[William Sommerwerck]

"Gary Eickmeier" wrote in message
.. .
"William Sommerwerck" wrote in message
...

Rather than bore the group with a repeat of my blather, I would like
to send you a .pdf of my Image Model Theory and maybe one other
paper. Have you seen it? May have been in the BAS Speaker. It says
that the problem is that there still is no model, or paradigm, for the
process of the facsimile reproduction of auditory perspective. I have
proposed one.

By all means send it along.


What you are saying is very true, and the reason is that the stereo
process - any process actually - changes the spatial nature of the
original
to that of the reproduction system. In other words, the complex original
sound field has been reduced to, and squeezed through, those two miserable
stereo speakers, making it impossible for it to sound anything like the
original. Surround sound is a partial remedy and a step in the right
direction, but you still don't have quite enough channels to do it, and
the
room is still there - and needs to be there by the way.

Floyd Toole told me an interesting experience. He was visiting a demo of
Ambisonics in an anechoic chamber. Like most of us, he wondered if this
would be an "ear opening" experience - after all, no more interference
from
the room, and near perfect encoding of all directions, even periphony.
What
he experienced was In Head Localization, much like with headphones! This
surprised me, because I thought that if you could turn your head you
wouldn't get this. The answer must be that without SOME real reflections
to
clue you in to a real space, the perspective is still FIXED as with
binaural.

I don't know if this is true. Nor do I understand why anyone would
demonstrate any kind of sound reproduction process in an anechoic chamber.

The best demos of Ambisonic playback I've heard were in large rooms on the
neutral-to-dead side. I set up one of these in a huge meeting room at NPR in
DC. It was perfect, in particular the way the image did not collapse toward
the nearest speaker as you moved around. And the "looking into the concert
hall from the gods' perspective" effect from outside the array was perfect.
As the room was deadish and had long early reflections, this is strong
evidence that such characteristics are not antithetical to Ambisonic
reproduction. Quite the contrary.

I'm in no position to gainsay Count Floyd on this particular issue, but I
don't trust his opinion on /anything/. He is not a good scientist.


Those of you who've made live stereo recordings know that, even with the
mics close to the orchestra, there is too much reverberation. This is one
of
the reasons for multi-miking, as it suppresses hall sound. J Gordon Holt
told me that it usually took many recording sessions to find mic
positions
that caught an appropriate balance -- and these were usually above the
orchestra, rather than in front of it.

By "too much," what you really are saying is that we cannot make it come
from an evenly spaced, correct set of incident angles, just from near the
speakers, so there is what is interpreted as too much reverb.

Yes. The same amount of reverb /from the correct directions/ wouldn't be
considered "too much".

It's interesting that adding ambience to the room with a hall synthesizer
/does not/ produce a "swimming in reverb" effect, and sometimes sounds
/less/ reverberant than the recording by itself.


So how does one solve the problem? The ideal way is to use a
recording technology that actually captures the direct and reflected
sounds /correctly/ at a particular point. I only know of two systems,
binaural and Ambisonics. Neither became popular.

There are still problems with binaural. Not sure why Ambisonics didn't
catch though, it is after all just another surround system, and surround
has caught on big time in home theater.

Ambisonics has multiple practical problems, the principal of which are that
it requires phase-matched speakers which are not too-close to the walls in a
not-very-live room in more-or-less strict layout.


I am trying to prepare some discs for you, but I want to get it right
first so you can report on how I did.

Which I will.