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
Audioholics?
Since they don't believe that cables make a difference, they should just shut up about it and let us 'delusional' audiophiles enjoy our hobby.
Sean:

0"What the audioholics article is/should be really implying is, for example, that connections are critical for, say RF (i.e. it simply won't work) and uncritical for audio frequencies (i.e. it WILL work -- but perhaps badly, i.e. with high losses and noise introduction)."

THis is what you are saying. That article simply points out that dielectric loss tangents/DF are meaningless at audio band frequencies. It's not that an audio connection is uncritical, it's just unnecessary to view it like an RF transmission line. A ~50 kHz signal has a wavelength of 1000's of meters (lambda = propV / f ). Please someone, explain to me why anyone thinks this scenario should be treated the same as one where the conductor length itself is at or bigger than the wavelengths traveling on it.

That is why it's effectively DC (from a tl standpoint) on a wire of typical home cable lenghts.

"Helping me to understand that all cables of reasonable construction and parts quality sound identical"

1)I was trying to say that all cables do not sound the same b/c of , say reflections (vswr higher than 1), but rather lumped (rlc) chraracteristics. Inductnace and mutual inductance are based on geometry and small changes may manifest in different "sounding" (i think more like filtering) cables.

Gregm:
1"Unfortunately, if you use a 50ohm cable on 75ohm connection you'll have reflections even at audio freq"
Hmmm are you sure about this? please show me the article or data you have. Perhaps I am missing something

2"if you create a highly capacitive interconnection, you may get oscillation, and will probably get attenaution of frequencies, even at audio frequencies"

im with you on that. This has nothing to do with TL theory, this is basic lumped circuit analysis of the RLC.
Excessive capacitcane can make sources with high output Z unstable. No big deal. Once again the attenuation is due to 1st order RC filter. Not dielectric absorption or mistmatch

3"if you use additional conductors (say for shielding) you will change the electrical charactersitics of your connection and introduce shifts in the transmission;"
I think your partly right: you will add inductance. yes this changes the lumped characteristics. Any filter causes phase shifts but don't confuse this with V/I lag due to VSWR (voltage standing wave ratio).

4"simple: if you use a thin conductor you introduce a higher resistance than with a thicker wire, and possible phase shift in lower frequencies vs higher frequencies -- even in the audible range (try it, it works!)."
Once again you are describing the RLC componenets of a cable. I agree that changing these will change the sound.
Again this is not due to inherent mismatch b/t cable and source or sink.

We should not confuse source output impedance and sink input impedance with characteristic impedance as it applies in RF (freq >>100kHz) signal transfer.

And dudes: I am not trying to pick arguments with anyone. I am not the one who invented the theory. I am trying to relay the facts as i understand them. I sure might get confused myself in the description of them ( i try not but it's early and the java is empty) but they are out there for all to see. I am not a "measurement type" or one who sucks the life out of audio enjoyment. I just like to stick to the facts and separate myself from the rampant bullshit from marketing departments.

please show me the article or data you have. Perhaps I am missing something
Why on earth do you need an article or "data" or any other, further erudition? You might measure it, if you wish -- but better still, don't bother:) What may usually happen is noise pick up.

And no, you're not missing anything :) IMO it's not a matter of crucial importance...
I just like to stick to the facts and separate myself from the rampant bullshit from marketing departments.
With you, 100%. You must admit though, sometimes they are very creative. Cheers
Dpac: One can pick and choose as to what they think matters at audio frequencies, but the bottom line is that Audioholics believe and teach that all reasonably well constructed cables sound the same.

Since we know that all cables don't sound the same and / or provide consistent results under various types of installation conditions, all of their math equations obviously don't cover / explain all of the various aspects that alter cable / component interaction and system sonics. I'm not just picking on Audioholics, but all of those that blindly spout the same "cables are cables are cables" dogma.

As far as using smaller / larger conductors changing the sound of an interconnect, most cables terminate into a component that has an impedance that is hundreds to thousands of ohms higher than the series resistance of the cable. As such, changing the series resistance by even an ohm ( a LOT for a reasonable length cable ) via altering conductor size becomes a moot point. Please remove that factor from your arsenal of responses.

The fact that tonal balance and high frequency resolution, which is attributable to skin effect, are directly altered by changing conductor size, doesn't seem to phase them. One can build identical cables with the same nominal LCR, grades of conductors, grades of dielectric, grades of connectors, etc... with the only variable being conductor size and hear the audible differences. The fact that Audioholics profess that skin effect does NOT come into play at audio frequencies what so ever makes me want to disregard their findings all together.

No matter how much math one does, you can't explain away things that are really happening. When theory doesn't fit reality, which one is wrong???

As far as your comments go about shielding, this typicaly adds capacitance, not inductance. It can also change the velocity of propogation, depending on how the shielding is implimented. In doing so, it effectively changes the path length and loading characteristics that the source component sees, following some of the same principles that apply to transmission line theory.

I'm not saying that audio cables work the same as RF cables, but that many of the same principles can be applied. I also think that, because people like Audioholics / believers in archaic dogma have been conducting most of the testing in this area, we don't have many of the answers that might have otherwise already been explained.

Thinking within the box only lets one see what is in the box. Obviously, the variable results that occur under many different situations of cable / component interaction are OUTSIDE of the box, negating that line of thinking. As such, it leads to limited conclusions and possibilities, hence the problem with the theory not always fitting reality. Sean
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I have very great doubts that the RF Transmission line theory that Sean promotes has any relevance to audio. He couldn't convince me with all his words. But then he did something simple...loaned me a couple of speaker cables which I compared with zip cord. That won him the debate. The difference was not nearly as dramatic as some advocates of fancy wire claim, but there was something there. I still doubt his theories, but I went out and bought some speaker cables.