Can You Tell The Difference? I Can't
A long post - give it a miss if you're in a hurry
I recently did a blind test at my home with a friend, comparing each others IC cables (he has some very expensive Cardas cables he's replacing due to a house move) and comparing them against the freebie phono leads I got with my old Technics mid-fi system. We wanted to see just how much difference they made.
I stripped my system down to the minimal stereo setup (Linn Unidisk SC, 2x Linn AV5125 amps, 2x Linn Akurate 212 speakers, driven 4 channels active on each). We spent a day swapping ICs for each other, listening to our favorite tracks, and making notes.
The result was that neither of us could consistently tell the difference between Linn Black, BlueJeans Belden 1505F, and his expensive Cardas Golden Reference cables. This didn't surprise me a great deal, because they're all well-engineered cables.
What was really surprising was that we couldn't tell the difference between these and the unshielded no-name freebies either! Perhaps we might have done if all the gear had been plugged in and switched on, because of the EM noise it all makes, but with a minimal system we couldn't tell.
My friend was puzzled and a bit angry, because when he bought his system, he was told the cables were so much better than any others, and would enhance any good system (he loves music, but isn't really a hifi geek). So we repeated the blind comparison of Cardas vs no-name freebies using good quality headphones (Sony MDR SA5000 through Graham Slee Solo amp), and still couldn't tell the difference.
So from now on we're both now going to stick with the lowest price, well-made cables we can find
On a Linn forum I visit, some members spend hours comparing various expensive cables, listing them in order of preference, and describing how different they are from each other. But it seems to me, that if the ideal cable has no effect on the signal at all, then a not so good cable is adversely affecting the signal. If this difference is audible, as they say, then for a hierarchy of, say, five cables, each audibly better than the last, the audible difference between the best and the worst cable must be at least five times greater than the threshold of audibility - enough so that even my cloth-ears should be able to detect it.
The Cardas Golden Reference cables are near the top of most of the lists I've seen, and the Belden 1505F and Linn Blacks are several (supposedly audible) steps down, so we should have easily been able to tell the difference between them
if there really is an audible difference between all these cables. And, of course, by this reckoning, the no-name freebie phono cables ought to be worse by many times more than the audible threshold...
Of course, in the electronics lab, where all our hifi kit is made and measured, we can also measure the various thresholds of audibility and discrimination of our ears for the different modalities (frequency, tone, loudness, noise, distortion, etc). The measuring instruments have much finer resolution than does the human ear in each of these modalities, so you'd expect them to be able to measure the differences between these cables, if they're audible - but they can't. There doesn't appear to be any significant measurable difference in the performance of well-made cables used within their intended limits (reasonable length, loading, etc). Considering that this well-known, tried and tested physics and these measuring devices are what has given us such wonderful hifi equipment in the first place, it seems unlikely that they could fail to match the ear on the simplest test of all - listening to a piece of wire.
Then there are blind tests - if the audible differences are so clear, a good blind test that removes as many distractions and interferences as possible, should easily verify them, or at worst, should give a statistically acceptable confirmation... but since my own experiment, I've done some searching for blind-test results, and although there are quite a few online, I have not found any that even minimally confirm an audible difference between well-made cables used within their limits.
When I have described the above findings to the cable enthusiasts, they generally criticize blind testing, and suggest that lab measurements are 'not the whole story', but no-one has yet responded to the argument about the summed audible differences between the 'best' and 'worst' cables.
To cut a long story short ('too late!' I hear you cry), everything I can find points to the perceived audible differences between well-made cables being caused by something other than the physical properties of the cables themselves.