AudioQuest Headquarters Tour

The Southern California headquarters of cable manufacturer AudioQuest, which includes their offices, a listening room, conference rooms, a very very large warehouse, assembly rooms, a graphic design room, a few kitchens and various and sundry other more mundane but just as important places, is within a few-minutes’ drive from T.H.E. Show at Newport Beach. Shane Buettner, AudioQuest's Director of Education who you will most likely recognize as the former Editor-In-Chief of Home Theater magazine, Joe Harley VP of AudioQuest (Joe Harley is also a recording engineer/producer responsible for among others the Blue Note 45rpm reissues from Music Matters and he's a musician), and Andrew Kissinger, Regional Sales Manager, gave a group of A/V journalists, including Tom Norton, Senior Editor and Video Technical Editor of Home Theater magazine, the full tour.

My comments on the tour/AudioQuest facility can be summed up by saying that this is one of the most organized, clean, neat and tidy places I've ever seen. And it's not the kind of organized, clean, neat and tidy you can fake for a tour. From the huge warehouse to the tiniest Ziplock baggy, everything had its place and label. Impressive.

We also partook of a few demonstrations that are meant to highlight the differences cables can make and I'll give you an overview of what we heard. I'm not going to get into describing sonic minutiae since a) it's my belief that you really need to experience this kind of thing for yourself, and b) those who believe cables do not and can not make a difference won't believe a word I have to say so I'm not going to waste my time gilding a dead lily. To get right down to it, the Emperor does in fact have clothes; you cable deniers just have dirty minds.

The first demo involved a simple setup and premise: one inexpensive micro-component system, different speaker cables—stock and AudioQuest—connected to each speaker and a balance control. As you listen you or someone else switches from one speaker/cable to the other using the balance control. And back again as many times as you'd like. It took one swap to hear a difference and few more to hear it again and again since it was not subtle—the AudioQuest speaker cable improved the presentation and the most obvious change can be described as lending the music a more natural voice. Or if you prefer, the micro system simply sounded better with the AudioQuest cable.

The next demo, and you'll notice that AudioQuest had cleverly setup these demos in order of least controversial on up, involved a B&W Zeppelin boombox and two power cords—stock and AudioQuest. Listen, swap, listen. You could also keep your eyes closed for this one, I didn't, but the improvement in sound quality was easily and readily apparent after the first swap. I'd characterize the most obvious improvement as a less constricted presentation—the sound was no longer tied so tightly to the box.

Next up was the new favorite bugaboo on the block—the HDMI audio cable. Yes, we're going there. One modest system, two HDMI cables—stock and AudioQuest. Listen, swap, listen. Blind or not your choice but I preferred to watch everyone's reaction, which was the same as mine—wow! The difference was not subtle and can be summed up as a lack of compression when the music was played using the AudioQuest HDMI cable as compared to the stock piece of crap. The change in the quality of the vocals stood out so much that it enhanced the emotional impact of the song.

Lastly, we moved to the big rig: Rockport Aquila loudspeakers, Ayre MX-R monoblocks, Ayre KX-R preamp, Ayre DX5 Universal A/V Engine, AudioQuest Oak speaker cables, Wild and William E. Low Signature interconnect and power cords. It's worth noting that the previous demos were intentionally set-up on moderate to damned-cheap gear to illustrate, in addition to the basic premise that cables do in fact make a difference, that you don't need to have fancy-assed audiophile stuff in order for cables to make a difference. This time we listened to HDMI audio cable's more popular cousin—the USB cable.

Listen, swap, listen. Shane swapped the USB cables from the external 2TB hard drive to the Mac mini and from that to the Ayre player from stock to AudioQuest and back again. He also introduced a few levels of AudioQuest USB cables—the Carbon, Cinnamon DBS, and the Diamond, as well as adding and taking away AudioQuest Q Feet isolation devices under the external hard drive and Mac mini. In each and every case, the improvement when moving up the USB cable line or adding isolation to things that spin was readily apparent to everyone. In fact swapping just one stock USB cable for an AudioQuest Carbon improved the sound quality to such an extent as to render the music more engrossing. More groovy, if you will, as if the band had just hired a better bass player or drummer or both and the lead singer had removed his scarf from covering the microphone.

