Abstract: A speaker system includes a speaker driver loaded by a horn waveguide. The speaker driver reproduces sound within an extended frequency range that includes a high frequency band between 8 kHz and 11 kHz. In the preferred embodiment, the extended frequency range includes a wide frequency band between 2 kHz and 11 kHz (and most preferably including the frequency band between 800 Hz and 11 kHz). The horn waveguide has an axi-symmetrical waveguide surface that provides uniform polar dispersion at dispersion angles greater than 90 degrees for sound within the extended frequency range. The waveguide surface preferably has an annular cross section with a radial dimension that increases curvilinearly from its throat to its mouth, such as a tractroid surface.

Abstract: This invention provides a method for designing a waveguide profile based upon predicted performance measurements of the waveguide. The method involves establishing a design metric, such as the change in acoustic reactance along the transition of the waveguide. Initial values may then assigned for the radius or diameter of the throat of the waveguide as well as values for the initial slope of the waveguide along the major and minor (or x and y) axis and the depth of the waveguide. The waveguide may then be divided into two or more sections. The values of the slopes for each section are then altered based upon the design metric. When using the change of acoustic reactance as the design metric, the slope of each section of the waveguide is adjusted to minimize the change in acoustic reactance between the sections, which is the desired performance standard.

Abstract: A horn or waveguide public address unit, enabling to adapt the dispersion characteristics of the horn or waveguide. The unit is provided with at least one profiling component (21a, 21b) constituting a removable dispersion shaper, capable of being mounted on the inner wall of the horn (13) or waveguide between the throat (17) and the mouth (19) thereof.

Abstract: A horn assembly for high frequency acoustic speakers. In an array of speakers, a spacing between adjacent speakers needs to be less than the wavelength of sound being emitted in order to combine effectively. For high frequency sound, a relatively small wavelength imposes a limitation on such a spacing. Such limitations are sometimes physically difficult to implement. A horn assembly increases the exit dimensions of the small speaker to larger desired dimensions by utilizing one or more plugs that divide a larger horn cavity into smaller horn cavities and creating similar pathlengths thereto. The similar pathlengths and the smaller horn cavities having desired dimensions allow the exiting sound to combine effectively. The overall dimensions of the exit portion of the horn assembly can be selected to match the dimensions of larger bass speakers, thus allowing improved arraying of the high frequency speakers with respect to other larger speakers.

Abstract: A flush mountable ceiling speaker (10) with individual coaxial waveguides (20, 22) for both the lower and high-frequency transducers (11, 12). The lower frequency radiation is combined with the sonic energy radiated by the high-frequency transducer (12) and shaped by the high-frequency waveguide (20) to create a coherent, uniformly controlled coverage pattern. The loudspeaker (10) creates a well defined sound dispersion pattern over a relatively large bandwidth, resulting in increased vocal intelligibility and more accurate reproduction of music at relatively great distances from the loudspeaker, as is particularly useful in association with high ceiling installations.

Abstract: A phase plug for optimally matching a drive-unit's diaphragm to the throat of a waveguide is disclosed. Specific embodiments of a circular diaphragm matched to an elliptical waveguide and a circular diaphragm to a rectangular waveguide are disclosed.

Abstract: This invention provides a two-stage phasing plug located within a compression driver. The two-stage phasing plug housed within the compression driver may be coupled to a horn. The two-stage phasing plug includes first and second phasing plugs. The advantages of having a two-stage phasing plug is that the first and second phasing plugs may be simpler to manufacture, cost less and the overall dimensional tolerances may be tightly controlled. The higher dimensional tolerances may be obtained because the first phasing plug may be made from a unitary work-piece, and therefore, may be tooled and cut in the same machining set up. This allows the unitary work-piece to be machined and cut very accurately when compared to assembling separate components together during the manufacturing process. Since the most dimensionally critical area is the rear side of the first phasing plug, the tolerances of the second phasing plug may not be as critical.

