Abstract: A flat panel loudspeaker includes a planar resonant panel insertable into an opening in the mounting surface and including a front surface and a rear surface. The front surface faces outward in the mounting surface. The loudspeaker also includes an exciter coupled to the rear surface of the planar resonant panel and a support frame for mounting in the mounting surface. The rear surface of the planar resonant panel is fixed thereto around substantially the whole of the outer boundary of the planar resonant panel. The outer boundary of the planar resonant panel is fixed relative to the mounting surface. The loudspeaker further includes at least one tab configured to extend away from the support frame and be substantially flush with the front surface of the planar resonant panel, which is substantially flush with the mounting surface when the tab is against the mounting surface.

Abstract: A flat panel loudspeaker includes a planar resonant panel insertable into an opening in the mounting surface and including a front surface and a rear surface. The front surface faces outward in the mounting surface. The loudspeaker also includes an exciter coupled to the rear surface of the planar resonant panel and a support frame for mounting in the mounting surface. The rear surface of the planar resonant panel is fixed thereto around substantially the whole of the outer boundary of the planar resonant panel. The outer boundary of the planar resonant panel is fixed relative to the mounting surface. The loudspeaker further includes at least one tab configured to extend away from the support frame and be substantially flush with the front surface of the planar resonant panel, which is substantially flush with the mounting surface when the tab is against the mounting surface.

Abstract: A moving coil drive unit for exciting a resonant member into a vibrational state is disclosed. The moving coil drive unit comprises a magnet assembly and a coil assembly comprising a voice coil arranged concentrically with the magnet assembly and configured such that the voice coil is moveable axially relative to the magnet assembly in use. The magnet assembly comprises a permanent magnet and one or more pole pieces. The magnet assembly is configured to provide an annular magnetic gap, the voice coil being suspended therein. The pole piece is configured to have a laminated structure comprising at least two spaced layers. One or more of the layers of the pole piece may be shaped, in at least a region thereof surrounding the magnetic gap, so as to generally follow and guide the magnetic field lines emanating from the permanent magnet.