Abstract: A high-frequency cinema loudspeaker module for deployment behind a perforated cinema screen is configured with a waveguide to compensate for the beam-spreading effects of the perforated screen at the high end of the frequency range and to facilitate and co-ordinate integration with a complementary midrange module of a total sound system in providing defined coverage in a theater. A compression driver is coupled to a waveguide that is specially shaped to narrow the horizontal beamwidth at the higher frequencies affected by the perforated screen, and thus provide compensation that results in a more uniform overall defined sound coverage in the theater within the designated high-frequency range. The module is configured with the driver and waveguide axes inclined downwardly at an angle of 6 degrees from horizontal to facilitate overall coverage.

Abstract: A method of manufacturing speaker diaphragm for a loudspeaker that has a composite material formed of two layers of ceramic material separated by a light metal substrate and wherein the core is formed by stamping a sheet of standard gauge aluminum to form a speaker core and then deep anodizing the core to obtain a ceramic layer of alumina on each surface (Al2O3) which is at least about 1 mil. thick.

Abstract: A system is disclosed for steering a monaural audio signal representing a source of sound into left and right audio signals for presentation to the corresponding ears of a listener so that the listener perceives the sound source in a specific location relative to his head. The left and right signals may be provided through headphones or loudspeakers, in the latter case employing techniques to cancel the crosstalk from each loudspeaker into the opposite ear of the listener. The monaural audio signal is filtered using head-related transfer functions (HRTFs) into the left and right outputs, these being equivalent to the acoustic HRTFs that would be generated if a source of sound were placed at the specific location relative to the listener.

Abstract: An improvement in small round loudspeakers of popular standard types used in vehicle assembly is obtained by modifying a standard-sized basket in a manner to provide a polar array of special mounting openings located on a concentric mounting circle of larger than standard diameter, thus allowing the use of a larger cone for improved performance and allowing the loudspeaker to be mounted in different-sized popular mounting hole patterns in the baffle panel; for example an aspect of the invention enables the "6.5 inch basket", associated with Asian-built vehicles, to be fitted with a larger-sized cone used in the "170 mm basket" associated with European-built vehicles, thus providing a loudspeaker, with the improved performance of the larger cone, that can be installed in a range of different baffle panel cutout sizes and configurations of either type of vehicle.

Abstract: An improved electromagnetic transducer able to produce more power per mass than a conventional transducer. This increased power per mass is made possible by combining a properly designed housing, a neodymium magnet and a dual coil structure. This design dissipates the heat generated by the transducer, increasing the efficiency and power of the transducer. Also, by dissipating heat more efficiently, the transducer can be made smaller and more powerful than conventional transducers.

Abstract: A surround sound processor system for multichannel redistribution of stereophonic signals has digitally controlled gains in each input and each output channel, controlled by a microprocessor, which receives an input signal from a microphone placed at the preferred listening location within the listening area for automatically balancing the input signals and setting both input and output gains during a calibration process so as to provide the listener with the best possible surround sound reproduction of the stereophonic source material. As a visual aid, the microprocessor displays menus and messages on a video screen, and a visual display shows the relative levels of the six axes of control signals within the surround sound processor.

Abstract: A surround sound processor for presenting stereophonic audio signals on a number of loudspeakers surrounding a listening area, comprising an input matrix stage, a detector filter and matrix circuit, a direction detector circuit incorporating improved filters, a novel detector splitter circuit providing three direction signals from the two direction detector circuit outputs, a novel three-channel servologic circuit with improved variable filters responding selectively to the rates of change of the direction signals and providing six control voltage signals through linearity correction networks to six voltage-controlled amplifiers, the outputs of which are combined in an output matrix to provide a number of loudspeaker feed signals through buffer amplifiers to the output terminals of the processor. The detector splitter circuit is configurable to either a forward oriented or a backward oriented mode of operation, corresponding changes being made to the voltage-controlled amplifiers and output matrix circuitry.

Abstract: A surround sound processor for redistribution of stereophonic audio signals into multiple channels for presentation on a plurality of loudspeakers surrounding a listener has an improved direction detector filter circuit, a peak hold circuit in the direction detector for better dynamic separation, improved time constants in the servologic circuit, improved linearity correction in the control voltage generator to match the characteristics of the new voltage controlled amplifiers which are applied to the separation matrix, a separation matrix having cancellation of unwanted signals wihtout gain modification for desired signal components, and improved shelf filters in the rear channel outputs.