Lindsay-Geyer Highly Magnetic Cables

Why cable again?

Well, the obvious reason is that it has been a while since my last foray into Cableland (July 1988). Many new products have been introduced in the interim, so it appeared appropriate to once again open Pandora's Box. Those of you who still remember my speaker cable article of 2½ years ago will recollect the considerable controversy that evolved from that project.

Some of the response was quite predictable, though the venom with which it was laced was not. The manufacturers of those outrageously priced "garden-hose"–type cables that I failed to rave about were more than just perturbed. After all, if you had a goldmine with market momentum primed by pseudoscientific technobabble and another magazine's endorsement, the last thing you'd want to see is even a murmur of critical dissent. One of these good fellas went so far as to threaten me with a personal lawsuit should my survey result in the loss in sales of "even one cable."

Others objected to my findings because I wasn't rigorously "scientific" in my methodology. I was guilty of using the time-honored audiophile method of forming a subjective opinion on the basis of careful comparative listening tests; essentially the same approach as I would have used for testing a loudspeaker or an amplifier.

There's a popular myth about scientific measurements that regards such data as enjoying an objective and independent existence in the outside world. The problem with this view is that the data must be perceived by an observer. The observer structures and interprets the data in accordance with his cognitive or theoretical framework. A scientist's preconceived notions, or theoretical view he is out to prove, will provide cues as to which data are essential or on how to pattern the data in order to support the theory (footnote 1). Thus, the data are imprinted with an unconscious subjective bias. James Clerk Maxwell, the father of classical electromagnetism, is said to have remarked once that "There are two theories of light, the corpuscle theory and the wave theory; we used to believe in the corpuscle theory; now we believe in the wave theory because all those who believed in the corpuscle theory have died."

The point, of course, is that the significance of particular data patterns depends very much on who is perceiving these as cues for confirming particular theoretical assumptions and inferences. It's amazing how many times scientists have reported positive findings on the basis of "data" that were actually buried below the noise floor of the experimental apparatus. Eddington's measurement of the gravitational bending of light by the sun during the solar eclipse of 1919 was hailed as confirmation of Einstein's theory. Einstein's theory of general relativity has, of course, been verified numerous times since then. But it was later discovered that Eddington's results were fortuitous. The experimental errors associated with his photographic plates were such that he could just as easily have obtained a negative result.

Scientists are basically deterministic in outlook and are conditioned to search for causality. The simplistic reduction of such an attitude leads to the following dictum: If it exists, it can be measured. The corollary of which is that if something cannot be measured, it does not exist. Thus, one can understand the logic behind the assertion that all cables that measure identically should sound alike. This might be true if we could assure ourselves that the measurement set was all-inclusive and sufficiently refined or sensitive to establish a particular pair of cables as identical twins. But how can you know a priori all of the factors which impact sonic performance? And at what level do these factors make an audible difference? To argue simply, as opponents of exotic cable have done, that impedance variation is all that matters because nothing else appears to matter, reflects a lack of imagination. It is to such skeptics that this article is dedicated.

Science is about the search for a hidden reality. To say that all of the important design considerations for cables and amplifiers can be condensed into a simple recipe is to say that these aspects of audio are closed and require no further investigation. This mirrors the view of many physicists in the latter part of the 19th century. Many budding physicists were advised to pursue another discipline because pretty soon there would be nothing left to discover about reality.

Fortunately, for the time being, high-end audio remains largely an art. A high-end product should evolve on the basis of extensive listening tests. The same circuit can be made to sound differently with different boards, layout, or part selection, and in all these cases the differences would be impossible to discern, measurement-wise, at the current state of the art. Take the soundfield produced by a conventional two-channel audio system. Aspects of this soundfield could be measured at various levels of accuracy, but none of these measurements can reliably answer the question of "how close to 'live' will that soundfield be perceived?" The soundfield at the head is processed and interpreted by the ear/brain and results in the perception of a soundstage projected outside of the head. Just how realistic that soundstage is must be decided by the audiophile on the basis of subjective listening tests. High-end audio is about the conviction with which the "illusion of live music" can be reproduced.

