect.

Phil, did you notice that none of his measurements showed as much as a full dB of loss at 20k, and never enough phase (temporal) shift to be suspect? Do you know of anyone, other than me, who has measured a wire induced anomaly greater in magnitude than what is presented in this JAES paper? I've measured 2dB at 14k, but can you point to ANY other tests of ANY kind that that show greater problems in typical wire configurations? I'm not aware of any, so if they exist I'd appreciate a few links.

What exactly do you think the author (and the AES peer review) overlooked?

No Chuck, I'm asking exactly what I asked and I didn't mention his assertion. Again, I'm asking whether conducting a test under similar conditions, but measuring distortion characteristics of the waveform, including temporal distortion, could possibly have yeilded different results? Stated another way, is it possible to extrapolate from his tests that measurement of waveform distortion would show nothing of use that was not shown in his test? I think what you are saying is that there is no need to measure waveform distortion. Somehow, though, that doesn't make intuitive sense to me.

What do I think they overlooked? Possibly waveform distortion. That's why I asked the question. Why do you have to turn that question into something it is not. That's a Jon Risch trick, who would far rather discuss naysayers and yeasayers than technical issues..

[mtrycraft]

I've measured 2dB at 14k, but can you point to ANY other tests of ANY kind that that show greater problems in typical wire configurations? I'm not aware of any, so if they exist I'd appreciate a few links.

But it is not a mystery why this happened, right? The speaker load at that frequency is 1/2 ohm, close to the wire impedance there, no? Close enough to give this drop. And, this is just what physics would predict when you have similar loads, power will be similarly divided.

[skeptic]

I must say I was quite disappointed with both articles. The first article treated speaker wires mathematically as the lump sum parameter equivalents of distributed parameter linear filter networks. As I have said all along, if this is the best case that cable advocates can make then they have no case at all. ALL linear (frequency response) distortion due to inductance, capacitance, and resistance of the cable interacting with the speaker and amplifer can be compensated for by adding complimentary filters at any signal level but preferably at the preamp level using an adjustable equalizer is by far the best because it can be infinitely adaped to any situation. Because the degree of filter effect of any wire will not only depend on the nature of the wire but its length and the complex impedences of both the amplifier output stage and the loudspeaker it is connected to, unless you are an engineer, it is impossible to predict in advance how the cable will affect the sound and if it has any audible effect at all, what creates an improvement (meaning flatter overall frequency response) in one system may cause a deterioration in another. There were NO DBTs to back up the conclusions, no control using duplicate setups with filters simulating wires, no complex waveform analysis and absolutely no discussion of non linear distortion. We heard much of nonlinear distortion without evidence form people like Jon Risch here (digital jitter and insulation induced memory) and John Curl at CA (Fermi velocity and the difference of -120db versus -135db seventh harmonic distortion of a 5 khz waveform.) There are as many others as there are cables for sale.

The second article was all about well known myths that audiophiles love to to use to challenge electrical engineering facts. About the only thing there to take issue with is number 10 as it is obvious that the level of auditory accuity varies from individual to individual, mostly the self appointed "golden eared" audiophiles having poorer auditory accuity having exposed themselves to loud rock and roll at live concerts and with their very loud sound systems at home and in their cars. In fact, like most other senses, you can be trained (usually fairly easily) to become more discriminating to the differences of different sensations you experience which you would otherwise overlook so you can become more attuned to auditory differences but this is a matter of mental concintration than of more accute sense organ sensitivity.

[Chuck]

Skeptic, I'm sorry to hear that you were so disappointed, but as we can see in the responses above, the articles actually generated some lively discussion. It's interesting that for once (is it the first time ever?) you and PCTower agree on something. Neither of you liked the articles very much.

[skeptic]

Skeptic, I'm sorry to hear that you were so disappointed, but as we can see in the responses above, the articles actually generated some lively discussion. It's interesting that for once (is it the first time ever?) you and PCTower agree on something. Neither of you liked the articles very much.

I was disappointed because these articles are so old as to be trite already. I expect more from JAES than the umpteenth rehash of old well worn ideas. Yes every electrical engineer knows all about LCR networks, distributed parameter models of wire and their lumped sum equivalents, how to analyze them and has made up his mind a long time ago one way or another whether a few tenths of a db difference at 20khz can make an audible difference, and whether it's worth hundreds of dollars to get it. It seemed like the writer was looking for something to publish with his name on it. Anything to publish with his name on it. It's high time that at a professional level, the debate moves much further along and delves much deeper if someone wishes to engage it at that level.

As for the second article, it was a consumer directed article which also rehashed old ideas for the umteenth time. And while it may come as a surprise to many newcomers that anyone would challenge the prevailing notions among audiophiles that tubes are better than transistors, vinyl phonograph records are better than cds, audiophile wire is important, and the sales people who have capitalized on these notions to the point where they will sell $500 worth of cables to someone who is buying a $1000 HT system, these issues were resolved a long time ago also by electrical engineers and audio engineers who buy and use this kind of equipment for a living and where cost often is less of a consideration than performance. And while engineers also like to get nostalgic and revisit the masterpieces of yesteryear, they have no doubts about what they have to buy or use when it comes to competing in the real world. Yes a 1963 Corvette will outperform a 2003 Toyota Corolla but not a 2003 Corvette. Technology does move forward, like it or not.

[Pat D]

I was disappointed because these articles are so old as to be trite already. I expect more from JAES than the umpteenth rehash of old well worn ideas. Yes every electrical engineer knows all about LCR networks, distributed parameter models of wire and their lumped sum equivalents, how to analyze them and has made up his mind a long time ago one way or another whether a few tenths of a db difference at 20khz can make an audible difference, and whether it's worth hundreds of dollars to get it. It seemed like the writer was looking for something to publish with his name on it. Anything to publish with his name on it. It's high time that at a professional level, the debate moves much further along and delves much deeper if someone wishes to engage it at that level.

