From: rsd@sei.cmu.edu (Richard S D'Ippolito)
Newsgroups: rec.audio.high-end
Subject: Re: High End is Humorous
Date: Wed, 30 Sep 1992 19:03:02 GMT
Organization: The Software Engineering Institute
NNTP-Posting-Host: 129.89.7.4
Originator: tjk@csd4.csd.uwm.edu


In article <m0mXun1-000OUoC@gasco.com>, Frank Ferguson writes:

|> >Can you please tell us just what that information is?  Are you perhaps
|> >confusing perception with information?  (D'Ippolito)
|> 
|> Obviously, if current measurement techniques fully map all of the 
|> variables that determine the human listening experience, then champions
|> of high-end gear can slink, red faced, to the shadows.  If McVey (or
|> anyone) could answer D'Ippolito, we could then proceed to design and
|> produce truely perfect reproduction instruments.

Perhaps you misunderstood what I was asking.  One can certainly measure and
quantify, in the case of an electrical signal (the topic of the original
discussion), what the information content is.  There exists equipment to do
that to a level of precision far exceeding current CD resolution.

We were not speaking of the human listening experience, but of amplifiers.  I
and others have made suggestions several times what electrical measurements
are possible that will characterize these devices down to third-order effects
under static and dynamic conditions, but, as far as I know, few manufacturers
ever do the analysis that makes fly-by-wire aircraft fly.

These measurements can be made for simple conductors and compared to those
made for active devices.  It is my understanding that for every electrical
propagation test that I can subject a wire to, that same test reveals
amplifiers to be orders of magnitude worse.  Simple mathematical reasons would
surely lead me to conclude that the small measurable differences in
comparably-sized wires are not having audible effects.  At least, we can all
agree on the ideal characteristics (or can we?!).

Note that speaker manufacturers are considerably more timid about such tests,
and can't even agree on a set of standards for what the ideal speaker's
transfer characteristics are.  Under such conditions, comparison is
impossible.

Now, there have been many scientifically repeatable experiments on human
perception of audio information which seem to place bounds on our ability to
hear noise and other forms of distortion (jj has cited several).  The fact
that these experiments have been used to determine ability to at least the
99th percentile allows us to make reasonable judgements regarding electrical
transducers.

What always surprises me is the percentage of the population whose
capabilities lie in the top 1% of the curve and how often these gifted folks
have net accounts.

Regarding audio fields, we can't agree on what to measure -- regarding
amplifiers and wire, we can measure far better than over 99% of you can hear.
I'll put money on it.


|>  Perceptions ARE information...

I the sense I was using it, processed information would be a better term.

I'm curious -- how many high-enders listen to Mozart performed on a Steinway,
Beethoven on a modern violin, and Brahms played with vibrato?


Rich


   "Please keep in mind that the ultimate goal [of hi-fi] is the
   reproduction of art, and that the invocation of science, while a neat
   parlour trick, is often unnecessary, flawed, and unreasonable."
   --  name mercifully withheld...                            rsd@sei.cmu.edu