There's another, and even more important reason, for treading these waters again. The Lindsay-Geyer cable, or L-G for short, represents a conceptual breakthrough in cable design, one that could revolutionize the industry. When a product single-handedly redefines the state of the art, as this one does, it becomes a cause célèbre and a story that must be told.

Making waves
Traditionally, audio cable has been conceptualized as a conductor facilitating current flow between various components. From this standpoint, a cable's cardinal design aspect is minimal impedance to current flow over the bandwidth of interest, hence negligible resistive losses. The ideal cable, from such a perspective, would be one with optimum power transfer. Clearly, such a cable is mandatory for a low-impedance circuit, such as that between a power amp and a loudspeaker. A modern power amp's output impedance is a fraction of an ohm. A loudspeaker's impedance magnitude is typically in the range of 3 to 8 ohms. This is a low-impedance circuit characterized by low voltages and high currents. Peak currents in such a circuit may exceed 40 amps; because ohmic losses go as the square of the current, the cable's impedance becomes a major factor. In this case, the speaker cable's impedance had better be minimal, or else the cable will soak up power from the speaker to a degree dependent on the speaker's impedance curve. The frequency at which the speaker's impedance dips to a minimum is where the percentage of power dissipated by the cable will be greatest.

However, the situation is drastically different for an interconnect. An interconnect typically operates in a high-impedance circuit where the source and load impedances are several hundred to several thousand ohms. Currents are in the milliamp range at most, and ohmic losses are therefore not a major concern. Here, it is much more instructive to investigate the propagation of the voltage signal rather than the current distribution.

We normally focus on the current distribution in a wire. There is a "skin effect" in that the current is progressively squeezed toward the periphery of the wire with increasing frequency. But we can gain more insight into the physics involved by analyzing the electromagnetic (EM) signal propagating down the wire. Such a description is complementary to and dependent on the current distribution in the wire, but sheds more light on how information is propagated along the wire. The following discussion is based on David Lindsay's white paper on highly magnetic wire, L-G's patent application, and information readily found in any graduate-level text on electrodynamics. My favorite text is Holt's (that's Charles A. Holt's—not JGH's) Introduction to Electromagnetic Fields and Waves (Wiley & Sons, 1963).

With a perfect conductor, say a superconductor, the signal propagates on its surface. However, until room-temperature superconductors become a reality, we'll have to make do with copper and silver. In an ordinary or "imperfect" conductor the signal sinks into the wire as an inverse function of frequency (the skin effect). The magnitude of the signal decreases exponentially with depth of penetration because of ohmic losses. At each frequency, a skin depth may be calculated at which the attenuation is exactly 1/e, or 36.8%. The signal is also retarded in phase as it sinks into the wire because of the finite velocity of propagation inside the wire. At one skin depth, the phase angle lags the phase angle at the surface by one radian, or 57.3°.

The problem, as Lindsay points out, is that if the wire is thin enough—less than several skin depths—some of the signal can sink entirely through the center of the wire and come out the other side. The time delay of the re-emergent signal can be significant. We all know that EM signals propagate at the speed of light—but that's true only in a vacuum. In copper at 1kHz, the signal speed is a relatively pedestrian 13 meters per second. At that speed, a signal will sink through a 1mm wire in about 70 microseconds. A 70µs delay should clearly be audible, assuming the magnitude of the delayed signal is significant—which is the case here. The skin depth at 1kHz is 2.1mm in copper, so the magnitude of the re-emergent signal for a 1mm wire is only down about 4dB.

