Cable Nonsense

How much difference do cables make? My experience and several experts listed below is “not a lot”. I participated in a blind A-B test which compared a $1.50/meter 12 gauge speaker cable from a hardware store and a number high end audiophile cables that cost an average of  $2000/meter.  I didn’t notice a difference.

There is some research which suggests you might be able to perceive  a drop and audio quality when a cable is >18 gauge. I believe I could hear slight differences between some 24 gauge wire and my 12 gauge cables, but it wasn’t a blind test.  My interconnects are made by monoprice, and my speaker cables are the typical 12 gauge speaker cable which I purchased at a hardware store.

Roger Russell, who was the Director of Acoustic Research at McIntosh Laboratory notes in his  History of Speaker Wire that the main issue in cable is the resistances, which basically means that heavier gauge is better. For a bit more explanation, see the Cables & Sound Quality column.

Years earlier, John Dunlavy make a series of posts called Cable Nonsense. Below is a stashed copy of his posts. I would suggest you check out audio postings by dunlavy for even more information.

Date: Tue, 5 Nov 1996 13:08:50 -0500
From: 102365.2026@compuserve.com (Dunlavy Audio Labs)
To: bass@mcfeeley.cc.utexas.edu (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 audiophileapplications 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

Notes #2

The many well-written responses to my recent “cable postings” have convinced me that a significant number of readers have awakened to the mess that exists with respect to questionable advertising claims being made for the properties and performance of audiophile cables.

It has become increasingly obvious that many audiophiles are well aware that most cable advertising is based upon gibberish intended to sell expensive, “high-tech looking” cables that seldom perform as claimed. Indeed, it is a provable fact that most cables, regardless of cost or appearance, are not designed according to the teachings of credible engineering criteria, confirmed by meaningful measurements and properly conducted listening evaluations.

Intrigued by the questionable technology underpinning the advertised claims for patented cable designs, I contacted a friend who is both a patent attorney and a competent E.E. As a result of our discussion, he secured copies of several patents relevant to some of the most expensive, well-advertised and best-selling cables presently available. Perusing these patents, I was shocked by much of what I read. I was also dismayed that the U.S. Patent Office issued them, in view of the flooby-dust and gobbledygook explanations given for how they were supposed to work and perform.

Over the past 33 years, I have participated in numerous listening comparisons, often in the presence of knowledgeable, well-intentioned audiophiles claiming the ability to “always hear a difference between cables”. These listening sessions frequently took place within listening rooms that most audiophiles would probably “kill for”! Initially, before appropriate controls were introduced, results always favored the most expensive cable with a high-tech appearance and the greatest “sex appeal”!

However, when “blind”, but non-intimidating, controls were instituted, the differences originally identified could no longer be recognized – and tabulated results revealed scores very close to those expected for random-guessing. Yet, many self-proclaimed golden-ear audiophiles continue to insist that they can always identify audible differences between cables and abhor “blind evaluations” on the basis of perceived intimidation.

Reliable studies have conclusively proven that “audible differences” perceived during poorly-controlled subjective listening comparisons almost invariably vanish when proper “listening controls” are instituted. Without proper “blind” controls, listening evaluations almost never yield any relevant or reliable information regarding possible differences between cables. (However, such controls must be designed to effectively eliminate “listener stress” – claimed by some who do not believe in the relevance of blind comparisons.)

In attempting to eliminate (or reduce) the effect of such perceived intimidation, we have devised an interesting “deception technique”, wherein we pretend to change cables, letting listeners believe they know which cable they are hearing, when in reality they are hearing the same cable throughout the entire session. Interestingly, all participating listeners invariably continue to identify differences they believe exist, even though they have listened to the same cable throughout the evaluation.

An alternate version consists of actually changing cables but mixing up the order, permitting listeners to believe they are listening to a particular cable they have earlier identified as possessing certain audible differences – when they are actually listening to a different cable. Again, their choice of descriptive adjectives always tracks the identity of the cable they thought they were listening to, but were not!

Of course, as I have reiterated many times, it is indeed possible to sometimes identify barely perceptible differences between cables. These are almost always traceable to cable/equipment interface problems, etc., and have always proven to be measurable, quantifiable and explainable, using well-understood theory and technical knowledge, along with adequate measurement tools.

