[Tom McCreadie]

Mike Rivers wrote:

On 2/2/2015 8:23 PM, Fran Guidry wrote:
This certainly doesn't match my experience. If I use matched or
similarly sensitive mics and matched gain settings the S signal
is_much_ lower than the M signal and if this were not the case I
would start looking for my error.

Of course that makes sense since they're pointed so that the null is
toward what you're trying to record. However, I usually adjust the
preamp gain so that I get a good level out of the preamp and then adjust
the mid and +/- side mix for the stereo spread that I want.

Agreed, and sensible advice. A reasonable start is with the applied M and S
channel gains of the preamp/recorder at ca. 1:1 (after due allowance for any
sensitivity differences between M and S mics), then tweak it in real time from
there.

If, instead, you fixated on setting the channel gains purely to ensure that the
recorded signals on the meters flux at equal levels for M and S, you would
almost always be recording with too much S. (Some people do hang on to recording
with M and S both maximized, though, on the dubious rationale that it still
contributes a little to a better S/N ratio or cleaner AD conversion.)

I find it's important to home in fairly close to an optimum M:S ratio in real
time before the concert starts, for only then are you able to properly address
that other important parameter: direct to reverberant ratio.

Image width and direct/reverberant ratio are alas not independent variables - if
you widen the image by increasing the S to M ratio you always get a concomitant
increase in the reverberant to direct ratio. So it pays to strive to nail the
direct/reverberant balance at concert time, by adjusting the stand placement
distance and height.

In post in a DAW, one can always adjust the M to S ratio...but no DAW
post-processing can ever re-adjust the stand position.