Next, let's consider what happens to a transient waveform propagating down this 1mm copper wire. Because the waveform is composed of many harmonics and because the "sinking speed" is a function of frequency, a transient that sinks through the wire will be smeared out in time. The typical interconnect then propagates the original signal plus a smeared-out copy of that signal. It is possible for the smeared copy to sink through the wire again and generate another smeared copy of itself. But for every traversal of the wire, the magnitude is reduced by 8.7dB for each skin depth traversed. So only the initial few traversals are likely to be significant.

What can be done to improve the situation? One possibility is to make wire which represents a fractional skin depth over the entire audio bandwidth in order to make time dispersion negligible. Such a wire would have to be thinner than a human hair, and as a result it would be extremely fragile and impractical. But even if a thin wire could practically be made, multiple traversals of the wire would simply build up the delay to the threshold of audibility.

All right—if thin wires won't do the trick, how about fat ones? The idea here is that a signal "dies" out as it sinks through the wire at the rate of 8.7dB for each skin depth it sinks through. Therefore, make the cable fat enough so that the re-emergent signal is negligible in amplitude. If we define "fat" as five skin depths, that will provide 43dB of attenuation. At a frequency of 100Hz in copper, the skin depth is 6.6mm. Thus, to make a copper wire appear fat at 100Hz will require a diameter of 33mm or about 1.3". Again, that's rather impractical. Incidentally, a ribbon construction would not work, as the signal would simply sink through the thin part of the ribbon.

Another strategy is possible, one representing the essence and insight of the L-G cable: Make the wire appear "fat" over the audio bandwidth by reducing the skin depth itself. In other words, maximize the skin effect over the audio band in order to minimize dispersion.



Footnote 1: As a physicist at Los Alamos, DO knows of that of which he speaks.—John Atkinson
COMPANY INFO
Lindsay-Geyer
Company no longer in existence (2018)
ARTICLE CONTENTS

COMMENTS
Ali's picture

Thanks for such an informative review. But is this cable brand still iin business since you mentioned the company is no longer in existance. Are they availabel for purchasing?

geoffkait's picture

Couple things. One is that High Fidelity Cables also employ mu metal as conductor. As well as magnets in design of their cables. Two, drift velocity of electrons in a conductor is extremely slow, about a foot per hour, whereas the audio signal travels at a high percentage of the speed of light in a copper conductor due to the fact that the audio signal is comprised of photons. Photons are the only particles/waves capable of lightspeed in a vacuum, in fact they must travel at lightspeed as their speed is a constant. In a medium they travel at some large fraction of the speed of light. All electromagnetic waves are comprised of photons, everything from X-rays to radio waves to the audio signal.

T.S. Gnu's picture

Dear Sir,

While it is a fitting addition to your narrative, your comment that.

Quote:

But it was later discovered that Eddington's results were fortuitous.

is incorrect.

This trope has been dealt with and put to rest as far back as 2007 with the final analysis showing that Eddington did not allow any personal bias to influence his results. This has been published in one of the more prestigious peer-reviewed journals — Nature; there has been no refutation since. It is now the accepted version of history and, is indeed taught as such in physics.
https://www.nature.com/news/2007/070910/full/news070903-20.html

While the trend to occasionally ignore scientific information is disturbing but is, however, par for the course, it is not befitting a publication such as this to promote information that is wrong. It would be much appreciated by the general readership if this error were corrected.

Respectfully,
T.S. Gnu

misterc59's picture

It appears to me that the author says "The experimental errors associated with his photographic plates were such that he could just as easily have obtained a negative result". At no time do I read that "personal bias" was the part of the message. I would interpret this as the experimental method used at that time was not as accurate as we may be able to do in this day and age. However, perhaps my interpretation of the author's writing/intent is incorrect, but I believe the words speak for themselves, bias intent is not mentioned.

Cheers,
Terry

T.S. Gnu's picture

You may perhaps read the article again if "at no time" you read what was pointed out in my post. In particular, you may find it useful to refer to:

Quote:

The observer structures and interprets the data in accordance with his cognitive or theoretical framework. A scientist's preconceived notions, or theoretical view he is out to prove, will provide cues as to which data are essential or on how to pattern the data in order to support the theory.

