[vorbis] CVS RC4 -q0 too good!

[Robert Woodcock]

[At the risk of going even further offtopic...]

On Tue, Jul 09, 2002 at 11:46:03PM +0200, Robert Adolfsson wrote:
> The skinning effect that makes a particular wire configuration like
> solid core better than multistrand for music transmission.

Skin effect means that electrons only flow on the skin of a conductor - the
middle sits there doing nothing. It only affects AC current and gets worse
at higher frequencies.

I would have never guessed that skin effect was even remotely a factor for
audio frequencies - it's more something covered in ham radio books.

All it does is change the effective impedance and resistance of the line.
Now who here has that matched anyway? Has anyone really heard of 8-ohm
speakers hooked up to 8-ohm impedance cable? Are anyone's cable runs even
close to a quarter wavelength at 100khz (750 meters)? Can such low-impedance
cable really exist? (The lower theoretical limit for balanced lines is
~75ohms, coax goes lower.) Has anyone hooked up an SWR (Standing Wave Ratio)
meter to their speaker cables?

The resistance loss would perhaps attenuate the higher frequencies a little
bit, but that can be compensated for with any equalizer and calibrated with
a real-time frequency analyzer. Anyone who's spending over $5 on a power
cable for their amp or marking the edges of their CD's green should have
those two pieces of equipment and be very familiar with their usage anyway.

Stranded wire actually has less of a skin effect problem because it has more
skin. There's such a thing as Litz wire which has individual insulated
strands to increase the effective amount of skin above that of stranded.

-- 
Robert Woodcock - rcw at debian.org
"Man is the best computer we can put aboard a spacecraft... and the only
one that can be mass produced with unskilled labor."
	-- Wernher von Braun

--- >8 ----
List archives:  http://www.xiph.org/archives/
Ogg project homepage: http://www.xiph.org/ogg/
To unsubscribe from this list, send a message to 'vorbis-request at xiph.org'
containing only the word 'unsubscribe' in the body.  No subject is needed.
Unsubscribe messages sent to the list will be ignored/filtered.