Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site rabbit.UUCP
Path: utzoo!linus!decvax!harpo!eagle!allegra!alice!rabbit!jj
From: jj@rabbit.UUCP
Newsgroups: net.audio
Subject: Re: 200-201kHz flaming (meta-flame follows)
Message-ID: <2247@rabbit.UUCP>
Date: Mon, 5-Dec-83 11:25:24 EST
Article-I.D.: rabbit.2247
Posted: Mon Dec  5 11:25:24 1983
Date-Received: Tue, 6-Dec-83 23:31:51 EST
References: <3287@tekecs.UUCP>
Organization: AT&T Bell Laboratories, Murray Hill
Lines: 51


Wrong, Keith, WRONG!  You miss the point entirely. (Your 
comments, though, are quite correct, if a bit
optimistic. ?perhaps for politeness?...)


The person who was claiming that at least 100kHz bandwidth
was necessary didn't consider any of the electronic 
problems, neither did I in my response.    (Even though all the 
problems would certainly detract from their arguments, I don't
have the energy to be precise, I only wanted to make the point.)

Certainly the electronics will intermodulate like mad.
Certainly the tweeter (if it lives at all) won't even SEE
any current in its voice coil <a piezo might, but....>
Even IF you manage to get it through the electronics,
and into the voice coil (I'm assuming a dynamic tweeter of
some sort, perhaps ribbon/leaf), you will STILL get a real
mess from the Tweeter. (Intermodulation will be the LEAST of
the problems.)

Now then.  Let's assume for a minute that we DO get the two
signals into the air.  Let's assume (for purposes of argument)
that they get into the ear intact (fat chance, the atmospheric
absorbtion will be tremendous, just like at a real performance,
where the high frequencies would vanish without a trace).  
What will happen?
Well, the EAR is quite non-linear itself.  You will get AT LEAST
the first order intermodulation tones.  These intermodulation tones
will be the detectible part of the signal.

When I posted the article, I was trying to point out to the
people complaining about digital reproduction the fallacies that
they were espousing.  

Distortion in amplifiers, the lack of even electrical input
into the tweeter, etc, are ALL items that they had ignored.
Just trying to make such a test (with low levels, so as to be
non-destructive, please) would point out a number of
difficulties. 

What's the point? 
	I don't know.  Perhaps that the physical limits of acoustic
propigation, electronics, etc, should be  required reading.


Have an overly precise day, Keith! (-:
-- 
-Diogenes stopped here-

(allegra,harpo,ulysses)!rabbit!jj