A comment that the editor has, interestingly, now added a footnote to in an attempt to subtly establish grounds for argument from authority. I have, however, provided a peer reviewed reference rather than add my own substantial bonafides and degrees in physics.

Whilst I respect and admire the authors contributions to audio reporting, vague references to being "a physicist at Los Alamos" without more detailed background detract more than they add. My own work at present in JPL should not give me any more, or less, credibility. You may also have overlooked the line immediately following.

Quote:

Thus, the data are imprinted with an unconscious subjective bias.

If "personal bias" were not part of the message, then the message ought not to be presaged by the aforementioned buildup. Also, while the author writes

Quote:

The experimental errors associated with his photographic plates were such that he could just as easily have obtained a negative result.

And states that the results were "fortuitous," at no point is there mention of the fact the arrival at the (correct) conclusion was anything but fortuitous, although there is an implication to the contrary.

There is also a logical fallacy in the comment

Quote:

The simplistic reduction of such an attitude leads to the following dictum: If it exists, it can be measured. The corollary of which is that if something cannot be measured, it does not exist

The corollary is a simplistic, and incorrect, reduction. The correct view is that if something cannot be measured, it is what Rumsfeld referred to as either a known unknown or an unknown unknown. Trotting out these convenient tropes to denigrate established scientific process is at best misguided, and at worst misleading, diminishing what we have accomplished as a species. This is the disturbing point that I addressed in my original post.

With respect to the questions

Quote:

But how can you know a priori all of the factors which impact sonic performance? And at what level do these factors make an audible difference?

We don't. Possibly lower than (or in a different arena to) what we measure. I agree with the author on the existence of the gaps. I do not think that an agendum undermining Eddington's work (and scientific approaches in general) is necessary to make the point. I would say that this approach, in the authors words.lacks imagination" and lowers the tone of discussion.

Since English is not my first language, the effort to write a short post instead of a long one is a bit higher than the effort it would take a reader to peruse the long post. I would like to express my gratitude, in advance, for the readers indulgence to that effect.

Respectfully,
T.S. Gnu

John Atkinson's picture
T.S. Gnu wrote:
A comment that the editor has, interestingly, now added a footnote to in an attempt to subtly establish grounds for argument from authority.

"Now"? This footnote was published as part of the original 1991 review and has always been included in this website reprint.

John Atkinson
Editor, Stereophile

PAR's picture

" This trope has been dealt with and put to rest as far back as 2007" etc.

You do appreciate that this article is dated February 1991 ? I doubt that Dick Olsher had the ability to foresee the orthodox opinion of 16 years in the future.

T.S. Gnu's picture

I trust you do appreciate that the column was posted in this space on the web in 2018 without correction or comment from the editor. While Olsher didn't have the luxury of foresight, Atkinson does have the luxury of hindsight. A magazine website and editor do have the obligation of presenting facts as they are at the time of online publication if they devote space to an article published online at the time of online, you would agree? Else it is merely propagating falsehoods.

With respect to your comment title, it's not the problem with time, but the problem with the space devoted to propagating an (in retrospect) incorrect, or perhaps ill-represented, view. I hope you understand that this may be viewed as a particularly vexing problem especially when considering the image heading the article

Regards,
T.S. Gnu

dalethorn's picture

In many cases it's best to read history without attaching commentary, unless there is a clear danger of accepting facts that have been proven false in the years since. I don't see such a danger here, because the article lays out the areas of investigation clearly, and the date is prominently noted at the top.

T.S. Gnu's picture

Ah yes the old, "I don't see a danger, therefore there is no danger" premise. Makes it a bit easy to be caught out by the existence of known and unknown unknowns there. Thanks for the insight and example, though.

dalethorn's picture

The actual danger is in propagating falsehoods, as you said. But who is propagating those falsehoods? I suggest it's persons who we don't know who they are.

