After watching this thread with great interest, the impression I get after it rising and now cooling off is that we STILL know very little about high end audio cabling.
I've seen folks of all manner of approaches and background have theories, but no real knowledge. By this, I don't mean to offend, just that my definition of knowledge is something on a higher plane that what I am reading. So far, only "I've seen this", "I hear this", or "I tested that". Yet, day after day I read how this cable sounds too dull in system A, while another member disagrees, saying it drove his ears to bleed.
Does surface oxidation exhibit a detrimental effect on a wire or not? Doesn't seem as if we're sure - some say yes and some no, both being just as emphatic as the other.
Are those who feel cable geometry trumps all other factors (material, insulation, etc.) the ones who have the real answer???
And, as far as the point of the thread, what do we really know about the effect of a dielectric on things? Is teflon necessarily better than PVC, polyethylene, polyester, kapton, or polypropylene? For at least a decade now, we have been voting yes with our wallets because that is the conventional wisdom, not because we "know" it's true. What about PVDF (Kynar), which has probably the highest dielectric constant of any stable polymer I can think of. How do cotton and silk rate in absolute terms? Why not think about acrylic or wool?
If air is truly superior, while oxidation is to be avoided (for the sake of argument, again, I have no true idea how critical it is), the cost of filling a tube with a gas such as nitrogen (the main component of air apart from oxygen), argon, helium, or whatever to protect the copper from oxidizing is not very expensive whatsoever. After all, they used a ton of nitrogen (or, possibly, 5% hydrogen in 95% nitrogen - forming gas, which is used in a reduction furnace) to anneal the wire, correct?
And, I have yet to touch on copper, silver, gold, alloys of all manner of metals (for example, 55% palladium/45% silver - the most stable conductor in terms of temperature coefficient of resistance, environmental degradation, and the like), aluminum, carbon...
Hopefully, JD's (Jadem6) thread will spur additional research into the subject. His has been the most valuable thread I have seen here in any audio discussion forum in years. It's certainly got me thinking of cable in a very big way.
In my view, we should have come to definitive answers long ago. Not to seem as if I am on a high horse as I've also done just about nothing to advance the craft. Wish I was still a chemist/material scientist in many regards because I know I would devote a substantial part of my time researching all manner of variables.
Wire remains more or less black magic. Not because it is, but due to our fundamental lack of understanding of the subject. Unfortunately, there doesn't seem to have been much in the way of research since the late 1990s. There's certainly no impetus for it, as we're mostly served by ultra niche companies run by folks without the knowledge, training, or money to conduct it, who are making big profit doing things as they are doing them. Why change? WE certainly aren't demanding it.
As much of a subjectivist as I am, there is a downside to such thinking being so pervasive in this hobby. We are, more or less, simply at the mercy of swapping products in and out of our systems, not knowing how they will sound.
We probably should be at the point where we say this cable will tame brightness, and this one will give you a bit more bass impact and on and on. And, because we truly do not understand why one cable sounds better than another we are apt to pay hundreds and thousands of dollars for products that can often be bought for pennies and dollars. The end result being far more consuming of time and money than it probably should be.
