Abstract: An electronic device that coordinates a playback operation is described. In particular, an interface circuit in the electronic device may calculate, based on differences between transmit times when packets were transmitted by a second electronic device and receive times of the packets, relative drift as a function of time between a clock in the interface circuit and a second clock in the second electronic device. Then, the interface circuit may adjust, based on the relative drift, a clock circuit that provides the clock to eliminate the relative drift, and may determine a remaining time offset between the clock and the second clock. Next, the interface circuit may modify a future time when the second electronic device is to perform the playback operation based on the remaining time offset to determine a corrected future time, and may transmit information to the second electronic device specifying the corrected future time.

Abstract: An audio/video (A/V) hub that selectively determines one or more acoustic characteristics of an environment that includes the A/V hub is described. In particular, the A/V hub may detect, using wireless communication, an electronic device (such as a speaker) in the environment. Then, the A/V hub may determine a change condition, such as when the electronic device was not previously detected in the environment and/or a change in a location of the electronic device. In response to determining the change condition, the A/V hub may transition into a characterization mode. During the characterization mode, the A/V hub may: provide instructions to the electronic device to playback audio content at a specified playback time; determine one or more acoustic characteristics of the environment based on acoustic measurements in the environment; and store the one or more acoustic characteristics and/or a location of the electronic device in memory.

Abstract: A diaphragm for a loudspeaker drive unit or for a microphone includes a rigid dome-shaped member having a thickness that varies from a first thicker thickness at a first location at the periphery of the dome-shaped member to a second thinner thickness at a second location, which is nearer to the center of the dome-shaped member. There is a step-wise change in thickness at a location between the first location and the second location. Having greater thickness at the periphery of the dome-shaped member may improve stiffness of the diaphragm and may allow for an increased break-up frequency. Having thinner material elsewhere in the dome-shaped member may allow the mass of the diaphragm to be kept low and may result in better acoustic sensitivity.

Abstract: A diaphragm for a loudspeaker drive unit or for a microphone includes a rigid dome-shaped member having a thickness that varies from a first thicker thickness at a first location at the periphery of the dome-shaped member to a second thinner thickness at a second location, which is nearer to the centre of the dome-shaped member. There is a step-wise change in thickness at a location between the first location and the second location. Having greater thickness at the periphery of the dome-shaped member may improve stiffness of the diaphragm and may allow for an increased break-up frequency. Having thinner material elsewhere in the dome-shaped member may allow the mass of the diaphragm to be kept low and may result in better acoustic sensitivity.

Abstract: A diaphragm for a loudspeaker drive unit or for a microphone includes a rigid dome-shaped member having a thickness that varies from a first thicker thickness at a first location at the periphery of the dome-shaped member to a second thinner thickness at a second location, which is nearer to the center of the dome-shaped member. There is a step-wise change in thickness at a location between the first location and the second location. Having greater thickness at the periphery of the dome-shaped member may improve stiffness of the diaphragm and may allow for an increased break-up frequency. Having thinner material elsewhere in the dome-shaped member may allow the mass of the diaphragm to be kept low and may result in better acoustic sensitivity.

Abstract: A loudspeaker chassis assembly (2) comprises a loudspeaker chassis (4) and one or more mass damping elements (6), which dampen vibration of the chassis (4). The mass damping elements (6) may be directly attached to the chassis (4) and may be tuned to dampen one or more particular vibrational modes of the chassis (4).

Abstract: A loudspeaker enclosure defined by one or more panels housing a drive unit. The drive unit includes a coil, a diaphragm, and a magnet. The magnet is decoupled from the one or more panels of the loudspeaker enclosure. Sound is generated by the movement of the diaphragm and complementary movement of the magnet, on application of an appropriate electrical signal to the coil. The moving diaphragm acts against a first volume of air within the enclosure, while the movement of a surface coupled to the magnet, acts against a second air volume, different from the first volume. The surface coupled to the magnet is decoupled from the one or more panels of the loudspeaker enclosure.

Abstract: A diaphragm for a loudspeaker drive unit or for a microphone includes a rigid dome-shaped member having a thickness that varies from a first thicker thickness at a first location at the periphery of the dome-shaped member to a second thinner thickness at a second location, which is nearer to the centre of the dome-shaped member. There is a step-wise change in thickness at a location between the first location and the second location. Having greater thickness at the periphery of the dome-shaped member may improve stiffness of the diaphragm and may allow for an increased break-up frequency. Having thinner material elsewhere in the dome-shaped member may allow the mass of the diaphragm to be kept low and may result in better acoustic sensitivity.

Abstract: A loudspeaker enclosure for mounting in an aperture in a cavity wall with a part of the enclosure being located within the wall cavity adjacent the aperture, comprises a main enclosure unit for mounting in the aperture and housing one or more loudspeaker drive units, and a supplementary enclosure unit for location within the wall cavity and being acoustically connected in use to the main unit to increase the effective internal volume of the enclosure beyond that of the main unit. The supplementary unit is connected to the main unit by an articulated connection enabling the main unit to be angled relative to the supplementary unit while the supplementary unit is being inserted through the aperture and into the wall cavity, and enabling the main unit to be aligned with and acoustically coupled to the supplementary unit when the main unit is positioned in the wall aperture.

Abstract: A loudspeaker enclosure for mounting in an aperture in a cavity wall with a part of the enclosure being located within the wall cavity adjacent the aperture, comprises a main enclosure unit for mounting in the aperture and housing one or more loudspeaker drive units, and a supplementary enclosure unit for location within the wall cavity and being acoustically connected in use to the main unit to increase the effective internal volume of the enclosure beyond that of the main unit. The supplementary unit is connected to the main unit by an articulated connection enabling the main unit to be angled relative to the supplementary unit while the supplementary unit is being inserted through the aperture and into the wall cavity, and enabling the main unit to be aligned with and acoustically coupled to the supplementary unit when the main unit is positioned in the wall aperture.

Abstract: A diaphragm for a loudspeaker drive unit (1), the diaphragm comprising a block of material having a first, sound-radiating front face (20) and a second, rear face (22). The block is stiffened by being bound about over the first and second faces (20,22) by a multiplicity of turns of one or more elongate members of flexible material (36) stiffened by a stiffening composition.

Abstract: A diaphragm for a loudspeaker drive unit (1), the diaphragm comprising a block of material having a first, sound-radiating front face (20) and a second, rear face (22). The block is stiffened by being bound about over the first and second faces (20,22) by a multiplicity of turns of one or more elongate members of flexible material (36) stiffened by a stiffening composition.