The Truth About Interconnects and Cables

"I refuse to prove that I exist," says God, "for proof denies faith, and without faith, I am nothing."

- The Hitchhikers Guide to the Galaxy, Douglas Adams

The above could just as easily be re-phrased - for example ...

"I refuse to prove that my cables will make your system sound better", says the snake oil vendor, "for proof denies faith, and without faith, you will hear nothing."

The tenets of faith are an absolute requirement for many of the claims that are made for many (probably most) of the "esoteric" hi-fi additions that you will find everywhere on the web. There is no real information, technical, scientific or otherwise, and the only terms you will hear will be of a subjective nature - for example "solid, sparkling, sweet, musical" will be contrasted with "muffled, veiled, grainy, harsh" - the very selection of the words is designed to sway you to their position, preferably subconsciously.

Do Expensive Audiophile Cables Really Sound Better?

The marketing is often very subtle, and extremely persuasive, and there is no confusing techno-talk in there to confuse the non technical reader. While it may seem like Nirvana, the claims are nearly all completely false.

Faith (in the religious sense) is based on the premise that faith is God's proof that God's existence is truth and does not rely on facts. Indeed, if facts were available, then faith is not required - so in a sense, faith can be seen to be based on an absence of evidence - a fiction.

Believers may also qualify faith as either representing truth or they will represent it as being above and beyond our understanding. Truth becomes a consequence of faith which is the believer's recognition of the absence of evidence. Truth is therefore defined according to a circular perception.

I am not about to dispute the religious beliefs of anyone - these are sacrosanct, and belong to the individual alone. When the same arguments are used for audio, this is a different matter. Audio (unlike religious beliefs) is based on science. Without the efforts of scientific work and studies over many years by a great many people, we would not have audio as we know it. Now, we have charlatans and thieves claiming that science is ruining audio, and that we have to get back to the basics to enable real enjoyment.

You need, nay! must have! the latest shiny rock on top of your CD player, lest the sound be harsh, grainy, and lacking bass authority, and without the latest cables at only $200 per foot, you are missing out on half of the music. But ... you must believe, for the magic will surely be dissipated instantly should you attempt even the most rudimentary scientific test, or even request any technical information.

Now, consider the situation with watches. Has any ultra-high-priced watchmaker ever claimed that the "quality" of the time told by their watch is superior to that from "ordinary" watches, or that the "sense" of the time has greater depth and more "chi"? Maybe they just haven't thought of that angle yet, but I expect that this is unlikely. The simple fact is that these pieces of jewelry are finely crafted and superbly executed timekeepers, but are usually no better or worse that "lesser" brands that do exactly the same job.

The situation with cables is no different - you may choose to pay outlandish prices to get something that looks amazing, and demonstrates to everyone how much money you have, but it will not make a magical difference to the sound, there will be few (if any) real differences in the electrical characteristics, and it will sound much the same as "lesser" cables, selling at perhaps 100 ^th of the price.

If image is important to you, and you can afford it, then that is your choice - just don't expect that it will make your system better, and don't try to convince others that without "it", they are missing half their music or their sounds are being mangulated in some mysterious way that can only be "fixed" by spending vastly more than they may be able to afford.

Despite what you may read in various forum pages, this entire series of articles is not intended as a "beat up the subjectivists" tale, but rather a discourse based on research that I, and a great many others before me, have done. The idea is not to ruin anyone's enjoyment of audio, but to make sure that the facts are available, without the hype and BS so commonly associated with high fidelity.

The major (and well respected) audio companies did not develop their equipment using only their ears as a guide. Without exception, all the big (and very expensive in many cases) brands have been measured, probed, simulated, then measured some more - before anyone actually gets to hear one. How much of this pure research has gone into most of the overpriced cables and "accessories" currently available? I don't think I need to answer that, as we all have a pretty good idea.

So much has been said about cables over the past few years that there couldn't possibly be any more to discuss. Nice theory, but the wheel has turned a full circle, and there are now people claiming that there is no difference at all between any speaker cable or interconnect. In exactly the same way as the claims that there were "huge differences" were mainly false, so too are claims that there are none.

There is no "black and white" in this topic, but a great many shades of grey, and the latest update to this article attempts to clarify the position. Speaker cables in particular are still a major topic of conversation on many forum sites, and remain one of the more contentious issues.

A quick summary of the topics to follow (in the cable discussion, at least) would be ...

• Power leads will rarely (if ever) have any effect on the sound, provided they are of reasonable construction and are not inducing noise into (unshielded) interconnects. The only exceptions are those that use filters of some sort, which will reduce the noise floor in areas where interference is a problem.
  Some leads are of flimsy construction, and may reduce the available power for sustained loud passages, however, the difference will rarely exceed 1dB in most cases.
• Speaker cables can (and sometimes do) sound different with a given amplifier and loudspeaker combination, even where they are well designed and of reasonable gauge. Excluded are very thin or extremely silly combinations - these will always do something to the sound, rarely good.
• Interconnects might sound different, but only if they use odd construction techniques. Generally speaking, all properly (sensibly) designed and well made interconnects will sound the same - excluding noise pickup which is common with unshielded designs.

This is not to say that some people will not derive great enjoyment from the fact that they have spent as much on their cables as mere mortals can afford for their whole system, but this is "enjoyment", and has nothing to do with sound quality. This is about prestige and status, neither of which affect the sound.

Try This Next Time Someone Tries to Sell You Something ...

Thanks to a reader for the suggestion, this is a wonderful way to prove something to yourself. Next time a salesperson tries to flog you the latest and greatest (and of course most expensive) cable they have on offer, just use this technique ...

Suggest that you would like to hear the cable in action before committing yourself. As you walk to the demo room with the salesperson, come up with 'spontaneous' bright idea - suggest that you swap the cables, and if the salesperson can correctly identify the 'super cable' that s/he so desperately wants you to purchase, then you will do so. Naturally, you will want to make the swap several times, and the salesperson will have to get it right at least 75% of the time.

There is every chance that the packet will never be opened, the comparison never done, and you will save a bunch of money. There is nothing dishonest about what you are doing - you simply want (and are entitled to) verification that the cable will make a difference, and if the salesperson is unwilling to participate in the test, s/he knows something that s/he hasn't told you!

Beware! If there is any suggestion that the cable needs to be 'broken in' before you hear the difference, the salesperson is lying! At this point, you should immediately let them know that you know that they are lying, and leave the shop. Cable 'break-in' is a myth, and is perpetuated by those with something to hide - no-one has ever been able to show that there is any scientific justification to the claim, nor shown that the performance has changed in any way whatsoever. Cable break-in is real, and occurs between the ears of the listener - nowhere else (most certainly not in the cable).

Preamble

The last link entry for the ABX Home Page has been included so you can have a look at some actual ABX double blind tests that have been carried out. The listing at the ABX site is not extensive, but is excellent reference material. You will find some of the results surprising, and when viewed and interpreted sensibly, they tend to support the comments I have made in this article.

In some cases, the results surprised me, in that I was expecting the listener panel to declare various items as different, and they instead thought they were the same (which is to say that the two items under test could not be identified with certainty, so any choice was pure guesswork).