(A Free AudioQuest Tip: If your external hard drive offers both Firewire and USB, you can improve the sound quality of your computer-based playback by using Firewire from your hard drive to your computer and USB from your computer to your DAC.)

Of course this wasn't a science experiment and I readily admit that all kinds of things could have influenced what I heard, especially the most obvious one which is that cables, even HDMI audio and USB, can make a difference in sound quality. If you remain skeptical, and some skeptics always do no matter what, I'd suggest that AudioQuest set up a series of demos for each and every cables-don't-matter skeptic. They could easily bus them in from nearby John Wayne Airport, let them listen for themselves and then put them back on the bus and drive them into the middle of the desert and leave them there to fend for themselves. At least that's what I'd do.

I don't know about you, but I was shocked to see the size of the AudioQuest warehouse. Shocked to discover that so many people buy so many cables. I had never given this matter much thought. But with fan blades larger than any helicopter, even one former-Governor Arnold would use in his next action flick Predator III, the Housekeeper, hanging over your head and row after row after row of cables stacked up to the ceiling, you have to accept the fact that cables make a difference to a lot of people.

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Comments
Mattias Alm's picture
"Listening tests"

Michael Lavorgna wrote: "Of course this wasn't a science experiment and I readily admit that all kinds of things could have influenced what I heard, especially the most obvious one which is that cables, even HDMI audio and USB, can make a difference in sound quality. If you remain skeptical, and some skeptics always do no matter what, I'd suggest that AudioQuest set up a series of demos for each and every cables-don't-matter skeptic."

One controlled blind test would suffice, thank you very much.

Best regards,
Mattias Alm

John Atkinson's picture
Re: "Listening Tests"

Quote:
One controlled blind test would suffice, thank you very much.

Michael Fremer and I independently took part in a blind test organized by a Wall Street Journal editor at a CES a few years back. When the scoring was analyzed after the test, it appeared that each of us could distinguish between the cables by listening. Interestingly, neither of us knew we were listening to cables  when we took the test. Instead we were under the impression that the test was investigating lossy codecs.

 

John Atkinson

Editor, Stereophile

Mattias Alm's picture
Blind test

JA wrote:
Quote: One controlled blind test would suffice, thank you very much.

 

Michael Fremer and I independently took part in a blind test organized by a Wall Street Journal editor at a CES a few years back. When the scoring was analyzed after the test, it appeared that each of us could distinguish between the cables by listening. Interestingly, neither of us knew we were listening to cables  when we took the test. Instead we were under the impression that the test was investigating lossy codecs.

 

That's interesting. Is the report available somewhere?

Regards,
Mattias

andy_c's picture
Hello Mattias, The WSJ guy's

Hello Mattias,

The WSJ guy's name is Lee Gomes. The article about these tests is here. Notice how the test was set up. Here's the pertinent quote:

I set up a room with two sound systems, identical except for one component. Everything except the speakers was hidden behind screens.

So, rather than having a given system and changing only the cables and nothing else, two entirely separate systems were used. Since the speakers of those two systems probably can't take up the same physical space simultaneously, one must assume the speaker locations of the systems were different. Obviously a totally incompetent test.

There was a thread about this on Audio Asylum. One of the more telling comments by someone who was there can be found in this post.

In audiophile land though, only the methodologies of tests whose results contradict audiophile dogma are ever questioned. Totally incompetent tests such as this one, that substantiate audiophile dogma are treated as gospel and repeated ad nauseum.

Mattias Alm's picture
Thanks, Andy

Oh dear, oh dear. Not only does the test not give any valuable information, it is obviously totally flawed in both set-up and methodology.

No proper level matcing? Two different system with obvious audible differences to begin with?

Type 1 Error

"Type I error, also known as an error of the first kind, an α error or a false positive is the error of rejecting a true null hypothesis(H0)."

As I said, one properly conducted blind test would suffice. Why not set up a test with two set of cables that measure the same within audible limits, and see if it is possible to hear a difference?

Regards,
Mattias

michaelavorgna's picture
Demonstration

The demo approach worked for me.

Blind listening tests are funny – the people most interested in their results appear to be as uninterested in performing them as the people who are uninterested in performing them. My guess is its because both feel they already know the outcome.

