Abstract: Various implementations include loudspeakers and related waveguides. The loudspeakers can include an adjustable waveguide for modifying the coverage pattern of the audio output. In some particular aspects, a loudspeaker includes: a single speaker box with at least one driver; a waveguide having: a pair of opposing walls that are fixed with respect to the at least one driver; and at least one adjustable wall that is adjustable relative to the at least one driver; and at least one fin coupled to the waveguide for accommodating a gap between the pair of opposing walls and the at least one adjustable wall.

Abstract: A high frequency energy converter which has application as an acoustic actuator for converting incoming high frequency energy into outgoing harmonized high frequency mechanical (e.g., sound) and electromagnetic waves. The energy converter is adapted to improve the quality of sound heard by a listener by reducing random and spurious harmonics that are introduced by the environment in which the listener is located. The energy converter includes an outer body and a reactive crystalline material (e.g., quartz) lying at the bottom of the outer body that is responsive to the incoming high frequency energy. A dispersion horn is located at the top of the outer body to be seated upon the crystalline material. The dispersion horn has a throat extending therethrough so that both incoming high frequency energy and outgoing high frequency mechanical and electromagnetic waves are transmitted through the throat of the horn in opposite directions.

Abstract: A behind the detector sounder has a base plate and walls which define mechanical horns having throats which open into a space at the centre of the base plate. The mouths of the mechanical horns are at the outer periphery of the base plate and the walls bound sound paths which are longer than the straight line distance from the throat of each mechanical horn to the mouth of that mechanical horn.

Abstract: A phasing plug for a compression driver includes a base portion and a hub portion. The base portion includes a first side, a second side, and a plurality of apertures extending between the first and second sides. The hub portion extends from the base portion along an axis. The hub portion includes an outer surface and a plurality of ribs disposed on the outer surface. A plurality of recesses are defined by the outer surface and respective pairs of adjacent ribs. At least one aperture fluidly communicates with at least one of the recesses.

Abstract: A behind the detector sounder has a base plate and walls which define mechanical horns having throats which open into a space at the centre of the base plate. The mouths of the mechanical horns are at the outer periphery of the base plate and the walls bound sound paths which are longer than the straight line distance from the throat of each mechanical horn to the mouth of that mechanical horn.

Abstract: A loudspeaker horn includes a pair of opposed flared sides defining a passage diverging to a mouth, and a vane positioned in the passage for steering sound waves through the passage. The vane may have a straight configuration and be either centrally located between the flared sides or laterally offset in the diverging passage. The vane may be fixed in position or, more preferably, be pivotable so as to be adjustable before each new use according to conditions at that use. The horn may be part of a horn unit that includes a funnel for feeding sound to the horn, and the horn or horn unit may be part of a horn loudspeaker.

Abstract: Ulstrasound typically in the range 15 KHz to 1 MHz and at a power of about 100 watts over a zone of a few sq. cm is applied via a horn shaped cavity of a transmitter for processing a fluid medium, for example for processing a body of liquid having a foaming surface layer whereby the foaming can be quelled rapidly.

Abstract: A loudspeaker horn (11) having a throat end (13) for receiving acoustic power from aligned acoustic power sources (41, 43, 45), an elongated throat (33), and a flared section (17) is provided with grating lobe mitigation fins (27, 29) that extend substantially parallel to the propagation axis of the horn from the throat end toward the mouth end of the horn's flared section. The length of the grating lobe mitigation fins is established in accordance with the degree of suppression of the grating lobes produced by the aligned acoustic power sources that is desired.

Abstract: A sounder is disclosed which has walling (36, 38) defining a first air column (26) leading to a first sound aperture (34) through which the first column opens to atmosphere, and walling (40, 44) defining a second air column (60) leading to a second aperture (64) through which the second column opens to atmosphere. A diaphragm (16) is between the air columns and means are provided for causing said diaphragm to vibrate.

Abstract: A loudspeaker horn (11) having a throat end (13) for receiving acoustic power from aligned acoustic power sources (41, 43, 45), an elongated throat (33), and a flared section (17) is provided with grating lobe mitigation fins (27, 29) that extend substantially parallel to the propagation axis of the horn from the throat end toward the mouth end of the horn's flared section. The length of the grating lobe mitigation fins is established in accordance with the degree of suppression of the grating lobes produced by the aligned acoustic power sources that is desired.

Abstract: A manifold for a horn loudspeaker has an input end having at least one input port for receiving acoustic power from at least one acoustic driver, and an output end for delivering acoustic power to the throat end of the horn. The output end of the manifold has at least two and suitably multiple output ports. An acoustic power waveguide is provided for each output port and connects each of the output ports to the input port of the manifold. Acoustic power received by the input port is divided between the acoustic waveguides such that it is delivered to the aligned output ports to simulate a line array of acoustic power sources.