In this article, I shall attempt to explain some of the misconceptions and untruths that are rife in the audio industry. This article is bound to offend some, but the information is based on fact, scientific data and the results of my own (and others') testing, plus the help I have received from readers, who have provided more information on a number of topics.

In contrast, much of the disinformation comes from the rantings of Hi-Fi reviewers, most of whom know so little about electronics that it is shameful (and fraudulent) for them to be in a position to tell the unsuspecting public what to buy, based on entirely subjective criteria.

In almost all other areas of human interest, objective measurements are paramount. A domestic vacuum cleaner's performance is based on how much dirt it collects from the carpet - any philosophical discussion about the type of motor used, or it's rotational direction having a subtle effect on how clean the carpet feels is at best a pointless and tiresome exercise, and (I hope) has never been entered into.

Discussion - indeed, heated debate - on parameters not dissimilar to those above are commonplace in the high end audio industry, and have been raging since the late 1970's. The majority of people who listen to music generally listen to a few systems at a non-specialist retail outlet, and buy a combination that sounds good (to them), has the features they want, and fits their budget. They are no more interested in the great audio debate than they would be in the philosophy of the rotating mechanical components of their vacuum cleaner.

In his article "Science and Subjectivism in Audio", Douglas Self [ 1 ] wrote

A short definition of the Subjectivist position on power amplifiers might read as follows:

• Objective measurements of an amplifier's performance are unimportant compared with the subjective impressions received in informal listening tests. Should the two contradict the objective results may be dismissed out of hand.
• Degradation effects exist in amplifiers that are unknown to engineering science, and are not revealed by the usual measurements.
• Considerable latitude may be used in suggesting hypothetical mechanisms of audio impairment, such as mysterious capacitor shortcomings and subtle cable defects, without reference to the plausibility of the concept, or gathering any evidence to support it.
  

I believe this is a reasonable statement of the situation. Meanwhile the overwhelming majority of the public buy conventional hi-fi systems, ignoring the expensive and esoteric high-end sector where the debate is fiercest.

In our many following technical articles we shall dissect some of the claims made on many of the components in the audio chain, and show why they are misleading, false, and in many cases downright dishonest.

Special thanks to Rod Elliott from Elliot Sound Products

 

The Truth About Interconnects and Cables - page 2

Preamble Part 2

A fairly well known person (rampant on certain forum pages) has claimed that I consider all conductors and insulators to be "perfect", and that "all engineers who design in the real world know this is not the case". Oh really! ... and where exactly did I say that all conductors and insulators are "perfect"? Where did I imply that they are perfect?

These questions remain unanswered (of course) because I have never claimed, assumed or implied that they are perfect.

No insulator or co nductor is perfect - in fact, no "anything" is perfect. The simple fact of the matter is that these imperfections are not significant at audio frequencies, except perhaps in "unusual" cable constructions (of the type often suggested by the lunatic fringe). This is one of the typical "red herrings" that raving psychotics will bring up time and time again, to bolster their unsubstantiated and flawed "reasoning". Claims like that are typical of delusional thinking, and the delusional only have to claim that I (or someone else) said that "all conductors and insulators are perfect" (for example), and it somehow makes it "true" that these words were in fact used.

Well, I have some news that may come as a shock - anyone can say anything they like, but the saying does not make it so! I have never claimed that all conductors or insulators are perfect, but I have challenged anyone who claims that the imperfections are audible to please do so. So far, there has not been one shred of evidence that indicates that Teflon ^TM (wonderful stuff that may well be) is audibly superior to PVC in a properly controlled double-blind (or ABX) test.

Differences are measurable (with the right equipment) but are not relevant to the audio range unless the "facts" or cable topology are manipulated to influence the test.

I have asked every person and/or company named in the Mad As Hell articles for any information they have that substantiates their outrageous claims, and not one, not a single one , has supplied anything more than some useless promotional material or "satisfied customer" e-mails. Why is "satisfied customer" in quotes? How do I, or anyone else, know that they are genuine? For all we know, they are fabricated (i.e. lies), without an iota of truth in any of them. Oh, but I am so negative !

Of course I am, these people are liars, charlatans and thieves, either by accident (they may actually think they are realistic because of mental illness [such as delusion or psychosis] or some other mitigating circumstance) or by design - they simply have one goal ... to separate people from their money. The actual "mechanism" is unimportant - the fact that they are wrong does not enter into their equation of life, so whether their claims are due to mental illness or greed makes no difference to the consumer, who is being ripped off and lied to either way.

I recently had an e-mail exchange on the topic of interconnects, and the "conversation" started out innocently enough. I was advised that by using the tape loop on a preamp, I could listen to the effects of different interconnect cables, simply by switching to/from tape monitor.

I firstly suggested the test methodology suggested was flawed, since any additional circuitry used to make up the tape loop circuit would have some influence. In addition, the feedback to the brain (knowing which switch setting was which) means that a genuinely objective (double blind) test was impossible. The test method does not even qualify as single blind - it is an open test, and the experimenter expectancy effect will confer non-existent attributes to the material being tested, based on preconceived ideas and expectations.

The e-mails went back and forth for a while, and eventually I was finding that it took up too much of my time, and the topic is not all that interesting anyway - after all, how excited can one get over ordinary signal leads.

This is doubly true when the other party invents reasons that ABX tests are "invalid" for audio - something about the signal complexity, and the psychological effects of the music was mentioned. This is exactly why we must use ABX or similar double blind tests - anything else will fail to properly eliminate feedback cues, and these will be used (albeit subconsciously) to determine whether the "standard" or "test" item is currently in circuit. Any test where there is any possibility of identifying the components under test is completely invalid.

It is interesting that in a relatively non-demanding application such as an interconnect, a material such as aluminium would likely be sneered at by any audiophile, yet this very same material is used regularly in loudspeaker voice coils. I am reasonably sure that sonic performance of an aluminium interconnect would be deemed to fall way short of excellence, yet I hear (or read) no highly critical comments about using it in a voice coil. This is an extremely demanding role, and the performance of aluminium is (or can be) audibly and measurably worse than copper. *

My (almost) final e-mail pointed out that no metallic conductor introduces distortion. Now, I must admit that I did not qualify this, but when I speak of distortion I refer almost invariably to non-linear distortion (i.e. the type introduced by all active components, that generates harmonics and intermodulation products not present in the original signal). A simple question would have cleared this up, but ...

The response I received astonished me - suddenly, my statement that "no metallic conductor introduces distortion" was utterly misconstrued, and became "all metals are perfect conductors"! It was inferred (of course) that this was the reason that my tests and experiences are simply invalid, while those of my correspondent were reasoned and obvious.

This is absolutely the sort of thinking that got everyone to this impasse in the first place. I never suggested that all metals are perfect conductors - I said that they don't generate (non-linear) distortion. By means of misinterpretation, the subjectivist camp will now think it has another "weapon" against the enemy - the fact that it is the result of a gross mangling of the original statement is of no consequence ... "Never let the facts get in the way of a good story".

The fact of the matter is that no metallic conductor causes (non-linear) distortion.

