XY Stereo Microphone Technique
From WikiRecording
X-Y Stereo Microphone Technique
XY creates a stereo image by using two cardioid or hyper cardioid microphones placed as near as possible to each other (and up to 12 inches apart) at 90-135 degrees spread and with the center of the spread pointed at the sound source. The angles create a stereo image when panned because of the polar pattern of a cardioid microphone that limits off-axis sound, or in other words creates a stereo image because cardioid mics reduce the level from the sides and back. You cannot use Omnidirectional microphones with this technique because the microphones are close enough to each other not to employ delay in creation of the stereo image, compared to the AB Stereo Microphone Technique.
Because the microphones are so close, phase problems are almost completely eliminated so it is commonly used in radio, where the recording might be heard in mono. Of the stereo techniques XY is the best choice if you think you might bounce it down to a mono signal at some point.
