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Post-manufacturing cable treatments & double-blind subjective tests - Part II

[1 2 3, easy as a b c, oh which cable will it be?]
[Italian version]

A - B - C,
It's easy as: 1 - 2 - 3;
which cable,
Will it be?

Product: post-manufacturing cable treatments & double-blind subjective tests
Price: N/A
Author: Mark Wheeler - TNT UK
Reviewers: Many & Various
Reviewed: 2006-2007

I continue to maintain that cable reviews are usually useless and that the most thorough of them, involving many listeners and many systems, tend to be inconclusive. This tends to reinforce the commonly held hypothesis (to which I also subscribe) that cables are too system dependent to be able to make blanket recommendations, and that the only time a cable recommendation can be made confidently and unequivocably are in very specific system contexts, such as an all Naim system or other one make system where that manufacturer applies a single philosophy across components and price points.

Ben Duncan made thorough explorations of loudspeaker cables some years ago, published in HiFi News & Record Review, while attempting to develop tests that might replicate, or even predict, listener experience. His thorough exploration and treatise implied that a good starting point for a speaker cable should be good (low and even) LCR performance (inductance, capacitance, resistance), and indeed one of the listening test results correlated, loosely, with that hypothesis. Ben Duncan's proposed, indeed innovative, test procedure demonstrated even closer correlation with the preferences of the listening panel. This was the first time I had seen evidence of any significant correlation between collective subjective experience (the listening panel preferences) and any physical measurements of audio cables.

Equally interesting to me is that the most thorough tests demonstrated then, and continue to demonstrate now, very subtle audible differences between electrically and constructionally similar cables rather than the night-&-day hyperbole of many advertisements and reviews.

Many readers misinterpreted my original Bits of Wire article, believing it to deride all subjective test results. Many readers wrongly believed that I was pouring scorn on the idea that we can hear effects we cannot measure. We can, and do, hear effects we do not yet measure regularly in all audio components, including bits of wire, both within and between active components. If you are reading this webzine you must suspect that there is more to audio equipment evaluation than measurement; learning how to measure bits of wire for audio performance is just not important enough to justify the research budget into this level of subatomic physics. However, we do often allow our sense of proportion to become overwhelmed, simply because it is cheaper and easier to play with five 400€ cables than two 2000€ pre-amps.

So I did receive supportive communications from objectivists who believe that what isn't being measured doesn't exist. Just because we don't yet have all the tests available to explain every physical phenomenon in the universe does not mean that such things do not exist until we test them. The solar system did not suddenly rearrange itself when we noticed the earth orbits the sun. Investigating the physical properties of wire in audio systems has to take a lower priority than research into other phenomena that may be as small as those in subatomic particles or as big as distant nebulae.

Wire in hifi really does not matter enough to climb far up the scientific priority ladder, so the poor (very poor after buying some bits of wire) audio consumer exists in a world of almost medieval alchemical discourse. Wire tech is dressed up in the most entertaining b*ll*cks (by which I mean, of course, the structural linguistics of a testosterone fuelled patriarchy), a language only previously so mutilated in hair shampoo and anti-ageing cream advertisements. It is true that I do pour scorn on the ludicrous pseudoscientific claims surrounding many cables, but what if we rubbed anti-ageing cream on our cables to maintain their performance and enhance their loveliness?

Having said all that...
indeed, having said all that in over 500 words, I also say that wire does really matter to those of us obsessed with getting the best possible musical experience from the electronics in our homes. Cables are the vital final piece in the evolution of our stereo systems, but cannot be properly evaluated until the rest of the audio edifice is as good as it can be.