There are various resistances depending on the metal, but it's basic conductivity is completely linear. Check things like thermal coefficient of resistance for any metal - it is linear. There are no curves or "fudge factors" to be taken into account. While it may be possible to make an alloy that exhibits some degree of non-linearity, this would not be used as an electrical conductor, and would certainly not be suggested as an alternative to copper. Even then, within the very limited range of acceptable temperatures in the listening room, such non-linearities could easily be less than that of air - the medium that carries the sound from the speakers to our ears..

None of this has anything to do with skin effect, velocity factor or any of the other seemingly strange behaviours of all conductors at high frequencies (none of which are non-linear distortions), we are interested in the simple ability to conduct current from point A to point B without any form of rectification or other non-linear effect. All metallic conductors in common use will do this perfectly well, and will not add harmonics or change the waveshape in any non-linear way.

Harmonics can of course be removed - this is a filter effect (a completely passive linear function), and is caused by capacitance and inductance. All cables have these parameters as a fact of life - a silver wire and an aluminium wire of the same length and diameter have different resistance, but inductance and capacitance are the same.

The degree of hostility I experienced towards ABX testing was equally puzzling. I don't know of any designer who will claim that listening tests are invalid - only that they may not reveal the entire truth of the matter, and that additional "technical" evaluations may be needed to find out why the listening tests did (or did not) correlate with the measurements.

On the other hand, many subjectivists claim that anything other than a listening test is invalid, and commonly and even vigorously eschew ABX testing - possibly because they know in their hearts that they will be unable to find any difference. This is very confronting, and to have one's beliefs shattered is not a pleasant experience.

What is the most interesting to me is the "head in the sand" behaviour. I was automatically wrong in my thinking, and I suspect that anything that I said would have been twisted around to make sure that I stayed wrong. I could (of course) have simply agreed with the subjectivist's position, however to have done so would have been a lie on my part.

The issues at stake here are the crux of the on-going debate between the two "camps". While I will admit that not all designers will take any subjective opinion seriously, I do know from my own testing and from a huge amount of reader feedback that some of my designs sound better with different transistors or power supply configurations (for example). Most of these differences can be quantified, although some are elusive, and that is something that I live with, knowing that many of the further "tweaks" are assessed by purely subjective methods. There is every chance that ABX testing would reveal no audible difference.

The Truth About Interconnects and Cables - page 3

* More on Aluminium (Aluminum)
I mentioned above that aluminium interconnects would generate scorn and derision from the audiophiles. Well, it seems that for some, even using it for shielding is bad ...

"Unused RCA inputs on the back of [amplifiers] are prone to pickup stray RF Interference and EMI. This can cause a higher level of background noise, haze and grain. For years audiophiles have used shorting plugs or (gag!) aluminum foil, to remedy the situation. Unfortunately, many preamps do not like to have their inputs shorted. What to do?"

Wonder what "gag!" implies - I think I can guess. Needless to say, the answer was in the product line for the site in question - I shudder to think how much their little RCA "hats" cost.

I saw remarkably few references to aluminium even being used (let alone sounding "bad") in interconnects, and no adverse comments at all about it's use as a voice coil winding wire. I must confess that I did not spend a vast amount of time on this, partly because as I said early in this section - cables are just not very interesting :-)

How does this thinking occur? An excellent article on the human belief system is The Belief Engine, which is to be found at http://www.csicop.org/si/9505/belief.html . The article describes the mechanisms we use to generate beliefs, and the ways that these beliefs are reinforced as we go along. One tiny quote from the article ...

Our brains and nervous systems constitute a belief-generating machine, a system that evolved to assure not truth, logic, and reason, but survival.

What does survival have to do with interconnects - nothing at all, of course. But this does not change the way we think, and especially does not change the way we think we think. Beliefs are extremely powerful, and can be almost impossibly difficult to shed once they have become entrenched ... I have no expectations at all that this article will change that one little bit, but if it helps others (not yet contaminated) to stay well clear of pseudo science, then I have done what I could.

Speaker Leads

Speaker leads have been discussed extensively in my article on impedance, but I shall repeat some of this here for the sake of completeness. For the full text, see Impedance [ 2 ] and Amp Sound , an article discussing the influences that affect the sound of amplifiers.

This was pointed out to me by a reader, and was originally published in the New York Times (on-line edition) a while ago ...

http://www.nytimes.com/library/tech/99/12/circuits/articles/23down.html

Copyright 1999 The New York Times Company

December 23, 1999

A Spat Among Audiophiles Over High-End Speaker Wire
By ROY FURCHGOTT

In the last year, Lewis Lipnick has tested high-end audio cables from 28 manufacturers. As a professional musician with the National Symphony Orchestra and as an audio consultant, he counts on his exacting ear to tell him if changing cables affects the accuracy of the sound from his $25,000 Krell amplifiers.

His personal choice is a pair of speaker wires that cost $13,000. "Anyone would have to have cloth ears not to tell the difference between cables," he said.

"In my professional opinion that's baloney," said Alan P. Kefauver, a classically trained musician and director of the Recording Arts and Sciences program at the Peabody Institute of Johns Hopkins University. "Has the wire been cryogenically frozen? Is it flat or round? It makes no difference, unless it makes you feel better." His choice for speaker wire? Good-quality 16-gauge zip wire.

The disagreement would be unnotable except for one thing: experts are in agreement that most cables that claim to improve the sound of audio equipment don't. Even cables costing thousands of dollars per foot are often little more than sonic snake oil, experts say. Consumers trying to purchase audio cables often find themselves buying high-end replacements because the only cables in the store are expensive ones.

A purchaser of an entry-level $550 stereo system might be sent home with $55 worth of the least expensive middle-quality audio cables. While experts agree that most cables make exaggerated and unfounded claims about improving sound, they cannot agree on which cables actually do improve sound and which do not.

The scientific record is unclear. So far no research paper contending to prove or disprove the value of fancy wires has been accepted by the leading industry publication, The Journal of the Audio Engineering Society, said Patricia M. MacDonald, its executive editor. She said there were dozens of reasons a research paper might not meet her journal's standards.

"I don't think anyone should infer anything from it," she said.

The manufacturers and sellers of audio goods like to stay above the fray. Cables are a highly lucrative item that may account for a modest percentage of sales but a greater percentage of profit. Even audio manufacturers not directly involved in the cable business like to steer clear of the debate.

[Related Articles: Do It Yourself: A Little Soldering Goes a Long Way; (December 23, 1999) ]

Polk Audio, a well respected manufacturer of loudspeakers in Baltimore, no longer makes cables but declined an invitation to set up a listening test in its laboratories. One reason it gave was that the test could affect relationships with audio stores. "We would be hearing from every retailer in the country," said Paul Dicomo, communications director for Polk Audio. Kerry Moyer, staff director for the Consumer Electronics Association, which represents manufacturers, said accessories were usually the highest markup items, wires included. Sales of high-margin accessories have become critical in the current market, where prices of components like receivers, amplifiers and DVD players, have had profit margins squeezed by competition.

