On 11 Sep 2003 15:25:29 GMT, Lou Anschuetz wrote:
chung wrote in
news:d6N7b.413447$uu5.75550@sccrnsc04:
Lou Anschuetz wrote:
(Stewart Pinkerton) wrote in news:bjnmtj014u5
@enews3.newsguy.com:
At audio frequencies, you will *never* measure artifacts in cables
above -140dB referred to a 10 vrms signal, and usually much lower
than that, right at the -160dB or so limit of the measuring gear.
While there may be no _audio_ research going on in this area, there
is other continuing research on insulation properties at low
frequencies.
At very low voltages, with frequencies just above the
audio range, this is certainly active work.
Can you provide a little more detail on what research you are talking
about?
Actually no. It would be unwise for me to comment on unpublished
research.
Hmmmmmmmm. Didn't stop you commenting on it previously......
While nature is wonderful, it is also pretty consistent. To believe
that the range 20-20,000 is somehow protected or asymptoted out of
all effects is, IMHO, pretty bold.
No one suggested that *low* frequencies were exempt, simply that
effects which occur at tens or hundreds of MegaHertz have little or no
relevance to things that happen below 20kHz. Can you show *any* AC
effects below 100Hz?
Yes, many individual effects can
be said to be negligable - but with the complexity of a musical
signal, there is the *potential* for multiple small effects to
interact. I'm not trying to rule out Occam's Razor here, just pointing
out that this stuff is not easy to model perfectly.
It is in fact *trivially* easy to model at low frequencies, and
absolutely *no* effects can be shown above -160dB at low frequencies.
Let's go back to Materials Science 101 for just a moment.With the
exception of a perfect vacuum (which we don't have anywhere) there is
no perfect insulator. All materials react in some way to
electrical/magnetic fields. Fortunately, electricity mostly acts like
water and doesn't "leak out" like alpha particles 
But, those
insulators around wires do react. I'll certainly grant any day of
the week that at low voltages and mostly small frequencies, those
reactions may be *very* weak.
Indeed so - see above.
However, with the complexity of a
musical signal, the rules tested for single frequency, single voltage
reactions *may* not apply in a linear way.
Excuse me? Musical signals are not in fact particularly complex, and
*no* non-linearies have been noted anywhere near audible levels. See
above.
Not a lot of folks spend
a lot of time looking at this (other than high-end cable makers) since
there is, frankly, little value or profit.
Indeed so, probably similar to the number of people who investigate
the possibility of the Moon being made from green cheese.
But, you'll also note that
there is no uniform, best-of-breed, do-all, be-all cable construction
for audio either.
Well of course there isn't - because *it makes no difference*.
This is the likely outcome of modeling when there
are lots of parameters with potential multiple interactions.
No, it's the likely outcome of the desperate scrabble for difference
to provide a Unique Selling Point among cables which *all* sound
identical.
In fiber
optics there is a "best of breed" for insulation, construction - though
the crimp-on fiber connector is *new* (relatively) and the result of
continuing research.
Unfortunately, the 'best of breed', which is the monomode quartz
fibre, is not sold by high end audio companies, only professional
communications companies - who have been selling it for *decades* at
prices well below those asked by so-called 'high-end' audio companies
for vastly inferior products. Also, the termination of such fibres is
a matter of precision engineering, not 'crimping'.
All of us involved with music know that there are effects with every
cable.
All of us who have tried level-matched blind comparisons know that
there is *no* audible difference. Have you ever wondered *why*, when a
pool of around $4,000 has lain on the table for more than five years,
no one has ever even *tried* to collect it by differentiating two
cables?
But it has always made me aware that testing by
listening alone is not to be trusted - thus gives me pause when
suggesting any kind of "audio" test of cables will be conclusive.
Oh right, so cable differences are not audible, but still matter in
music reproduction systems? :-)
--
Stewart Pinkerton | Music is Art - Audio is Engineering