Lets now consider the relevance of the many impressive-looking, high-tech appearing specs and graphs that regularly appear in expensive magazine advertisements, used to compare presumably important “measurable” differences between cables. These include graphs supposedly comparing a zip-cord and one being promoted on the basis of its superior curve of Joules versus frequency. But a Joule is defined as a unit of energy or work in the MKS system. In electrical terms, a Joule is simply a “watt-second”. With respect to energy, it is the work done when “a force of one Newton produces a displacement of one meter in the direction of the force”. However, neither definition seems very relevant for describing an audible or measurable property of an audiophile cable.

A similarly impressive-looking graph, advertised as comparing the “efficiency” of different cables, also begs examination. Here, the advertisement defined efficiency as being related to “the phase between voltages and currents along the cable”. In the graph, zip-cord is depicted as exhibiting an efficiency very close to zero at frequencies below 100 Hertz, including the mains frequency of 60 Hz. But if zip-cord exhibited such a low “efficiency” (according to normal use of the term), it certainly would not be usable for supplying A.C. current from an outlet to lights, toasters, fans, etc. (Indeed, in most household applications, zip-cord would likely overheat and probably catch fire!) Hmmm!

A further, frequently encountered advertising claim for cables is the use of “six nines” or 99.9999 percent pure copper (usually designated 6N copper). Such ads usually imply that 6N copper is unique and is used only in the world’s finest and most expensive audio cables. Further references are often made to an audible correlation between the use of 6N copper and sonic purity. But, according to the Directors of the Engineering Departments of several of the largest wire and cable manufacturers in the United States, virtually all of today’s copper wire is made of “six nines” copper. Every one of them claimed it would be hard to find any cable, whether zip-cord, house wiring, etc., that did not use it.

Some cable manufacturers even refer to their products as being made of special “grain-oriented” copper or copper with “directional properties”, with respect to current/signal flow (gulp)! All large, reputable wire and cable manufactures, with whom we have spoken, laugh (or cry) at such assertions and claims. Indeed, if a wire exhibited directional properties with respect to current flow, the directionality would “rectify” audio signals (like a diode in series with a wire carrying an A.C. current), creating unlistenable levels of second-order harmonic distortion components (wow!).

Another means for selling more loudspeaker cables is that referred to as “bi-wiring”, requiring the use of two cables. However, bi-wiring does not work in the simplistic fashion imagined by audiophiles lacking the engineering credentials to analyze the potential system degradation in accuracy that can result from using separate cables to connect the output of the power-amp to the separate high and low-frequency input connectors at the loudspeaker. In fact, such usage can induce many expensive high-slew rate amplifiers to oscillate at frequencies above the limit of audibility. This condition can arise because of the added (effectively doubled) capacitance introduced by the “bass cable” not being “resistively- terminated” above the bass crossover frequency and the “mid-tweeter” cable not being resistively-terminated above the tweeter range, where a typical tweeter’s impedance nearly doubles within each octave above the audio range.

As well, the issue of bi-amping should be addressed with regards to using this application in an attempt to better the quality of sonic reproduction. A straight-forward analysis reveals that this process may actually adversly affect sound reproduction. This is especially true when the amps have different properties, such as a tube-amp for the treble and a solid-state amp for the bass, each possessing different gains, output impedances, etc. Amplifiers with different gains, unless compensated to be equal, can audibly affect the frequency-response, etc. of the loudspeaker.

I could go on and on, ad nauseum, reciting more nonsense, but it seems prudent to preserve readers from further pain and anguish!

To see what a sampling of competent engineers had to say about typical cable advertisements, I had three E.E. types (all holding Ph.D’s from different major U.S. universities) read several examples and provide me with their opinions. Their comments and explanations matched my own, with all three being in full agreement with the comments I expressed above. Some of their comments incorporated expletives I prefer to not to repeat!

Many readers may question my motives for making the above comments and observations. Well, I originally undertook the task of studying the properties and design criteria for audio cables for three reasons: (1) I am the curious type that cannot rest until I have studied the relevant facts concerning controversial subjects, (2) Measurements of the electrical properties of a large sampling of commercially available cables revealed relatively poor performance properties, that did not correlate with their cost, advertised attributes and or high-tech appearance, (3) I needed loudspeaker cables and interconnects with performance as close to “perfect” as possible, so that I could rule out any contributions from the loudspeaker cables and interconnects when making measurements of our loudspeakers or performing critical evaluations with them within our listening room.

