Manley Labs

I found this on google in 5 seconds. But to answer your question... in general, no you don't need to flip the phase. It all depends on what and how your recording. If you just using the pair as drum overheads, both pointing the same direction, then NO don't flip the phase. But if you are micing a snare drum, one on each side of the drum pointing inwards (opposite directions), then YES you'd want to flip the phase. The sine wave diagram on the website should make everything clear.

You might be confused with the method of testing for matching pairs. See, if you put both mics as close as possible together pointing forwards and talk into it evenly, the signal capture by each mic should be identical. (though, in a perfect world, they can't be, due to limits of physical space, but it's close enough) Now, if you flip the phase on one of them, the combined signal should end up silent, because if you look at two mirrored sine waves, +1 plus -1 should equal ZERO. I hope that makes sense.

Don't flip the phase. Theres no reason to. If you get phasing in your overheads its time to move the mics.

Yo Scott! The most common ways to use a pair of stereo mics are coincedent(X-Y), ORTF (/), as a spaced pair, and MS (mid side). Way too much info to type, check the link above and check each of those options. None of them call for phase reversal, except MS, where it has a very specialized function.-Richie