"It becomes a question of where are we going to make a little money?" he said. Mr. Moyer, whose $3,000 sound system uses about $300 worth of cables, said the technological superiority of a cable is not the issue -- it is the perceived value to the hobbyist.

"If someone feels good about buying it, whether it works or it doesn't, it makes them feel good," he said. "I don't think we should question."

John Dunlavy, who manufactures audiophile loudspeakers and wire to go with it, does think questioning is valid. A musician and engineer, Mr. Dunlavy said as an academic exercise he used principles of physics relating to transmission line and network theory to produce a high-end cable. "People ask if they will hear a difference, and I tell them no," he said.

Mr. Dunlavy has often gathered audio critics in his Colorado Springs lab for a demonstration.

"What we do is kind of dirty and stinky," he said. "We say we are starting with a 12 AWG zip cord, and we position a technician behind each speaker to change the cables out." The technicians hold up fancy-looking cables before they disappear behind the speakers. The critics debate the sound characteristics of each wire. "They describe huge changes and they say, 'Oh my God, John, tell me you can hear that difference,'" Mr. Dunlavy said. The trick is the technicians never actually change the cables, he said, adding, "It's the placebo effect."

This leads to disagreements based on competing science. Bruce Brisson, who owns Music Interface Technology, an ultrahigh-end wire manufacturer in Rockland, Calif., also wants to see cable charlatans revealed and may use his extensive laboratory to do it.

"I am getting ready to expose this in the year 2000," he said. "People are paying a lot of money and getting nothing for it." But he disagrees with Mr. Dunlavy on the effectiveness of wires, saying that the theory Mr. Dunlavy uses to design his cables is not the right theory and that is why listeners cannot hear a difference. **

Some scientists say it would be difficult to prove one way or another. Changing cables leaves a time lapse that makes comparison difficult. Putting several stereos side by side with the different wires would mean that the speakers would be different distances from the ear, which could have an effect. And while a switch could be made that would send a signal through each of several cables to a speaker from a single sound system, cable makers say the switch itself might spoil the advantages of their wires.

Part of the difficulty is that there are still unexplained acoustic phenomena. William Morris Hartmann, a professor of physics at Michigan State University in East Lansing, works on psycho-acoustic projects, which investigate the way sound is perceived, rather than the way it is produced. There are examples, he said, of sounds that measure beyond the range of human hearing, and yet some people seem to perceive them. That means the market is left open to wild claims and psuedoscience. "It's annoying, but it's hard to disprove," Professor Hartmann said.

Perhaps the closest thing to middle ground is the position taken by Russ Hamm, an electrical engineer whose New York company G Prime Ltd. installs digital processing equipment for studios. Mr. Hamm said that indeed, wires do make a perceivable difference, but very little, and then only to professionals, like the engineers at BMG Music. He
lent them new high-grade cables for use on roughly $250,000 of equipment. On his system, Mr. Hamm uses a specialty cable manufactured in Vienna that costs $2 a foot.

"We are talking subtle differences, but that is what the high end is all about," he said.

It is a subtlety he describes as a 2 percent difference on a high-end system. "If you had a fine Bordeaux wine, how much does it matter if it's in a nice wineglass or a Riedel crystal glass?"

His advice to audiophiles: "I would say that you want to put the first $10,000 into your equipment."

Copyright 1999 The New York Times Company

The above is reproduced verbatim, and I hope that this information is helpful to your understanding of the topics to follow. Remember that the purpose of this article is not to try to sell you something, but to inform and rationalize the many myths that abound regarding the audibility (or otherwise) of different cables.

** It is worth noting that the year 2000 has come and gone, and to my knowledge, neither Bruce Brisson nor anyone else has produced a scientifically sound explanation for the alleged superiority of any one cable over another. There is simply little or no validation available for the vast majority of the outlandish claims made.

The Truth About Interconnects and Cables - page 4

We hear so much about damping factor, the effect of speaker leads (and how much better this lead sounds compared to an "ordinary" lead), and how amplifiers should have output impedances of micro-Ohms to prevent "flabby" bass and so on. But what does it all really mean?

Before an informed judgement can be made, we need to look at some of the real factors involved. There are a multitude of impedances involved in a typical amplifier to loudspeaker connection, most of them having a vastly more profound effect than the impedance of the speaker lead alone.

For example, my own (tri-amped) hi-fi uses separate amps for the bass and mid with a designed output impedance of about 2 Ohms. This provides a useful extension of the bottom end (I'm using sealed enclosures), without excessive peaking at resonance. Much the same effect is found with most valve amplifiers, which typically have an output impedance of 1 to 6 Ohms.

Ignoring the losses in the speaker lead (which are usually very small), the impedance of the cable is very low compared to that of loudspeaker crossover networks and the like. While there is no denying that some speaker leads do sound different, the important thing is "different" rather than "better".

A double-blind test carried out by an Australian electronics magazine many years ago found that most listeners thought that the really thin figure-8 type speaker cable had better bass than all the more expensive ones. Treble response was generally thought better using a heavy duty 3-core mains cable. No-one thought that any of the high priced cables sounded better than anything else.

Other workers in the field, such as Douglas Self [ 1 ], have determined much the same, so even in the light of some convincing evidence to the contrary, we have reviewers still extolling the virtues of cables costing more than a decent set of loudspeakers.

Generally, resistance and inductance in the speaker lead can (and does) cause minor variations in level, especially with difficult loads. These deviations are likely to be less than 0.1dB for reasonable cable constructions, with inductance less than 4uH. The resistance of a typical cable (perhaps 0.1 Ohm) causes response variations across the band, following the loudspeaker impedance curve, but these are usually even less at around 0.05 dB. Neither variation is audible.

You will even find references in some cases to the cable's characteristic impedance - a value that is only useful if cables are used for radio frequencies, or are many kilometres in length. These are uncommon in audio listening rooms in my experience. The characteristic impedance of a cable has no effect whatsoever on signal frequencies that are low compared to cable length. At the worst (using coaxial cable) a signal travels at 0.8 of the speed of light (3x10^8 m/s).

Assume that for an adequate safety margin we want to be able to pass up to 100kHz through the speaker cable. The wavelength at this frequency is 3000 metres, or in coax, 3750 metres. A typical listening room may require up to 10 metres of cable, so at the very worst case, the cable is 1/300 to 1/375 times the wavelength of the signal. The effect is utterly insignificant in all respects. The signal will be delayed by an amount that is less than that experienced if the listener were to move his/her head by 1mm towards or away from the loudspeaker. This is of course a common occurrence, and often by several millimetres, even while asleep.

Difficult Loads
While it is true that reasonable quality twin cables (figure eight or zip cord) are adequate for nominal 8 ohm loads over short distances, there are a number of popular loudspeakers that are anything but nominal at high frequencies.

Two that a reader advised me about are the AR11 and the Quad ESL (old model). Both of these drop below 2 ohms in the treble frequencies. The AR bottoming out at 5kHz and the Quad at 18Khz (although anything from 15kHz to 18kHz is common). The dips are fairly sharp and so the load impedance is highly capacitive on the way down and inductive on the way up. The frequencies are high enough to not worry good amplifiers but what about the response at these dip frequencies?