  1. Choose the right sources that perform similarly to each other (otherwise you'll have to unbalance the system elsewhere and at least one source will never sound right) and to suit your priorities
  2. Choose speakers you can live with and will work in your room and then place them optimally
  3. Choose the right amplification to drive these speakers within your budget
  4. Site the equipment well on good supports with proper attention to vibration isolation
  5. Supply the system with clean mains power (preferably by separate spur)
  6. Now play with cables until you establish which work best with your equipment

Cables are the last items to consider as they are so system dependent. As Martin Colloms points out in his recent HiFi Critic articles, cables are a vital component in the fine-tuning of a high resolution system. One does need to reach an evolutionary point where it is the system resolution that is revealing cable differences, not be at a point where cables are serving as clumsy tuning devices to overcome mismatches between components. Equally, components cannot be evaluated properly when connected with inferior or eccentric cables. Every audiophile on an upgrade path should have a stock of adequate cables to try with any new component before establishing which cable avenue to explore further and more expensively. I also do not believe it would ever be possible to justify a 10k€ speaker cable between a 10k€ amplifier and 10k€ speakers. Surely 1k€ on the cable and 29k€ between the amplifier and speakers would get a better sound for your 30k€? And I have to question the sanity of ever spending so much cash on a piece of wire when that same money could be of so much more benefit elsewhere in the world. The feelgood factor derived from doing some good with one's dosh must be balanced against sating our personal obsessions.

I have received far less feedback from my Great Balls of Wire double-blind test proposal. Perhaps nobody noticed it, or though that if they ignored it for long enough it would just go away quietly. No such luck.

Back in the real world of three bits of wire in front of me, I am tasked with identifying whether there is any audible difference between them. These three cables are from the upper echelons, though by no means the top, of the Black Rhodium range. By normal mortals' standards they would be very expensive as bits of wire, but by hifi standards they would exist in the lower price reaches of audiophile cables. If they perform well at such prices they would represent good value. I say this to indicate that the baseline has to be good enough. These are not eccentrically engineered cables that will emphasise particular frequencies or parameters.

Three sample cables

  1. Black Rhodium Concerto cable A
    may be cryogenically treated or may be untreated
  2. Black Rhodium Concerto cable B
    may be cryogenically treated or may be untreated
  3. Black Rhodium Concerto cable C
    may be cryogenically treated or may be untreated

I listen to my system for a while with the ancestor of these cables between my modified Shanling CDT100c and my modified Assemblage SET300B fitted with Western Electric 300B output valves, NEC 6BXGT drivers and Brimar black 6SN7 input; tube-rolling makes as much difference as the most optimum choices of cables. Speaker cables are Black Rhodium S900 (the bigger version of the S600 that did very well in the Ben Duncan tests) and speakers are based on Hammer dynamics 30cm bass-mid driver, Focal (prototype version) titanium-dioxide inverted dome treble, with litz-wired air-cored inductor crossovers. There is good system synergy and excellent vibration control and support throughout the system. The Hammers and Western Electrics emphasise midband quality and dynamics, both macro and micro, but combine feebly at the frequency extremes.

Meanwhile I run all three test cables to an old integrated amp from a cd player, using a cobbled-up hydra-headed adapter, set on repeat 24hours per day for 3 weeks. Some commentators have suggested that cryogenic treatment is a substitute for burn-in. I have not tested whether lengthy burn-in makes more difference than one day, but I wish to minimise any potential variable, so all three get the same lengthy preconditioning.

At last I substitute the first of the test cables (cable C, as it happens) in my system and there is an immediate lift in performance. Obviously 15 years of development have made big advances between the new Black Rhodium Concerto and the older Sonic Link Blue that feature similar conductors but different insulation and construction. I carefully dress the cables as I find this can have as much difference as differences between cables or cable direction, where that applies. Good cable dressing, the physical arrangement of the cables is very important in terms of vibrational effects between components and on the cable itself. These Black Rhodium Concerto wires seem immune to obvious vibration effects, but some fine coaxial silver wires from another manufacturer, that I used on my SME3012, are so prone to triboelectric effect that I have had to sleeve them in fibre renforced silicone and support them on clips to keep them off shelf edges.

Group behaviour & cables

It is possible for whole groups to deceive themselves, especially if just one member holds any particular belief, however bizarre or erroneous, where the remainder of the group holds no particular belief. Psychological tests have shown that where one member of a group expresses an opinion first, in contradiction to the sensory experience of the remainder of the group members, the rest of the group will tend to adapt to that first expressed opinion, often by withholding expression of their contradictory experience.

