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Re: [ARSCLIST] Thirties Stereo

----- Original Message ----- 
From: "Mike Richter" <mrichter@xxxxxxx>
> Steven C. Barr(x) wrote:
> > ----- Original Message ----- 
> > From: "Mike Richter" <mrichter@xxxxxxx>
> >> Of course, the Cook (at least) were not stereo but binaural. 
> >>
> > What is the difference between "stereo" and "Binaural?" I always
> > thought these were two ways of saying the same thing...
> A very great difference indeed!
> Binaural recording is made to be reproduced through headphones. It is 
> best made with microphones implanted into a model head positioned as it 
> might be in the venue for the work. As the listener's head turns, the 
> image moves with it, but otherwise binaural can provide a truly 
> effective sound stage.
> Stereo recording is done with two (or more) microphones positioned 
> across the sound source. Played back on loudspeakers, relative position 
> is preserved and some semblance of the sound stage may be retained, but 
> that is neither accurate nor persuasive. However, the image remains 
> stationary as the listener moves, providing a different aspect of reality.
> Once upon a time, I began an analysis of the amplitude and phase sensed 
> at the ear from 'perfect' stereo reproduction. That is, assume two 
> perfect microphones positioned on the stage for recording which are 
> replaced by two perfect speakers for reproduction. Then for a sound 
> source between the two mikes or speakers, what are the amplitude and 
> phase of the signals perceived at two ears located somewhere in the 
> 'hall'? The result was a remarkably complex set of functions with 
> strange dependencies on frequency and position of the source - and that 
> was before I added a third dimension of distance of the source 
> perpendicular to the line joining the mikes/speakers. It was clear that 
> there is no simple transform between stereo and binaural and that the 
> computation was far beyond my patience (if not my competence).
First...thanxes for the explanation!

Second...another consideration would be that records are usually
made in "echo-free" environments (other than added artificial
"reverb." The human mind/ear combination derives a lot of
information from the "echo" component of heard sound, and as
a result, sound without any (or sound with artificial reverb
added, resulting in information the mind recognizes as
gibberish) doesn't appear to be "correct" to someone who
hears it! Humans spent "megennia" (millions of years) learning
how to establish location "the hard way" (if you knew where the
bear was, you ate the bear...if not, the bear ate you!), so
sound without "echo" is like opening a book and finding 
every other letter missing...

As far as trying to define sound (outside a "theoretically
perfect room" created in a laboratory?) in any actual sonic
environment...the mind boggles! Think about all the reflections
(some coming off angular or curved walls!) and the additions
and cancellations of waves that result! And that's before we
add any furniture or other miscellaneous impedimenta...

Steven C. Barr

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