Abstract: The invention relates to a loudspeaker system for omni-directional sound emission consisting of a elongate member forming an air column and a plurality of annular speaker units mounted in axially spaced relationship on the elongate member. Diffusors also mounted on the elongate member are provided with conical surfaces facing the speaker units. Electrical wiring and auxiliary speaker components such as crossover networks may be mounted in the elongate member.

Abstract: An improved transducer which includes a rigid frame and a permanent ring magnet mounted to the frame. A small bobbin, preferably formed of aluminum foil, is sized and arranged to fit within the open end of the magnetic gap while permitting motion of the bobbin therein. A voice coil is wound on the bobbin and connectable to receive an audio signal, similar to a conventional voice coil driver system. A pair of flexible, curved diaphragms are disposed in the frame, generally free to move except for a distal end of each diaphragm which is fixed to the frame. The diaphragms can be of generally cylindrical or partial-cylindrical shape.

Abstract: A planar film speaker(200) utilizes a first planar film diaphragm (102), and a second planar film diaphragm (104). A taut armature reciprocating impulse transducer (100) is positioned at an edge between the first planar film diaphragm (102) and the second planar film diaphragm (104). A first transmission medium (120) couples the taut armature reciprocating impulse transducer (100) to the first planar film diaphragm (102), and a second transmission medium (122) couples the taut armature reciprocating impulse transducer (100) to the second planar film diaphragm (104). An audio input signal is converted to tactile energy by the taut armature reciprocating impulse transducer (100), which is then converted by the first planar film diaphragm (102) and the second planer film diaphragm (104) into acoustic energy.

Abstract: A sound focusing speaker system includes a sound focusing lens having an upper parabolic portion and a coaxial lower parabolic portion, each defined by different parabolic equations. A conical skirt is also provided adjacent the lower parabolic portion, and a lower lip is provided around the conical skirt. A speaker driver system is provided within the sound focusing lens. The speaker system includes a high frequency driver, a low frequency driver, and a sound dispersion lens into which the low frequency driver fires. The high frequency driver is vertically aligned with the focus of the upper parabolic portion, and a central portion of the sound dispersion lens is vertically aligned with the focus of the lower parabolic portion. The conical skirt contains reflected waves. The coaxial dual parabolic sound focusing speaker system is optimized to accurately reproduce a broad frequency spectrum of sound and to reflect the sound into a substantially vertical beam.

Abstract: A loudspeaker unit comprises a loudspeaker box, a first loudspeaker attached to a front panel of the loudspeaker box, and a second loudspeaker having the same diameter as that of the first loudspeaker and attached to an upper panel of the loudspeaker box. The first loudspeaker is driven in a positive polarity and the second loudspeaker is driven in a negative polarity. Driving voltages E1 and -E2 respectively for driving the first and the second loudspeaker are optional voltages meeting E2/E1<1. The sound pressure of sounds radiated by the second loudspeaker is lower than that of sounds radiated by the first loudspeaker. The directivity factor of the synthesis sound pressure of the first and the second loudspeaker at a sound receiving position with respect to the 90.degree.-direction is equal to the product of the directivity factor D(90.degree.) of the loudspeaker and a value (1-.alpha.) smaller than one. Accordingly, the output sound pressure of the loudspeaker can be reduced regardless of frequency.

Abstract: A double cone-type loudspeaker which comprises a subcone made of highly heat-conductive material, attached to the front of the main cone and to a voice coil bobbin made of highly heat-conductive material. Heat generated in the coil portion of the voice coil travels directly to the bobbin portion and subcone, and is released to the front of the speaker. Consequently, a double cone-type loudspeaker with high maximum input power and high heat radiating capability is achieved.

Abstract: Passive radiators of the same effective vibration area and the same effective vibration mass disposed in mutual opposition, and driver units of the same effective vibration area and the same effective vibration mass disposed in mutual opposition, are mounted to a bandpass type enclosure. The vibration-reaction forces of the opposing passive radiators and opposing driver units on the enclosure are thereby mutually cancelled, and enclosure vibrations are thus greatly reduced. Powerful bass output can be achieved because the diameter of the passive radiators can be increased at will and the use of two passive radiators achieves an extremely large vibration area.

