Abstract: A sonar system includes an objective having reflecting surface(s) with coincident forward radiant axes. Each of the reflecting surfaces defines sets of equivalent acoustic output/receiving locations allowing the use of a plurality of transducers with each reflecting surface. When used in a projection mode, and depending upon the frequency radiated, the sound sources may function as a distributed, functionally continuous sound source. In a passive mode use of a field reflector allows determination of bearings.

Abstract: A performance venue with a main speaker system is provided having a target coverage area within the performance venue. A performance area is located within the performance venue outside the target coverage area of the main speaker system. A low frequency directed audio source is positioned with respect to the performance area for active cancellation of low frequency sound spilling over into the performance area from the main speaker system. Control of the low frequency directed audio source is effected by an audio sensor is located in the performance area for generating an output correlated with low frequency spill over into the performance area.

Abstract: An acoustic radiator for underwater application is provided by opposing boundaries mutually spaced and centered on a common axis, a plurality of radial barriers located perpendicular to and connected between the top and bottom boundaries to define a plurality of adjacent radial waveguides, and a plurality of transducers disposed in each radial waveguide, and with one group of transducers being located radially outwardly from another group, the groups being defined in part by all members of the group being the same distance from the apex of the radial waveguide.

Abstract: A horn based loudspeaker system provides control over peak to peak pressure of an acoustic signal across its frequency spectrum. Frequency spectrum matched acoustic energy added to the acoustic signal at diverse points distributed along the horn.

Abstract: A push-pull magnetic-planar acoustic transducer provides easy field replacement of a diaphragm. Push-pull magnetic-planar acoustic transducers are known for the relative vulnerability of their diaphragms to damage. Replacement of the transducers in the field as been problematic because of the high repulsive force between the front and back panels and the need to obtain even tension across the diaphragm. The push-pull transducer assembly incorporates an edge hinge on which the panels can be pivoted to bring the panels into facing positions and a plurality of set screws to be fitted around the perimeter of the panels allowing essentially flat closure of the panels on one another to a working spacing engaging the diaphragm.

Abstract: A broadband sound generator and transmitter provides minimal attenuation of sound over the distance between the generators and a point at a selected distance. The transmission component includes a parabolic dish and a positionable framework for the sound generators. The sound generators are positioned in front of the dish and oriented to direct sound into the dish for reflection toward a target. Drive signal conditioning circuitry apportion components of the drive signal to the several sound generators and adjust the signal in terms of delay and phase to accommodate changes in position of the generators relative to the dish.

Abstract: A curve fitted planar loudspeaker minimizes variation and dead zones in the sound field propagated by an array of the loudspeakers. The curve fitted loudspeaker provides a plurality of sound generating transducers. The diaphragm is curved and each adjacent section fits as a section into a larger curve, eliminating or minimizing breaks in the propagated sound filed at the target distance to the target.

Abstract: A loudspeaker system comprises a plurality of speaker transducer units divided among and arrayed in at least three linear arrays. The linear arrays are disposed in a like plurality of elongated rectangular baffles. The elongated rectangular baffles are disposed in side by side relationship along the respective elongated sides of the baffles in the form of a tube. The speaker transducer units are aligned in a plurality of ranks. The ends of the tube are closed with the result that one side of speaker transducers radiates into the interior of the enclosure and the other side radiates into the environment. The speaker transducers of each rank are spaced no further from one another than one quarter wavelength at a selected frequency.

Abstract: A blended acoustic folded horn and reflector provides for throughput of higher frequency bands without giving rise to standing waves. The horn includes a parabolic region intersected by a first direct radiant axis centered on the throat. The parabolic region is shaped and oriented to define a reflected radiant axis through the mouth for frequency components of the acoustic input above a cut-off frequency. The parabolic region operates to focus sound in the upper portion of the operational frequency range of the loudspeaker and to reflect the resulting focused sound beam along a second radiant axis through the mouth of the folded horn.

Abstract: The sound generating and transmitting apparatus is based on a radiator including at least a first, and possibly two or more, shaped reflecting surface(s) having a forward radiant axis. Each of the shaped reflecting surfaces defines sets of equivalent acoustic input locations, with each set being a ring of non-zero circumference centered on the forward radiant axis. The sound source is a distributed, functionally continuous sound source adapted to exploit this feature. In its preferred form the sound source is a sort of closed line array of loudspeakers providing a torodial shaped acoustic source to direct at the hyperbolic cone, the transducers being disposed in a circle with all of the loudspeakers oriented inwardly toward or outwardly from the forward radiant axis.

Abstract: Front to back linear arrays of loudspeakers provide a sound field compressed both vertical and horizontally with the horizontal directivity patter exhibiting a cardioid shape. The problem addressed is improving the horizontal directivity of linear arrays. A linear array of bass units is placed behind a linear array of mid to high frequency range devices to improve horizontal directivity. The first and second linear arrays are placed back to front, oriented to radiate in a forward direction and spaced by a known distance “d”. The distance “d” may be selected to determine the degree of narrowing of the cardioid pattern sound field generated. Greater directivity is also achieved by adding additional linear arrays of bass units behind the second array. The upper frequency knee of the bass unit arrays must overlap the lower frequency knee of the mid/high-frequency unit array.

Abstract: A loudspeaker assembly is described suitable for flown arrays and incorporating a horn load planar or ribbon transducer. Planer acoustic transducers have a relatively limited power output capacity. Addition of a horn suitable for an elongated source effectively amplifies the power output capacity of the planar devices.

Abstract: The sound generating and transmitting apparatus is based on a radiator including at least a first, and possibly two or more, shaped reflecting surface(s) having a forward radiant axis. Each of the shaped reflecting surfaces defines sets of equivalent acoustic input locations, with each set being a ring of non-zero circumference centered on the forward radiant axis. The sound source is a distributed, functionally continuous sound source adapted to exploit this feature. In its preferred form the sound source is a sort of closed line array of loudspeakers providing a toroidal shaped acoustic source to direct at the hyperbolic cone, the transducers being disposed in a circle with all of the loudspeakers oriented inwardly toward or outwardly from the forward radiant axis.

Abstract: A single folded, expanding horn loudspeaker reproduces low frequency audible sound at high power output levels. A compact enclosure houses a plurality of identical transducers, characterized by small vibrational surface areas. The throats for each transducer into the horn are acoustically differentially spaced from the mouth of the horn with the spacing between adjacent throats progressively increasing in the acoustic direction of the horn mouth from the throat origin.

Abstract: An omni-directional acoustic horn for applications in a liquid transmission medium deploys a plurality of transducers distributed along an interior face of the horn to radiate against an opposed surface. The arrangement mimics operation at a greater depth of submergence to depress development of acoustic cavitation bubbles.