Cheers,
Michael

gmgraves2's picture
RE: Demonstration

To be fair, Michael, Most people are reluctant to perform DBTs simply because they are a LOT of trouble. A DBT cannot be done easily, it requires a lot of setup, finding a suitable venue, getting the equipment together, cobbling together some kind of comparator apparatus, getting a group together, matching levels precisely, etc. I've performed and been party to enough of them to know how non-trivial DBTs can be.

Mattias Alm's picture
Blind tests

Hi,

Yes, it might have worked for you, but since I wasn't there, unfortunately it doesn't for me.

I've performed a number of blind tests over the years. The biggest insight from those were not technical issues (yes, there might be audible differences between cables, nobody is denying that), but psychological: how easy it is to hear differences (when listening open) that are not really there. Either you draw the consequences from that or you don't.

I have the experience that many that hear differences in open listenings do not want to listen blind, because then the differences most often disappear.

Regards,
Mattias

michaelavorgna's picture
Demos

 

Either way Mattias, I'll stick with my statement that you really to need to hear this kind of thing for yourself.

Let’s say I had participated in a controlled blind test that you felt was conducted properly and I determined there was an audible improvement between cables. I still would not recommend running out and buying anything until you heard it for yourself.

The final determination of whether or not an audible change is worth the money is a purely subjective valuation.

> I have the experience that many that hear differences in open listenings do not want to listen blind, because then the differences most often disappear.

Of course you do ;-)

M

WillWeber's picture
but...

Would we want to go out of our way to hear it for ourselves if there were no controlled blind tests reported by the scout? We might. But if the scout did it "scientifically" then we will be more likely to want to venture to hear it ourselves, since there would then be more likelyhood of a payoff. We can't go out and test everything, not in my world at least.

Anyway, thanks Michael for your scouting! I believe good cables can make a difference over crummy cables. I'm not convinced that exotic cables make a difference over good cables. But I intend to test drive some though, but which ones?? Yikes! My system already performs quite nicely. Will exotic cables really matter?

Cables are difficult to A/B test. Takes time to changeover, need to have someone else do it to be blind, and the cable layout and interaction with other cables is a variable(s) that is complex and can influence the results. So "listeneing for oneself" is not so obviously conclusive unless really carefully done.

WillW

michaelavorgna's picture
Never follow a blind scout.

Sorry, I couldn't resist.

It was my pleasure WillW.

ctbarker32's picture
Cable audio quality biggest fraud perpetuated by Hi-End industry

This writeup continues to confirm for me that the ongoing cheerleading by the Audiophile press for expensive cables is self delusional and fraudulent.

The reporter of this event fails to factor in the group think and subtle coercion brought about an "invitation" to a "spotless" facility. If someone invites you to their home and provides refreshments and convivial conversation, do you think you will be inclinded to trash his house and talk derisively about their decor and tastes? The obviousness of these social truths is astounding!

Of course, the high-end cable fraud will continue on unabated because of credulous reporters like this one. And if you dare question the group think, you are attacked for having inadequate component quality, poor hearing ability, or just plain stupid ignorant views.

Indeed, belief in High-End audio cable quality is a religion with all the mystery and voodoo that word often connotes.

John Atkinson's picture
Re: Cable audio quality biggest fraud perpe

Quote:
Of course, the high-end cable fraud will continue on unabated because of credulous reporters like this one. And if you dare question the group think, you are attacked for having inadequate component quality, poor hearing ability, or just plain stupid ignorant views.

No-one in this thread or in the magazine has said anything like this. In fact, Michael Lavorgna reported that AudioQuest demmed the different cables with a high-quality boombox.

Quote:
belief in High-End audio cable quality is a religion with all the mystery and voodoo that word often connotes.

In your opinion, of course. But please read the essay I wrote in 1997 on this subject at http://www.stereophile.com/asweseeit/84, in which I offered several scientifically valid hypotheses why cables should differ in sound quality. See also Malcolm  Hawksford's analysis at http://www.stereophile.com/reference/1095cable.

John Atkinson
Editor, Stereophile

ctbarker32's picture
Do the link articles apply to USB and HDMI?

John,

I will read the articles you link to. I have done a quick glance and I am assuming because of the dates that that they only address Analog connectors and do not address the more recent Digtal conncectors such as USB and HDMI?