Abstract: Improved loudspeakers, systems and components are adapted to interconnect with many forms of communication media. In one embodiment, a speaker is mountable within a receptacle. The speaker includes a magnetic driver and a diaphragm mounted to a frame. The frame includes a mounting member extending from a surface of the frame behind the flange plane. The mounting member is engagable in a notch formed in the receptacle for securing the speaker within the receptacle. In another embodiment, a low-profile loudspeaker has a front-mounted magnetic driver disposed within a cone-shaped acoustic diaphragm. The magnetic driver includes a first rare earth magnet centrally disposed within an electromagnetic shielding material. In another embodiment, a low-profile, two-way loudspeaker includes a cone-shaped diaphragm and a dome-shaped (tweeter) diaphragm. A front-mounted magnetic driver comprises first and second rare earth magnets each centrally disposed within electromagnetic shielding material.

Abstract: Either a tweeter or a woofer diffuser may alternatively be detachably secured to a driver holder of a speaker base through axial engagement of lugs carried by the holder with guide grooves formed in a skirt of the driver and thereafter rotating the driver to dispose the lugs in a circumferential groove and out of alignment with the guide grooves.

Abstract: An active noise reduction headset including a headband and at least one earcup secured thereto. A microphone is mounted within the earcup for detecting and transducing acoustic pressure within the earcup to a corresponding microphone electronic signal. An electronic signal processing unit is mounted within the earcup and coupled with the microphone for generating an anti-noise signal from the microphone electronic signal. A first speaker is mounted within the earcup for receiving and acoustically reproducing an electronic anti-noise signal from the electronic signal processing unit. A second speaker is mounted within the earcup for receiving and acoustically reproducing an electronic communication signal.

Abstract: A composite speaker system includes a tweeter or high frequency transducer attached to an adjustable flexible arm or arms which is mounted directly to the pole piece or adapter member connected to the pole piece of a woofer or low frequency transducer. The tweeter can be adjusted in any direction to improve the sound quality because the listener can actually aim the tweeter at himself or herself and the composite speaker system can be mounted anywhere in an automobile or room.

Abstract: A composite speaker system including a high frequency transducer and a low frequency transducer. An adjustable rod is attached to a pole piece of the low frequency transducer and a back side of the high frequency transducer. The high frequency transducer can be adjusted in any direction to improve the sound quality because the listener can actually aim the high frequency transducer at himself or herself and the composite speaker system can be mounted anywhere in a vehicle or room.

Abstract: A loudspeaker has a pole (6) and a surrounding magnet (3) which together define an annular gap (7). A voice coil (12) supported on a tubular former (8) is disposed within the gap (7) as is a conductive skirted dome (13). The dome (13) is supported upon an insulating gasket (14) providing three arcuate points of support and a phase plug (16) extends through a central opening (15) in the dome (13). The dome (13) and phase plug (16) are preferably separated by a second gasket (27) which may or may not be bonded to both and the phase plug (16) suitably includes an integral horn (20) extending beyond the former(8).

Abstract: A multiple cone type loudspeaker having a construction including a plurality of vibrating plates and a plurality of baffle plates protruded forwards from an enclosure of the loudspeaker. Each of the baffle plates serves to effectively isolate both spaces respectively defined at front and back sides of each corresponding one of the vibrating plates protruded forwards beyond the front surface of the enclosure. As a result, there is no phenomenon that the density of air is equalized in both spaces respectively defined at front and back sides of each vibrating plate as the vibration of the vibrating plate is continued. Accordingly, it is possible to achieve an extension in regeneration band, an improvement in directivity and a generation of dynamic sound.

Abstract: A body-acoustic device is provided which comprises a housing (1), a diaphragm (4) dividing an inner space of the housing into a first chamber (5) and a second chamber (6), and a loudspeaker (7) mounted to an opening provided in the diaphragm, wherein the diaphragm is made of a transversely vibratory member and/or has a perimetric edge supported by an inner surface of the housing via an elastic member (10), and wherein the diaphragm (4) is further provided with a port (9) for air movement between the first and second chambers (5), (6). When the loudspeaker (7) is operated, the diaphragm vibrates with a cone paper (8) to generate sufficient heavy bass sound with high sound clarity as if the diameter of the loudspeaker had increased. The port provided in the vibrating diaphragm facilitates the vibration of the diaphragm, further increasesing the sound pressure created by the diaphragm vibration due a sound throttling effect caused by the port.

