Advance in Quadraphonic Matrix Broadcasting

TMStereo-and mono-compatible stereo-quadraphonic (SQ) "matrix" recording and broadcasting is in wide use in the U.S.A. and abroad. Nevertheless, arguments continue about the need for "discrete" recording and broadcasting because of implied improvement they afford in channel separation and in artistic freedom in the use of the four channels. Both of these inferences are adduced to be fallacious. SQ quadraphonic broadcasting in the form of SQ records, syndicated productions, and encoded four-channel sources followed by full-logic decoding at the receiver end meets the identified needs of quadraphony. Two new advances are described in this paper: the SQ Ghent Microphone System which, from a single point in space is capable of picking up and transmitting a stereo-and mono-compatible pair of signals replicating the original directional performance either of the ambiance or surround-sound type, and a center-back "London Box" signal processor which encodes a stereo-and mono-compatible center-back signal and allows it appropriately to be decoded in the quadrilateral space with an SQ decoder.