Abstract: A loudspeaker unit comprises, in combination, a pistonic loudspeaker and a resonant panel loudspeaker arranged such that the resonant panel is movable, for example by rotation, with respect to the pistonic loudspeaker. The resonant panel may be movable with respect to the pistonic loudspeaker between a first position in which the resonant panel covers the pistonic loudspeaker, and a second position in which pistonic loudspeaker is uncovered from the resonant panel. The resonant panel may be movable by means of a motor, for example by remote control. A loudspeaker assembly comprising a resonant panel loudspeaker, a support to which the resonant panel is attached, and a motor by which the resonant panel is movable with respect to the support, is also disclosed. The assembly may form part of the unit. The assembly or unit may be attached to a wall or other boundary, for example in a recess.

Abstract: A mid-frequency loudspeaker drive unit includes a substantially conical diaphragm having a forward periphery and a surround connected to and extending from the forward periphery of the diaphragm to form a substantially smooth transition from the diaphragm to the surround, the diaphragm and the surround presenting a substantially smoothly continuous outwardly facing surface. The drive unit can be part of a compound loudspeaker drive unit including a high-frequency drive unit coaxially disposed within the diaphragm and a chassis encompassing the mid-frequency drive unit with the surround being secured to the chassis to form the smooth transition from the diaphragm to the surround.

Abstract: A loudspeaker assembly includes a chassis, a magnet assembly supported by the chassis and disposed at a rear side thereof, a moveable voice coil, a rear suspension, and a diaphragm connected to the voice coil and to the chassis. The assembly defines a voice coil gap receiving the voice coil. To improve the cooling of the assembly, particularly when the magnet assembly includes neodymium, the assembly is positioned at least substantially in front of the diaphragm, and the chassis is positioned outwardly of the magnet assembly. Heat generated by the coil, which could adversely affect the magnet, is dissipated by conduction to the chassis and by convection and radiation to ambient air. The rear suspension supports the voice coil, is secured to the assembly and is connected to the chassis only through the magnet assembly and through the diaphragm.

Abstract: A generally cylindrical pole piece for a moving coil loudspeaker includes a blind recess in the axial end face that faces an air-permeable dust cap. The recess is lined with a plurality of spaced ribs or fins to increase the surface area available for heat dissipation. The recess and ribs are preferably tapered, to enable the pole piece to be made as a forging.

Abstract: An improved acoustic horn for loudspeakers is provided. The acoustic horn of the referred embodiment of the present invention includes a one piece body that incorporates damping material within the body. Preferably, the one piece body is slotted and vibration damping material is provided within the slots. The horn is fabricated by casting from suitable metals and metal alloys. In the preferred embodiment, the body comprises four outwardly curved and flared side walls and is generally rectangular. Each wall of a pair of the opposed side walls is cast with a slot. Vibration damping material is provided in each slot to substantially reduce the structural resonances of the one piece body, so that the acoustic horn has enhanced vibration damping. Various vibration damping materials that are flexible relative to the body and have a high loss tangent are used. Suitable materials include hot melt adhesives, epoxy resins, and commercially available elastomeric materials.

Abstract: A loudspeaker clamping structure embodying an improved compression driver is provided. The clamping structure is configured to utilize a totality of the air contained within a cover coupled to a magnet structure of a loudspeaker. The clamping structure includes a compression driver that extends about the periphery of a membrane for clamping the membrane to the magnet structure. The cover includes an annular ring configured to engage the compression driver. At least one of the ring and compression driver is configured with a plurality of interstices along its length to provide interstitial gaps when the ring and compression driver are engaged.