This invention concerns a loudspeaker driver includes at least one actuator connected to a vibrating support to impart excitation to the latter when caused to move, wherein the loudspeaker driver further includes a plurality of sensing members arranged to move with the at least one actuator, each sensing member providing output sensing data dependent on the velocity of said at least one actuator, and means for determining the position of the at least one 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.