Convention Paper
Obtaining a Highly Directive Center Channel from Coincident Stereo Microphone Signals
AES Convention 124 · Paper 7380 · May 2008
Abstract
Time-frequency based post-processing applied to a coincident stereo recording is proposed to generate an audio signal with a highly directive directional response pointing straight forward. Assuming an ideal coincident stereo microphone, the directional response of this center channel is effectively
time and frequency invariant. Further, the look direction can be steered to left and right front directions. The technique is based on the insight that the signal which predicts left from right, modified by limiting the magnitude of the frequency domain prediction gains, has a center forward directional response. The center channel is generated using both, a left-right and a right-left magnitude-limited-predictor signal. Applications of the proposed scheme are use of stereo microphones as ``digital steerable shot gun microphones' and center channel generation for music recording.
