The Ghent Microphone System for SQ- Quadraphonic Recording and Broadcasting
The Ghent Microphone System is an array of transducers concentrated at a point in space and followed by processing electronics, which receives surrounding directional sounds and delivers a stereo- and mono-compatible SQ-Quadraphonic encoded pair of electrical signals suitable for recording or broadcasting. The Ghent System is adaptable for positioning in a concert hall so that its front reception area covers the stage while the balance of the microphone perimeter receives the hall ambience. It also can be used conveniently for picking up surround sound performances, quartets, rock music, and dramatic presentations with the distance of the performers relative to the microphone being used to balance loudness and signal/reverberation factors, the angular displacement determining the direction of the encoded signal. The code produced by the Ghent Microphone System is equivalent to that of an SQ forward-oriented encoder, the cardinal decoded directions in space being Center Front (0°), Left Front (-50°), Left Back (-130°), Right Front (50°), and Right Back (130°). The Ghent System consists of four limacon transducers oriented at ±65° and ±165° responding to the equation 0.30 + 0.70 cos Ø (in practice formed electrically by matrixing the output signals of a standard 4-cardioid microphone) and a special encoder which is connected to the 4211 SQ-encoder module. The Ghent System has been tested successfully in the CBS Technology Center anechoic chamber, at Tanglewood (Lenox, MA, USA) with the Boston Symphony Orchestra, and at the Royal Albert Hall (London, UK) with the BBC Symphony Orchestra, verifying its predicted performance.
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