How to reduce ambient noise using omnidirectional mics

The mics must be similar and one is connected out of phase.


We sing to one of them.


An easy way to implement the connection is to connect the mics in series, like Christmas tree bulbs or like resistors, or batteries. But he connection is not (+ -) to (+ -), it is (+ - ) to (- +). So we take XLR  pin 3 of one mic and connect to XLR pin 3 of the other. Then pin 2 of one mic is connected to a new XLR at pin 2. And pin 2 of the other mic is connected to the new XLR at pin 3.


Reference:


Microphones: Design and Application - Lou Burroughs