Abstract: Acoustic waveguide contours that approximate either or both of the Elliptic Cylinder and the Prolate Spheroidal coordinate systems that allows for a more accurate prediction and control over the sound radiation polar pattern are disclosed.

Abstract: An improved throat (2) for transmitting acoustic energy from a source driver unit (7) to a feeder section (3) of a directivity controlling acoustic horn is disclosed. The throat (2) comprises: a circular throat entrance (2i) connectable to the source driver unit (7); a rectangular throat exit (2e) connectable to or integral with the feeder section (3); and a circular cross-section to rectangular cross-section transition portion (2a) extending between the throat entrance (2i) and the throat exit (2e). The throat (2) is shaped such that its profiles initially diverge from an axis longitudinal to the throat (14) at the same angle in a direction from the throat entrance (2i) towards the throat exit (2e). Such a throat, when fitted in an appropriate acoustic horn with a source driver unit having a taper matching the aforesaid profile angles, provides a smooth transition for sound waves propagating out from the source driver unit into the horn.

Abstract: A horn-loaded compression driver or a loudspeaker has a phasing plug with multiple slots and a common annular chamber. The slots extend from an inlet side to the common annular chamber, which extends to an outlet side. Each slot has a path length extending to a common focal point in the common annular chamber. The common focal point has a common path length extending to the outlet side. The phasing plug provides an approximately flat acoustic wave front from the compression driver to the horn.

Abstract: A midrange loudspeaker for operation in conjunction with low-frequency and high-frequency loudspeaker modules in a theater sound system, having a reduced depth for deployment in limited space. The midrange module is configured with a plurality of drivers and a waveguide unit that provides uniform sound coverage throughout a theater auditorium with substantially seamless crossovers at 250 Hz and 1.5 kHz and with the vertical beam-width held substantially constant by an electrical filter network.

Abstract: A loudspeaker comprising a phase uncorrelated diffuse sound source and a duct or wave guide coupled to the sound source to direct acoustic energy from the source, the duct or wave guide having a substantially parallel section extending from the vicinity of the sound source and a termination positioned remotely from the panel.

Abstract: The invention relates generally to the field of audio loudspeaker enclosures, and more particularly to a method of mounting the internal components in the loudspeaker so as to control the loudspeaker output. Specifically a mounting structure and method for mounting the loudspeaker horn to its associated compression driver are disclosed. The mounting structure allows the directivity of the loudspeaker output, and the frequency/phase control of the loudspeaker, output to be controlled by the spatial arrangement of these components in the loudspeaker enclosure.

Abstract: A noise attenuation system (10) for an air induction system (12) includes an air inlet duct (16) having an open end (18) to draw in air and a loudspeaker (22) mounted within the inlet duct (16) and facing the open end (18) of the inlet duct (16). The air horn (24) is connected to the loudspeaker (22) to tune the sound output and increase the sound power from the loudspeaker (22) to optimize cancellation of noise generated by the air induction system (16) at lower frequencies. An open end (18) of the air horn (24) is positioned within a plane defined by the open end (18) of the air inlet duct (16). A microphone (26) is positioned near the air inlet duct (16) and is in communication with a controller (28). The controller (28) generates an input to the loudspeaker (22). The input to the loudspeaker (22) is out of phase with the noise detected by the microphones (26) to cancel a portion of noise emitted from the open end (18) of the air inlet (16).

Abstract: A directional loudspeaker unit for reproducing mid-range audio frequencies, comprising a cone loudspeaker and, disposed forwardly of the surface of the cone of the loudspeaker, a phase plug and a horn, wherein the phase plug and preferably also the horn are arranged co-axially on the axis of the cone, and wherein the phase plug has a central aperture. Preferably the horn has a diffraction slot defined by lateral walls which converge from the entrance (throat) of the horn.

