Basic spaced omni/A-B technique

[Steve House]

Originally Posted by Douglas Spotted Eagle

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As far as distance, I prefer A/b, where the omnis are less than a yard apart, or X/Y where the heads cross at near angles.
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For small rooms, the NOS formation, which is the opposite of the X/Y, as the butts of the microphone cross at near angles, is really useful.

Finally, there is the ORTF combination, where the mics cross each other mid-body at an angle of 110 degrees. This is good for small churches and other mid size rooms, and is closest to the human ear.

I don't use Blumlein, because I don't have a good matched pair of figure 8 mics/bidirectional mics.

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Have you worked very much with M/S mic'ing?

Recently I've read a paper from Schoeps about using a double M/S arrangment for surround sound, adding a second rear-looking cardioid to a conventional M/S cardioid / figure-8 array to generate the rear surround, the figure-8 doing double duty for both cardioids. And they also discuss adding a pair of widely spaced omnis with low-pass filters on either side of double M/S array to record the signal for the sub channel.