From the original article:

Quote:
In each and every case, the improvement when moving up the USB cable line or adding isolation to things that spin was readily apparent to everyone. In fact swapping just one stock USB cable for an AudioQuest Carbon improved the sound quality to such an extent as to render the music more engrossing. More groovy, if you will, as if the band had just hired a better bass player or drummer or both and the lead singer had removed his scarf from covering the microphone.

I continue to take issue when audiophile mythology from the analog realm is applied to computers and digital technology. I worked as a computer engineer since the early 1980's. I have a hard time accepting that properly constructed digital cables for USB and HDMI will have any effect (subtle or otherwise) on sound quality. It is literally just 0 and 1's.

John, I have a great amount of respect for you and and have read Stereophile for decades. I cannot think of a better person to run a magazine like yours with your skills in engineering, sound recording, musical training/playing, and of course writing. I just think that time has come for High-End audio to shed some of the mystical qualities of the past and come clean about some things. Just as it was shown that Global Warming is a fraud with the revelation of the University of East Anglia’s Climatic Research Unit data manipulation, I believe that audiophile cable mythology needs to be exposed and put to rest.

There, I've done it. I've managed to skewer two of the most treasured mythologies of modern times!

John, have you ever considered hiring an ombudsmen type writer that would take on some of these disputed issues?

John, would you ever hire an audio writer who had impecable writing skills and audio reviewing credentials but was fervently anti audiophile cable?

John, are there currently anyone on the Stereophile staff that is an audiophile cable skeptic?

A final question, in the pictures in the article there appear to be at least a half dozen or so attendees. Did every attendee hear all the same changes with no disagreement among any of them? I find it suspect and reinforces my theory of group think if every attendee was in agreement.

I would find it more interesting if this "test" could have taken place over several days. In my test, a person would listen on several separate trips and not know if anything had changed or not. Sometimes a change would be made between trips, other times no chages would be made. I would expect the results to fall closer to statistical normalcy of 50/50 (i.e. pure chance - randomness).

I believe the expectation of a change brought on by being told a change has taken place is a proven psychological manipulation that is always a factor in these cases.

John Atkinson's picture
Re: Do the link articles apply to USB and HDMI?

Quote:
I have done a quick glance and I am assuming because of the dates that that they only address Analog connectors and do not address the more recent Digtal conncectors such as USB and HDMI?

That is correct, analog connectors and transmission only.

Quote:
I worked as a computer engineer since the early 1980's. I have a hard time accepting that properly constructed digital cables for USB and HDMI will have any effect (subtle or otherwise) on sound quality. It is literally just 0 and 1's.

Not at all. It is an analog signal that carries that information and is subject to the usual woes of analog signal transmission. HDMI cables, for example, suffer from crosstalk between the various twisted pairs that contaminates the audio data with video clocks, worsening jitter in the reconstructed analog signal. This degradation is measurable and can be audible. USB cable has a fairly hard length limit due to its analog bandwidth limitation and you also have to consider the fact that it also carries a voltage supply and ground connection. See this interesting post on the subject from John Swenson, who writes modified code for the Squeezebox Touch: www.audioasylum.com/forums/pcaudio/messages/9/90278.html.

Quote:
John, have you ever considered hiring an ombudsmen type writer that would take on some of these disputed issues?

I regard that as my role, as the magazine's editor.

Quote:
John, would you ever hire an audio writer who had impecable writing skills and audio reviewing credentials but was fervently anti audiophile cable?

There are people who are both anti-audiophile and anti-audiophile cable, but most of those whom I have encountered have a religious, non-scientific point of view that I see no need to air in my pages.

Quote:
John, are there currently anyone on the Stereophile staff that is an audiophile cable skeptic?

Probably Jim Austin comes closest to that description, but to be honest I steer clear of anyone who describes themselves as a "skeptic." They tend to be joyless, small people who deplore what they can't understand, envy what they can't appreciate, and feel they gain status by trying to rob others of the same.

John Atkinson
Editor, Stereophile

gmgraves2's picture
RE: Do the link articles apply to USB and HDMI?`

"It is an analog signal that carries that information and is subject to the usual woes of analog signal transmission."

