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From: max@eros.uucp (Max Hauser)
Newsgroups: rec.audio,sci.physics,sci.electronics
Subject: Re: Mercury Filled Speaker Wire
Message-ID: <1860@ucbcad.berkeley.edu>
Date: Tue, 15-Sep-87 04:33:23 EDT
Article-I.D.: ucbcad.1860
Posted: Tue Sep 15 04:33:23 1987
Date-Received: Thu, 17-Sep-87 00:48:18 EDT
References: <3816@watdcsu.waterloo.edu> <578@uthub.toronto.edu> <1700@crash.CTS.COM> <1854@ucbcad.berkeley.edu> <1709@crash.CTS.COM>
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Reply-To: max@eros.UUCP (Max Hauser)
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Organization: University of California, Berkeley
Lines: 53
Summary: Rhetoric, electronics, art and life
Xref: mnetor rec.audio:3237 sci.physics:2170 sci.electronics:1302

In article <1709@crash.CTS.COM> bblue@crash.CTS.COM (Bill Blue) writes:
> In my view, the big culprit that kills the 'hardware store' variety
> cables is the varying time of arrival of different frequencies at the
> other end of the cable due to skin effect propagation and other factors.

OK, I will concede that hardware-store cables of the casual variety
may suffer from this problem. When I asserted that one could build
hardware-store cables meeting arbitrary specifications, I specifically
meant reactance and dispersion as well as resistance, based on some
knowledge of these effects and on the properties of copper wire.
However I have not tried it, while bblue has, and I value that 
experience. Nevertheless, I am convinced that high-quality cables,
even with these subtle problems resolved, need not be expensive.

Understand that in the following I am now speaking of VERY
high-quality speaker cables, since even casual hardware-store
cable, heavily stranded and paralleled, and kept as short as
possible, will palpably outperform even many "audio" cables.

Now, to hear it described recently on the net, one would think 
that Dick Olsher and co. had discovered dispersive propagation and
its relation to conductor effects.  In reality these are old, prosaic
problems, familiar to thousands of people in this country (some
of whom are even on the net). In fact, since these problems first
surfaced in long-disance wired telegraphy, they even predate 
electronics (a term, incidentally, coined by McGraw-Hill to title
a trade magazine -- the magazine came before the field). 

Varying time delay for signals of different frequencies (also 
called dispersion, or phase nonlinearity) comes up in many contexts
(phase nonlinearity in analog filters for digital audio was 
discussed to death on rec.audio), as do such conductor nonidealities
as skin effect and distributed inductance. However, these problems
also admit creative solutions, which can be as simple as tolerating
the cable effects and adding a small compensating network in the 
preamp, properly done, of course. That the problems are unfamiliar
to consumers does not mean that their solution requires genius,
or an approach obviously related to the source of the problem, or
even (the seemingly inevitable) hundreds of dollars per unit.

Moreover, if you are going to seriously regard [good split infin.]
"skin effect propagation and other factors" as physical, rather
than just rhetorical, effects, and then someone comes up with
a nice cheap solution that measurably fixes these physical effects,
then you are bound to (as Sam Spade said to Joel Cairo) "take it and
like it," or else stop claiming that you know the *physical basis*
for cables' sonic imperfections. For many people this is a tall order.

Max Hauser

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