| 摘要 |
PURPOSE:To obtain a lot of sound from a loudspeaker without any howling by making the sensitivity of the microphone to the speaker installed in a conference room zero. CONSTITUTION:The amplitude and phase of the output from the microphone units 1-5 is made equal to each other by pre-amplifiers 6-10 that are controlled by a control part 12 of its amplitude and positional-adjustment amount, and the output is supplied to a synthesizer part 11. By thus providing the pre- amplifiers 6-10 and the control part 12, the adjusting work to make the sensitivity against the speaker installed on the ceiling is made extremely simple. In result, an electronic conference system or speaker system for conference room which furnishes a large amount of sound without howling, is attained. |
