Transmission and reproduction of stereophonic sound - uses basic signal and two side signals radiated by three loudspeakers

摘要

The device consists of a directional microphone unit with quickly rotating directional characteristic on the input side, and a reproduction side with loudspeakers in series with channel modulators synchronised by a pilot tone. Two LF sound voltages are derived from the sound signal. They are converted at the reproduction side to stereo signals, and converted back in channel modulators modulated in opposite senses in corresponding loudspeaker channels. The sum of the two AF voltages is added, and the sum voltage applied to the channel loudspeaker through a low-pass filter.