GB996002A - Improvements in or relating to stereophonic sound translating arrangements - Google Patents

Abstract

996,002. Stereophonic systems; supporting microphones. ELECTRIC & MUSICAL INDUSTRIES Ltd. Nov. 1, 1961 [Nov. 1, 1960], No. 37428/60. Headings H4J and H4R. A stereophonic sound translating system comprises two signal channels and more than two microphones mounted on a boom so that the spacing between the microphones can be adjusted, and means for feeding signals from the microphones to the two signal channels, said means being such that one or each of a plurality of the microphones can be caused to feed portions of its output simultaneously to each of the channels. Seven microphones A, B . . . G (Fig. 1), preferably of cardioid type, are mounted on a horizontal boom 9 supported at each end by a tripod X, Y. Each tripod is adjustable in height by a handle 13 (Fig. 2). Cables 14 from the microphones feed into a control box 15 containing splitter transformers for dividing the output from each microphone into two portions which are applied to output channels 17, 18 respectively. Potentiometers or balanced attenuators are provided in the output leads from the splitter transformers to vary the input to channels 17, 18. Preferably a pair or pairs of potentiometers are ganged together so that the output from a pair of, or pairs of, microphones (e.g. C, E) to channels 17, 18 may be varied in complementary manner. Microphone A may feed its entire output to one output channel, microphone G may feed its entire output to the other output channel, while the output from microphone D may be divided equally between both channels. The microphones 1 (Fig. 3) are gripped by a clamp 7 (Fig. 3) within which is a layer 2 of resilient damping material. Each microphone is counterbalanced by a weight 5 and is adjustably secured to the boom 9 by a clamp 21. The clamp 21 has a mark 8 for alignment with a mark 3 on the boom 9. The boom 9 may be of telescopic construction.