Gorging on Sound
I wanted to respond to your remarks about surround sound, but carelessly
discarded the original e-mail. Here goes with what I remember.
Conventional two-channel stereo is fundamentally incomplete. It can never --
ever -- sound like what you hear in a concert hall, jazz club, church,
what-have-you. The basic reason is that it isn't enough to record the hall
ambience -- it has to be recorded in a way that allows it to be /correctly/
presented to the listener in playback. Two-channel stereo not only does not
do this, it /cannot/ do this.
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.
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.
The most-important component of the ambience is the lateral sound, and in
playback, it /must/ come from the sides. (This is why the ITU standard
specifies that the rear or side speakers be located within +/- 15 degrees of
the listener's sides.) This means that you can never correctly reproduce
lateral sound from the front speakers. It is mixed in with the direct sound
(in a way that colors it), and the brain will never hear it as lateral
sound, because it /isn't/.
As for the rear levels... In theory, they should be at the same level they
were recorded. If they are at such a low level that a logic-directed decoder
can't handle them -- well, that's the way it is. Logic-directed decoders are
not optimum for ambience reproduction.
I could talk more about this, but I don't have the time. I'd certainly like
to hear the views of others who've made surround recordings, of all types.
|