Abstract: A bass loudspeaker apparatus capable of according with a horn-type midbass in both the appearance and acoustics is disclosed. A bass loudspeaker apparatus A is provided with a cabinet 70 having an inner space 75 and a sound emission opening 71 in a front section; a corn-type woofer 3 disposed within the cabinet 70; a baffle plate 2 having a woofer mounting section 72 and vertically disposed in the inner space 75 so as to face the sound emission opening 71; a resonant chamber 73 defined in front of the baffle plate 2 for communicating with the sound emission opening 71. The front ends of the loudspeaker apparatuses A and 80 are approximately aligned in the state that the sound source position of the bass loudspeaker apparatus A is aligned with that of the horn-type midbass 80. Thus, the uniformity in the appearance is secured.

Abstract: A waveguide system for radiating sound waves. The system includes a low loss waveguide for transmitting sound waves, having walls are tapered so that said crosssectional area of the exit end is less than the cross-sectional area of the inlet end. In a second aspect of the invention, a waveguide for radiating sound waves, has segments of length approximately equal to A ⁡ ( y ) = A inlet ⁡ [ 1 - 2 ⁢ Y B + ( Y B ) 2 ] where l is the effective length of said waveguide and n is a positive integer.

Abstract: A signal-horn has an electromagnetically actuated oscillating membrane coupled to an acoustic amplifier having a volute wound duct formed of a first length with generally constant section having an inlet for the sound signal and a second length with variable section in the form of a conical exponential having an outlet for the sound signal. The ratio of the figure representing the volume defined by the oscillating membrane between two points of maximum elongation and the figure representing the area of the cross section of the first length is between 16 and 20.

Abstract: There is disclosed an acoustic driver having a phasing and compression plug and its direct coupling to an acoustic waveguide having an entry throat with a non-unity aspect ratio, such as a rectangular diffraction slot. The phasing and compression plug has an input end with an input surface having a plurality of input apertures configured in a parallel array of spaced-apart chordal slits. The opposite, output end of the plug has a like plurality of output apertures contained in an output region having unequal length and width dimensions such that the area of the output region is less than that of the input surface. A plurality of passages through the plug body connect each respective input aperture to the corresponding output aperture wherein the relative lengths of the passages are preselected to provide an acoustic wavefront which is concave at its major (vertical) axis and planar or convex across its minor (horizontal) axis.

Abstract: The present invention provides a design of a horn for vibration actuators. In general a driving actuator generates vibrations and a horn amplifies the vibration amplitude where the amplification is related to the ratio between the surface area of the horn at the contact with the actuator and the tip surface. The acoustic path of existing direct horn designs is modified to adopt at least one change in direction, or fold, so as to produce a compact design Preferably there are three parallel, concentric, acoustic paths and two folds. A second embodiment has an internal horn that is concentric and internal to the actuator. A third embodiment uses a tubular horn where an electroactive stack is encircled by the horn. The device may have a hollow core for the transfer of materials from one side to the other.

Abstract: A new approach has been developed to combine mid-range and high frequency sound into the throat of a horn designed for sound reinforcement. An acoustic low pass filter element is interposed between the lower frequency passage and the higher frequency passage, so that a smooth combination of the two frequency bands is achieved at the entrance to the horn bell. Thus, each frequency band has nearly identical dispersion, and the two sources have equal delay.

Abstract: An acoustic-signal emitting device for vehicles comprises an electronic control circuit (50) for generating driving signals and a loudspeaker (LDSK). The loudspeaker includes a transducer device (1) connected electrically to the electronic control circuit (50) in order to receive the driving signals and to convert them into acoustic radiation. The transducer device (1) being a moving-coil device with a compression chamber and having dimensions such that it can generate acoustic radiation characteristic of an alarm siren in a first operative condition and acoustic radiation characteristic of an acoustic warning device in a second operative condition. A twisted horn (2) is coupled acoustically with the transducer device (1) in order to propagate the acoustic radiation emitted in the two operative conditions, outside the emitting device (100).

