Well phase isn't just a potential problem with microphones. It's a problem with any energy. (So it's also a problem with room acoustics and recording a bass DI with an amp at the same time).
I started writing an epic saga about phase, but figured the interest would be low so I never finished. Here's a quick explanation.
http://www.recordingreview.com/music...6/06/02/phase/
Phase in an extremely important fundamental to audio engineering and applies anytime you use are snagging more than one signal out of an instrument at the same time. Drums are probably the most effected.
While a signal being out of phase with another signal can completely cancel out the bottom end, the most common problem is comb filtering.
http://www.google.com/custom?hl=en&i...dingReview.com
Let me know if you have any questions. I've done my homework on this phase thing enough times that I should be able to help you.
Brandon