| 摘要 |
PURPOSE:To provide a low sound reproducing device capable of flatly reproducing a very low frequency sound at a maximum output sound pressure level even by its compact size. CONSTITUTION:A driver unit 1 to be driven by a power amplifier 4 is fixed to a cavity dividing member 3c dividing the inside into two parts, a passive radiator 2 is arranged on the outside of a cabinet 3 and the voltage of a sensor 5 for detecting the oscillation of an oscillation system in the unit 1 is fed back to the amplifier 4 through a feedback circuit 6 to apply speed type feedback and acceleration type feedback to the amplifier 4. Since the electromagnetic braking resistance and effective oscillation mass of the unit 1 can be equivalently increased, a peak can be suppressed in addition to the reduction of resonance frequency and a flat sound pressure frequency characteristic in a very low range can be obtained in the large effective oscillation area state of the unit 1. |