Abstract: An electroacoustic transducer of a horn loudspeaker emits sound, which is supplied through a sound conduit pipe to a horn and propagated out of the horn through a mouth of the horn. The sound conduit pipe is coupled to the horn via a rectangular opening in the upper one of the upper and lower walls forming the horn, to thereby provide a linear sound source for the loudspeaker. The location where the sound conduit pipe is coupled to the horn and/or the tilt angle of the sound conduit pipe with respect to the horn may be varied to control the sound radiation characteristic of the loudspeaker.

Abstract: Disclosed is a speaker system that can be advantageously used in a television set. The speaker system has a support member which is provided with a partition wall and mounted on both sides of the television cabinet. A speaker is securely installed in the partition wall of the support member and provided with a frame. An amplifying horn is connected to the frame for collecting and amplifying the sound waves projected toward the frame. A cover is coupled to the rear side of the support member. The speaker system collects and amplifies not only the midrange-frequency and high-frequency sounds projected toward the front of the speaker, but also some of the sound waves projected in the backward direction of the speaker, thereby providing greatly amplified bass and harmonious and sensitive sound.

Abstract: A directional loudspeaker unit for reproducing mid-range audio frequencies, comprising a cone loudspeaker and, disposed forwardly of the surface of the cone of the loudspeaker, a phase plug and a horn, wherein the phase plug and preferably also the horn are arranged co-axially on the axis of the cone, and wherein the phase plug has a central aperture. Preferably the horn has a diffraction slot defined by lateral walls which converge from the entrance (throat) of the horn.

Abstract: A horn-loaded compression driver or a loudspeaker has a phasing plug with multiple slots and a common annular chamber. The slots extend from an inlet side to the common annular chamber, which extends to an outlet side. Each slot has a path length extending to a common focal point in the common annular chamber. The common focal point has a common path length extending to the outlet side. The phasing plug provides an approximately flat acoustic wave front from the compression driver to the horn.

Abstract: An upper base/low mid loudspeaker comprises a conical driver and a channel defined by a housing and a central member. The central member has a portion extending into the cone to form a first generally ring-shaped region whose cross-sectional area increases in the direction of sound propagation. A second generally ring-shaped region is defined between a portion of the housing and a portion of the central member. The cross-sectional area of the second region decreases in the direction of sound propagation. The channel continues with a throat and a horn.

Abstract: A yoke, a permanent magnet, and a top plate are stacked on a frame in order, and adhered with each other. The frame has a positioning protuberance projected from the frame, and each of the yoke, permanent magnet, and top plate has a central hole and is engaged with the positioning protuberance at the central hole.

Abstract: A loudspeaker system of improved clarity, coherence and uniformity of energy distribution containing mid frequency sound chambers with an annular input and approximately rectangular output for use in multi-way co-axial horn loaded line array systems. The sound chambers propagate the annular mid frequency sound wave co-axially with a high frequency sound wave, gradually changing the cross section of the mid frequency wavefront resulting in co-linear acoustic mid and high frequency wavefronts from multiple devices which range from the shape of a flat ribbon to that of a curved ribbon. The sound chambers may be arrayed contiguously and placed at the entrance of a suitable waveguide to form a wide band width acoustic line source of extended length and controlled beamwidth.

Abstract: A horn loudspeaker comprises: a horn (22) having a throat (26) and a mouth (30); a primary electro-acoustic driver (24) mounted at or adjacent the throat of the horn and directed generally along the horn; and at least one secondary electro-acoustic driver (32T, 32B, 32L, 32R) mounted part-way along the horn and directed generally across the horn. The secondary driver(s) can be used to change the local impedance conditions in the horn and therefore to change the polar response of the horn loudspeaker. At least one filter (12A, 12E) is provided for filtering an input signal (34) for the primary driver to produce a filtered signal for the primary driver or each of the secondary drivers. Such a filter may be chosen or designed so as to optimize some aspect of the polar response of the horn loudspeaker, for example to increase directivity, or flatten the polar response within a specified included radiation angle, or to increase omnidirectionality.

