| 摘要 |
PURPOSE: An acoustic device for lectures is provided to maximize linearity of sound and audible angle and reduce power consumption by turning off an amplifier when no signal is received from a microphone. CONSTITUTION: A housing includes an upper plate which is longer than a lower plate. An acoustic guide member includes an inner upper plate, an inner lower plate, and inner left and right plates. A vibrating plate(40) includes more than one air duct for sealing a front portion of the vibrating plate. An acoustic output portion includes high frequency and low frequency speakers. An acoustic absorber(70) is condensed into a space An amplifier(60) is implemented between a rear portion of the low frequency speaker and the rear plate of the housing. A system controller(90) includes a controller, a power breaker, and a switch. The power breaker automatically breaks power supply to the amplifier when no signal is received from a microphone or after a predetermined time interval. |