Abstract: A loudspeaker system includes a first loudspeaker driver with a voice coil mounted thereon and a second loudspeaker driver with a voice coil mounted thereon. A carrier has a bearing plate and a leg member which is mounted to the first loudspeaker driver for supporting and spacing the bearing plate apart from the first loudspeaker driver. The bearing plate has a flat bearing surface. A support plate can support the second loudspeaker driver and has a flat base surface disposed on the bearing surface of the bearing plate. A retaining unit can retain releasably the support plate on the bearing plate. First and second contact members are mounted respectively to the bearing and base surfaces of the bearing and support plates. A connecting unit can connect electrically the first and second contact members to the voice coils of the first and second loudspeaker drivers, respectively. The first and second contact members make electrical contact with each other when the support plate is disposed on the bearing plate.

Abstract: A composite speaker system includes a tweeter or high frequency transducer attached to an adjustable flexible arm or arms which is mounted directly to the pole piece or adapter member connected to the pole piece of a woofer or low frequency transducer. The tweeter can be adjusted in any direction to improve the sound quality because the listener can actually aim the tweeter at himself or herself and the composite speaker system can be mounted anywhere in an automobile or room.

Abstract: An audio transducer having a cylindrical diaphragm molded with contoured ridges. The diaphragm includes at least two lobes, each extending from a central expanse to the transducer frame. The lobes may have different radii and different angular arc lengths. A driver attached at the central expanse may include a double-sided etched coil, or may be provided by an electrostatic driver having a charged filament attached to the diaphragm. The transducer diaphragm may include a central third lobe having different size and structural characteristics to provide added low frequency response. The transducer may be configured to provide omnipolar sound radiation with opposed spaced-apart semi-circular cylindrical diaphragms arranged to pulse symmetrically toward and away from each other.

Abstract: An omni-directional stereo speaker especially useful in high fidelity sound reproduction applications, comprised of a polyhedron speaker enclosure, separate speakers or drivers mounted in some or all of the faces of the polyhedron enclosure, an acoustically transparent cover or outer housing for the enclosure, and a mounting means for positioning the speaker unit away from walls or other flat reflecting surfaces so as to provide an aural stereo effect throughout a room or other limited space. The polyhedron enclosure and multiplicity of speakers therein approaches ideal spheroidal projection of the reproduced sound wave, i.e. the sound appears to be emanating from a point source, and thereby produces a realistic stereo sound image in all parts of the room.

Abstract: A planar-type loudspeaker incorporating a substantially planar diaphragm constructed from a pre-expanded cellular plastic material, such as polystyrene, in which separate portions of the diaphragm have different densities. The higher density portion is designed for the reproduction of high frequencies, and the lower density section is used for the reproduction of low frequencies. In one embodiment, the diaphragm is formed by laminating together a pair of diaphragm members having the different densities to define a single sound producing region, to which a single voice coil assembly is coupled. In another embodiment, the diaphragm is formed as a unitary, one-piece structure having separate but contiguous sound producing regions, each with its own density material and voice coil assembly for reproducing a specified frequency range of sound.

Abstract: Coaxial loudspeaker arrangements (10) are usually so configured, that the loudspeaker (12) located in the bellmouth (29) of the conical loudspeaker (11), is placed on the pole core (17) of the conical loudspeaker (11). However, the contact of the loudspeaker (11) has a disadvantage, with respect to automated manufacture, because either the connection cables (24) for loudspeaker (12) must be threaded through the pole core (17), or the connection cables (24) must be connected to the soldering joints in the diaphragm (15). It is also known to place the loudspeaker (12) into a preform, and to attach this preform to the edge of the loudspeaker frame (14) of the conical loudspeaker (11). The latter is very costly and detrimental to the acoustical effect. For that reason the invention has the task of indicating a coaxial loudspeaker arrangement (10), which is simplified with respect to automated manufacture, without impairing the acoustical effect.

Abstract: The composite electroacoustic transducer for reproducing medium and high frequencies comprises a transducer assigned to reproducing midrange frequencies provided with a dome-shaped membrane which extends in an annular shape. A transducer assigned to reproducing high frequencies is provided with a dome-shaped membrane and is arranged coaxially to the center of the transducer assigned to reproducing midrange frequencies.