Even more interesting is how group members will even outwardly concur with an expressed opinion contradicting the current evidence of their own eyes or ears. This may extend to unconsciously hinted opinions, possibly by vocal nuance or body language, and therefore undermines the authority of findings by listening panels, except those that are double blind. Listening panels are, however, inevitably academically more rigorous than single opinions in qualitative research, but unconscious influence cannot be ruled out.

I have cobbled this summary together from diverse research sources but without quotation or reference, so it is necessarily oversimplified.

Unlikely as it seems, these conditions are not just possible, but rather likely, in group behaviour. It is possibly an evolutionary adaptive behaviour that has helped us to live in societies, even if it has also enabled groups to commit horrible acts in contradiction to individual conscience.

I begin my own listening, and note what I hear. I try cable C then cable B then cable A then cable B and back to cable C again, while making notes using my judging system. When the numerical differences are equal in both orders (but obviously reversed) after many albums over a few days I begin to worry. A clear 'one cable is different from the other two' pattern has not emerged. Without knowing my findings, my two sons (12 and 14) listen and report hearing similar. I then pass the three cables on to another listener to try in his high resolution system.

When returned, I try the cables each side of my variable transformer attenuator. Here I learn that the differences are clear when the cable test samples are positioned between source and transformer but inaudible when placed after the transformer. Some might argue this is because transformers inherently phase-shift with respect to increasing frequency, while others may counter that the cable LCR terminates the transformer almost as a Zobel network. I will not argue either explanation, I just note that differences were similar between source and transformer to differences between source and pre-amp or pre-amp and power amp. Every music loving friend gets dragged into the audio room and browbeaten into listening to cables. One friend comments, "This is as bad as those times we had to listen to Jazz at The bl**dy Pawnshop, over and over and over again [in the late 80s] while you fiddled with wires [again interconnects] and bits of amplifiers [active crossover and pre-amp power supplies] until I got sick of Take Five."

Deliberately mismatching my system, by feeding the variable output of the Shanling to the high-gain high-power bipolar class AB 100wpc amplifier to the 95-97dB Hammers, is a horrible experience that just adds evidence to the argument that a system should be well-matched before trying cables, even though the same cable differences are also audible in this arena of antisynergy. Less sensitive speakers confirm these findings with less discomfort.

Between the Aqvox 2Ci and the transformer attenuator on The good The Bad and The Queen, the title track (last track side 2 of the vinyl) sounds best in reverse order of the other material. I suspect that this is because the less refined cable restores some of the track's grinding distortion that gets smoothed by modern production values and overcompression. On other material only very slight differences emerge between A, B & C, possibly a testament to the pro-audio heritage of the Aqvox and its ability to drive all cables with impunity, even on the unbalanced output.

The Avondale AAA5 feeding the SET300B via the passive attenuator portrays gloriously natural timbres and superb tingle factor. 3 more plays of The good The Bad and the Queen, this time on cd, was more revealing of A - B - C wire differences in this system context than the vinyl. Tingle factor is one dimension not yet explored with this trio of cables. Both Neil Young and Arvo Pärt work really well through this system, whose balance of virtues is beyond synergistic, almost attaining syzygy. In this combination, the test cables inserted between AAA5 and the transformer, and Kimber Silver Streak hard wired from the transformer on the output side (having established that A & B & C are indistinguishable on the tx output side), demonstrate the widest diversity of high-end clues between the test cables A - B - C.

Here cable A allows more hifi virtues like soundstage depth and solidity, but again the differences are subtle. Timbre is good with all three, but something about human voices (as opposed to orchestral voices which are identical with all three cables) catch some subtle emotional clues better with cable A in this pairing. The Mapleshade CDs sound particularly fine in this equipment combination and aided my jaded ears in reaching conclusions.

Most visitors to my listening room hear little or no difference at all between any of the cable pairs in any hardware combinations. When they do hear a difference between these cables their observations are often vague or contradictory in preference, even if similar in observation, e.g. "That one [B] is slightly clearer" or "This one [A] is more mellow". There is no clear consensus and no one is able to identify which is which, blind.