Abstract: The invention relates to a signal-horn (1) of electromagnetic type comprising a generator (2) of sound waves having an oscillating membrane (4) actuated by an electromechanical propulsor unit (5) coupled to an acoustic amplifier (3) consisting of a duct (6) wound as a volute in which there is a first length (7) with generally constant section (8) provided with an inlet (9) for the sound signal to be amplified and a second length (10) with variable section (11) according to a conical exponential rule ending with an outlet (12) for the amplified sound signal. The ratio of the figure representing the volume (13) defined by the oscillating membrane (4) between the two points of maximum elongation (14, 15) and the figure representing the area of a cross section (8) of the first length is a number comprised between 16 and 20.

Abstract: A portable electronic device, such as a portable notebook computer, that includes a case made up of a top portion and a bottom portion with a base surface. The case contains a speaker having a front portion and a back portion, where the back chamber is formed in association with the back portion of the speaker. A first aperture is disposed through the bottom portion of the case, and an acoustic insulator is attached to the base surface of the case such that the acoustic insulator encircles the first aperture forming an external chamber. The external chamber is defined by the base surface, and the acoustic insulator being adapted to rest upon a support surface upon which the portable electronic device rests. The external chamber is coupled to the back chamber by the first aperture.

Abstract: For loudspeaker components with flat and/or curved panel-like regions that require hard surfaces along with sound-damping properties to minimize sound feed-through and resonances, a three-layer laminate is formed from two surface layers of commercially available thermosetting molding compound, co-molded in a single molding operation with an embedded core of suitable sound damping material such as filled vinyl copolymer compound or filled silicon rubber compound. The core region is dimensioned to leave a peripheral margin in which the two layers of molding material become bonded together so as to fully encapsulate and seal the sound-damping core. Furthermore, the margin can be made to have any desired size, thickness or shape to also serve as a mounting, fastening or other function of the component.

Abstract: A directional speaker system includes an enclosure having an inner surface, an outer surface, an open end, and a closed end, a speaker driver directed toward the open end and mounted near the closed end of the enclosure, an in-line phase plug mounted in front of the speaker driver for manipulating the wavefront of sound waves produced by the speaker driver, and a preferably frustoconical shaped wave guide provided between the speaker driver and the open end of the speaker enclosure. A preferably annular space is provided between the enclosure and the wave guide and a plurality of openings are provided between the enclosure at the open end of the enclosure. Out-of-phase sound waves produced by the speaker driver travel into the space and exit the speaker system through the openings.

Abstract: A first feature of the present invention is that the opening of a sound output port 3b is smaller in area than the opening of a sound input port 3a in a horn 3. A second feature is that the sound output port 3b of the horn 3 is located so as not to be in the way of a center axis of sound radiation from a speaker 2. A third feature is that a length L of the horn 3 is set at 370 mm or below. A fourth feature is that the horn 3 is gradually narrowed such that vertical sections thereof from the sound input port 3a to the sound output port 3b respectively have areas based on a predetermined rule. Thus, it is possible to realize a speaker apparatus in which a sound output port of a horn is smaller in area than a vibrating surface of a speaker while reproducing sound whose quality is equal or similar to that in conventional speaker apparatus, and a television set equipped with the speaker apparatus.

Abstract: A modular horn loudspeaker principally intended for use on emergency vehicles consists of three coaxially aligned cup-shaped parts, a sound chamber, a cover fitted to the sound chamber and a housing. The first embodiment of the modular, compact horn loudspeaker is implemented with a single siren driver and includes a dome-shaped driver diaphragm integrally formed onto an interior surface of the sound chamber. The sound chamber is an acoustical boundary defining member having curved propagation paths or horn throat channels formed in relief on a cup-shaped exterior surface. The sound chamber is coaxially aligned with and received in a tightly fitted cup-shaped cover member to define a plurality of curved horn throats of expanding rectangular cross sectional dimension directing the sound waves rearwardly around the diaphragm periphery and toward a housing rear wall.