But other reasons cut deeper: when advertised performance claims for products are structured to convey integrity and a sense of being true in every respect, yet in reality are either misleading or outright false, the basic covenant of trust that should exist between manufacturers and consumers is breached. If permitted to continue unabated and without appropriate redress, increasing consumer distrust will eventually destroy the integrity of the audiophile industry as a whole. Ultimately, I believe this has the potential to erode the rewards available from a very neat hobby, especially for those in pursuit of “true, documentable perfection” in the reproduction of music.

When profits and desired market share are given priority by any manufacturer over their obligation to provide products with performance and features that conform to advertised claims, I believe that consumers have a right to know and be concerned. Too many innocent and uninformed consumers wrongly assume that Government “protection agencies” are vigilantly pursuing false/misleading advertising claims and products that do not perform as claimed. Not so! Today, most government regulatory agencies effectively have their hands tied behind their backs by bureaucrats representing “special interest groups” whose only gauge of success is profit – and profit, alone! As such, they are frequently impotent to take any meaningful action against companies engaged in advertising, marketing and selling products whose performance does not meet the rightful expectations of the purchaser.

Note #3

Thanks to all who responded to my original posting concerning audiophile cables and their audible/measurable properties.

Since some of the responses seemed to convey a discordant position, perhaps a more detailed exploration of the issues is justified. A good beginning might be to examine the issues that separate those whose opinions are based mainly (or entirely) on subjective grounds (perhaps from poorly controlled listening evaluations) from those who favor an objective approach based upon correlating relevant measurements with the findings of “blind”, “double-blind” or other types of properly-controlled listening comparisons.

To begin, I would like to make clear that I do not believe that a set of cable measurements, taken alone, can consistently and reliably predict how one cable will sound when compared to another cable, without considering relevant “system interface parameters”. This is because the interaction between the electrical properties of a cable and the input/output impedances (and other properties) of typical audio equipment/components being connected by the cables are an integral part of the overall performance equation. Thus, a full and accurate set of measurements is only relevant if interpreted in the context of such system interactions.

Given such interpretation, measurements can provide an important, if not indispensable, guide as to the potential performance of a given cable within a given system. To say otherwise is to acknowledge an incomplete grasp of present-day measurement technology and the ability of credible engineering knowledge/expertise to fully define and accurately assess all of the relevant properties that affect the performance of cables within an audio system. Despite the pontificating of some individuals to the contrary, well-known laws of physics and principles of engineering are fully adequate to meet the challenge. (A Nobel nomination awaits anyone who discovers and adequately identifies a property that proves otherwise!) The notion that “physics lies”, expressed in a recent magazine editorial, is absolute hogwash!

Most “seemingly” unexplainable, yet truly audible differences between cables, can be explained if critically examined with respect to equipment interface considerations. For example, a well-designed, low-loss loudspeaker cable (with a relatively-low characteristic-impedance of perhaps 6 to 8 Ohms) can cause many expensive, well-regarded power-amps (with a slew-rate exceeding stability limits created by an improperly designed inverse-feedback loop) to oscillate at frequencies well above the audio range. This is sometimes audible as a low-level, high-frequency “crackling noise” (usually emitted by the tweeter as it’s voice-coil is being cooked). Such amplifier instabilities may also alter the “sound” of the amplifier by creating an “edgy” quality on musical transients or an exaggeration of high-frequency notes, etc.. But the amplifier, in this case, is at fault – not the loudspeaker cable.

Unfortunately, this is the reason many audiophiles avoid using high-performance cables. Yet, a simple “Zobel” network (typically a 6.8 Ohm resistor in series with a 4.7 uF capacitor) in parallel with the loudspeaker end of the cable can almost always cure the problem. (A multi-turn coil of 20 AWG wire wound around a 6.8 Ohm, 1 watt resistor, connected in series with the amplifier output terminals, will usually accomplish the same thing!)

However, while low-loss, low-impedance loudspeaker cables are technically the ideal choice, from a purely academic point-of view, most loudspeaker cables are quite short with respect to a wavelength within the audio spectrum, diminishing the effects of “standing-waves” and “reflections” that would normally be of concern at frequencies well above the audio spectrum. But low-impedance low-loss loudspeaker cables, represent the technical and deserve serious consideration where “ultimate accuracy” is the goal!