As for the second article, it was a consumer directed article which also rehashed old ideas for the umteenth time. And while it may come as a surprise to many newcomers that anyone would challenge the prevailing notions among audiophiles that tubes are better than transistors, vinyl phonograph records are better than cds, audiophile wire is important, and the sales people who have capitalized on these notions to the point where they will sell $500 worth of cables to someone who is buying a $1000 HT system, these issues were resolved a long time ago also by electrical engineers and audio engineers who buy and use this kind of equipment for a living and where cost often is less of a consideration than performance. And while engineers also like to get nostalgic and revisit the masterpieces of yesteryear, they have no doubts about what they have to buy or use when it comes to competing in the real world. Yes a 1963 Corvette will outperform a 2003 Toyota Corolla but not a 2003 Corvette. Technology does move forward, like it or not.

Well, I find it strange that you would put Fred E. Davis in the cable camp! His conclusions do not support that. He does point out that 12 AWG wire performs very well, well enough.

I also see nothing in Peter Aczel's article which denies the efficacy of training. The Audio Critic is a consumer magazine so it is appropriate that it counterbalance some of the audio misinformation which abounds in many other magazines.

[skeptic]

Well, I find it strange that you would put Fred E. Davis in the cable camp! His conclusions do not support that. He does point out that 12 AWG wire performs very well, well enough.

I also see nothing in Peter Aczel's article which denies the efficacy of training. The Audio Critic is a consumer magazine so it is appropriate that it counterbalance some of the audio misinformation which abounds in many other magazines.

What I said about the first article is that it retraces old ground that has been trod into a ditch already. At that level, I expect something new but this guy was much to lazy or ill equipped to offer it. He did not offer one technical fact that any electrical engineer already doesn't know except for the measurements of specific wire. It's about time the engineering pros take a much harder and in depth look at the whole question meaning accuracy of reproduction of real waveforms using computerized analysis seeking non linear distortions and DBTs to back up their findings. In 1984 this might have been a little new. In 2004 it's kindergarten.

I'm not quite so critical of the consumer article in that it merely rehashes what the overwhelming majority of electrical engineers and professional audio engineers know and agree with. I suppose it is useful to reprint these once in a while even though most beginners will take their cues from audiophiles who don't believe a word of it and they of course will scoff at all of it. However, we've been there, done that a million times too so it's rather boring to read it again.

[pctower]

Skeptic, I'm sorry to hear that you were so disappointed, but as we can see in the responses above, the articles actually generated some lively discussion. It's interesting that for once (is it the first time ever?) you and PCTower agree on something. Neither of you liked the articles very much.

Chuck - please stop putting words in my mouth. I thought the first article was good. I just questioned whether more work needed to be done. Is that an inappropriate question in engineering or science circles? If it is, I can't imagine how science ever progresses.

As to the second article, you are correct that I didn't particularly care for it, but I stated specific reasons - primarily that it seemed to contain a number of unqualified pronouncements backed up with little empirical or reasoned support. I also shared my recollection of the author's history.

[Chuck]

Chuck - please stop putting words in my mouth.

My take is that you are grossly over-reacting in a highly emotional and illogical way, and I have no interest in that type of discussion. As a result I've asked Chris (our moderator) to comment, and until I see some change I intend to try to improve your comfort level by adding you to my blocked-posters list. Perhaps you could do me the courtesy of doing the same?

We can easily unblock at some time in the future if there is any reason to believe that we can have an enjoyable conversation without you getting upset over something that doesn't amount to a hill of beans. In the interest of peace and harmony on the forum let's both do Chris a favor and ignore each other.

Thanks.

[pctower]

My take is that you are grossly over-reacting in a highly emotional and illogical way, and I have no interest in that type of discussion. As a result I've asked Chris (our moderator) to comment, and until I see some change I intend to try to improve your comfort level by adding you to my blocked-posters list. Perhaps you could do me the courtesy of doing the same?

We can easily unblock at some time in the future if there is any reason to believe that we can have an enjoyable conversation without you getting upset over something that doesn't amount to a hill of beans. In the interest of peace and harmony on the forum let's both do Chris a favor and ignore each other.

Thanks.

Presumably you won't even see this, but I have no interest in blocking anyone, including you; nor do I have any interest in "wining" back unblocked status from anyone, including you.

You can run crying to the moderator if you want, but you must have very thin skin indeed.

[mtrycraft]

unless you are an engineer, it is impossible to predict in advance how the cable will affect the sound and if it has any audible effect at all, what creates an improvement (meaning flatter overall frequency response) in one system may cause a deterioration in another.

Now that I reviewed that paper fot the umpteenth time, Davis did plot two system reactions to cable, amp and speaker together and separately. Figures 9 &10 is one speaker load, fig 11 is another. About .4dB difference between the best cable of the 12 and the worst at 20kHz foe speaker A and .2dB for speaker B, although he used only 4 cables there. Hardly needs further speculations there.
Similar for the amp, fig 12.
Figs 13-17 measured total system response. .75dB or less at 20kHz.





There were NO DBTs to back up the conclusions,

This was not a listening evaluation.

But to date, we know what the DBT results have been. Rather dissapointing.

[Chuck]

Off topic, but possibly relevant to some, the "blocking" function of our forum is pretty cool. All you have to do is access a users profile and elect to have their messages blocked. Their names still show up when they post, but even if you accidentally click on one of their posts, the message text is not displayed. Gives one an easy way to avoid reading the drivel from people who they find offensive or undesirable and if used liberally it just might make this forum an even more enjoyable place to visit.

Overall I like the new format and options.