Abstract: A loudspeaker includes a cabinet designed so as to define a central compartment sandwiched between upper and lower compartments. The cabinet is symmetrical about a vertical central, fore-and-aft extending plane. Located in each of the upper and lower compartments are a pair of vertical horn walls which are exponentially curved and diverge forwardly from an inlet located at a rear part of the respective compartments, to the front of opposite side walls of the cabinet. These horn walls define bass horns which have drivers coupled to their inlets. Located in the middle compartment and diverging at an angle of 15° from each other are a pair of mid/high frequency horns that are each formed by a pair of vertical horn walls that are exponentially curved and diverge forwardly from respective inlets located in a rear part of the middle compartment on opposite sides of the plane.

Abstract: An integrally formed ported reflex horn comprises an outer housing having a plurality of side walls disposed about a central axis, an open discharge end and a second closed end, oppositely disposed to the open end. The horn also includes a compression driver reception member, for rigidly maintaining a conventional compression driver within the hollow interior of the horn housing, and sound wave guide structure which defines a plurality of ports and a divider for splitting sound waves exiting the throat of the compression driver into a plurality of constituent sound waves of substantially equal sound pressure levels. The constituent sound waves are redirected toward the housing open end as they travel through respective ports and are recombined into a single wave front after exiting the ports upstream of the housing open end.

Abstract: The horn and sounder includes an upper body, a lower body, and a mouth piece. The upper and lower bodies are provided at their rear outer periphery with annular ribs to engage with grooves formed inside the mouth piece, so that the mouth piece can bind the upper and the lower bodies together. The upper and the lower bodies are provided on their inner plane near a rear central portion with a protuberance, making the two bodies slightly separated from each other at their front potions. The present invention can be used to produce loud sound simply by patting it.

Abstract: An acoustic horn assembly for use as part of an electronic siren system for an emergency vehicle comprises a pair of integrated molded, rigid plastic members which cooperate to define a pair of divergent sound passages. The entrance ends of these sound passages are displaced do that they may be coupled to separate sound generators, the sound generators being supported from respective vehicle frame side rails. The sound generators are coupled to the sound passage entrance ends by adjustable length sound transmission conduits which are in the form of elbows.

Abstract: Monophonic sound is transformed into a stereo pattern by arranging two reflectors on a common axis at a predetermined distance from each other with both facing in the direction of the sound. One reflector has a larger diameter than the other and is provided with a central aperture into which a tone generator is mounted and spaced from the smaller reflector.

Abstract: A megaphone apparatus includes an elongate conical conduit directed into an outwardly flaring forward body portion. The conduit includes an entrance opening, with the flaring body including a plurality of exit openings defined by a central outlet conduit coaxially aligned with the inlet conduit, with a plurality of right and left branch conduits extending laterally to each side of the central conduit aligned in a single plane along a common diameter of the various conduits. A modification of the invention includes various residence modulating caps selectively positionable over the conduits to include a flexible web, with at least one slit directed diametrically therethrough, and including a plurality of pockets arranged in a spaced relationship relative to the slit to include a flexible rod selectively positioned within each pocket as desired for varying modulation of the flexible web of each cap in use.

Abstract: A cinema sound system for unperforated screens includes for each stereophonic channel a floor positioned direct radiator bass speaker unit radiating into quarter space and an upper frequency speaker unit mounted above the screen. Each upper frequency speaker unit includes a middle frequency driver mounted in a sealed rear enclosure which is attached to the throat of a middle frequency horn. A constant directivity high frequency horn with a high frequency driver attached to a rear end is mounted coaxially in the middle frequency horn. Sharp cutoff active crossover filters divide the input signal into low, middle, and high frequency band signals which are separately power amplified. The middle frequency horn is adapted to function as a direct radiator at a lower end of the middle band and as a sectoral horn above an unloading frequency of the middle frequency horn.

Abstract: A speaker and horn array having improved audio characteristics is formed in a baffle case. A plurality of small speakers are mounted in the baffle case in a vertical array in close proximity with one another. Each of the speakers has an acoustic baffle over the back of the speaker with an opening located in the baffle. An array of small horns are located in association with the speakers in the baffle case. As with the speakers the horns are also in a vertical array. Each of the horns includes an individual throat, however, all of the horns are joined into a common vertically oriented mouth. The throat of each horn is connected to the opening in the baffle of one of the speakers. This backloads the individual speakers with the common mouth of each of the horns resulting in common backloading of each of the speakers.

