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Re: Ah, thanks.

Tom: ""
I don't know why not, since I targeted the range at 20khz and above initially and backed it up with plots showing some cables exhibiting this effect an octave lower, although they were not even solid conductors.""

Note that the two stealth products started jostling around a bit at about 10Khz. And note also that they get ragged as the frequency gets into the meg range. Both of those effects, coupled with the fact that the capacitance is way low on each product, tells me that there is more going on than the measurements are showing. The meter and setup is having difficulty discerning the resistance accurately for those cables. Could be just a simple ranging thing, or a result of the test setup not being auto-zero'd.

As I stated, their calculation of skin effect resistance increase was 34% rise, but yet they measured it pretty darn flat at 20K. I did not say the calculation was not in line with measurement, Gene did.
Tom: ""

This is not to discount that there is a more complex characteristic than a first order effect to skin effect's onset as you said, which also suggests to me that there may be also some resultant nonlinearity associated with the phenomenon in the near audio band. However, that does not seem sufficient grounds to me to justify ignoring skin effect in speaker cables. It might be worthwhile proposing an equation that more accurately models skin effect in round solid copper conductors near to and within the audio range.""

I didn't say ignore it. I said the exponential equation for skin depth was inaccurate for standard audio wire sizes and audio frequencies, giving numbers which are off by factors of about 4 for #14 size at 20K, and the equation is even farther off for smaller guage wires.

I would not say "non linearities" per se...although there certainly are issues with the self inductance and quashing therin as a result of current slews.

Hmmm..To prevent swamping out the measurements by the magnitude of the inductive numbers, ya'd hafta keep the inductance low....hmmmm.

I think I'm gonna do some measurements of some solid wires enclosed by a shield braid, to remove the bulk of the inductance of the system..that would be interesting..


Cheers, John


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  • Re: Ah, thanks. - jneutron 10:00:20 05/16/06 (0)


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