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Analysis of Paper on Measurements of RCA Cables by Kunchur (Video)

Date: Tue, 5 Nov 1996 13:08:50 -0500
From: [email protected] (Dunlavy Audio Labs)
To: [email protected] (bass group)
Subject: Cable Nonsense (Long)

Having read some of the recent comments on several of the Internet audio groups, concerning audible differences between interconnect and loudspeaker cables, I could not resist adding some thoughts about the subject as a concerned engineer possessing credible credentials.

To begin, several companies design and manufacture loudspeaker and interconnect cables which they proudly claim possess optimized electrical properties for the audiophile applications intended. However, accurate measurements of several popularly selling cables reveal significant differences that call into question the technical goals of their designer. These differences also question the capability of the companies to perform accurate measurements of important cable performance properties. For example, any company not possessing a precision C-L-R bridge, a Vector Impedance Meter, a Network Analyzer, a precision waveform and impulse generator, wideband precision oscilloscopes, etc., probably needs to purchase them if they are truly serious about designing audio cables that provide premium performance.

The measurable properties of loudspeaker cables that are important to their performance include characteristic impedance (series inductance and parallel capacitance per unit length), loss resistance (including additional resistance due to skin-effect losses versus frequency), dielectric losses versus frequency (loss tangent, etc.), velocity-of-propagation factor, overall loss versus frequency into different impedance loads, etc.

Measurable properties of interconnect cables include all of the above, with the addition of those properties of the dielectric material that contribute to microphonic noise in the presence of ambient vibration, noise, etc. (in combination with a D.C. off-set created by a pre-amp output circuit, etc.).

While competent cable manufacturers should be aware of these measurements and the need to make them during the design of their cables, the raw truth is that most do not! Proof of this can be found in the absurd buzzard-salve, snake-oil and meaningless advertising claims found in almost all magazine ads and product literature for audiophile cables. Perhaps worse, very few of the expensive, high-tech appearing cables we have measured appear to have been designed in accordance with the well-known laws and principles taught by proper physics and engineering disciplines. (Where are the costly Government Consumer Protection people who are supposed to protect innocent members of the public by identifying and policing questionable performance claims, misleading specifications, etc.?) --- Caveat Emptor!

For example, claiming that copper wire is directional, that slow-moving electrons create distortion as they haphazardly carry the signal along a wire, that cables store and release energy as signals propagate along them, that a final energy component (improperly labeled as Joules) is the measure of the tonality of cables, ad nauseum, are but a few of the non-entities used in advertisements to describe cable performance.

Another pet peeve of mine is the concept of a special configuration included with a loudspeaker cable which is advertised as being able to terminate the cable in a matter intended to deliver more accurate tonality, better imaging, lower noise, etc. The real truth is that this special configuration contains nothing more than a simple, inexpensive network intended to prevent poorly-designed amplifiers, with a too-high slew-rate (obtained at the expense of instability caused by too much inverse-feedback) from oscillating when connected to a loudspeaker through a low-loss, low-impedance cable. When this box appears at the loudspeaker-end of a cable, it seldom contains nothing more than a Zobel network, which is usually a series resistor-capacitor network, connector in parallel with the wires of the cable. If it is at the amplifier-end of the cable, it is probably either a parallel resistor-inductor network, connected in series with the cable conductors (or a simple cylindrical ferrite sleeve covering both conductors). But the proper place for such a network, if it is needed to insure amplifier stability and prevent high-frequency oscillations, is within the amplifier - not along the loudspeaker cable. Hmmm!

Having said all this, are there really any significant audible differences between most cables that can be consistently identified by experienced listeners? The answer is simple: very seldom! Those who claim otherwise do not fully grasp the power of the old Placebo-Effect - which is very alive and well among even the most well-intentioned listeners. The placebo-effect renders audible signatures easy to detect and describe - if the listener knows which cable is being heard. But, take away this knowledge during blind or double-blind listening comparisons and the differences either disappear completely or hover close to the level of random guessing. Speaking as a competent professional engineer, designer and manufacturer, nothing would please me and my company's staff more than being able to design a cable which consistently yielded a positive score during blind listening comparisons against other cables. But it only rarely happens - if we wish to be honest!

