Abstract: An audio system comprises three or more loudspeaker units and a source of four or more audio channels, each loudspeaker unit comprising a monopole loudspeaker and a dipole loudspeaker, or a pistonically driven diaphragm loudspeaker and a resonant panel loudspeaker. The system may be arranged such that, for any position relative to a listener at which a loudspeaker unit is situated in use, sounds emitted in response to signals carried by the audio channel for which the designated intended output position corresponds most closely to the position of that loudspeaker unit are emitted from the monopole loudspeaker or pistonically driven diaphragm loudspeaker of that unit. If a loudspeaker unit is not situated approximately at such a position, then sounds emitted in response to signals carried by that channel may instead may be emitted from the dipole loudspeaker or resonant panel loudspeaker of that loudspeaker unit.

Abstract: The assembly comprises a loudspeaker drive unit having terminals for connection to an audio signal source. The drive unit has a chassis with a mounting ring which has first and second opposed surfaces for, respectively, abutment against a seating in a mounting ring and abutment by a retaining circlip. The mounting ring is retained in an aperture in, for example, a ceiling by spring clips. The design of the drive unit allows it to be substituted for the sealed halogen light bulb in a conventional light fitting having such a bulb. A simple and convenient way of mounting the loudspeaker, particularly in a ceiling in a room such as a kitchen or bathroom where space elsewhere is limited, is therefore provided. The invention also facilitates conversion between a light fitting to a speaker installation.

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 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.