[Gary Eickmeier]

"Audio Empire" wrote in message
...

While I agree with you in theory, the reality is that the "sweet spot"
concept is part of the baggage that stereo recording methodology carries
with
it. I've mentioned this before, but it doesn't hurt to reiterate:

When you are at a live, unamplified concert, and you move around with
respect
the stage (or other locus of performance) your ears go with you and your
perspective changes with location. When listening to a recording, and you
move around the room, your surrogate ears, the microphones, and
ultimately,
(in the case of multi-miked, multi-channel recordings) the final mix has
one
set perspective because the "mikes" DON'T move. That being the case,
there
is only ONE set place where the perspective is correct, IOW, there is only
one place in front of the speakers (right to left) where the listener is
on
the same axis as the surrogate ears. Naturally, this is the place where
the
imaging and soundstage snap into sharp focus. If you aren't in that spot,
you
still hear a sound-field, but the focus will be gone. An analogy would be
a
3-D visual image. As you move the right-eye image and the left-eye image
closer together and further apart, there is only one relative position
where
these two images coalesce in your mind as a single 3-D image (assuming, of
course, you are wearing the glasses) with depth as well as height and
width.
That's because your surrogate eyes are a pair of lenses on a camera that
are
a set distance apart. That means that when viewing those images they must
give the illusion of being the same distance apart to your brain, or you
won't see the stereo effect - with or without the glasses.

No. Not analogous.

There need not be a single "sweet spot" nor a single perspective that was
viewed by some single stereo microphone.

The example in my Mars paper - which I think I sent you - was of an
imaginary recording made with one microphone per instrument, then played
back on speakers that have similar radiation patterns to the instrument they
are reproducing, and are placed in positions that are geometrically similar
to the original. Such an ideal system creates a sound field that is
spatially a duplicate of the original. You can move around in it just like
live. The realism of it depends on the size of the room being similar to the
original, or what the original would be good in. And most notably, neither
the recording nor the reproduction have anything to do with the number of
ears on your head or the spacing between them or any single position of any
microphone during the recording. Stereo is not a head-related system like
binaural, nothing to do with the human hearing mechanism, but rather the
creation of sound fields in rooms.

It is confusing when we begin to simplify the system down to fewer channels,
especially if it gets all the way down to two channels, because then we
begin to think that the two speakers are reproducing EAR SIGNALS, which they
are not. The only aspect of playback that relates to the human hearing
mechanism is the summing localization that is employed to create the phantom
imaging between speakers. Discrete surround sound with the center channel
gets us some of the way away from that confusion, but the nature of the
system remains the same, and the confusion will always be with us. But even
with a simplified-down system there needn't be a single sweet spot or single
perspective on the instruments, if you employ a proper radiation pattern,
speaker positioning, and a good room.

Gary Eickmeier