This statement is wildly misleading, Mr. Atkinson - especially to those readers who lack the technical expertise to place your comment in proper perspective. With all due respect, while from one standpoint, it is true that a digital signal is an analog waveform and that this waveform is subject to the characteristics of all of the circuitry through which that waveform passes, including cable characteristics such as DC resistance, impedance vs frequency, etc. But, here's the thing, though. The digital circuitry that receives and performs the digital to analog conversion of that waveform doesn't recognize those "woes of analog signal transmission" until those "woes" get so bad that said digital circuitry can no longer find the transitions from one to zero and back again that make up the data located in that analog waveform. Even if that signal integrity is momentarily lost, the error correction algorithms used in digital conversion can pretty much reconstruct what's missing, making the system pretty robust (too many errors, however, can affect sound quality, especially if those errors are too large to correct and must be interpolated). IOW, as long as the data arrives at the other end of transmission intact, whether that transmission consists of a half-meter or so of USB cable, or an Internet radio station streaming from half-way around the world, the DAC can reconstruct the quantized music. In the same way and for the same reason that digital tape recordings don't care about the analog tape noise (hiss), digital to analog conversion circuitry doesn't care about cable characteristics. The transitions from bit to bit is all that digital circuitry in the DAC cares about or is looking for. I've seen intact computer applications pulled out of a bit stream so noisy that the human eye could not find the digital data for the noise on an oscilloscope . The application copy pulled form that noise by the copy software, OTOH, was clean as a whistle and bit perfect. Pretty impressive (to me, anyway).  

If you are to assume that cables make a difference in the sound of a digital source, you're going to have to keep looking for a technical explanation for it because this one won't fly. Perhaps Stereophile could fund research to find the "unified field theory" of cable sound that would encompass and explain both digital and analog cable sound. 8^) 

JimAustin's picture
Probably Jim Austin comes

Probably Jim Austin comes closest to that description, ...They tend to be joyless, small people who deplore what they can't understand, envy what they can't appreciate, and feel they gain status by trying to rob others of the same.

Thanks John. :-(

gmgraves2's picture
RE: AudioQuest Cables

Being both an electrical engineer and an audiophile, with many DBTs (Double-Blind-Tests) under my belt, I can say with absolute certitude, that at audio frequencies, the standard lengths of wire commonly used in audio simply cannot have any effect whatsoever on the sound. I spent years, early in my engineering career measuring, testing and spec'ing wire for use in America's defense and payload rockets (ICBMs, satellite-carrying boosters, etc.). I performed every test imaginable on wire: frequency response (from "D.C. to daylight") permeability, inductance, capacitance, resistance (and, of course impedance) and well as insulation break-down (called a hy-pot test). This experience has shown me that, at audio frequencies, anyway, wire is wire. Then there's the numerous carefully set-up DBTs to which I've been party as well as the number of similar ones that I have read about in AES and JAES journals which have all come to the same inescapable conclusion: Wire, by itself, can have NO EFFECT on sound, and if one runs across any interconnect or speaker cable which does affect the sound, it's because it has OTHER COMPONENTS associated with it (beware of cables with little boxes in them at one end and/or the other. They likely contain resistors, capacitors and inductors) and are no longer "cables" but rather are "fixed filters" of some type. Physics and all electrical theory literally scream the impossibility of this supposition, and if these sciences are wrong, then, were I you, I'd stay off airplanes, out of cars and we aren't having this conversation on the Internet, because computers can't work. 

Now, to play devil's advocate here, for a moment. Let's suppose for the sake of discussion, that cables actually DO sound different. How would anybody know which is best? Is "different" better or worse? Does a $25000 pair of speaker cables always sound better than a $2500 pair, or a $250 pair or even a $25 pair? It's all mental masturbation and if the differences are not clearly evident in a series of DBTs (one DBT demonstration is not statistically significant) and REPEATABLE, then, well, we all know that humans are very susceptible to suggestion and expectational bias. 

michaelavorgna's picture
Coincidentally

My father was an electrical engineer and an audiophile and we had some interesting conversations on this very subject. Suffice it to say that he believed cables could make a difference but I will concede that he wasn’t nearly as pompous as you appear to be gmgraves2.

gmgraves2's picture
RE:Coincidentally

Standard "religiously inculcated" Cool-aid drinking, audiofool reaction to a reasoned argument: Can't contest the merits of a debate opponents points, so attack the debate opponent personally. Nice. 

michaelavorgna's picture
No that was a considered response.