Twin wire cables all have significant inductance which increases in proportion to length. With 10 amp rated twin flex over only 5 metres the response was down by 2.5 dB into one Quad ESL at 18 Khz, and 3.5 dB into the other speaker which had 8 metres. This was audible and unacceptable.

The only way to reduce cable linear inductance is to make the two wires talk to each other. Running in close parallel is a start, tight twisting is better but only by using multiple wires for each and interweaving can you really get the inductance down. Several cable makers have done this and sell them as low impedance cables, which is exactly what they are. There are several different cables that use this method, and twin coaxial cable is also used to achieve a similar result.

One construction uses two groups of 72 strands of enamelled wire plaited around a solid plastic core. Using these cables with difficult loads, the droop at either 5 or 18 kHz disappeared and the sound was distinctly better. There would be virtually no other way to solve the problem short of mono amplifiers sited next to each loudspeaker.

One (potentially major) drawback ocurs if you own certain amplifiers that are unstable with capacitive loads. Typical multiple twisted pair cable has about 9nF per metre of capacitance with little resistance or inductance, which causes many amplifiers to go into parasitic oscillation. The fix is simple, wind twelve turns of wire around a pen and put it in series with the beginning of the cable. This tiny coil has far less inductance than even one metre of twin flex.

This description of the possible issues with speaker cables is the first I have seen that makes some sense from a technical perspective. There is sufficient evidence from my own measurements and those of many writers that there are indeed some detectable (and measurable) differences. With this in mind, and wanting to provide all the information I can, I have included this information - and this is the one area where properly sized and well made cables really does make a difference. If you own speakers that present a highly capacitive load, or have deep "notches" in the impedance curve, I would take this information seriously.

Summary
Essentially, the main offenders in speaker leads are resistance and inductance. Of these, inductance is the hardest to minimise, and although usually small, it may still cause problems with some loads (see update, below). Many construction methods have been used, from multiple CAT-5 data cables, with the wires interconnected (usually all the coloured leads are deemed the +ve conductor, and all the white wires - the "mates" - are used as the negative). Because of the tight twist, the inductance is minimised, but at the expense of capacitance. In some cases, the capacitance may be high enough to cause instability in the amplifier, which not only does awful things to the sound, but can damage the amp.

Another popular method of minimising inductance is to use a pair of coaxial leads (e.g.75 Ohm TV/video coax or similar). The inner conductor of one and the outer conductor of the other are joined to make the +ve lead, and vice-versa for the negative. A good quality coax has a relatively low capacitance, and by interconnecting in this way, inductance is also reduced by a very worthwhile margin.

It is widely held that with difficult loudspeaker loads - as presented by many modern speaker systems with complex crossover networks - that reducing inductance can be very beneficial. This is especially true where the crossover causes significant drops in impedance at some frequencies. This also places unusually high demands on the amplifier - one of the reasons that some amplifiers just don't "cut it" with some speakers.

These problems can be reduced or even eliminated entirely by biamping or triamping [ 3 ], allowing the use of good quality but not extravagant speaker leads.

Resistance, which is easy to eliminate, reduces the damping factor and wastes power. With even reasonably robust leads, this should not be an issue.

Bottom Line on Speaker Leads
Use quality cable, but extravagance will buy no more genuine performance. You will be able to obtain far greater benefits by biamping the system [ 3 ] than spending the same amount on esoteric (read "expensive") speaker leads.

Be willing to experiment, using 3-core mains cable (not the types described above, either), and paralleling two of the conductors for the speaker negative connection (or the positive - the speaker will not care either way). Save yourself a fortune, so you can buy more music instead.

I have seen several references on the web regarding the use of Cat-5 network cable and specially wired coaxial cable for speakers. The idea with network cable is to parallel the wires (these cables are usually 4-pair), and it is claimed that the sonic performance is excellent. I haven't tried it, but Cat-5 is relatively inexpensive, and might work quite well. Try it if you want to. Wiring coaxial cables for speaker use is also not too hard, and it is claimed that this can beat most of the really expensive cables.

Before one even considers the alleged benefits of one cable over another, here is something to think about ...

"What does "veiled" mean (in reference to high frequency reproduction), and how is it determined that the veiling effect is caused by anything specific, as opposed to everything in general? This includes state of mind (i.e. good day, kids acting up, wife annoyed about something), health (cold or flu, hay fever), position of listening chair (was it moved to vacuum the floor?), etc."

And, no, these are not trivial questions. They are every bit as important as anything else, and all the more so if we have only a subjective interpretation of the sound, without measured results that show the effect. Have a look at the article " Amplifier Sound " for more info.

The Truth About Interconnects and Cables - page 5

Interconnects

All well designed interconnects will sound the same. This is a contentious claim, but is regrettably true - regrettable for those who have paid vast sums of money for theirs, at least. I will now explain this claim more fully.

The range (and the associated claims) of interconnects is enormous. We have cables available that are directional - the signal passes with less intrusion, impedance or modification in one direction versus the other. I find this curious, since an audio signal is AC, which means that electrons simply rush back and forth in sympathy with the applied signal. A directional device is a semiconductor, and will act as a rectifier, so if these claims are even a tiny bit correct, I certainly don't want any of them between my preamp and amp, because I don't want my audio rectified by a directional cable.

Oxygen free copper (or OFC) supposedly means that there is no oxygen and therefore no copper oxide (which is a rectifier) in the cable, forming a myriad of micro-diodes that affect sound quality. The use of OFC cable is therefore supposed to improve the sound.

Try as I might (and many others before me), I have never been able to measure any distortion in any wire or cable. Even a length of solder (an alloy of tin and lead) introduces no distortion, despite the resin flux in the centre (and I do realise that this has nothing to do with anything - I just thought I'd include it :-). How about fencing wire - no, no distortion there either. The concept of degradation caused by micro-diodes in metallic contacts has been bandied about for years, without a shred of evidence to support the claim that it is audible.

At most, a signal lead will have to carry a peak current of perhaps 200uA with a voltage of maybe 2V or so. With any lead, this current, combined with the lead's resistance, will never allow enough signal difference between conductors to allow the copper oxide rectifiers (assuming they exist at all) to conduct, so rectification cannot (and does not) happen.

What about frequency response? I have equipment that happily goes to several MHz, and at low power, no appreciable attenuation can be measured. Again, characteristic impedance has rated a mention, and just as with speaker cables it is utterly unimportant at audio frequencies. Preamps normally have a very low (typically about 100 Ohms) output impedance, and power amps will normally have an input impedance of 10k Ohms or more. Any cable is therefore mismatched, since it is not sensible (nor is it desirable) to match the impedance of the preamp, cable and power amp for audio frequencies.

Note: There is one application for interconnects where the sound can change radically. This is when connecting between a turntable and associated phono cartridge and your preamp. Use of the lowest possible capacitance you can find is very important, because the inductance of the cartridge coupled with the capacitance of the cable can cause a resonant circuit within the audio band. Should you end up with just the right (or wrong) capacitance, you may find that an otherwise respected cartridge sounds dreadful, with grossly accentuated high frequency performance. The only way to minimise this is to ensure that the interconnects have very low capacitance, and they must be shielded to prevent hum and noise from being picked up.