Abstract: A speaker includes a disk-shaped base. A substantially hemispherical surface vibrator is fitted into a substantially circular groove provided in the base and bonded therein. Terminals are attached to electrodes provided on both surfaces of the vibrator. The terminals, passing through the terminal grooves provided in the base, are led out in a direction that is substantially perpendicular to the plane of the base. Further, a horn as a separate member may be attached to the outer surface side of the vibrator.

Abstract: This invention provides a baffle formed from a thermoset composite material such as Bulk Molding Compound (BMC), Thick Molding Compound (TMC), or Sheet Molding Compound (SMC). Due to the physical properties of BMCs, TMCs, and SMCs, the baffle may be molded to minimize the propagation of vibrational energy and resonant mode behavior while providing high strength and rigidity. The baffle may also be formed so transducer mounts, ports and wave-guides may be molded into the baffle shape.

Abstract: A high-frequency cinema loudspeaker module for deployment behind a perforated cinema screen is configured with a waveguide to compensate for the beam-spreading effects of the perforated screen at the high end of the frequency range and to facilitate and co-ordinate integration with a complementary midrange module of a total sound system in providing defined coverage in a theater. A compression driver is coupled to a waveguide that is specially shaped to narrow the horizontal beamwidth at the higher frequencies affected by the perforated screen, and thus provide compensation that results in a more uniform overall defined sound coverage in the theater within the designated high-frequency range. The module is configured with the driver and waveguide axes inclined downwardly at an angle of 6 degrees from horizontal to facilitate overall coverage.

Abstract: A loudspeaker system of improved clarity, coherence and uniformity of energy distribution containing mid frequency sound chambers with an annular input and approximately rectangular output for use in multi-way co-axial horn loaded line array systems. The sound chambers propagate the annular mid frequency sound wave co-axially with a high frequency sound wave, gradually changing the cross section of the mid frequency wavefront resulting in co-linear acoustic mid and high frequency wavefronts from multiple devices which range from the shape of a flat ribbon to that of a curved ribbon. The sound chambers may be arrayed contiguously and placed at the entrance of a suitable waveguide to form a wide band width acoustic line source of extended length and controlled beamwidth.

Abstract: The present invention relates to systems and methods for sound reproduction employing a unity summation aperture loudspeaker horn taking advantage of the frequency response of horn flare characteristics for positioning of audio drivers along the outer wall of the loudspeaker horn. The loudspeaker horn may be embodied as any of a variety of pyramid shapes which allows for sections for driver positioning in correlation with the frequency response of the horn. Positioning the driver sources along the sides of the horn and out of the way of the audio field facilitates at least two modes of operation including a transformation operation for acoustical impedance matching and a waveguide operation for directing the reproduced audio signals. The single horn, multi-driver approach provides highly coupled audio drivers to generate sound reproduction employing unity summation aperture loudspeakers.

Abstract: The present invention relates to systems and methods for sound reproduction employing a unity summation aperture loudspeaker horn taking advantage of the frequency response of horn flare characteristics for positioning of audio drivers along the outer wall of the loudspeaker horn. The loudspeaker horn may be embodied as any of a variety of pyramid shapes which allows for sections for driver positioning in correlation with the frequency response of the horn. Positioning the driver sources along the sides of the horn and out of the way of the audio field facilitates at least two modes of operation including a transformation operation for acoustical impedance matching and a waveguide operation for directing the reproduced audio signals. The single horn, multi-driver approach provides highly coupled audio drivers to generate sound reproduction employing unity summation aperture loudspeakers.

Abstract: The sonic soot blower includes a sonic wave oscillator that oscillates sonic waves by compressed air or steam, a frequency-regulating portion that varies the frequencies of the sonic waves oscillated by the above-described sonic wave oscillator, a resonance tube that resonates the oscillated sonic waves, and a horn that amplifies the same, wherein powdery dust adhered to members installed inside a boiler furnace, etc., are removed, and are prevented from adhering to the above-described members. The above-described frequency-regulating portion is a gas mixer which is connected to the upstream side of the sonic wave oscillator and is provided with two or more gas conducting flow channels for conducting a compressive gas whose temperatures and/or densities are different from each other, or a slide mechanism that varies the length of the above-described resonance tube.