If you don't feel as if you appear to be pompous, which is exactly what I said, I'll have to respectfully disagree.

gmgraves2's picture
RE: No that was a considered response.

Sorry, but an ad hominem attack is always bad form in a debate. It usually means that the debater who resorts to those types of attacks has run out of ideas. Can't we keep these discussions civil? They're much more informative and a lot more fun that way. After all, Flaming is so 1980's. 8^) 

John Atkinson's picture
Please do your homework

Quote:
Can't contest the merits of a debate opponents points, so attack the debate opponent personally. Nice.

You have now twice been asked to read the Hawksford article before you continue with your rant, Mr. Graves. Please do so.

John Atkinson

Editor, Stereophile

(Also an audiophile who happens to be an engineer.)

Stephen Mejias's picture
The Essex Echo

Fascinating. Have you read Malcolm Omar Hawksford's article, gmgraves?  I would love to hear your opinion on it.

gmgraves2's picture
RE: the Essex Exho

Yes, I've read it and I'm familiar with the work or Maxwell, and Hawksford, and others who have studied the properties of conductors. Everything Mr. Hawksford says is absolutely true and certainly becomes a primary effect at some frequency and at some cable length for that frequency or set of frequencies, but these effects are so far below the threshold of human hearing when applied to audio frequencies in the lengths commonly used in audio systems (a few meters (max) for interconnects, and about 16 meters for 14 Ga speaker cable), that they essentially, don't exist. Raise the spectrum to HF, VHF and UHF RF and these things (and others) become very important. 

But at audio frequencies, you can't measure the effects and even if you null-out a signal that's passed through a cheap throw-away mass-market cable you will find that it nulls perfectly and you can't even see any residual signal on a very sensitive oscilloscope, and if you replace that throw-away interconnect with a $4000 Nordost (for instance) Valhalla, nothing changes. you don't have to re-null because there's NO difference. You can do this using sine waves, square waves OR music and the results are the same. Take the same two cables and try them on a listening panel of 10 to 12 listeners in a series of carefully set-up and calibrated DBT or ABX test, and you will find that NOBODY can tell the slightest difference. 

 

But you do bring up a good point (and I thank you). I've seen lots of RF conductor characteristics wrongly applied to the audio spectrum (mostly by the marketing departments of cable makers) in an effort to convince the unwary that things like skin effect and wave propagation and linear crystal copper conductors vs amorphous copper conductors and how they affect audio signals actually mean something. While under some conditions and at some frequency, all of these characteristics become crucial to proper signal flow, audio meets none of those criteria. Audio is just a low-frequency wave form, no different from any other low frequency signal (like seismograph data). I was party to a DBT once where a half-meter length of AudioQuest interconnect was compared to a piece of coathanger wire! Nobody could tell which was which in repeated tries. 

 

Now, I realize that this question has become a religious issue with many audio enthusiasts, and I'm just trying to interject a little sanity into the discussion. Needless to say that I have no personal stake in this issue and if one wants to spend many thousands of dollars chasing cables and cable sound, let them do so. Me? I'd rather spend that money on music. 

John Atkinson's picture
RE: AudioQuest Cables

Quote:
Being both an electrical engineer and an audiophile, with many DBTs (Double-Blind-Tests) under my belt, I can say with absolute certitude, that at audio frequencies, the standard lengths of wire commonly used in audio simply cannot have any effect whatsoever on the sound.

Perhaps, just perhaps, Mr. Graves. you don't know _all_there is to know about cable theory. Read, for example, Malcolm Hawksford's article linked to in my previous post, which would seem to contradict your statement. (Dr. Hawksford is also an electrical engineer and an audiophile, BTW.)

 

John Atkinson

Editor, Stereophile

gmgraves2's picture
RE: RE AudioQuest cables

I have read it (and long before this thread was started) Mr. Atkinson. And I agree with everything he says. His math is right and his conclusions are right. What I disagree with is his assertion that the characteristics he speaks of are applicable to the audio passband in any audible way. The first time I went through Mr. Hawksford's article, I remember doing the math for several audio frequencies. I found that some of the effects of which he writes, are indeed there, but were more than -140 dB down. I'm sure that you will agree that this is far below the threshold of human hearing and even below the noise floor of any sound source or amplifying device that you would care to name.  

