| 摘要 |
PURPOSE:To instantaneously hear a clear sound by providing more than two kinds of circuits having various characteristics for controlling the respective gains of high and low frequency parts in an acoustic frequency, and automatically switching the characteristics of high and low frequency parts in the acoustic-frequency according to a pilot signal for switching the highfrequency and low-frequency characteristics. CONSTITUTION:This system is equipped with Bass circuits 1 and 2 for low-frequency cut-off frequencies f1 and f2, Treble circuits 3 and 4 for high-frequency cut-off frequencies f3 and f4, CPU 6 to receive a pilot signal 5 for switching the characteristics of the acoustic frequency and to transmit a switching signal to the switching part of a characteristic switching circuit 7, and control circuit 8. When the contents of a broadcasting is changed from music to a speech in the state of selecting the Bass circuit 1 for the low-frequency cut-off frequency f1 and the Treble circuit 1 for the high-frequency cut-off frequency f3 with music as the main broadcasting contents, the pilot signal transmits a CPU operation starting pulse and continuously transmits a data for deciding the operation of a changeover switch Thus, a circuit for deciding the acoustic frequency characteristic is automatically selected, and the clear sound can be heard at all times. |
