Abstract: An inertial exciter (40) for an acoustic radiator (42), and a loudspeaker incorporating an acoustic radiator and such an exciter. The exciter has a massive member (44); a coupler (56) adapted for attachment to the acoustic radiator (42) and adapted for relative movement with respect to the massive member (44); a motor for effecting relative movement of the coupler with respect to the massive member; and a suspension (60) for supporting the massive member relative to the coupler. The suspension (60) acts in a plane generally passing through the center of mass of the massive member, thereby reducing any moment acting on the suspension. Also disclosed is a loudspeaker exciter assembly (70) that has a base plate (86) for attachment to an acoustic radiator in a non-repeatedly engageable manner, and an exciter (40) attached to the base plate (86) in a repeatedly engageable manner; and a loudspeaker incorporating such an exciter assembly.

Abstract: An inertial exciter (40) for an acoustic radiator (42), and a loudspeaker incorporating an acoustic radiator and such an exciter. The exciter has a massive member (44); a coupler (56) adapted for attachment to the acoustic radiator (42) and adapted for relative movement with respect to the massive member (44); a motor for effecting relative movement of the coupler with respect to the massive member; and a suspension (60) for supporting the massive member relative to the coupler. The suspension (60) acts in a plane generally passing through the center of mass of the massive member, thereby reducing any moment acting on the suspension.

Abstract: A bending wave panel-form loudspeaker comprises a spaced pair of panels supported at their edges and defining between them a shallow sealed fluid cavity. Vibration exciters are disposed in the fluid cavity and are arranged to drive the respective panels. The electrical connections to the exciters are at least partially in antiphase such that the predominant motion of the panels is in phase to provide a degree of dipole radiation property for the loudspeaker. The gap between the panels is in the range 2 to 25 mm such that the shallow cavity provides conditions in which fluid coupling dynamics and behavior is asserted between the pair of panels due to the fluid layer between them.