Miking a comedian from the inside....need to reverse phase?

Maybe it may just seem like semantics, but there is a big difference between phase and polarity. For the most part, what everyone here is talking about is reversing the *polarity*. This is what the switch incorrectly labelled 'phase' on your console is doing.....making all positive voltages negative and visa versa. Phase is a much more complicated beast. Flipping the polarity makes most sense when in a situation like micing a tom from the top and bottom. If you think about it, the intial attack is going away from the top mic, but toward the bottom mic... In the case of other multiple mic setups, the situation is more complicated and you might like the sound of the polarity reversed, but you'll probably have more luck dealing with the phase issues by changing relative mic placement or experimenting with a delay line.

180° phase shift = changing the polarity

olivier wrote:180° phase shift = changing the polarity

This is not true and is reason why I said this may just seem like semantics. Phase shift means there is a difference in the time domain, polarity is independent of the time domain. They may seem like they are the same, but they aren't. Here is a decent article with illustrations:

http://www.digitalprosound.com/Htm/Tech ... reOne1.htm

of course you are right but it's very usual for people to speak about phase instead of polarity .. so i think the polarity button of the mixdesk is called phase because it help to fix phase problem ?

http://www.prosoundweb.com/studyhall/la ... _phase.pdf

olivier wrote:180° phase shift = changing the polarity

Only if you're dealing with a sine wave of one particular frequency. If you changed to a different frequency you would also have to alter the amount of delay required to achieve a 180 degree shift.
But we don't work with sine waves. Most sounds are more complex than that. You could hone in on the resonant frequency and as long as the song had only one note you could phase shift the resonant frequny by 180, but all the overtones would spill over.