From k2mojo@groovedaddies.com Thu Jan 27 10:00:23 2005
Subject:OT: stereo mics - live gig recording

(Apologies for the OT, but since many of you in these groups record your live gigs I thought it might be useful to extend this
thread from the Electro Group over to Clonewheel and Organ-ized since the Electro group is relatively smaller.)

This thread is intriguing and timely for me because I was just thinking about picking up a stereo mic for just this use. A couple
of questions:

1) For recording our live gigs for posterity, I'm planning on using a stereo mic (placed somewhere near the soundboard) in tandem
with the mixing board stereo line feed into 4 channels of a small HD recorder (i.e. Tascam 788, Korg D16, Roland VS-1680). Our
board mix recordings, especially in small clubs, usually don't have much guitar because the guitarist's stage volume usually keeps
him low in the mix, and additionally they're usually too heavy on the vocals and sax. I figure that starting with 2 board mix
tracks and 2 stereo mic tracks, I can mix that down to stereo and get a reasonably even mix of all the instruments with a little
room ambience to boot. And this keeps the setup simple, instead of running separate lines from everybody to multiple tracks; I
figure I can set this up in 5 minutes. Bottom line is that I want to be able to capture all the instruments with as simple a setup
as possible. Anybody here doing anything similar, or any other methods, suggestions, etc.?

2) Is this model stereo mic (Sony ECM-MS907) considered a pretty good mic for this application, or can someone recommend a better
mic (within a reasonable price range) that they like instead?

Ed Fliege
k2mojo@groovedaddies.com

----- Original Message -----
From: "Barnaby Bristol"
First off, the 1ms delay on the left channel. Don't do it. You
perceive location by the direct or first sound you hear. Your
recording sounds right heavy to me. Even if the levels are the same
for both channels, our brains are going to tell us everything is
coming {more or less} from the right channel. This can also cause a
comb filter especially when played in mono that really colors the
sound. It's cheap ear candy that can create problems.

"So how do I get width in my recordings?" inquires Bo.

You're in luck. From a quick search I believe your Sony ECM-MS907 is
a mid/side or MS microphone. Perfect for this application.

* Mid/Side (MS) capsules for natural stereo panorama; the Mid
capsule picks up monophonic sound while the Side capsule picks up
left/right difference sound; subtracting and adding the two capsule
signals yield separate Left and Right channels - also permit
electronic adjustment of pickup angle
* Mid/Side (MS) switch selects pickup angle between left and
right channel; choose 90° for a single voice or instrument or 120° to
pick up many voices and instruments, arranged across the stage

What I cannot determine is whether the microphone decodes the MS
signal to L/R or whether it just gives you MS and you have to do so
afterward. However, your recordings don't sound too wide so I
suspect the later which is preferred. RTM

When an MS microphone is properly decoded, as you move from left to
right in front of the microphone, the location of the sound should
move from left to right in the speakers.

http://www.sounddevices.com/tech/ms_stereo.htm

Put the mid signal up the center. Pan the side signal (+S) hard
left. Pan the side signal with polarity reversed (-S) to hard right.
As you add more +S/-S the image will get wider. Keep the levels of
+S-S the same to keep left/right balance. If you're doing this in
software make sure that there is no time difference (latency) between
the +S/-S. Some plugins will decode the whole MS with equal delays.

If you don't have a plugin for this, but are using a multitrack DAW you can:

- put the M track panned up the center.
- put the S track panned hard left.
- duplicate the S track, pan it hard right, and use an offline plug
in to create a file with the polarity reversed. Do not use a
software plug in as in this instance as it will introduce a slight
time delay compared to the +S.

If you need more info, let me know.

cheers,
Barnaby