Abstract: A loudspeaker horn, loudspeaker and a loudspeaker system wherein at least one loudspeaker includes a horn composed of a waveguide, a plurality of throats acoustically coupled to a single waveguide at their mouths and to respective drivers of a plurality of drivers at their inlets. The axis of the throats form an arc in the plane of the long axis of the waveguide to optimize energy distribution in this plane.

Abstract: A sound field equalizing apparatus for a speaker system which is capable of widening a region in which it is possible to effectively hear a sound field. The apparatus includes a sound field equalizing member disposed in a dispersing hole formed in a cabinet of a speaker for separating a sound dispersed from the speaker into a forwardly dispersed sound which is dispersed in a central direction and a laterally dispersing sound which is dispersed in a peripheral direction of the forwardly dispersing sound.

Abstract: A multi-speaker apparatus generates and transmits sound waves in all directions toward and away from a surface upon which the apparatus is installed or mounted. The multi-speaker apparatus includes a middle/high frequency sound range speaker and a low frequency sound range speaker. The middle/high frequency sound range speaker and the low frequency sound range speaker are arranged relative to each other such that center axes thereof are aligned with an axis that is substantially perpendicular the surface upon which the apparatus is installed or mounted. A horn and a cabinet are arranged such that sound waves generated from the middle/high frequency sound range speaker and the low frequency sound range speaker are emitted in all directions both toward and away from the surface upon which the apparatus is supported or mounted.

Abstract: This invention provides a two-stage phasing plug located within a compression driver. The two-stage phasing plug housed within the compression driver may be coupled to a horn. The two-stage phasing plug includes first and second phasing plugs. The advantages of having a two-stage phasing plug is that the first and second phasing plugs may be simpler to manufacture, cost less and the overall dimensional tolerances may be tightly controlled. The higher dimensional tolerances may be obtained because the first phasing plug may be made from a unitary work-piece, and therefore, may be tooled and cut in the same machining set up. This allows the unitary work-piece to be machined and cut very accurately when compared to assembling separate components together during the manufacturing process. Since the most dimensionally critical area is the rear side of the first phasing plug, the tolerances of the second phasing plug may not be as critical.

Abstract: A loudspeaker system of improved clarity, coherence and uniformity of energy distribution containing mid frequency sound chambers with an annular input and approximately rectangular output for use in multi-way co-axial horn loaded line array systems. The sound chambers propagate the annular mid frequency sound wave co-axially with a high frequency sound wave, gradually changing the cross section of the mid frequency wavefront resulting in co-linear acoustic mid and high frequency wavefronts from multiple devices which range from the shape of a flat ribbon to that of a curved ribbon. The sound chambers may be arrayed contiguously and placed at the entrance of a suitable waveguide to form a wide band width acoustic line source of extended length and controlled beamwidth.

Abstract: A loudspeaker includes a compresion chamber, a first electroacoustic transducer and a horn. The first electroacoustic transducer is disposed inside the compression chamber. The horn is mechanically and acoustically coupled to the first electroacoustic transducer. The loudspeaker also includes a second electroacoustic transducer. The second electroacoustic transducer is disposed outside the compression chamber. The second electroacoustic transducer is mechanically and acoustically coupled to the horn.

Abstract: The compression driver includes an annular diaphragm with a voice coil which is disposed in a magnetic gap of a magnet assembly which supplies a magnetic field to the voice coil. The annular diaphragm has a first support portion, a second support portion, a first curved resilient portion, a second curved resilient portion and a voice coil support portion which is disposed between the first and second resilient curved portions. The voice coil is wound on the voice coil support portion. The voice coil is disposed in the magnetic gap of the magnet assembly. The compression driver also includes an inner support ring and an outer support ring. The inner support ring has a bottom surface with a first curved groove. The outer support ring has a bottom surface with a second curved groove and is disposed concentrically around the inner support ring.