Saturday, 17 December 2011

How do audiophile cables work? Part 2 - the cable makers.

Cable makers and many of their customers state they can hear a difference in their cables. I say that they are correct as they can hear a difference in the cable. However, what causes that difference?

Here I argue it is not down to the cable itself, there is nothing inherent in a cable that changes sound.  What I will show by various examples is that cable makers are continually missing the link needed between how a cable is made and how that affects sound quality. Cable makers have failed to show a connection between their products and  not just sound quality but any audible difference at all.

Instead I will show that it is the hype, (by both cable makers and many of their customers) about cables working to change sound quality that causes some people to hear a difference. Hype about cables is a better explanation for hearing differences.

Cables come in all sorts of shapes and sizes. Much of that hype is to suggest new knowledge and R&D that has resulted in evidence cables do affect sound quality. However, what follows is a series of  non sequiturs. Even the basic argument of ‘cables are different, I can hear a difference in sound, therefore cables cause the difference in sound’ is clearly potentially flawed. But that is what cable makers rely upon.

The ability to harness and transmit electricity and turn it into something useful is just about the biggest and most influential scientific step taken by mankind. The likes of Benjamin Franklin, Alessandro Volta and Thomas Faraday were conducting experiments and learning how to harness the power of electricity in the 18th and 19th centuries. Various laws of electricity have been known for a good length of time, such as Ohms Law published first in 1827 and have not found to be flawed.

The electric power that we need to power our hifis was first distributed to houses in NY in 1882, though before that individual wealthy people had their own power supplies.  Since then with the likes of the  current war between AC and DC, experience of and knowledge about the transmission of electricity down a cable has increased dramatically.  (2) But we are still using the original discoveries of the 19th century as the basic principles of transmitting electricity down a cable, such skin effect first noted in 1883. (3 )

It was in the 1970s that the idea that cables could be used to improve the  sound quality of hifis. QED cables were founded in 1973 and state by 1978 their speaker cable was considered a serious Hifi component.  ( 4) Now that idea is common place.  There are numerous companies making and marketing cables. A lot of study has gone into the construction of these cables.

What is clear in the following is that cable makers are still using the knowledge that was first being found back in the 19th century. There have been no new discoveries about cables and their inherent properties.  It is instead hype.

What is also clear is that they can show different cable construction means differences when it comes to transmitting a signal. But the science runs out when it comes to showing whether those differences are audible or not and how cables can affect sound quality.

In 2008 Russ Andrews claimed and then backed up that claim by measurements that they could show reduced RFI by they way they made their cable. But, they could not link reduced RFI to a better sound, they could only suggest it. As such in 2011 they had to stop advertising their cables as improving sound quality by reducing RFI until they had more ‘robust substantiation’ (5)

Tara Labs have a paper on Constant Current Impedance Testing (CCZT) which shows that there is a measurable difference in differently made cables frequency response. They are not alone there, as such has been shown with various studies.  (6) There are measurable differences between cables. Tara Labs say that such differences ‘highlight’ the reason why cable sound different. They say the measurements correlate with what ‘we can hear’. and they can ‘reliably correlate the listening experience to the test bench experience’. But there is no evidence presented to back up how they directly link a difference in the cable to a difference in the sound, beyond they can hear it.  They introduce the part of the paper correlating the cable with what they hear simply as ‘the sound…‘.

In 1995 QED published their ‘Genesis Report’ on loudspeaker cable. (7)They comment on the mysticism and pseudo-science around claims about cables. As with Tara Labs, there is a lot of evidence presented to show how a cable can measure differently. Again , that is little doubt. However, there is the issue of linking construction to sound quality.

They put forward an argument that applies to many cables, not just their own that accurate and consistent sounding speaker cables will have low capacitance, inductance, resistance and dielectric losses. They state that certain factors are unlikely to be audible such as skin effect. They also say that blind testing has shown that listeners are unable to discriminate cable directionality. The actual test is not shown and they do not apply blind testing to anything else in their paper.  Why use blind listening in one part only, why not use it for all of the claims made by QED?

Chord Cables claim lots of links between cheap cables which come free and ‘destroy‘ the information conveyed by music and their own which allow you to ‘really hear and enjoy your music‘, but as for evidence, none. (8)

ALO cables are superior because they are ‘built by hand’ and they ‘use only the finest materials available’. That is hype about build quality which is then contradicted when they acknowledge the Jena Labs cables copper discolours over time, but that does not affect sound. Yet later they state copper oxide is detrimental to sound. (9)  So which one is it? They do not evidence any link to sound quality.

Cardas provide a history of the development of cables from the earliest telegraph systems.  By the 1970s, like QED, Cardas state cables were seen as a part of the Hifi chain and along with that came ‘the scream of nay sayers’ who had  managed to ‘lose the lesson of our ancestors’.  By 2000 the ‘overall depth of knowledge is now at a new level’.  That is not the case. I have shown what they are speaking of has been known about for decades or longer. Cardas say that the most important issue is conductor/dielectric transition time differential. But no evidence of how that works or how audible it is, is put forward.(10) Their use of the ‘Golden Ratio’ in cable design is not linked to any claims about audibility.  Their use of ‘ultra pure and homogeneous metals’ are supposedly proven to produce the best sound. But no proof is shown. (11) Instead it is hype about build quality. Overall there is a large section on Cardas’ insights into cables, but none contain evidence on how they make their cable is linked to better sound. (12)

Blue Jeans Cables have again gone down the route of showing how there are differences caused to a signal in the way a cable is made. (13)  But, again they cannot link that to audibility and only say
“It's fair to say that people differ greatly in their ability to tell the difference between cables or components.” Yes, that is fair, but it is also suggesting the link without evidencing it. (14)

Instead of evidence to show the link we get hype that build quality and differences in cables cause improvements in sound.

Something else lacking in all of the cable company’s claims is peer reviews. If you are going to present white papers, Genesis reports or even insights, a second opinion would be nice.

I have listened to Hifi’s with expensive audiophile cables, bought a few relatively expensive audiophile cables and at different times heard and not heard a difference between them. I have made my own cables, I have blind tested and in my own experience the above holds true. I also secretly hope that a cable company can one day find the missing link, the quality in a cable that makes it inherently and provably sound different to other cables. But at the moment there is none and I doubt that there ever will be.

EDIT - Further evidence of the lack of a link is here in a paper submitted for an electrical engineering degree at MIT

(3 )

(Original version posted on Head-fi forum)

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