A loudspeaker driver with sensing coils for sensing the position and velocity of a voice-coil

摘要

The loudspeaker driver comprises an actuator connected to a vibrating support to impart excitation to the latter when caused to move, and a plurality of sensing coils 22, 24, 26 arranged to move with the actuator, each sensing member providing output sensing data dependent on the velocity of said actuator, and means for determining the position of the actuator based on at least one ratio (X/Y) of output sensing data or of linear combinations of output sensing data provided from the plurality of sensing members, said at least one ratio being independent of the velocity of the at least one actuator. Other sensing data processing arrangements are disclosed.