Abstract: A variety of loudspeaker arrangements may have any of multiple adjacent magnetic circuits, single magnetic circuits, an improved loudspeaker voice coil assembly, multiple voice coil windings (124-127, 315-317), and commutated current. The radial direction of flux may alternate at adjacent poles and may have a controller that commands the current through each of the windings. The position of the moving components may be measured or inferred by the controller (213). An encoding track (318a) applied to the surface of the assembly may allow the assembly to function as part of a position transducer to permit appropriate action based on position. Calculated or sensed actual position may be used to determine the relative current in each of the windings and the controller may have compensation such as a motion control algorithm, thermal monitoring, and management of the driver.

Abstract: A variety of loudspeaker arrangements may have any of multiple adjacent magnetic circuits, single magnetic circuits, an improved loudspeaker voice coil assembly, multiple voice coil windings (124-127, 315-317), and commutated current. The radial direction of flux may alternate at adjacent poles and may have a controller that commands the current through each of the windings. The position of the moving components may be measured or inferred by the controller (213). An encoding track (318a) applied to the surface of the assembly may allow the assembly to function as part of a position transducer to permit appropriate action based on position. Calculated or sensed actual position may be used to determine the relative current in each of the windings and the controller may have compensation such as a motion control algorithm, thermal monitoring, and management of the driver.