Multidirectional sound signals are optimally matrixed to increase the psychoacoustic directional fidelity as compared with prior systems. Four (or more) azimuthally spaced loudspeakers are fed from two transmission channels with very satisfactory directional sensing accuracy and full compatibility with conventional single-channel and two-channel reproduction equipment. Further auxiliary transmission channels may be added to produce a form of discrete-channel capability having even greater azimuthal fidelity than obtained in speaker-identified channels, while at the same time maintaining compatibility both with conventional reproducing equipment and with equipment for the basic two-channel transmission of the invention. The auxiliary channels may be transmitted in a relatively narrow frequency range, thus reducing the total bandwidth requirement for recording or broadcasting as compared with full conventional discrete channels.
Signal matrixing for directional reproduction of sound