At radio frequencies, Litz wire is often used to eliminate the skin effect. This occurs because of the tendency for RF to try to escape from the wire, so it concentrates on the outside (or skin) of the wire. The effect actually occurs as soon as the frequency is above DC, but becomes noticeable only at higher frequencies. Litz wire will not affect your hi-fi, unless you can hear signals above 100kHz or so (assuming of course that you can find music with harmonics that go that high, and a recording medium that will deliver them to you). Even then, the difference will be minimal.

In areas where there is significant electromagnetic pollution (interference), the use of esoteric cables may have an effect, since they will (if carefully designed) provide excellent shielding at very high radio frequencies. This does not affect the audio per se, but prevents unwanted signals from getting into the inputs or outputs of amps and preamps.

Cable capacitance can have a dramatic effect on sound quality, and more so if you have long interconnects. Generally speaking, most preamps will have no problem with small amounts of capacitance (less than 1nF is desirable and achievable). With high output impedance equipment (such as valve preamps), cable capacitance becomes more of an issue.

For example, 1nF of cable capacitance with a preamp with an output impedance of 1k will be -3dB at 160kHz, which should be acceptable to most. Should the preamp have an output impedance of 10k, the -3dB frequency is now only 16kHz - this is unacceptable.

I tested a couple of cable samples, and (normalised to a 1 metre length) this is what I found

NT - Not Tested

These cables are representative of medium quality general purpose shielded (co-axial) cables, of the type that you might use for making interconnects. The resistance and inductance may be considered negligible at audio frequencies, leaving capacitance as the dominant influence. The single core cable is obviously better in this respect, with only 77pF per metre. Even with a 10k output impedance, this will be 3dB down at 207kHz for a 1 metre length.

Even the highest inductance I measured (1.2uH) will introduce an additional 0.75 Ohm impedance at 100kHz - this may be completely ignored, as it is insignificant.

The only other thing that is important is that the cables are properly terminated so they don't become noisy, and that the shield is of good quality and provides complete protection from external interfering signals. Terminations will normally be either soldered or crimped, and either is fine as long as it is well made. For the constructor, soldering is usually better, since proper crimping tools are expensive.

The use of silver wire is a complete waste, since the only benefit of silver is its lower resistance. Since this will make a few micro-ohms difference for a typical 1m length, the difference in signal amplitude is immeasurably small with typical pre and power amp impedances. On the down side, silver tarnishes easily (especially in areas where there is hydrogen sulphide pollution in the atmosphere), and this can become an insulator if thick enough. I have heard of some audiophiles who don't like the sound of silver wire, and others who claim that solid conductors sound better than stranded. Make of this what you will :-D

The use of gold plated connectors is common, and provides one significant benefit - gold does not tarnish readily, and the connections are less likely to become noisy. Gold is also a better conductor that the nickel plating normally used on "standard" interconnects. The difference is negligible in sonic terms.

There is no reason at all to pay exorbitant amounts of hard earned cash for the "Audiophile" interconnects. These manufacturers are ripping people off, making outlandish claims as to how much better these cables will make your system sound - rubbish! Buy some good quality audio coaxial cable and connectors from your local electronics parts retailer, and make your own interconnects. Not only will you save a bundle, but they can be made to the exact length you want.

Using the cheap shielded figure-8 cable (which generally has terrible shields) is not recommended, because crosstalk is noticeably increased, especially at high frequencies. That notwithstanding, for a signal from an FM tuner even these cheapies will be fine (provided they manage to stay together - most of them fall to bits when used more than a few times), since the crosstalk in the tuner is already worse than the cable. With typical preamp and tuner combinations, you might get some interference using these cheap and nasty interconnects, but the frequency response exceeds anything that we can hear, and distortion is not measurable.

Digital / Optical Interconnects
Recently I have seen adverts and reviews on fibre optic digital interconnects. Some are supposedly far superior to others, despite the fact that 1s and 0s (light present, light not present) are all that is passed. IMHO, it would take truly monumental incompetence to design any digital interconnect that was incapable of passing a digital signal without corruption. Since fibre optics (non-audiophile grade) are used to carry phone calls and data all 'round the world, with very low error rates and over huge distances, it is ludicrous to assume that any commercial digital interconnect will make any difference over a distance of a metre or so.

Bear in mind that the receiver reconstitutes the signal wave shape, it is usually buffered, and will use some form of error correction as well. As for claims that the difference is audible ....

Summary
Aside from interference pickup, capacitance and crosstalk are the only real potential problem with interconnects. Capacitance can be minimised by selection of the cable. In come cases, even though the impedance of the preamp may be low enough, use of a highly capacitive cable may cause RF instability in the output stages - this will definitely ruin the sound.

Crosstalk is all but eliminated by the use of good quality shielding, which will generally also reduce interference. Keeping lead lengths to the minimum needed will also help reduce any possible negative influences.

Bottom Line on Interconnects
Use home made ones, or buy cables that are well made and reasonably priced. The expensive ones that will "make your system sound better" won't - you are just making some idiot richer, and yourself poorer.

I know that this is heresy to some, but I really don't care. This is factual, and I can prove my claims, while the makers of these fancy cables can't.

I have seen home-made cables, braided from multiple strands of wire-wrap wire. The shielding on some of these can be mediocre (at best), so experiment, but don't expect miracles.

The Truth About Interconnects and Cables - page 6

Power Leads

The power lead (cord or cable if you prefer) is how mains power at 220V, 240V, 110V at 50 or 60Hz gets to your system. The specifics of the voltage and frequency are determined by where you live, and the available household mains provided by your electricity company.

There are mains cables (power cords) available that defy belief. Would you spend US$3000 for a 2 metre mains lead? You can buy a very nice amplifier indeed for this sort of money, but they are there, and someone must be buying the stupid things.

What possible effect 2 metres of flexible cable can have to counteract the kilometres of power company's wiring is a simple question to answer. None. Or, to more precise, none whatsoever. I am not referring to cables with inbuilt filters or other esoterica here, just perfectly ordinary mains leads.

I have measured the distortion on the mains at my workshop test bench. Last time I did this it was 5.6%, and there is absolutely nothing that a cable can do to change this, regardless of cost. The distortion is caused by a multitude of things completely outside our control, with power supplies for computers and other equipment being only one group of offenders.

These draw power at the peak of the AC waveform, causing it to become flattened (similar to clipping in a power amplifier). The various power company transformers along the way will also introduce some degree of distortion, and there are inductive and capacitive losses within the distribution system. As well, there are large motors being controlled by various speed controllers (most use large solid-state switches), used in industry and commercial centres. Lifts, air compressors, machinery, the list is endless.

