Newsgroups: rec.audio

In rec.audio, rsd@sei.cmu.edu (Richard S D'Ippolito) writes:



> Gee, Dan, what they teach us in engineering school brought you audio in the
> first place, and is what keeps buildings standing, bridges bearing loads,
> cars running, airplanes flying, radio stations on the air, and the telephone
> systems working.  

Every example listed has had complete failures by unforeseen factors, not to 
mention high degree of quality variances.  You aren't trying to imply some 
know-it-all universally respected status for engineers are you?  Isn't 
that a bit pretentious?  Audio has been around since cave men wacked hollow
tree trunks with their bare hands.  You can work music halls to death
trying to improve them, like the $10 million Davies Symphony Hall acoustic
renovation.  They are now in the evaluation phase of that investment, AFTER
the measurements are complete.  This is yet another iteration for that hall.
If the engineers are so good, why is everything undergoing revision?  Because
they still don't know everything.

> Now, what makes you doubt its applicability to electrical
> signal propagation in a simple conductor?

Well, for me it's the incomplete knowledge of everything in engineering, like
in the list you provided.  Is there really such a thing as a "simple 
conductor"?   Sure, it's those straight lines on the schematic.  I'll tell
you what's printed in the cubicle of one of our best analog engineers: 
There is no such thing as ground.  And that's the truth.  If you can't get
ground potential, what can you get right?

> Perhaps you doubt the experiential data from myriads of psychologists on the
> difficulties involved in accurately measuring human perception and preference
> through even carefully controlled experiments.

Those difficulties keep everything open to debate.

> Oh yes, there are differences in cables, and they are measurable according to
> some very well-known models which have been quantified and validated
> independently uncountable times.  My experience on this board is that all of
> the engineers who have commented on cables have at one time or another offered
> evidence to show what the differences are and under what conditions they will
> have an effect, so your characterization above seems a bit unfair.

What is your point here?  Are you saying that all cabling problems are simple
to correct, and is insignificant?  I understand that, and I would like a 
bunch of cables to see which does it best for me.  Is that so hard to 
understand?

> The conclusion is that cables of similar size have measurable differences
> which are either insignificant at audio frequencies for the lengths normally
> encountered or are far below the limits of knowledge of the other components
> in the system.  How do I know this other than by personal experience as a
> practicing engineer?  Hewlett-Packard, Tektronics, General Radio, Marconi, and
> others have made successful businesses in instrumentation, and the NIST hasn't
> called any of them on it yet, so it's not exactly blind faith.

First you say there are differences, then you say they don't matter to anyone?
And what does my company's products have to do with
audio quality, except by verifying a few cursory parameters?  And what, pray
tell, does NIST have to do with any of this?  Are you trying to say that all
the measurements are complete in characterizing audio quality and NIST 
proves the final accuracy?  I'll have to disagree.

> When people insist on patronizing speaker manufacturers who won't follow
> reasonable practice standards of impedance stability and amplifier
> manufacturers who use vacuum tube circuits (or similar output driver
> topologies) that result in high impedance outputs not approximating voltage
> sources, they've predictably got far more than cable problems.  In spite of
> the cost of such components, I would not call the match a "reasonably good
> system".

And don't even listen, because you might like it and it hurts your sense
of engineering correctness?  Or you just know what works and doesn't without
even having to listen?  Of course there are mismatches, but why do some 
people like Apogees with tubes and the power hungry Thiel CS5 also?

> Does anybody still listen to music?

Well I do.


>      "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...       

I buy that.