Oh yes, we have heard of golden-eared audiophiles who claim to be able to consistently identify huge, audible differences between cables. But when these experts have visited our facility and were put to the test under carefully-controlled conditions, they invariably failed to yield a score any better than chance. For example, when led to believe that three popular cables were being compared, varying in size from a high-quality 12 AWG ZIP-CORD to a high-tech looking cable with a diameter exceeding an inch, the largest and sexiest looking cable always scored best - even though the CABLES WERE NEVER CHANGED and they listened to the ZIP Cord the entire time.

Sorry, but I do not buy the claims of those who say they can always audibly identify differences between cables, even when the comparisons are properly controlled to ensure that the identity of the cable being heard is not known by the listener. We have accomplished too many true blind comparisons with listeners possessing the right credentials, including impeccable hearing attributes, to know that real, audible differences seldom exist - if the comparisons are properly implemented to eliminate other causes such as system interactions with cables, etc.

Indeed, during these comparisons (without changing cables), some listeners were able to describe in great detail the big differences they thought they heard in bass, high-end detail, etc. (Of course, the participants were never told the NAUGHTY TRUTH, lest they become an enemy for life!)

So why does a reputable company like DAL engage in the design and manufacture of audiophile cables? The answer is simple: since significant measurable differences do exist and because well-known and understood transmission line theory defines optimum relationships between such parameters as cable impedance and the impedance of the load (loudspeaker), the capacitance of an interconnect and the input impedance of the following stage, why not design cables that at least satisfy what theory has to teach? And, since transmission line theory is universally applied, quite successfully, in the design of cables intended for TV, microwave, telephone, and other critical applications requiring peak performance, etc., why not use it in designing cables intended for critical audiophile applications? Hmmm! To say, as some do, that there are factors involved that competent engineers and scientists have yet to identify is utter nonsense and a cover-up for what should be called pure snake oil and buzzard salve - in short, pure fraud. If any cable manufacturer, writer, technician, etc. can identify such an audible design parameter that cannot be measured using available lab equipment or be described by known theory, I can guarantee a nomination for a Nobel Prize.

Anyway, I just had to share some of my favorite Hmmm's, regarding cable myths and seemingly fraudulent claims, with audiophiles on the net who may lack the technical expertise to separate fact from fiction with regard to cable performance. I also welcome comments from those who may have other opinions or who may know of something I might have missed or misunderstood regarding cable design, theory or secret criteria used by competitors to achieve performance that cannot be measured or identified by conventional means. Lets all try to get to the bottom of this mess by open, informed and objective inquiry.

I sincerely believe the time has come for concerned audiophiles, true engineers, competent physicists, academics, mag editors, etc. to take a firm stand regarding much of this disturbing new trend in the blatantly false claims frequently found in cable advertising. If we fail to do so, reputable designers, engineers, manufacturers, magazine editors and product reviewers may find their reputation tarnished beyond repair among those of the audiophile community we are supposed to serve.

Best regards,
John Dunlavy

Source http://verber.com/mark/ce/cables.html

RIP John.
 
"Humans are uncomfortable with uncertainty and the unknown, and yearn for explanations and understanding. This is what drives scientific research. Unfortunately, instead of pursuing the tedious route of formal science, some people join the cult of a self proclaimed guru. An interesting case study of this gullibility is provided by the Youtube channel Audio Science Review hosted by Mr. Amir Majidimehr, in particular his video “Scientific Proof of Measurable Difference in Audio Cables? Paper Review” about some papers written by me. Based on an entertaining cocktail of circular reasoning, irrelevant measurements, and plain dishonesty, Mr. Majidimehr has cultivated some loyal followers who are unable or unwilling to digest original sources of scientific information1 , and are indifferent to their cult leader’s qualifications, or lack thereof. From Mr. Majidimehr’s own LinkedIn page and Google scholar record, he has zero journal publications and has never been invited to speak at international conferences on audio. Yet we have a “critical assessment” of journal papers from someone who never published a single research paper himself! Mr. Majidimehr has no clue about how scientific research works. He does not know the difference between correlation and causation. This cult leader is stuck in a twilight zone of limited and faulty knowledge."

