Abstract: Embodiments are directed to speakers and circuits that reflect sound off a ceiling to a listening location at a distance from a speaker. The reflected sound provides height cues to reproduce audio objects that have overhead audio components. The speaker comprises upward firing drivers to reflect sound off of the upper surface and represents a virtual height speaker. A virtual height filter based on a directional hearing model is applied to the upward-firing driver signal to improve the perception of height for audio signals transmitted by the virtual height speaker to provide optimum reproduction of the overhead reflected sound. The virtual height filter may be incorporated as part of a crossover circuit that separates the full band and sends high frequency sound to the upward-firing driver.

Abstract: Embodiments are directed to speakers and circuits that reflect sound off a ceiling to a listening location at a distance from a speaker. The reflected sound provides height cues to reproduce audio objects that have overhead audio components. The speaker comprises upward firing drivers to reflect sound off of the upper surface and represents a virtual height speaker. A virtual height filter based on a directional hearing model is applied to the upward-firing driver signal to improve the perception of height for audio signals transmitted by the virtual height speaker to provide optimum reproduction of the overhead reflected sound. The virtual height filter may be incorporated as part of a crossover circuit that separates the full band and sends high frequency sound to the upward-firing driver.

Abstract: A soundbar of loudspeakers for use with a television or the like. The soundbar includes two, three, or more Bessel Arrays configured to produce sound for a corresponding number of audio channels. To reduce the transducer count and/or the soundbar width, adjacent channels may share a transducer in their respective Bessel Arrays, and/or one or more of the channels may use a Reduced Bessel Array.

Abstract: An MTM loudspeaker in which the Ms and/or the T is constructed as a Bessel Array. The shapes of the diaphragms, the transducer count, the Bessel type, and/or the acoustic center positioning can be adjusted to achieve desired packing factor, enclosure size, off-axis performance, and so forth.

Abstract: A dipole loudspeaker in which the oppositely oriented transducers each is a Bessel Array. Optionally, Improved or Super Bessel Arrays are used, and their half-amplitude end position transducers may be shared and aimed in a perpendicular—typically vertical—orientation. The Bessel Dipole is especially useful as a surround channel loudspeaker; for the same effective radiating area and/or sound production, the Bessel Dipole has a narrower cabinet than a conventional two-transducer dipole loudspeaker.

Abstract: An e.g. 7-element Bessel Array in which the null or zero positions are occupied with sound producing means producing sound outside the Bessel functional frequency range, such as a higher frequency Bessel Array, a higher frequency MTM, or a port.

Abstract: A Bessel Array loudspeaker in which identical transducers are fed full amplitude signals. The half amplitude output at some Bessel positions can be achieved by angling those transducers to the side or up/down. The half amplitude transducers can be coupled to separate cabinets which can be rotated left/right with respect to the full amplitude transducers' cabinet, and the rotation can automatically reconfigure the wiring of the half amplitude transducers. The half amplitude output can alternatively be achieved by driving only half of the voice coil windings of the half amplitude transducers. The other half of their voice coil windings can optionally be driven via a low pass filter, to achieve an Improved Bessel with increased bass output and sensitivity.

Abstract: An improved Bessel array of electromagnetic transducers, in which the Bessel coefficients (phase and/or magnitude) are applied only in the useful high frequency range, where off-axis interference patterns between the outputs of respective transducers cause undesirable acoustic results. One improvement is in using an all-pass filter or the like in lieu of an inverter in the inverting Bessel coefficient path, to provide an in-phase signal in low frequencies and an opposite-phase signal in high frequencies. This achieves the improved off-axis result of a conventional Bessel array, with improved low-frequency maximum sound pressure and efficiency. Another improvement is in using a frequency-dependent voltage divider, such as a shelf circuit, in the half-strength Bessel coefficient paths, to provide full-strength signals in low frequencies and half-strength signals in high frequencies. This achieves even more improved low-frequency maximum sound pressure.

Abstract: An electromagnetic transducer such as a tweeter audio speaker, having a very low density diaphragm constructed of a nanoporous material such as aerogel or the like. The solid aerogel diaphragm has improved rigidity and reduced susceptibility to breakup modes. The aerogel may be provided with a skin of e.g. metal, plastic, or oxide to protect it, and it may be built by filling a conventional cone. The skin may encapsulate part or all of the aerogel body's surface, and it may further encapsulate the bobbin, or even the entire voice coil assembly. The nanoporous material comprises a very large percentage of the diaphragm's overall volume, giving the diaphragm a very low overall mass density with respect to conventional diaphragms. This allows diaphragm configurations, such as solid filled spheres, which have excellent stiffness without suffering from the large mass that such shapes would mandate if constructed from conventional materials.