After months of listening to these cables, I can identify between pairings A-C and A-B inasmuch as I can note that I prefer A in each pairing but cannot state confidently that I know it is A or identify B from C at all. The pairing B-C also produces a reaction where I tend to prefer B over C but less than 50% of the time, which is not reliable, nor say that these are B & C rather than A & B.


Over a protracted test experience the difference between these cables becomes more difficult to identify. First exposure to them emphasised the differences in A-B, B-C, A-C pairings. Once they are experienced by numerous ears in numerous systems the differences become less marked and the results somewhat nebulous. It is much easier to hear and report differences in quick A-B comparisons than over extended periods. Prolonged experience of all three cables actually reduces the perception of difference compared to first exposure, which is the opposite of what I might have predicted.

Graham Nalty is convinced that he would be able to identify which cable is which, blind, in his system.

I have to say that I do not know yet which cable is which, and I would be happy to use all three in my system. I would prefer A in every position in my system, but the differences are so small that if I were to return all three cables to their maker and he gave me one back unmarked, I would not know which one it is.

Given the price differential between untreated and treated cables, at this time, with my system, I would spend the extra on more lps and cds. However, even at the elevated price point of the treated cable, these are fine bits of wire for the money. They are also not clumsy system tuners, like so many cables tend to be. These cables were not fazed by the variable output impedance of the Concordant Excelsior and managed a consistent performance at all volume levels. Some cables do vary performance with amplitude anyway, but any with curious LCR dimensions tend to vary their sound with this pre-amp. It was interesting to note that fed by a line-level transformer the differences were completely inaudible, which may explain the plethora of transformers in studios, and pro-sector scepticism about cable differences.

A notable exception to that pro-sector scepticism is Mapleshade studios, whose cds were equally noticeable in being the best tools to identify cable differences in this test. I found myself playing Yucca Flats every day without boredom or fatigue. I did find that the extra dynamic range of the Mapleshade cds made differences more worthwhile and nuances more significant.

All three cables worked really well in most equipment combinations I tried, and the untreated cable(s), whichever they are, therefore represent really good value. Perhaps ears younger than mine (35 of their 48 years listening to loud music), combined with a higher resolution system playing really good recordings, might reliably hear more difference than I did.

One serious conclusion is that subjective testing is never as certain as subjective writing implies. Certainty is very unlikely, and rarely safe. We must get used to the idea that uncertainty can be safe enough to enjoy our tunes at home, regardless of advertising-revenue-driven magazine paranoia.

Another most serious conclusion is that it is much easier to identify cable differences when you can see which cable you are about to hear, even if you do not know whether you are supposed to prefer A or B or C!

Music enjoyed during writing this review

  • Yucca Flats: Garden of Weeds, cd, current fave new discovery
  • National Razor: Naked Before God & Country, cd
  • Korn: Life is Peachy, vinyl lp
  • Korn: The Untouchables, vinyl lp
  • Return to Forever: Romantic Warrior, vinyl lp
  • The Good the Bad and the Queen: The Good the Bad and the Queen, cd
  • The Good the Bad and the Queen: The Good the Bad and the Queen, vinyl lp, love it
  • Neil Young: Greatest Hits, cd
  • Joni Mitchell: Blue, cd
  • Miles Davis: Tutu, vinyl lp
  • Neil Young: After the Goldrush, vinyl lp, worn but glorious
  • Arvo Pärt Beatus, cd, heart-aching
  • Jimi Hendrix: Blues at Midnight, 2x180g vinyl lp
  • Jimi Hendrix: Studio Out-takes Volume 2, 180g vinyl lp
  • Flora Purim: Welcome [back] '95, vinyl lp, sublime voice
  • Lee Perry: Megaton Dub 2, used lp, Scratch 'pon controls on sleeve-back pic in unusually tidy Ark
  • Mott The Hoople: Mott, vinyl lp bought on release on 14th birthday and played to death on Dad's Garrard autochanger

© Copyright 2007 Mark Wheeler - www.tnt-audio.com

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