cable dielectric cause of artificial sound


Hi folks, I would like to know what your opinion is about the following issue. About 90% of high-end cable manufacturers use PTFE as dielectric. Many of their cables sound much alike and they have a few of these characteristics in common: clean, relaxed and laid back sound but at the same time very dynamic (though a bit artificially), very quiet ("black background"), very good (also artificially) left/right separation. But I think albeit these traits, they tend to sound "technicolored", "sterile" and unengaging (lacking PRaT also). Some cable manufacturers are using bleached cotton as dielectric. These cables sound different: they have more natural dynamics, a mellower sound, more intimate soundstage, more tonal colors and so on. Are these differences mainly due to the dielectric material used? Why is for so many manufacturers PTFE still the ultimate dielectric for the use in audio cables?

Chris
dazzdax
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.
IMO, there will never be a perfect analog cable. Cable construction variables and system interfaces will always result in some sort of coloration. With digital HDMI interfaces progressing, we no longer need worry about analog cables. In that case, any cheap cable will suffice. As an audiophile junky I will dismiss what I just wrote.
Trelja,

I don't think we can underestimate the confusion sewn by the cable industry itself. When some cable designers claim that cable "x" in their lineup is more detailed than cable "z" because of some proprietary treatment or improved dielectric, when if fact they've also changed the geometry of cable "x" (but don't mention it), they just add to the confusion of listeners who are lead to think the sonic change is caused by factors that may have very little sonic impact compared to geometry.
JMO.
recently i went to radio shack and bought microphone cables which come with balanced ends. installed where resently i was using synergistic balanced. tell you what they sound great tight bass smooth mid and high end. very natural. then i used them on my sub where i was using single ended cables, sub never sounded better very tight and deep bass i am blown away. i have a talon rock sub 1000 watt. the balanced cables made a big diff over single end. very satified.
!!!Transmission line theory does not apply at audio frequencies, unless your cable is a minimum of 500 feet long, and even then this is at 100 kHz and 1/10th a wavelength!!!

There is no debating this, not b/c I mention it, but b/c this is physical reality.
Some cable vendors would have you believe that characteristic impedance actually matters at audio bandwidth (do i hear any ee's in the Audience?). What total rubbish.
However, any given cable, coax, twin, twisted pair, will indeed have a characteristic impedance (this is purely a function of geometry and is nothing more than the ratio of voltage to current along the line).
This (Znot), however only becomes relevant when the cable length is longer than a fraction (usually 1/4 lambda) of the transmitted signal's frequency.
The signal frequencies passing through analog interconnects and speaker cables are effectively DC b/c the wavelengths are so long.
All this yak about characteristic impedance, load matching, and dielectric loss tangents (aka dissipation factor) applied to cable in the audio band is akin to applying special relativity when describing the point at which two cars will intersect on the highway (unless your car is a super hopped up red civic with a really fat tailpipe and has a mighty rocket engine), when good old distance = rate x time works perfectly every time....

I am not trying to disagree with anyone, and I did not invent TL theory, i'm just chiming in to remind, or point out, that all this talk about transmission line theory (dielectrics/insulation having appreciable influence beyond stopping our conductors from shorting out) just is not reasonable at analog audio frequencies.

I do think it is possible for such an ill designed cable to hit the streets such that it's basic RLC can affect the signal, but this is different than transmission line issues.

This type of cable might even have a coloration some find pleasant in their system.

for a real interesting (if you are participating in this thread I assume you are interested) and downright truthful (no bs) discussion of the matter check out:

http://www.audioholics.com/techtips/audioprinciples/interconnects/DielectricAbsorption.php