Understand, my assertion is NOT that wire has no effect on an audio signal, it's rather that wire has NO AUDIBLE effect on an audio signal, unless it has been manipulated, purposely, by the manufacturer to introduce some filter effect. Then of course, I contend that it's no longer a conductor, but rather a fixed filter. 

fricc's picture
In defense of Mr Graves

Engineer audiophile here too, also particle physicist and computer scientist (sounds pompous, I'm sure about it).

I have a slight problem with Hawksford's article: it is only qualitative and not quantitative and offers no real measurements to back up a theory which the author itself disclaims as "finely etched with a little speculation".

The article in question doesn't seem to have appeared on any peer reviewed journal or conference, does not disclose the experimental setup under which measurements have been made so that they can be reproduced and verified by other competent people.

An article containing lots of "squiggles" and based on speculative logic is not a proof. It is not in the face of good common sense, the kind of thing that flies planes and lands them every day. With a little patience one can go through the equations of mr Hawksford and prove that the effect he is talking about are insignificant in the audio spectrum.

What can happen though is that "audiophile" cables have so much braided stuff inside to start significantly contribute to the capacitive load of the speakers, which can have the effect of a filter and change the frequency response of the system enough to be detected by a listener. Now my point is that different doesn't mean "better". Besides any filter will inevitably smear the signal somewhat.

I think it is educational to take a look at the amplifier tests that Stereophile is publishing and notice how much an amplifier frequency response changes when applied to a realistic speaker load as opposed to an 8 ohm resistor.

Quite frankly this kind of articles doesn't seem to be clarifying the issue in any way, it just obfuscates things with unnecesary complexity (the squiggles), and it appears to have the only aim to intimidate dissenting engineers endowed with good common sense.

 - Fabio

gmgraves2's picture
RE:In defense of Mr Graves

Fabio, you have hit the same nail on the head that I hit. While Hawksford brings up some interesting points, it becomes a matter of degree. Like I have said several times, it's not so much that the characteristics of capacitive reactance, inductive reactance, DC resistance or group delay, etc.,  don't exist in either an interconnect or a speaker cable, but rather whether those frequency-dependent characteristics affect the audio passband in any meaningful or audible way. As you reiterated, above, Hawksford's analysis certainly will effect some high frequencies in a meaningful way, but those frequencies don't seem to be in the audio passband. 

You are also correct about amplifiers. A modern, solid-state design is pretty close to transparent (this wasn't always the case). Any differences heard between amps (in a DBT) can pretty much all be attributed to the amp's interaction with the speaker load and the amp's power supply. Obviously, a cheap 150 WPC (for instance) amp with a just-adequate power supply. might be indistinguishable from a very expensive amp of the same power under the circumstances where neither is worked very hard (like driving very efficient loudspeakers designed to complement flea-powered SETs), they might sound very different, one from another, when driving difficult loads or very power-hungry speakers. Because the more expensive amp's power supply is bigger and can source more current. By the way, before somebody has an ah-ha moment, yes speaker cable is part of the amp's load. but again, reasonable lengths (8-20 ft) of adequately sized cable add almost nothing to a speaker's load profile (unless the cable's manufacturer has deliberately designed the cable with external components - beware of expensive cables with little wooden, plastic, or aluminum boxes as part of the cable. They probably have components in them large enough in value to alter the cable's frequency response. I suspect this is often done to make the cables in question sound "different" (or in marketing speak, "better") that the competition.). 

And your comment about complex and expensive cables actually being worse than cheaper, simpler cables because their construction adds more X-sub-C and X-sub-L to the equation is also well considered. 

This brings up (AFAIC, anyway) the ultimate question. If neither price nor design is a guarantee that a given cable is actually better sounding (assuming for a moment that cables do have a sound) than another cable, how is one to know that their new, expensive cables aren't really a step backwards from what they had before? One can't try all of the possible combinations and permutations, after all. Doesn't it makes sense to avoid that kind of (possibly expensive) crap-shoot and simply buy cables with good build quality (for reliability) and lest it go at that? 

 

Nice to have a chance to discuss these issues with somebody like you.

 

Ciao!

WillWeber's picture
truths with mystery

My, how this thread has grown!! I am going to risk getting sucked further in.

I find that there is truth in Prof. Hawksford, Mr. Graves, and Mr. Atkinson (and now gentleman Fabio too). So what gives?

