Re: [ARSCLIST] Thirties Stereo

[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).

Mike
--
mrichter@xxxxxxx
http://www.mrichter.com/