With respect to identifying the cause of audible differences between some interconnect cables, excessive capacitance is usually the villain. This is true because transistor output stages of pre-amps, CD players, etc. are frequently “load-sensitive”, especially with respect to excessive capacitance. This is also true of some single-ended tube types. Thus, an interconnect cable with a relatively high capacitance (exceeding 20-30 pF per foot) can often cause some equipment to exhibit non-linear properties at higher frequencies and/or higher output levels, resulting in audible levels of distortion. But again, the cable is not always to blame, although no good engineering reasons exist for not designing an interconnect cable with a suitably low capacitance, e.g., below 10-15 pF/ft. However, some of the most expensive interconnect cables, with a high-tech appearance, exhibit measured capacitance exceeding 75 pF/ft. while some of the least expensive ones clock-in at only 12-15 pF/ft. (We believed the problem sufficiently important to justify the development of an interconnect cable with a capacitance of only about 8-10 pF/ft.)

Thus, I sincerely hope that the above explanations help to explain why measurements alone may not always fully explain the differences heard between cables – without taking into consideration the interactions between cables and the proclivities exhibited by the output stages of some amplifiers, etc.. However, accurate measurements, properly made and interpreted, can almost always predict how a given cable will react within a given system, taking into account all of the “interface” considerations that must be evaluated. Therefore, measurements can be an invaluable design tool when properly interpreted by a competent engineer seeking optimum performance from a cable or a system.

So what about subjective listening comparisons for evaluating “audible” differences between cables? Well, I will once again state my belief that the “placebo effect is alive and well” and that listening comparisons are virtually useless unless significant differences exist and/or proper controls are employed! I base this belief on a considerable number of carefully conducted and critically analyzed comparisons between different cables over the past 20-plus years. Initially, I and my staff fully expected to observe audible differences – which we did, in the absence of proper and sensible controls. But in virtually every instance, when controls were instituted, the differences thought to be easily heard and identified, either totally disappeared or closely approached the level predicted by “chance”. Yes, we have frequently consulted psychologists and other experts familiar with “audibility testing” in devising procedures and controls for our comparison evaluations, etc. But the results we have obtained have always been consistent: we have simply not been able to identify any audible artifacts that could not be explained by a critical examination of the equipment, components, etc., coupled with an analysis of their interactions — period!

Note #4

The large number of recent postings regarding audiophile cables and loudspeaker design is encouraging. Perhaps, it is indicative of a newfound level of interest in the way cables work and perform. Several posts raised questions and or proffered information that deserve comment. Unfortunately, my cramped work schedule leaves little time for writing individual replies to everyone. Therefore, I will try and lump related answers together and attempt to cover as much important territory as time allows.

For those who asked how impulse response, step response, amplitude Vs. frequency response and phase Vs. frequency response are related to one another, lets consider the following. The impulse-response of any linear analog network, including amps, loudspeakers, cables, etc., is important because it contains information about virtually all other measurable and audible performance properties. Beginning with a measurement of impulse-response, the frequency-response, phase-response, cumulative-decay-spectra, step-response, energy-time response, etc., may be rapidly and accurately determined by FFT analysis, such as that provided by the now well-known, computer-based, MLSSA measurement system. (We have three MLSSA systems running full-time for R&D and production QC applications, in addition to spectrum analyzers, distortion analyzers, vector-impedance analyzers, complex waveform generators, etc.)

Further, in answer to another question posed on the NET, variations in phase Vs. frequency within a linear system are the “first derivative” of variations in amplitude Vs. frequency. And, variations of amplitude in the “time domain” produce variations of both amplitude and phase in the “frequency domain”. Indeed, virtually all measurable performance attributes of any linear system, whether it be an amplifier, a loudspeaker, a cable, etc., are related to each other in relatively simple ways that are easily treatable by mathematics – an extremely powerful tool for those who understand and know how to use and apply it.

Several posts seem intent on taking issue with what I said about low-loss, low-impedance loudspeaker cables causing some poorly-designed power-amps (with a slew-rate exceeding stability limits created by an improperly designed inverse-feedback loop) to oscillate. One recent post said: “This is the third time you have ascribed high slew-rate amplifiers to the problem of cable interface. This is misleading. It’s also the third time I have contradicted you on this point, which is why I’m sending this reply directly via email this time (as well as to the ng)”.

