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: Disclosed is an acoustic horn to aid in bulk powdered material handling particularly from trucks and railroad cars. Such acoustic horn is comprised of an external cone having a driver affix thereto. There is also an inverted internal cone contained within the external cone. There is a cylindrical throat communicating with the acoustic wave driver which extends into the internal cone, the combination of the throat extending into the internal cone contained within the external cone creates a folded horn arrangement wherein a horn of relative shortened length can achieve the desired low fundamental frequencies needed for bulk powdered material handling.Extending radially from the mouth of the external cone is a flange. Means are provided to detachably affix said flange from the flange on existing manways present on trucks and railroad cars.

Abstract: A sound source includes a plurality of drivers communicating with the common throat of a horn. The size of the radiating area of the throat is less than two or three wavelengths of the highest frequency to be produced such that the drivers operate conjointly from a virtual point. Means may be included to adjust the time delay or phase between drivers to control the dispersion angle.

Abstract: An improved sound reinforcement enclosure is disclosed which incorporates a cone-type loudspeaker operating into a generally cylindrical channel extending from the perimeter of the cone to free air. A central member is coaxially mounted within this channel, the central member having rear surfaces substantially parallel to the surface of the cone and external surfaces which, with the internal surfaces of the channel form an annular region, the central member also having at least one coaxial internal passage forming a concentric horn flare. Methods of coaxially mounting a high-frequency compression driver behind the magnet assembly of the loudpseaker and of mounting a second loudspeaker internally in an enclosure are also disclosed.

Abstract: A high-frequency constant-directivity horn including a relatively large throat driver and a relatively large throat for receiving sound from the driver, further includes a pair of vanes mounted wholly within the throat, respectively above and below the longitudinal axis in a vertical plane, for effectively dividing the throat into three smaller "pseudo horns" for directing and shaping sound waves from the transducer up to the point of termination of the vanes, beyond which the individual wavefronts mix within and fill a slot in a middle section of the horn, forming a coherent wavefront for passage into a front section of the horn and transmission therefrom, substantially free from wave interference and beaming effects.

Abstract: Opposed side walls of a loudspeaker horn are constructed to direct portions of a sound beam toward a target over different preselected included angles, producing an incident beam which is substantially coextensive with the target. The side walls preferably extend downstream at the preselected angles over a distance at least comparable to a maximum wavelength at which the horn is to be used.

Abstract: A sectoral horn type loudspeaker includes a throat section and a sectoral part where the width of the horn at the connection therebetween is less than the wavelength of the upper limit frequency. In order to make the sound pressure characteristic flat throughout the frequency range, the directivity angle is changed for frequency bands in correspondence to the horn driver energy conversion characteristic. In particular, the side walls of the horn are bent polygonally at at least one point to increase the opening angle stepwise.

Abstract: A loudspeaker and horn combination having desirable sound clarity characteristics and having a desirable per unit of electric power input to per unit of sound output ratio can be constructed using a horn body of one or more parts of a rigid, closed cell polyurethane foam material having a smooth exterior skin or surface shaped so as to include an internal horn cavity. A speaker is located so that its diaphragm extends across an entrance end of the cavity. The cavity is shaped in a bilaterally symmetrical manner so as to include a sound chamber region adjacent to and leading from the speaker diaphragm, this sound chamber region having a restricted throat located intermediate its ends and having a continuous curvature between its ends, a flare region diverging outwardly from the end of the sound cavity region remote from the speaker and a transitional region located generally between the flare and sound cavity regions so as to connect the adjacent surfaces of these regions.

Abstract: A loudspeaker having uniform horizontal sound dispersion characteristics in a design angle and minimal sound dispersion vertically comprises multiple sound energy sources forming an elongated line source of sound energy, and a waveguide having an elongated input portion coextensive with the elongated line source and substantially planar side walls defining an expanding cross-section from the input portion to an exit aperture, whereby sound dispersion in a direction parallel to the line source is minimized. The waveguide expands substantially only in a direction perpendicular to the line source, the rectangular input portion having substantially the same dimension as the exit aperture measured in the direction parallel to the line source.