T.S. Gnu's picture

As mentioned, your support for Messrs Dunning and Kruger is well received.

ThomasK's picture

This was all very interesting until I hit this:

'We all know that EM signals propagate at the speed of light—but that's true only in a vacuum. In copper at 1kHz, the signal speed is a relatively pedestrian 13 meters per second."

Do you really believe that signals propagate through a copper wire at ~29 miles per hour?

John Atkinson's picture
ThomasK wrote:
Do you really believe that signals propagate through a copper wire at ~29 miles per hour?

Please remember that the audio signal actually travels in the dielectric surrounding the conductor, penetrating the conductor in a frequency-dependent manner. See www.stereophile.com/reference/1095cable/index.html.

John Atkinson
Editor, Stereophile

spacehound's picture

You seem to be confused regarding signals, electromagnetic fields, maybe electron drift, and dialectrics.

A "signal", audio or not, will travel along a copper conductor at about 60% of the speed of light 'in vacuo', due to copper having a higher density than a vacuum, which of course doesn't have a density. Say 100,000 miles per second, NOT 29 miles per hour.

You don't agree? Think about this. The signal will still travel along the copper wire at that speed even if there is no dialectric at all, such as a bare copper wire in space.
Thus your "the signal actually travels in the dialectric" is wrong - what happens in the dialectric (if any, as above) is merely a side effect of the signal travelling in the copper conductor.

T.S. Gnu's picture

Unsurprisingly, your question has not been given a direct yes or no answer. Possible reasons would include an inability to differentiate between propagation velocity, Fermi velocity, and drift velocity amongst a myriad others. Confusion leads to some interesting conclusions, some of which best ought not to leap to without the aid of a parachute.

The number quoted is correct for A velocity; just not signal velocity, because that, as Pauli once said is not...even...wrong.

ThomasK's picture

Thank you for the reference, John.

About a third of the way down the second page, the author gives an expression for propagation velocity. Unfortunately, the expression given is for “phase velocity” which is a different quantity altogether. True propagation velocity or group velocity has no frequency dependency. The frequency dependent effect you mention is that of attenuation.

Joe8423's picture

if the signal hadn't already passed through 100 meters of typical cables before it got to its final place on the recording. We need a term to quantify cable distortion that is likely on the recording itself. How about Belden Meters. If the average recording has 100 BMs worth of distortion, can we really expect to hear an appreciable difference if we decrease the interconnect distortion from 1 BM to 0.15 BMs? I'm skeptical.

T.S. Gnu's picture

One wonders whether MQA might help with this blurring

dalethorn's picture

If we accept a recording as a done deal, to possibly be superceded by a remaster years hence, then the question becomes "Does my cable make a difference, and is the difference positive on most of my recordings?" Or I could phrase it as "Is there a cable that sounds neutral on the vast majority of my recordings?" The problem with changing any component is being certain of a neutral or positive effect, which is not just a boosted treble or agreeable distortion that "sounds better". If I were putting together a new system or adding new speakers, I wouldn't bet the farm on a cable choice made within the first few days.

doktorb's picture

This article dead on! Have gone through many cables over 20+ years, and always go back to the L-G. Modified the connectors with copper Eichmann Bullet RCA plugs (plastic connector housings)). Yes, ground loop needs to be managed at times. When accomplished, they are simply the best. Have compared them to Nordost, Analysis Plus, Shindo, and many others. Nothing comes close. Mine are .5 meter long. Not always good as they are ultra revealing. Ruthlessly will reveal weaknesses in your system or the recording. Keeping this set. Longest lasting component I have owned.

RH's picture

This old article but brings up some ongoing issues in high end audio writing.
It is typical of the “Science is great and all...BUT!...” article. Lip service is paid briefly
to the scientific enterprise - “it’s not like you have to be a flat earther to be an audiophile” - and then this is used to launch into some version of “science doesn’t know everything” where
enough suspicion is cast on the limits or problems in science to give space for whatever dubious
report you are about to read.

