Abstract: A loudspeaker driver moving system including a bobbin, a diaphragm and an elastic damping ring interposed between and attached respectively to the bobbin and the diaphragm.

Abstract: A protective screen for a diaphragm of a loudspeaker comprises a first side and a second side. The screen comprises a perforated region and an imperforated region. The perforated region comprises a first perforation having a first size and a second perforation having a second size, each perforation passing through the first side and the second side of the screen, and each perforation allowing sound waves radiated from a first portion of the diaphragm to pass through the screen. The imperforated region suppresses sound waves radiated from a second portion of the diaphragm. The first perforation is more adjacent to the imperforated region than the second perforation, and wherein the second size of the second perforation is bigger than the first size of the first perforation.

Abstract: The present invention discloses a high frequency transducer housing for use in a coaxial loudspeaker system to reduce diffraction. The coaxial loudspeaker system comprises at least one high frequency transducer that is arranged to be mounted with a second frequency transducer. The housing comprises a plurality of edges on a periphery of the housing. The edges of the housing have irregular shapes. The plurality of the edges are eccentric with a diaphragm of the second transducer.

Abstract: A loudspeaker driver has a diaphragm connected to a surrounding frame by a roll suspension which extends around the diaphragm and within the frame. The roll suspension connects the outer edge of the diaphragm to the inner edge of the frame and flexes as the diaphragm is displaced to and fro axially relative to the frame. In order to provide for better integrity of the roll suspension during its displacement, and reduce unwanted deformation and concomitant distortion, the suspension roll is provided with pleats extending across the roll suspension transversely to the direction of axial movement of the diaphragm to create a series of undulations (peaks and troughs) around the perimeter of the roll suspension. In transverse cross-section, the roll suspension is parabolic. The roll suspension varies continuously between each peak and adjacent trough.

Abstract: A remote-controlled audio system comprises sets of loudspeakers (14A-14D) connected to power amplifier units (22A-22D) in an audio distribution unit (10) to which several audio sources, such as a compact disc unit, a tape deck, etc., are connected. Remote units (34) are provided, one in each zone with a set of loudspeakers. The loudspeakers and the remote unit are connected to the audio distribution unit by four wires whereby audio and data signals and power are transmitted to the loudspeakers and the remote unit, respectively. Each power amplifier unit may have a pair of power amplifiers, each connected to one of the loudspeakers in the set, referenced to a first ground (1) and a second ground (2), respectively. The second ground (2) is maintained at a prescribed voltage relative to the first ground. The remote unit (34A) is connected between the “ground” terminals of the two loudspeakers of the set, i.e. those connected via the speaker cables to the first and second grounds in the audio distribution unit.

Abstract: A power supply circuit arrangement for electrical equipment, such as a loudspeaker with an integral power amplifier, which can be switched between an operational mode and a standby mode in response to a detected on/off signal, provides a desirable isolation of the main supply voltage from the detector. The arrangement comprises a transformer, having a primary winding and a secondary winding, and a switched impedance device between the transformer and the power supply input. The switched impedance device is switchable between high and low impedance states in response to the detected on/off signal. A control circuit for detecting the on/off signal and switching the variable impedance states is connected in common with a main circuit of the equipment to the secondary winding of the transformer, so that their respective supply voltages are both switched, in common, by switching of the impedance device. The control circuit and variable impedance device isolate the detector from the power supply.