Abstract: A planar-magnetic electro-acoustic transducer including a support structure and a magnetic structure carried by the support structure, the magnetic structure comprising a multiplicity of high-energy magnets configured so as to have shared loop field maxima and local loop field maxima, and a diaphragm carried by the support structure, comprising a plurality of conductors carried by and coupled to the diaphragm, said conductors being disposed in relation to local loop maxima and configured to exploit the energy of local loop maxima, as well as the energy of shared loop maxima in driving the diaphragm to produce an acoustic output; and the magnetic structure can be configured so that it includes magnet rows, and the transverse cross-sectional width of the magnets does not exceed their transverse cross-sectional height, and the distance between adjacent elongated magnet rows is greater than one half the width of either of the magnets of the adjacent magnet rows.

Abstract: A modulator-amplifier configured for use in parametric sound reproduction systems, including an input configured for receiving at least one input signal, a reference signal generator configured for generating a reference signal, and a comparator stage coupled to the input and the reference signal generator, the comparator stage configured for detecting relationships between a first signal based on the input signal and the reference signal. A switching power stage coupled to the comparator is configured to receive a second signal derived from a combination of an output from the comparators and the input signal, wherein there is a non-linear relationship between the input signal and the timing of state transitions in the switching power stage for the purpose of generating an output that has been shifted in frequency relative to a frequency of the input signal, and which includes at least one sideband.

Abstract: A bandpass loudspeaker enclosure having three sub chambers, a first subchamber being a Helmholtz-reflex chamber with a passive acoustic radiator operating in parallel with the transducer, and the remaining two chambers utilizing two passive acoustic radiators to achieve three Helmholtz-reflex vent tunings and a multiple of low pass acoustic filters that provide an acoustic bandpass with reduced diaphragm displacement and substantially reduced distortion and pipe resonances above the pass band. A further embodiment provides a reduced lowest frequency vent size for a given low frequency subchamber size and tuning frequency.

Abstract: A sound emitting device for providing at least one new sonic or subsonic frequency as a by-product of emitting a waveform of at least two ultrasonic frequencies whose difference in value corresponds to the desired new sonic or subsonic frequency. The device includes a parametric emitting perimeter or plurality of emitter segments positioned around a central open section. This open section is structured with a diagonal width greater than a cross-sectional diagonal of the parametric emitting perimeter. An ultrasonic frequency signal source and sonic/subsonic frequency generator are coupled together to a modulating circuit for mixing an ultrasonic frequency signal with an electrical signal corresponding to the at least one new sonic or subsonic frequency. The modulator output is coupled to the emitting perimeter which comprises ultrasonic frequency emitting material for propagating the mixed waveform into air for demodulating the waveform to generate the at least one new sonic or subsonic frequency.

Abstract: A planar magnetic transducer having enhanced magnetic structures which increases performance over a single-ended device but mitigates some of the drawbacks of double ended devices, including a supporting structure, a diaphragm incorporating a coil conductor at least a primary magnetic structure, and a secondary magnetic structure can be added, including mitigation of high frequency resonance and attenuation by providing a more open architecture, including spacing the magnets wider apart, configuring the inter-magnet spaces to provide better acoustic performance, using high-energy magnets, which magnets can be shaped to form at least a part of the shaped inter-magnet space.

Abstract: A sonic emitter, horn array with enhanced emitter-to-air acoustic coupling, with particular application to ultrasonic frequencies. The emitter comprises a plate support member having opposing first and second faces separated by an intermediate plate body. The plate body includes a plurality of conduits configured as an array of acoustic horns, with a small throat opening at the first face and an intermediate horn section which diverges to a broad mouth opening at the second face. An emitter membrane is positioned in direct contact with the first face and extends across the small throat openings. The emitter membrane is biased for (i) applying tension to the membrane extending across the throat openings and (ii) displacing the membrane into a non-planar configuration.