Because of the resistance of the supply authority's cabling and transformers (there are some massive cost considerations they must address), when a high power appliance is turned on, the mains voltage falls. This resistance (actually it is impedance) will cause the voltage to vary from one second to the next, with significant drops at the times when meals are being prepared (electric stoves switched on all over the place), and at other periods. I have measured the impedance at my house at 0.8 Ohms (we use 240V in Australia ), so an appliance that draws 10 Amps (such as a heater) will cause the voltage to fall by 8 Volts. This could be reduced by increasing the size of my internal wiring, but the gains would be few and the cost high. In 110V countries such as the US , the wiring impedance must be made lower, since all currents are higher for the same power. It is likely that this causes even greater compromise due to the larger wire sizes that must be used (larger wire means greater cost).

So, given that the mains is distorted, and varies in amplitude from minute to minute throughout the day, and has significant impedance, what can be done to fix this? One method would be to use an Uninterruptable Power Supply (UPS), which (if you get the right type) uses the incoming mains to charge batteries, then uses an inverter to supply power to your equipment. You can buy one of these for $3000, and the emerging mains supply will be as clean as the UPS can make it. No cable can do this, regardless of price.

Using a UPS will ensure that your 100W amplifier can provide 100W, despite the variations in the supply voltage. Whether you can hear any difference is doubtful, because even given that the mains can (and does) vary by up to 10%, your equipment should have a reserve power rating that can accommodate such variance.

I have been advised by a reader (in the US ) who reminded me that unless the UPS is specifically designed for sinewave output (and the distortion is quoted), it will probably have greater distortion than the mains anyway. The voltage will be stable, but the switching noise of the UPS may actually make matters worse.

A 100W amp (at nominal supply voltage) should give at least 100W. At 10% low supply, this drops to about 80W, a difference of less than 2dB. If you are operating power amps at close to clipping all the time, you will hear the difference, but this is not the way Hi-Fi gear is meant to be used.

Q: Having a nice clean sinewave from the UPS or power conditioner should make a difference though, shouldn't it?
Q: Why would it not make any difference to the sound from the amp?

The answers are simple and complex, but the result is the same. At the very best, transformer dissipation might be slightly lower, but the AC from the secondary of the transformer is rectified and filtered, making it into DC, since the amp cannot operate from AC power supplies. The amount of DC "ripple", or superimposed AC signal is determined by the design of the amplifier's power supply, and is completely independent of outside influences other than the mains supply impedance. Even this has a very minor effect in the greater scheme of things.

If I really wanted to be able to supply 100 Amps to my speakers for brief moments, my power supply can already do this. If I wanted to be able to do it all the time for extended periods, my speakers would catch on fire. No mains lead will give my power supply this ability, nor take it away. The limitations are in the supply itself, and include the transformer, rectifier and filter capacitors.

One useful observation is that the mains in the US seems to be basically pretty nasty, and not at all what we are used to in Australia . Interference seems to be a major problem, and if this is the case, it will find its way through the power supply and into the amplifier (or other equipment) if the power supply is not well designed.

Also, because of the lower mains voltage in the US (nominally 120V), the current drawn by power amplifiers in particular can cause real problems with cheap light duty cables. I have already made this point, but it is worth making again. Use of a heavy duty lead (possibly shielded if interference is a problem) will make a difference. Whether the power difference is audible or not is debatable, but elimination (or even reduction) of mains borne interference is likely to result in a worthwhile improvement in sound quality.

Normally I would expect that any interference would be audible all the time, and it seems very unlikely that it only manifests itself when there is music playing. Electricity is not that cunning, and is not by nature vindictive. Having said that, it must be noted that when an amplifier is producing a lot of power, the current spikes on the mains will be much greater, and may have an influence that would normally be un-noticed. The easy way to determine this is to move the leads about to find out if this changes the background noise level. If it does, then re-locating the leads will provide far greater benefit than spending a king's ransom on power leads.

Use of a proper power conditioner (or a "pure" sinewave UPS) will completely eliminate mains interference, and this will naturally be beneficial. This is not something I have encountered, but if there is a problem, then this is probably the best way to fix it.

In some cases, all that may be needed is interference suppressors ("spike arrestors"), to get rid of clicks and pops that get into the system via the mains. These are readily available and fairly cheap, and might be a good place to start.

I have examined several mains leads I have, and upon inspection I saw that the pins of the US plugs are of thin sheet metal (brass). This is folded over for the flat pins (active and neutral) and rolled into a tube for the earth pin. In contrast, our (Australian) plugs have solid brass pins, and are altogether much more substantial than the US ones (the US lead I have is rated at 13A, and is a very solid cable - but the pins are a weakness IMHO). The standard 13A fused UK plug is even more solid than ours - the pins are probably capable of at least 50A based on their size. One style of European style plug I have is also nice and solid. Elsewhere, I do not have samples, and can't comment.

To give you an idea. Listed below are the pin sizes and materials for 4 mains plugs I have

As you can see, even though the US lead has a higher current rating and requirement, the pins are smaller and capable of less current. Where the others use solid brass pins, the US lead has thin sheet brass folded over to give a thicker overall pin - which is still thinner than the others. It is also wibbly - you can quite easily bend the flat pins with your fingers - I did ! Bent them right over at the base, and bent them in the middle. This is impossible with any of the others. From what I recall of US wall outlets, they are also fairly wimpy affairs, with relatively poor contact surfaces.

Another point mentioned was that by using a high current shielded cable for the mains may prevent the current spikes caused by the amplifier's rectifier from injecting spurious noise into interconnects and other equipment. There may be some truth in this, and the effects are certainly measurable - this is why professional audio gear uses balanced connections, to eliminate exactly this sort of problem. Use proper "lead dress" - keep all power leads as far as possible from signal interconnects, and if they must cross, then cross them at right angles.

It also seems that the regulations in the US as to what you may (or may not) use as a power cable are somewhat lax (by Australian standards, anyway), allowing sub-standard connectors at both ends of the cable, and with seemingly minimal control over what may legally be sold as a mains lead.

Many (most?) of the high-end cables that I have seen referred to would not be legal in Australia , and in many other countries. No mains lead is allowed to be sold here without electrical authority approval - this is quite expensive to obtain, and involves voltage drop testing (the lead's resistance) and electrical insulation tests, along with various others. Shielded mains lead is uncommon, but I am sure that it would be available.

I have been taken to task seriously by some for not having tested any of the mains cables - well I can't, because I (like everyone else) have no criteria to base tests on. I know from experience that long (or light duty) leads will reduce the power available, but have no way to create interference of the type that could cause severe sonic degradation so I can verify that a cable eliminates it.

As to blanket claims that "the power cord has more influence than anything else in the chain other than room positioning of the speakers" (and yes, someone did make that claim), what can I say?

One of the respondents is apparently a distributor of high end power leads (so I discovered from someone else's posting), and he had no proof to offer, and nor did anyone else, so I am still left with the same conclusion as before (with some modification based on interference problems).

The Truth About Interconnects and Cables - page 7

Other (Cheap) Things You Can Do
I had an e-mail from one of my regular readers, who was telling me that his apartment is wired using aluminium cable. This is (apparently) no longer acceptable in the US , but the fact that it was ever allowed at all is quite amazing. He discovered that he was having mains problems, so rather than "invest" in high-end power cables, he simply decided to replace the wall outlets with new ones, and re-terminate the aluminium house wiring. This in itself is not easy, because aluminium forms an oxide ( very quickly) which is an insulator, and terminations need to be airtight - literally - to stop this from happening.