But in my post on the subject, I never directly related “slew-rate” to oscillation without the caveat: “… created by an improperly designed inverse-feedback loop”. Indeed, the following text (exactly as I posted it on the NET) is the relevant paragraph that seems to bother this particular contributor:

“Most “seemingly” unexplainable, yet truly audible differences between cables, can be explained if critically examined with respect to equipment interface considerations. For example, a well-designed, low-loss loudspeaker cable (with a relatively-low characteristic-impedance of perhaps 6 to 8 Ohms) can cause many expensive, well-regarded power-amps (with a slew-rate exceeding stability limits created by an improperly designed inverse-feedback loop) to oscillate at frequencies well above the audio range. This is sometimes audible as a low-level, high-frequency “crackling noise” (usually emitted by the tweeter as it’s voice-coil is being cooked). Such amplifier instabilities may also alter the “sound” of the amplifier by creating an “edgy” quality on musical transients or an exaggeration of high-frequency notes, etc.. But the amplifier, in this case, is at fault – not the loudspeaker cable.”

From the above, I fail to grasp how this person interpreted my comments as inferring that I believe amplifier stability is directly related to slew-rate – alone! Far from it, for some of the best power-amps I have heard and/or tested exhibited very high slew-rate performance – obtained by using proper high-frequency transistors in a “minimalist circuit configuration with relatively little inverse-feedback”. I sincerely hope that the above comments set the record straight and that I do, indeed, understand network/circuit theory, transmission-line theory, amp design, slew-rate, stability margin, inverse-feedback problems, etc.

One post on rahe recently noted that, “I’ve been following Stereophile’s analysis of time-coherence for a while now, and have noticed that almost none of the speakers reviewed are time-coherent, including those which received excellent ratings.” Without attempting to justify “excellent ratings” sometimes given by Stereophile for loudspeakers that do not exhibit “time-coherent” performance (good impulse, step, waterfall and energy-time responses), their reviews are most often an amalgam of two different approaches for judging “accuracy”: 1) subjectively perceived accuracy (based upon listening) and, 2) objective accuracy (determined by assessing a full-set of accurate measurements). The best reviews, in my opinion, are those that compare the results of both and attempt to resolve and explain any lack of correlation that might exist. Subjectively determined accuracy, taken alone, is an unreliable means for establishing the acoustical merits of audiophile components. This is because even the most honest attempt at determining accuracy by listening, is subject to personal experience, preferences, whims, long and short-term memory, program material, equipment interface problems, listening room modes, etc. Also, one reviewer might consider a “warm, mellow sound” to be most accurate while another might be attracted by a “more detailed, analytical sound” and so forth. If a multi-member group listens to a system and attempts to arrive at a consensus regarding its accuracy relative to some “standard”, the danger exists that the strongest-willed member may, without consciously intending to do so, inadvertently impose his or her choice on the other listeners.

Several individuals have inquired as to why we designed and sell our own loudspeaker cables and interconnects. The answer is simple: we believe that most audiophile cables are very over-priced, do not perform as advertised and do not provide the technical properties required to insure the best possible system performance (taking into consideration system interface problems). For example, most interconnect cables exhibit a sufficiently high capacitance (typically in excess of 30 pF/ft.) to cause non-linear distortion at high-frequencies when used with some pre-amps and power-amps. The relatively inexpensive top-of-the-line Radio Shack interconnects are a shinning example of an excellent performing, low-capacitance cable (typically about 15 pF/ft.) that is very, very affordable. Our own interconnect cable exhibits nearly half the capacitance but is a bit more expensive – though very affordable for most audiophiles.

With respect to loudspeaker cables, we measured most of the best known and most expensive audiophile brands and were shocked to find that little correlation existed between selling price and measured/audible performance. If you read back to some of my earlier postings on the subject, you will discover that I covered the matter in a reasonably thorough manner. We will continue to design and market our own cables to meet a consumer and professional demand for cables offering credible performance, based upon solid engineering criteria and accurate measurements of all relevant performance parameters – at very affordable prices. While we do so, we also tell audiophiles and professional users that, especially for relatively short lengths of cable, there appears to be no consistently audible difference between most loudspeaker cables (including high-quality #20 AWG Zip-cord). The same applies to most interconnect cables, regardless of their cost. But, in my opinion, it costs no more to design and manufacture cables that conform to the dictates of good engineering practice than those cables whose properties and performance are very questionable. So, why not do so – and give customers a break from all the flooby-dust, buzzard-salve, snake-oil and hokum that surrounds the advertising of too many of today’s cables?

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