I read the article by Prof. Hawksford, and his theory is correct, to a point. It is the classical approach for academic theoretical physics: a classroom lecture type of treatise for teaching the concepts. Hawksford does acknowledge that the effects are indeed of small magnitude in the audio range with relatively short cables. This is not an engineering effort and he does not quantify this. It is theoretically correct, although his derivation from Maxwell is hand-waved, plus he includes the usual mathematical simplifications for convenience sake. And that is OK, because these are insignificant in consequence, and the well-known wave equation is correct. Note that at 20 kHz the vacuum wavelength of an electromagnetic wave is 9.3 miles! Air induces only slightly smaller wavelength. It would take quite an interesting dielectric (I think cable designers avoid meta-materials) to slow the propagation to where the cables in a stereo system are anywhere near long enough to be considered as waveguides with distributed impedance factors (unless my components were in the next town). Now the error electric field vectors that Hawksford describes are real, but these too are quite a small magnitude at audio frequencies, even if they are of a significant time delay. He admits this as well, but again no numbers on the magnitude.

As Mr. Graves claims, the magnitudes of these effects are indeed quite small in the audio domain. I did not confirm his calculations, but I do have experience with scientific instrumentation and waveguides/transmission lines carrying very sensitive signals at various frequency ranges, from audio to optical. The effects described by Hawksford can be measured, but are only apparent at very high frequencies over long waveguides.

JA points out that cables do matter, and he gives practical situations in his article Wired:

  1. Wave physics per Hawksford: addressed above…
  2. Cable Dielectric linearity: does the lump capacitance of a cable have the same issues as a circuit capacitor? Perhaps, but is this significant? The capacitance of cables is quite low in comparison. Mr. Graves concurs. It may matter more in interconnects, but these usually can be kept short.
  3. Copper crystal granularity (and similarly purity): Again, we have very long wavelengths for the propagating waves. The electrons may be “surprisingly slow”, but they don’t move very far either. So any “defects” are essentially resistive, and of a small increment, easily made up for with slightly larger conductors, or slightly shorter cables.
  4. Grounding: of course, and that is dependent on the entire system. So some cables may work better in one system, while other cables may work better in another system.
  5. Component I/O impedance: again system dependent, and so may also benefit from cable matching.
  6. EMC (electromagnetic coupling--injection and susceptibility): amen brother, here we have many factors in one. The cable layout can affect the results, and this depends on the conductor geometry as well, as JA suggests, and on the same factors for other nearby cables and components that might couple with the cable in question. And all depending on the relative layout of all these items. All-righty-then, how can anyone do a conclusive A/B comparison if EMC is an issue?
  7. Microphonics: ya betcha! How about an inverse example. I once worked in a lab for laser induced atomic fusion. The laser amplifier stages are pumped with banks of very large Xenon flash tubes. Each lamp was fired with banks of capacitors of about 50 Farads each (that’s right, not µF) at several kilovolts. That’s a wompin’ lot of Joules, and released in a microseconds pulse over an RG-58 coax. These poor cables! It must’ve been like a garter snake swallowing a warp speed elephant. Anyway, they only lasted a few dozen pops before fatigue rupturing. So yes, a vibration is a reversible case, and will create currents even in coax.

There, in my view, it is these last four issues that make the largest difference in cable sound: grounding, I/O impedance matching, EMC, and microphonic sensitivity. I am assuming that for speaker cables that the cable resistance and complex impedance are sufficiently low to not degrade phase and damping factor. Of these, a cable designer can only control a portion: cable impedance, shielding, dielectric material, and microphonic sensitivity. A crappy cable can violate any of these. A good cable design can avoid them. Exotic cables? I don’t know, but I suspect that any differences compared to good cables are quite minute (but the jury is still out). Of course, a good cable may not have to be expensive, although a bad cable can be made expensively just because there is a market for pretty audio jewelry.

That leaves us with some variables that a cable design does not address, but are system/cable interactive. And an expensive cable does not guarantee it’s a good design. So it is no wonder there is so much agitated debate on this issue, and inconclusive or contradictory DBT tests reported. Yet, it appears to me that all the above cited authors are truthing. God I love this hobby!

WillW

(Another engineer, physicist, and dare I say “audiophile”, OK I did say it)

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