Abstract: A loudspeaker has a rigid sound radiator having a free edge and a electromagnetic drive mounted on an opposed hub edge and arranged to produce a torque on the radiator. Either a coil or a permanent magnet of the drive is mounted directly on the hub edge and has a radius which is substantially smaller than the radius of the radiator.

Abstract: A compound driver loudspeaker system combines a single exterior radiating loudspeaker with a plurality of internal auxiliary loudspeakers in a cabinet. The cabinet has an external baffleboard and an internal baffleboard, the external baffleboard having a single baffle cutout for receiving the radiating loudspeaker and a plurality of internal baffleboard cutouts for receiving each of the auxiliary loudspeakers. The baffleboards and loudspeakers define a desirable air chamber between them. The auxiliary loudspeakers are selected to be smaller than the radiating loudspeaker and the number of auxiliary loudspeakers is such that, taken together, they form an equivalent single driver which is matched to the radiating loudspeaker to provide the desired frequency performance of the loudspeaker system. Since the auxiliary loudspeakers are smaller than the radiating loudspeaker, the baffle cutout in the external baffleboard is larger than the cutouts in the internal baffleboard.

Abstract: The invention relates to an improved piezoelectric loudspeaker for high frequency, more commonly known as a tweeter. The invention embraces a technological improvement which permits the size of the tweeter to be substantially reduced while maintaining or even improving its performance when compared to other tweeters. In the device, a diaphragm is placed at least partially inside a coil so that the size of the tweeter can be reduced. The coil activates a piezoelectric element which drives the diaphragm causing it to vibrate and produce sound.

Abstract: The direct and reverberant sound fields heard at a live musical performance are reproduced by a speaker enclosure consisting of two sub-enclosures mounted on a base with each subenclosure housing at least one speaker, thereby realistically reproducing the music.

Abstract: An improved dipole type characteristic loudspeaker system has a pair of loudspeakers (1 and 2) which are mounted on the front baffle board (4) and the back baffle board (5) of a console (3) and are connected to be driven in each-other opposite phase relation and have substantially the same acoustic characteristics in the medium and high frequency range but different acoustic characteristic in low frequency range; such loudspeaker system produces good surround-sound effect when used as back loudspeakers only with small number.

Abstract: A speaker which is thin but which is capable of providing high-fidelity reproduction and ensuring a suitable level of sound pressure even when it is brought close to a wall. A closed chamber is formed behind one part of a disphragm mounted in an enclosure, and an open chamber is formed behind another part of the diaphragm. At least one voice coil driver unit is connected to the diaphragm. The phase difference between sounds radiated from the front and rear surfaces of the diaphragm is increased as large as possible by using an acoustic duct for the sound radiated through the open chamber, thereby minimizing cancellation of sounds and improving the sound pressure level.

Abstract: A multi-driver, coaxially mounted loud speaker array utilizing a high frequency bi-morph driving element that is totally contained within the hollow core of the voice coil former of a lower frequency loud speaker. The outwardly radiating conical edge of the high frequency device's diaphragm is annularly fixed by a compliance to the inner surface of the referenced voice coil former or to the diaphragm which radiates outwardly therefrom and is excited by the former. A significant advancement in the art is acquired by the realization of a cavity between the situs of the bi-morph driving element and the back of the former--excited diaphragm, behind the annular compliance. This feature allows a design engineer to literally tune the response of the higher frequency loud speaker by deliberately varying the volume of the cavity.

Abstract: A piezoelectric speaker which generates sound by vibrating a plane diaphragm using a plurality of piezoelectric drivers is disclosed. The diaphragm is formed of resin foam plates and the piezoelectric drivers are contained therein while being interposed and supported at the centers thereof. The piezoelectric drivers are divided into at least two groups which have different primary resonance frequencies.

Abstract: An improved flat sound transducer including a planar diaphragm having at least one region suited for reproduction of low frequencies and one region suited for reproduction of high frequencies wherein the frame of the flat sound transducer is used to sandwich a foam strip between the frame and the diaphragm in order to dampen low frequency vibrations and substantially isolate the high frequency region from the large amplitude low frequency vibrations while still allowing high frequency vibrations to emanate from the entire sound transducer diaphragm. The dampening strip may used with either a metallic frame or with a unitary plastic frame. A high frequency enhancement coating may be used to increase the frequency response in the high frequency region of the diaphragm.

