| 摘要 |
PURPOSE:To accurately and speedily match the size of sound pressure at a listening position with a phase by optically transmitting sound pressure detection data at the listening position and automatically controlling the size and phase of a woofer signal to be equal with that of a high and mid tone-range speaker. CONSTITUTION:A controller 18 controls an oscillator 19, generates two signals vertically sufficiently separated from a crossover frequency, detects the sound pressure from a super woofer 10 and a high and mid tone-range speaker 9 by a microphone 11 and optical transmitting means 15 and 16 and automatically controls a gain controller 4 so that the sound pressure can be made equal. Next, the signal of the crossover frequency is generated from the oscillator 19 and a phase controller 5 is automatically controlled similarly so that the synthesized sound pressure can be made maximum. Thus, the size and phase of the sound pressure at each listening position can be physically accurately and speedily matched without a special test record. Further, since the optical transmission is used, interference caused by another electromagnetic wave or acoustic wave is completely eliminated and the automatic control can be executed at high speed. |