Mr. Olsher starts out sounding like a skeptic, dismissive of “pseudoscientific technobabble” right up
to when he “tests” the claims of the cable maker. Then he relies on putting the cables in his system and listening with nary a thought about controlling for the effects of his imagination.

The same story seems to run through the manufacturer’s claims. It all sound “sciencey” right up until one asks for actual scientific methods of confirmation. David Lindsay
had essentially proposed a hypothesis based (it seems) on known measurable phenomena. Yet we see nothing in this report about the measured results from Lindsay showing at least he can measurably produce (or reduce) the effects he claims. That would be step one in Lindsay supporting his hypothesis. It would also include letting others know how to reproduce the measurements. Yet no measurements are given and John A was left to his own devices to figuring out how to test Lindsay’s claim. Sure enough, John could not confirm Lindsay’s claims via measurements.

But of course the reviewer “heard” this mysterious effect nonetheless, using only his own subjective impressions which are miraculously immune to all the known bias effects.

And so it goes, to this day, in high end audio reviewing. When there is no objective confirmation, well, too bad for science, my ears don’t lie!

I don’t think the article is “dedicated to the skeptics” as Olsher claimed so much as to the audiophile choir.

(Being an Audiophile and long time Stereophile reader I’m one of the choir, but this article certainly didn’t speak to the skeptic in me)

John Atkinson's picture
RH wrote:
But of course the reviewer “heard” this mysterious effect nonetheless, using only his own subjective impressions...

I am not surprised that the reviewer felt the L-G magnetic cables sounded different from conventional cables. How could they not? And it is always possible that in the context of specific system, that difference is perceived to be an improvement.

See, for example, the case of single-ended triode amplifiers, which can give large frequency response changes, depending on the loudspeaker's impedance curve, and can introduce significant amounts of second-harmonic distortion. As I wrote back in 1995 in a Cary review, these amplifiers are actually tone controls, and no-one would argue that a tone control won't have audible results.

John Atkinson
Editor, Stereophile

RH's picture

“How could they not?”

I’m not sure. I looked at your measurement section which seemed to suggest
capacitance effects of this cable (eg high frequency roll off) would only come in to play
in certain systems. Did your measreuments determine that the LG cables would have
likely audible variation in Olsher’s system? These things would be nice to know for audiophiles
trying to sift manufacturer and reviewers claims from the variables (I.e. if the sonic change Olsher
heard was more likely due to capacitance attenuation than the phenomenon claimed by the
manufacturer, that’s obviously relevant insight to gain).

I certainly did appreciate your efforts to evaluate the technical claims made for the cable.

John Atkinson's picture
RH wrote:
Did your measurements determine that the LG cables would have likely audible variation in Olsher’s system?

I am afraid I can't recall what components Dick Olsher was using when he prepared this review at the end of 1990, and contrary to Stereophile's policy, other than the power amplifier and speakers, he didn't say what products he used in the evaluation.

But the high capacitance may have been a factor, as was the tendency of the cable to pick up noise and hum. And I would not be surprised if the cable increased the level of non-linear distortion. But 27 years after the review was first published, I can only offer conjecture.

John Atkinson
Editor, Stereophile

spacehound's picture

It didn't prevent him writing pseudo-scientific technobabble, the very thing he accuses others of.
What's more 'skin effect' doesn't happen at audio frequencies.

And if he thinks his page 1 comments are an accurate description of how 'science' works he's wrong.
Also his "Maxwell" comments don't demonstrate a thing. Light is both waves and 'corpuscular' as they called it in Maxwell's time.
He is wrong about Eddington too. He said he needed further results, and he got them, as T.S. Gnu's reference shows.

[flame deleted by John Atkinson]

After two pages of utter nonsense I didn't waste my time reading beyond page 2.

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