| 摘要 |
PURPOSE:To optimize the presence of a human voice sound by adjusting the output of a center speaker automatically in response to a shift on a pattern in the speaker system outputting only the frequency component of a human voice from the center speaker. CONSTITUTION:Left, right signals L, R are inputted to band pass filters 14, 15 having a same performance and the amplitude is controlled by a gain control circuit 18 via an adder circuit 16 and the result is outputted to a center speaker 3 via an amplifier circuit 11. Moreover, outputs of the band pass filters 14, 15 are given to a subtractor circuit 17, the difference is given to a DC conversion circuit 19, in which the signal is converted into a DC, and it controls the gain control circuit. On the other hand, the left and the right signals are given respectively to subtractor circuits 8, 9, in which the frequency component of the voice outputted from the center speaker is subtracted and outputted to left and right speakers via amplifier circuits 12, 13. Thus, the outputs of the speakers are controlled automatically and the human voice is heard from the center of the pattern. |
