Richard Crowley wrote:
wrote ...
Now to partly answer my own question, I came across
a great website that discusses the issues I'm pondering.
He titles the articles "Skin effect" but in fact spends very
little time on true skin effect.
http://www.st-andrews.ac.uk/~www_pa/...io/Analog.html
He does provide many graphs showing very clear effects
of different cable construction--all at about 100kHz, and
most less than 0.1dB-- but measurable and predictable,
nonetheless.

But NOT audible. This is the kind of "pathological" wacko
"pseudo-science" that people get hung up with when trying
to avoid the real world (for whatever reason?) The website
appears to do a good job of explaining the physics, but it
doesn't follow through with what effect (or not) you will
actually HEAR at audio frequencies.

Woah there!

The guy in St. Andrews is very clearly talking physics, and doing
so correctly. The graphs speak for themselves. 0.1dB at 100kHz
is completely inaudible of course, and the fact that he doesn't
belabour the point doesn't make him a pathological wacko
pseudo-scientist. It just means that he assumes his audience is
smart enough to understand what he's saying.

That said, he does point this out:
"In effect, therefore, the above differential group delay is equivalent
to a sound source that seems 16 microns nearer at high audible
frequencies than at low audible frequencies."

Is it really necessary to explicitly FURTHER point out that a group
delay shift of 50nsec is inaudible?

"You should also understand how the Skin Effect can cause
problems with wideband signals..." But no explanation (that
I saw) AUDIO (20Hz...20KHz) is NOT "wideband".

But his analysis proves the point that skin effect is a moot point.
Consider it this way: the graphs are an integral part of his research
and presentation.

If you really want to discuss "skin effect" at 20KHz and
"audio harmonics" above 20KHz, you should probably
go and find one of the "golden-ears" high-end audio forums.
I would wager that only a small fraction of people on THIS
newsgroup can hear to anywhere near 20KHz. (Likely the
same on the "golden-ears" newsgroups, but they won't
admit it! :-)

Well skin effect is very real and measurable at 20kHz, just completely
irrelevant. :-)

As an aside, I was playing with a signal generator and amp this weekend.
Sadly, my hearing gives out somewhere between 16kHz and 17kHz. Gone
are my 20kHz days! :-(

Colin