I'm sure the late John Dunlavy would be a loyal follower of Amir if he was still around ;);) ;)

Having read some of the recent comments on several of the Internet audio groups, concerning audible differences between interconnect and loudspeaker cables, I could not resist adding some thoughts about the subject as a concerned engineer possessing credible credentials.

CURRICULUM VITAE OF The LATE JOHN DUNLAVY
January 1998


 
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I am wondering if by any chance we can get Milind N. Kunchur, Ph.D., APS Fellow Governor's Distinguished Professor, Michael J. Mungo Distinguished Professor CASE & Carnegie Foundation, South Carolina Professor of the Year, to test Ted Denneys dots?


If he wants to go after someone then go after TED
 
Maybe he can do a paper on the sound of fuses. Blue vs the Orange fuse ;)
 
My cables sound best when I turn my system on.
But just think how black the blacks would be if it was not switched on and the cables were operating at their best ;)
 
Well I hate to say this but you can measure cables. Mine are all 4 metres long.
 
LOL I especially cracked up when Brisson said he wanted to use his "lab" to disprove the cable charlatans like himself. He's one of the worst. (ps and guess he never got around to it, that was 22 years ago)
I knew Lipnick when he was customer of the HiFi store I worked 73-75 time frame. He was, shall we say, interesting, even way back then.
 
Hate to admit I was also into cables. Had a nice set of Kimber. Nice, saying, as they do look nice too. The select parts... In the end, I sold all my expensive cables, as I've been reading more and more and just accepting I got fooled. I also gotten a 48V unit from AudioQuest, what was I thinking... AQ are the biggest of them all. Worst part, they didn't even look cool. If it included a transformer to up the voltage in a exposed braided cable to make sure rats didn't eat the cable, it would've been worthwhile, haha. Maybe this is a business opportunity? (If you do so, let me know, Ill pitch in to claim some money and will think about beautiful marketing statements)

What I do like about expensive cables, is that they often really look good :D. I had some beautiful silver Phy-HP's :D, haha. I had to take them into the weekly cleaning cycle because they corroded like mad. But it gave me pleasure to look at.

Right now, I have studio-grade Mogami cable. Yes they are a little bit more expensive, but they do look cool, and are studio standards. I added WBT.. because they look cool and sit well on the speakers. Nothing less, nothing more :) Super super non sciency subjective, haha.

I'm thankful for Amir and everyone on this site that makes this happen.
 
All this debacle is basically due to some people believing that electricity is very hard to conduct, thetefore cables must be ultra magical to do that well.

Plot twist: it is actually easy to conduct and copper does a wonderful job.
 
which is why he says phase integrity is so important we should all be rushing out to buy Wilson Audio Chronosonics
Because nothing says true accuracy in the time domain like having an entire bucket brigade of drivers slathered in layers of felt to handle the audio spectrum. If anything, its a testament to how accommodating the auditory center is to imperfections.
 
which is why he says phase integrity is so important we should all be rushing out to buy Wilson Audio Chronosonics

Come to think of it, they are ugly toys for Adults:

WAMM v. MEGO.png


Maybe some people like them, but I could never see sitting in front of something like that for hours at a time. As far as the 2-XL, I don't recall having that older one here in the states, but I do remember the one from Tiger. I think the part that made toys like that actually fun was using them for everything other than their intended purpose. Kind of like how I used to use my Teddy Ruxpin to play Pink Floyd tapes when I was a kid. Still have fond memories of watching him sing along to Dark Side of the Moon. But anyway, I do digress.:)
 
Kind of like how I used to use my Teddy Ruxpin to play Pink Floyd tapes when I was a kid. Still have fond memories of watching him sing along to Dark Side of the Moon. But anyway, I do digress.:)
Haha, I do know Teddy Ruxpin, but never heard of the thing you mentioned. I did watch the cartoons. I was 4 or 5... I also listened to Pink floyd on my dad's headphones (I think it was an old Philips... It was amazing)
 
As someone who has both written and reviewed many scientific papers I can tell you that those papers should never had survived the review process. Also, when Jay of Jay’s Iaygi says that he has a background that allows him to comment on the paper, it is clear he is fooling himself and others. Peer review does not guarantee high quality.
 
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