In article .com,
wrote:
by what method do you determine the proper spacing distance between a
pair of omnis? i have read the general rule about 1/3 the soundstage
width, which may be about right for a small ensemble on a stage.

This is for A-B miking, which is probably the most common earlier method
and one that you will hear on a lot of fifties and sixties classical
recordings. You can go wider than this if you employ a third center
microphone, too. Spaced triad used to be very common.

and i
have read the earthworks literature that talks about very closely
spaced pairs (like almost coincident, or only a couple of inches apart)
for close-micing solo instruments in the studio.

This is not really conventional stereo miking. When you are doing
this, you are up very close and you are trying to collapse the stereo
image so it is not exaggerated by being so close. Don't think of this
in the context of regular ambient miking where you are trying to capture
a full soundstage.

i have also read of
omnis spaced 3 feet apart and 4 feet out for solo instruments. what
are your thoughts and experiences for both soloists in the studio and
small ensembles in a live venue? thanks.

Again, these are trying to collapse the stereo image somewhat, because
the mikes are being placed closer than a listener normally would.

My personal feeling is that all of the widely-spaced omni systems sound
very artificial to me. There are amplitude differences between channels,
but the phase differences between channels are so great that all of the
phase-related imaging goes away completely to my ears.

I have always much preferred the effects I have got from baffled omni
systems like Schneider discs or Jecklin discs.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."