Recently I was doing an experimental project (with my son's band) and the singer (if I dare call him a singer) insisted on useing his wireless mic. Since this was an experiment I agreed to give it a try. Initally we put the mic on a stand and it seemed to work OK. Then the singer decided he wanted to hold the mic (used to live and holding the mic felt more natural) so he could move around a little. I didn't notice it while tracking but upon playback the vocals had a really weird phasing sort of noise/effect, it was like the mic had been run through a flanger or something. The wireless unit (not sure of the model but it is a Shure mic and reciever) works fine through a PA but did some pretty weird things while recording. I don't plan to use this sort of thing again, but I would like to hear from anyone who has encountered a similar problem and would like to hear an explanation of what may have caused the problem. So far I've been calling it "proxemity EMI" for lack of a better term. I've never had anything similar happen while useing any wired mics (even cheap ones.)