Abstract: Herein disclosed is an exponential horn for use in a horn-type loudspeaker, of which the mouth is in the form of an ellipse and the longitudinal cross-section of the horn intersected in the direction of the semi-major axis of the ellipse shaped mouth describes a V-shape of a larger included angle.

Abstract: A loudspeaker horn having improving directivity has a pair of smoothly flared vertical sidewalls joined to a pair of smoothly flared horizontal sidewalls. In an exemplary embodiment, one pair of sidewalls is generated as a surface of revolution, with the curvature of the surface being defined by a power series formula. The contour of the remaining pair of sidewalls is also defined by the power series formula, although different constants may be used. The vertical and horizontal sidewalls are separately defined and are substantially congruent at the rectangular or square mouth. In the exemplary embodiment, the gap formed at the back of one of the pairs of sidewalls is connected to the throat formed at the back of the other pair of sidewalls by a connecting section having an arcuate area which monotonically increases from the throat to the gap.

Abstract: A low frequency loudspeaker apparatus includes a folded exponential horn which is divided to provide a bifurcated curved sound path from at least one electroacoustic transducer that is positioned at the throat of the horn to a volume into which sound waves are radiated that is located at the bifurcated mouth of the horn. The mean length of the folded exponential horn is such that, at an exponential rate of expansion between the throat and the bifurcated mouth, the area of the mouth is adequate for reproduction of low frequencies in the audible range. An illustrative embodiment of the low frequency loudspeaker apparatus has an effective low end cut-off frequency of 38 Hz. and affords 99 dB SPL output at three meters with one watt input which corresponds to about 20% efficiency measured in free space. Presence of a single boundary surface, such as a stage floor adjacent the mouth of the folded exponential horn, improves amplitude response by 3 to 6 dB.

Abstract: A loudspeaker horn has a throat section with a rectangular cross section to which the driver unit is coupled. The throat section has substantially parallel side walls joined together by diverging top and bottom walls. The horn has a rectangular mouth which is formed by a bell section which runs between the throat section and the mouth with an angular divergence corresponding to the desired horn dispersion pattern. If the mouth is made square, equal horizontal and vertical low frequency directivity roll off can be provided. On the other hand, with the speaker of the present invention, various relative horizontal and vertical directivity control can be obtained with different aspect ratios for the mouth. The walls of the bell section may be additionally flared outwardly at a portion thereof near the mouth to provide improved midrange directivity control. The use of planar sides between the throat section and the mouth also makes for an improved directivity pattern.

Abstract: An acoustical horn suitable for use in conjunction with an acoustical driver to form a loudspeaker has a first section between its throat and a predetermined point therealong which has a first exponential flare rate, and a second section between the predetermined point and the mouth which has a second flare rate. The flare rates are chosen to afford improved frequency response over a single section exponential horn with the same length, mouth area and throat area.

Abstract: A loudspeaker with a driver and horn in which the horn has a channel expanding in cross section exponentially from the throat of the horn to a second portion, the second portion expanding conically to a rapidly flaring bell portion which terminates in the mouth of the horn. In one embodiment, the channel has a rectangular cross section to provide a wider horizontal beam width than vertical beam width.

Abstract: An acoustic system for disposition proximate to an acoustical boundary comprising at least one acoustic transducer for directing acoustic energy away from the boundary and an acoustic reflector surface extending, without substantial acoustic discontinuity, from proximate to the center of the transducer to the boundary.

Abstract: A loudspeaker horn has a conical section adapted to receive the driver assembly of a speaker system at the small cone end. An exponential section secured to the large cone end, concentrically with the cone longitudinal axis, flares outwardly to terminate in a square cross-section horn mouth. A raised lip secured around the periphery of the horn mouth diffracts sound symmetrically through a dispersion angle of about 120.degree. with a drop of about six decibels or less.