Abstract: A parametric loudspeaker which uses multiple piezoelectric bimorph transducers. These multiple piezoelectric bimorphs have a resonant frequency which varies from unit to unit. The phase response at and near the resonant frequency changes at a very high rate with slight changes in frequency. The associated modulator electronics have a primary carrier frequency that is optimized for maximum parametric output. This is achieved by aligning the carrier frequency with the flattest portions of the phase curve for maximum phase coordination among the multiple devices.

Abstract: An electrostatic loudspeaker includes a high resistivity stator with electrode conductivity per square that is constant and/or decreases with distance from the connection point. A contact area of predetermined size is related to the highest frequency of interest. The constant or decreasing surface resistivity of the stators, interacting with the capacitive load of the stator to stator gap, operates as a distributed network such that the active acoustic output is attenuated in a predetermined manner with increased frequency at all points equidistant on the stator from the connection area. The apparent acoustic source size is reduced as the frequency increases to maintain enhanced dispersion across the operating range of the loudspeaker system.

Abstract: An electrostatic loudspeaker requires a high voltage DC bias power supply to bias the stators and diaphragms of electrostatic speakers. A self biased power supply eliminates the need for an external power supply by deriving a high voltage bias from the stator AC signal voltages which have been rectified and run from a high voltage tap and/or through a voltage multiplier which has a voltage limiting means.

Abstract: A method of preparing a parametric speaker transducer for (i) generating sonic or subsonic audio output by propagating two frequencies having a difference in value equal to the desired sonic or subsonic audio output and (ii) decoupling the two frequencies to generate the desired audio output, the method comprising the steps of:

Abstract: A bandpass loudspeaker enclosure system including at least one electro-acoustic transducer with a vibratable diaphragm having a first acoustical coupling surface and a second acoustical coupling surface, and at least one differential area passive radiator with three separate acoustical coupling surface areas. The first acoustical coupling surface of the vibratable diaphragm is substantially air coupled through a first enclosure volume to a first of the three separate acoustical coupling surface areas of the at least one differential area passive radiator. A second of the three separate acoustical coupling surface areas of the at least one differential area passive radiator is substantially air coupled through a second chamber to the external environment through a restricted acoustic opening or passive acoustic radiator of predetermined characteristics.

Abstract: An electrostatic loudspeaker requires a high voltage DC bias power supply to bias the stators and diaphragms of electrostatic speakers. A self biased power supply eliminates the need for an external power supply by deriving a high voltage bias from the stator AC signal voltages which have been rectified and run from a high voltage tap and/or through a voltage multiplier which has a voltage limiting means.

Abstract: A speaker device for emitting subsonic, sonic or ultrasonic compression waves comprising a a rigid emitter plate attached to the drum, and a plurality of apertures formed within the plate which are covered by a thin piezoelectric film disposed across the emitter plate. The thin film at the apertures distends into an arcuate emitter configuration capable of constricting and extending in response to variations in the applied electrical input at the piezoelectric film to thereby create a compression wave in a surrounding environment. Parametric ultrasonic frequency input is supplied to the piezoelectric film to propagate multiple ultrasonic frequencies having a difference component corresponding to the desired subsonic, sonic or ultrasonic frequency range.

Abstract: A biaxial parametric speaker having at least two different axes of sound propagation. The speaker includes a first parametric emitter including an ultrasonic emitter surface having a primary direction of propagation along a first orientation and a second parametric emitter including an ultrasonic emitter surface having a primary direction of propagation along a second orientation. The first parametric emitter is physically coupled to the second parametric emitter such that the first and second orientations do not coincide, thereby providing for relative angular displacement of the respective first and second orientations of propagation. Electronic contacts are attached to the respective first and second parametric emitters for coupling to a parametric signal source capable of generating parametric emissions from the respective emitters which decouple in air to generate audio output along each of the respective first and second orientations.