Aluminium also "flows" under pressure, so to terminate it properly needs a connector that applies constant pressure over a prolonged time - either that, or the terminations need to be tightened every couple of years. This can even happen with copper - many is the time I have found wall outlets where the connector screws were loose enough to allow the cable to move, this was not through negligence but simply the passage of time.

I quote (verbatim) from the e-mail -

About the power lead, it's a sad world. Actually, my apartment has aluminum wiring. It is deemed fire-hazard these days, but it's an old building and they're not going to re-do the wiring. I had to replace three receptacles because the contact points of the aluminum wires slowly burnt away and left the sockets unusable. Whenever I plugged in a high-power equipment, it'd crackle, lose power and cause even more contact point to burn away.

In that sense, buying a new $3 socket and getting it freshly connected to the mains wire helps HECK of a lot more than buying a $650 mains cable. As an added bonus, I get fresh copper socket holes. I'd think that helps a lot more than replacing a standard cable with a silver super-duper cable.

I couldn't agree more. This is a sensible approach, and does not cost a great deal. In addition, his apartment is (marginally!) less of a fire hazard than before, and the use of an expensive mains lead would not have fixed the underlying problem. Perhaps a few more people could adopt this sensible attitude and actually get some real (as opposed to imaginary or just "cover-up") improvements.

Bottom Line on Power Cables

I am still waiting for a "high-end" power lead manufacturer to supply me with some scientific proof of the advantages of their cable, and how they improve the sound. I have asked, and have not received the information. Nor do I expect to, since they cannot provide any sort of proof because they don't have any.

The last paragraphs of the above tell more of the truth of the matter than any high-end power lead maker ever will. The same (but to a lesser degree outside the US ) benefits can be had from anyone who has old wiring and wall outlets regardless of where they live. Even in my own home, I have completely rewired the mains, because the old wiring had perished insulation, and all the sockets were worn out. The difference was not audible, but at least I know that an electrical fault is unlikely.

Conclusion

Respected designers simulate, build, measure and modify until they are satisfied that the performance is as expected. Then, and only then, the amplifier (or whatever it might be) is auditioned in a proper listening test (as opposed to a lab speaker), and perhaps only the designer listens to it in the first instance. If the sound is as expected, then others will usually be invited to listen as well. Comments are made, and if it is felt that they are valid (a sufficient number of listeners made the same remarks, for example), then further modifications will be made, more tests, more listening, until everyone is satisfied that the measured and audible performance is in agreement. The measurements are available on the colour glossies, and are considered a part of the equipment - this is the specification, against which others can be compared.

Compare this to the snake oil vendors. As an example, they buy perfectly ordinary cable from an established manufacturer, clad it in some fancy heatshrink tubing, write their sales pitch, and sell it. They might actually bother to listen to it as well, but there isn't much point, since it is the same wire as used by others anyway. Do you see specifications, measurements, or other factual data? No! What you see on the colour glossies is a sales pitch, aimed directly at your emotional responses. There are no means for direct comparison, not a mention of anything that will help you to make a reasonable and informed decision as to which "thing" is (or might be) better than the other.

Non blind listening tests are flawed - and especially so when conducted by a dealer. Don't expect that the levels will be precisely matched, but absolutely expect the salesthing to tell you what to hear - not exactly a fair comparison.

When only emotions are allowed to make the decision on technical equipment, we can be fairly certain that we will make the wrong choice, other than by chance. Having spent all that money, no-one, and I mean no-one, will be willing to admit that they were defrauded, robbed or deceived. The survival instinct takes over, and we hear exactly what we expect to - whether it exists ot not.

In the long term, the subjectivist approach will cost you a lot of money, and possibly yield a system that is less hi-fi than something from a department store. A review without technical tests is without substance or meaning, and nearly all descriptions about amplifier sound should be taken with a large dose of salt (possibly epsom).

Claims that power leads and interconnects will magically transform the sound of your system are false and misleading in the extreme. The various system components may be influenced by some combinations, but a well designed system should not care.

The current impasse between the scientific and subjectivist camps is unlikely to be resolved in the near future, because as politics and religion have shown over the centuries, people will believe what they want to, despite any evidence that may be offered to show that they are misguided or just plain wrong.

There is great difficulty defining the quality of an audio experience - you can't draw a picture to show what something sounded like. In addition, our acoustical memory is far more fleeting and more readily fooled than visual memory. It is much easier to visualise what the Sydney Harbour Bridge looks like than to recall all but the basic details of a musical performance.

From Douglas Self -

It has been universally recognised for many years in experimental psychology, particularly in experiments about perception, that people tend to perceive what they want to perceive. This is often called the 'experimenter expectancy' effect; it is more subtle and insidious than it sounds, and the history of science is littered with the wrecked careers of those who failed to guard against it. Such self-deception has most often occurred in fields like biology, where although the raw data may be numerical, there is no real mathematical theory to check it against.

When the only 'results' are vague subjective impressions, the danger is clearly much greater, no matter how absolute the integrity of the experimenter. Thus in psychological work great care is necessary in the use of impartial observers, double-blind techniques, and rigorous statistical tests for significance. The vast majority of Subjectivist writings wholly ignore these precautions, with predictable results. In a few cases properly controlled listening tests been done, and at the time of writing all have resulted in different amplifiers sounding indistinguishable. I believe the conclusion is inescapable that experimenter expectancy has played a dominant role in the growth of Subjectivism.

It is notable that in Subjectivist audio the 'correct' answer is always the more expensive or inconvenient one. Electronics is rarely as simple as that. A major improvement is more likely to be linked with a new circuit topology or new type of semiconductor, than with mindlessly specifying more expensive components of the same type; cars do not go faster with platinum pistons.

All the above notwithstanding, most audio designers will still tend to accept (however reluctantly) some of the subjectivist propaganda, if only to be able to extract some of the obviously serious money that would otherwise go elsewhere. There is nothing wrong with this in principle, but where this happens, you will almost invariably get what you pay for, and the equipment's performance will be (hopefully) satisfying to both camps. Just as likely is that the subjectivists will determine that this same piece of equipment is hopelessly inadequate in all respects, despite the fact that it has zero distortion of any kind, and a frequency response from DC to daylight. (A good quality standard interconnect comes to mind!)

References

1. Wireless World, July 1988 - D. Self 'Science and Subjectivism in Audio' (See also The Self Site )
2. The Audio Pages, ESP, Impedance
3. The Audio Pages, ESP, Bi-amplification - Not Quite Magic (But Close)
4. Stereophile, Sept 1995 - R. Harley 'Review of Cary CAD-300SEI Single-Ended Triode Amplifier'
5. BBC Engineering Monograph No 52 - 'Stereophony & The effect of crosstalk between left and right channels'

Many Thanks to Rod Elliott from Elliott Sound Products for allowing us to republish this excellent article. We encourage you to check out Mr. Elliots very informative website and perhaps partake in some of the DIY projects that he offers.