| 摘要 |
PURPOSE:To select both pseudo stereophonic effect generating circuit and stereophonic sound field expanding circuit automatically and to perform sound processing easily and effectively by controlling both circuits and a selection switch for selecting either one of both circuits by a stereophonic/monaural discriminating signal. CONSTITUTION:When a connection switch S4 is turned on, a connection switch S1 is turned off during monaural broadcasting, so a monaural sound signal SMONO supplied to an input terminal 16L is supplied to the uninverted input side of an amplifier 18 through a low-pass filter 20. Consequently, a sound signal SMONO' whose high frequency phase is inverted appears at the output side of this amplifier 18. The sound signals SMONO' and SMONO obtained at output terminals 40L and 40R are compared with each other, and the signal are in phase in a low frequency range and out of phase in a high frequency range; when the connection switch S4 for processing for pseudo stereophonic effect generation is turned on, the connection switch S1 is turned on during the stereophonic broadcasting, so a left sound signal SL supplied to the input terminal 16L appears at the output side of the amplifier 18 as it is and processed for the expansion of the stereophonic sound field. |