Abstract: A siren having one or more stacked speakers, each speaker having a substantially circular lower horn member having an upwardly facing surface including a substantially convex annular portion and a substantially concave central cavity portion. A substantially circular upper horn member having a downwardly facing surface including a substantially convex annular outer portion and a central opening, is spaced above the lower horn member, thereby defining an annular, radially outwardly diverging sound director between the upper and lower horn members. A diffuser horn is coupled to a central opening in the upper horn member and projects downwardly into the cavity portion of the lower horn member. A siren driver is mounted in the upper horn member adjacent to the central opening for projecting a sound wave through the diffuser horn into the cavity, where the sound wave is reflected upwardly out of the cavity into the sound director, through which the sound is projected horizontally in a 360.degree. pattern.

Abstract: A dual diverging manifold loudspeaker system includes a generally cubically-shaped outer horn housing and an inner dome-like cap member for encapsulating therebetween a compression driver assembly. The loudspeaker system includes a back plate member which is secured adjacent to the rear end of the housing. The back plate member includes a first diverter member for diverting a planar sound wavefront into two diverging sound wavefronts, a pair of second diverter members for splitting the two diverging sound wavefronts into four separate planar wavefronts, and reflector members for deflecting forwardly the four separate planar wavefronts toward an open mouth of the housing. A manifold formed by the inner surfaces of the housing and the inner cap member is used to recombine the four separate planar wavefronts back into a single composite wavefront emanating from the open mouth of the housing.

Abstract: An omnidirectional sound emitter with separate sound sources (1, 2), each comprising a funnel-shaped horn (4), is characterized in that the sound sources (1, 2) are mutually arranged such that the acoustic main axes (6) of the horns (4) lie in essentially one and the same plane (7) and the sound-emitting open ends (8) of the horns are directed towards the central portion of the sound emitter and located at a distance (B.sub.S ; B.sub.D) from one another. Slot-shaped openings (9) are so arranged between the open ends (8) of adjacent horns (4) that sound emitted by the horns is caused to pass in a direction from the sound emitter through the slot-shaped openings (9), thereby to be dispersed through 360.degree. in the said plane (7) such that the sound representation from the sound emitter corresponds to the sound representation from a line source perpendicular to said plane (7).

Abstract: An improved outdoor warning siren comprising an electromechanical siren together with a multi-segment horn which effects an exceptionally smooth transition from a small high pressure area at the horn inlet to a larger low pressure area at the horn outlet thereby producing increased sound output with reduced power requirements.

Abstract: A sound projection system for use in diffusing sound of a frequency ranging from 160 Hz up to 5 KHz over a relatively long distance with a substantially constant distribution of the sound over a wide diffusion angle, whereby the quality and intensity of the sound transmitted by the system remain substantially constant for a listener even if this person is substantially offset from the general direction and orientation of the projection system. The system which is advantageously compact in size, comprises a cabinet defining an enclosure in which a loudspeaker is mounted. An acoustic channel of rectangular cross-section is connected to the cabinet in alignment with the loudspeaker.

Abstract: A loudspeaker horn which provides constant coverage angles in both the horizontal and vertical planes and affords proper driver loading and a smooth impedance curve down to the lowest frequencies of operation. The throat entrance of the horn is round, to match the driver exit hole, and the throat section expands exponentially, with substantially straight and divergent top and bottom walls and curved side walls. The throat section joins to a transition section in which the side walls expand outward at a more rapid rate and a central vane is introduced top to bottom that both maintains an exponential flare rate and divides the transition section into two vertical slits. The length and width of the transition section are determined by the upper limits of the frequency range and the horizontal coverage angle. The transition section joins to the wave guide section which has a substantially planar side walls forming a conical expansion wave guide with side angle equal to the coverage angles of the horn.

Abstract: An exponential folded horn loudspeaker enclosure is built so that all of its components are coaxial with respect to a line that is equidistant from three cooperating surfaces, including floor or ceiling, as well as the customary two walls of a corner. Perfect symmetry with all three cooperating surfaces permits a smooth transition to these surfaces, so that they become a balanced extension of the exponential horn, more than doubling its effective length. Approaching the configuration of a large ideal horn, this geometry is uniquely free of discontinuities and artificial resonances that are needed in other enclosures for boosting low frequency response; therefore, efficiency and fidelity of low frequency response are greatly increased over other enclosures of comparable size.

Abstract: A dual loudspeaker is set up to handle separately high frequency and low frequency sounds in the same piece of equipment. The apparatus comprises a single housing having a vertical partition dividing the housing into two chambers. A high-frequency driver in one chamber feeds into a relatively short horn path to a high frequency bell. A low-frequency driver in the other chamber feeds into a relatively longer horn path to a low-frequency bell. The high-frequency and low-frequency bells are located side by side on opposite sides of a partition and feed into a progressively expanding horn which serves simultaneously the output of both drivers.

Abstract: A horn speaker comprising a diaphragm positioned close to a throat and side walls forming sound passages for radiating the vibrations of the diaphragm effectively as sound waves from the mouth of the speaker.