Abstract: A piezoelectric speaker in which a diaphragm containing a piezoelectric driver is fixed on a frame through an elastic supporting member. The diaphragm is an assembly of two resin foam plates facing each other. Each resin foam plate has a recess and a projecting member at the substantial center of the recess bottom. The piezoelectric driver is accommodated in the space made of the two recesses while being interposed and supported by the projecting members at the substantial center thereof.

Abstract: A grille is attached to a woofer, and a tweeter is further mounted on the grille to mutually face the woofer and be at least partially disposed in a cavity defined by the woofer and grille to define a compact loudspeaker structure. The grille and a back of the tweeter face an environment to which sound is to be directed, and both contain structures and are arranged to allow sound from the tweeter and woofer to communicate with the environment, while resisting water from contaminating the woofer and tweeter. Further, the rim of the grille and a frame define a component storage space in which elements which constitute a dividing network or other discrete electronic components of the loudspeaker are housed.

Abstract: A loudspeaker transducer has a coil (5) and a metal dome (11) with a skirt (13) arranged concentrically in a magnetic gap between pol pieces (2 and 4). The skirt (13) is inductively coupled to the coil (5) but is mechanically independent of the coil former tube (6). The tube (6) is connected to a main low frequency cone (9) and to a short concentric additional cone (16). A fixed element (14) providing phase correction and/or horn loading is fixed to the center pole piece (4) in front of the dome (11) and within the tube (6). The member (14) and tube (6) co-operate acoustically.

Abstract: A low sound region reproducing speaker system comprising a box, a partition separating the internal space of the box into two spatial portions, a pair of speakers attached to the partition wall, and an aperture formed in the side wall of the box through which one of the spatial portions communicates with the external space. Right and left stereophonic channel signals are respectively reproduced through the pair of speakers. Only the low sound region is emitted into the external space. The partition wall has therein a communication hole for communicating the two spatial portions therethrough with each other.

Abstract: An open line source speaker system includes a first columnar cabinet enclosing a plurality of midrange or woofer speakers arranged in the cabinet in a vertical line and a second columnar cabinet enclosing a plurality of tweeters arranged in the cabinet in a vertical line, with the first and second cabinets being spaced a predetermined distance from each other by a pair of spacing elements and the base portion of the speaker system supporting the first and second cabinets. The vertical height of the speakers will be such as to offer a large listening window of approximately floor height to well above the listener's head. All frequencies of the music originate from the same plane as positioned from the listener thus maintaining correct time/phase relationship and correct stereo image in both the horizontal and vertical planes regardless of musical frequency.

Abstract: A speaker system for reproducing heavy low sounds comprises a tube body having a tubular straight portion and a pair of tubular arms, each of the arms extending substantially in parallel to each other in the forward direction to provide therebetween a wide space opening forward for accommodation, each arm further having sound radiation outlets formed in its forward end portion. A speaker driver is attached to the forward end of one of the arms and communicating with the sound radiation outlets, and a drone cone attached to the forward end of the other of the arms and communicating with the sound radiation outlets.

Abstract: A sound transducer converts electrical signals into mechanical motion. A transducer comprises a transducer housing including a diaphragm section having an inner concave surface and an outer convex surface. A stem element projects outwardly from the diaphragm housing section and has a structural configuration effective to penetrate a panel or sounding board. A securing device is adapted to cooperate with the stem for connecting the diaphragm housing section to the sounding board. An electromagnetic driver assembly is resiliently mounted to the inner surface of the diaphragm housing section. The electromagnetic driver assembly includes an annular magnetic gap and a voice coil assembly located in the magnetic gap. The voice coil assembly includes a coil member having a cylindrical voice coil portion at one end thereof disposed in the magnetic gap and the other end thereof connected to the stem.

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: An improved audio transducer includes a diaphragm having a pair of cylindrically-shaped webs that provide greater bandwidth, reduced distortion and greater horizontal dispersion of sound. The audio output of the transducer is further improved by forming the diaphragm of a polyvinyl fluoride film. Other improvements include the use of damping pads to damp internal sound waves and damping strips on the diaphragm to minimize distortion at the resonant frequency of the transducer.

