| 摘要 |
PURPOSE:To enable adjusting the increase/decrease of a whole level while keeping output balance by independently muting a center signal, a front signal and a rear signal. CONSTITUTION:The center signal, the front signal and the rear signal are outputted from a sound source 1 to electronic volume parts 4 and 5 the volume of an input signal is adjusted by the control of a microcomputer 2 receiving an operation signal from a key 3. Then, the output signal of the electronic volume 3 is muting-processed by a muting circuit 6, amplified and supplied to a center speaker 11. The front and rear output signals are muting-processed by the muting circuit 7, amplified and respectively supplied to a front speaker 12 and a rear speaker 13. The ON/OFF operation of the muting circuits 6 and 7 is controlled by the microcomputer 2 in accordance with a key input in the same way. |