Abstract: A parametric loudspeaker system using improved modulators to compensate for the non-linearity of the parametric process in air when driving the air at saturation levels and below saturation levels. The parametric loudspeaker uses a pre-processed single sideband modulator that offers ideal linearity as characterized by square root pre-processed double sideband modulators but with a lower carrier frequency and without the wide bandwidth requirements. By eliminating some or all of the lower sideband the carrier frequency can be reduced without producing sideband frequencies in the audible range. Lower operational frequencies result in greater translation efficiency and greater output capability before reaching the saturation limit of air. A pre-processor minimizes the effects of saturation limits for double sideband, truncated double sideband or single sideband processing to achieve superior output.

Abstract: A system for generating at least one remote virtual speaker location in connection with at least a partial reflective environment in combination with an audio speaker for creating multiple sound effects including a virtual sound source from the reflective environment which is perceived by a listener as an original sound source, by generating a primary direct audio output by emitting audio compression waves toward a listener, and generating a secondary indirect audio output from at least one virtual speaker remote from the audio speakers, by emitting ultrasonic sound from at least one parametric speaker associated with the audio speakers and oriented toward at least one reflective environment which is remote from the audio speakers, thereby indirectly generating sound from a reflective environment which is perceived as a virtual speaker, and synchronizing the primary audio output of the audio speakers with a secondary audio output from the at least one virtual speaker such that the listener hears a plurality o

Abstract: A system configured to dynamically adjust the ultrasonic carrier level in a parametric array system in response to changing source signal input levels, and which employs a look-ahead delay strategy to enable optimal modulation of the carrier wave to eliminate constant ultrasonic carrier emission and reduce the ultrasonic carrier emission to what is actually needed to accommodate the db range of the source material, and at the same time, to also minimize noticeable distortion and sound artifacts of a high-power ultrasonic carrier, and/or distortion/artifacts arising from modulation of an ultrasonic carrier to reduce average power output; and thus it realizes advantages of carrier modulation based on source-signal level, while minimizing inherent drawbacks of carrier modulation.

Abstract: A system configured to dynamically adjust the ultrasonic carrier level in a parametric array system in response to changing source signal input levels, and which employs a look-ahead delay strategy to enable optimal modulation of the carrier wave to eliminate constant ultrasonic carrier emission and reduce the ultrasonic carrier emission to what is actually needed to accommodate the db range of the source material, and at the same time, to also minimize noticeable distortion and sound artifacts of a high-power ultrasonic carrier, and/or distortion/artifacts arising from modulation of an ultrasonic carrier to reduce average power output; and thus it realizes advantages of carrier modulation based on source-signal level, while minimizing inherent drawbacks of carrier modulation.

Abstract: An electroacoustic transducer which has at least one stator member with an operating surface and a suspended emitter diaphragm spaced from the operating surface of the stator member to enable the diaphragm to oscillate in response to an applied signal voltage. The diaphragm has increased stiffness in a direction along the diaphragm and within the emitter section to enable the emitter diaphragm to oscillate without applying tension in the direction of stiffness. A clamp member secures the diaphragm to maintain the diaphragm in a fixed position relative to the stator to minimize distortion. The clamp member is positioned to define at least two isolated emitter sections for enhancing the frequency response of the transducer. A method is also provided for generating audio output from an electroacoustic transducer.

Abstract: A planar-magnetic electro-acoustic transducer including a support structure and a magnetic structure carried by the support structure, the magnetic structure comprising a multiplicity of high-energy magnets configured so as to have shared loop field maxima and local loop field maxima, and a diaphragm carried by the support structure, comprising a plurality of conductors carried by and coupled to the diaphragm, said conductors being disposed in relation to local loop maxima and configured to exploit the energy of local loop maxima, as well as the energy of shared loop maxima in driving the diaphragm to produce an acoustic output; and the magnetic structure can be configured so that it includes magnet rows, and the transverse cross-sectional width of the magnets does not exceed their transverse cross-sectional height, and the distance between adjacent elongated magnet rows is greater than one half the width of either of the magnets of the adjacent magnet rows.