invert phase

[avr]

Hello, first of all to say to them that I am a beginner in this of the audio. I have understood that if actors' dialogue is recorded with a microphone and with another microphone the environment is recorded, forthwith there is done an invert Phase and both channels are mixed the sound of the dialogues sera cleanly, without sound of bottom. How can I obtain this? It is possible to realize it in the location with a mixer for example?

Thank you.

 

[Gopher_Greene]

Re: invert phase

There are in line filters you can buy that will invert the phase 180 degrees. In theroy what your saying will work, but you never see any sound pro even attempting this. Why? because you will never get just room noise, you'll get your dialog as well, and if you invert it you be erasing dialog. secondly it takes perfect volume balance to "erase" the noise, much easier said then done. Where it does come into play once in a great while is when you have a single noise source your trying to eliminate. For instance a generator on site, has to be there, you have to have power. Then you can place a mia close to it with a 180 degree phase shifter and just maybe if your lucky in post you can cancell out the noise. Never tried it but saw it done once.
Good Luck