Motional feedback speaker unit inputs acoustic signal to first voice coil and senses vibration of a loudspeaker, returning feedback signal to an amplifier, which applies it to second voice coil

摘要

An motional feedback (MFB) speaker unit inputs an acoustic signal to a first voice coil (10-1). A sensor (31) detects vibration of a loudspeaker and returns a feedback signal to an amplifier (40). The amplifier amplifies the feedback signal and applies it to the second voice coil (10-2). The sensor may detect either displacement, velocity or acceleration. The feedback signal is composed of the sum of signals from a displacement sensor and/or a velocity sensor and/or an acceleration sensor.