Abstract: A speaker which is thin but which is capable of providing high-fidelity reproduction and ensuring a suitable level of sound pressure even when it is brought close to a wall. A closed chamber is formed behind one part of a diaphragm mounted in an enclosure, and an open chamber is formed behind another part of the diaphragm. At least one voice coil drive unit is connected to the diaphragm. The phase difference between sounds radiated from the front and rear surfaces of the diaphragm is increased as large as possible by using an acoustic duct for the sound radiated through the open chamber, thereby minimizing cancellation of sounds and improving the sound pressure level.

Abstract: New loudspeaker driver configurations comprise positioning the high frequency driver between symmetrically located lower frequency drivers and providing in combination electrical or acoustical delay to the high frequency driver relative to the lower frequency drivers. The lower frequency drivers are located above and below at equal distances from the high frequency driver or, with more than two lower frequency drivers, symmetrically about the high frequency driver. The sound pressure level and phase response is substantially equivalent to co-axial drivers including suitable high frequency electric delay circuitry operating at similar power levels. The delay for the high frequency driver is electrical or electrical in combination with a geometrical delay. With a stereo pair of loudspeakers the high frequency driver may be offset from the vertical between the above and below low frequency drivers in an outboard direction of the stereo pair.

Abstract: A system for reproducing sound, particularly musical sound, giving enhanced pleasure to the listener. The system utilizes a pair of low frequency range speakers, a plurality of high frequency range speakers and may employ one or more mid frequency range speakers, all of which speakers are of conventional construction. These speakers are, however, disposed in a novel mechanical arrangement and electrically interconnected in a manner to emanate sound in essentially a non-directional manner. The listener thus perceives the sound to be emanating from the diemensional space surrounding the system, rather than from a single point or plane, and experiences the sound much as if he or she were in the same enclosure with live performers, rather than listening to a recording.

Abstract: A speaker transducer assembly is disclosed which includes first and second speaker diaphragms supported on a frame in over and under juxtaposition. Each of the speaker diaphragms has a central opening defining an inner periphery which is attached to a voice coil form for coaxial movement therewith and in unison. An intermediate baffle is coaxially positioned between the speaker diaphragms to define upper and lower, separately vented chambers. The upper chamber is vented through an outlet in the region of the outer peripheries of the first speaker diaphragm and the intermediate baffle; similarly, the lower chamber is vented through an outlet situated in the region of the outer peripheries of the second speaker diaphragm and the intermediate baffle. Preferably, the two vent systems have different vent exhaust areas to obtain stagger tuning and thus achieve a split of the deepest frequency load.

Abstract: An electrodynamic transducer (1) comprises a diaphragm with a central part (2) and a peripheral part (3) and a voice-coil device (9, 10) coupled to the central part (2). The diaphragm (2, 3) cooperates with an enclosed volume (6), the enclosed volume being such that ##EQU1## where f.sub.o and f.sub.o ' are the anti-resonance frequencies of a transducer respectively with or without the enclosed volume behind the diaphragm. These frequencies each correspond to a local minimum situated between two maxima (f.sub.1 and f.sub.1 ' respectively, and f.sub.2 and f.sub.2 ' respectively) in the input impedance curves Z.sub.1 in the case of a transducer with the enclosed volume and in the case of a transducer without the enclosed volume. The maxima correspond to the two resonance frequencies for which the central part of the peripheral part move in phase and in phase opposition relative to one another, and S.sub.1 and S.sub.2 are the surface areas of the central part and the peripheral part, respectively, where S.sub.

Abstract: A device having two sets of oppositely facing corresponding resonance cavities; i.e., an upper and a lower resonance cavity. Each of the resonance cavities include a piezo-electric type diaphragm consisting of a vibration diaphragm and a start-up plate. Electric signals cause the piezo-electric type diaphragm to vibrate back and forth and produce sound waves from the upper and lower resonance cavity.

Abstract: A compound speaker system comprising a woofer, a squawker, a tweeter, and a super tweeter. The squawker, the tweeter, and the super tweeter are attached to a plate and the assembly is rotatably positioned within the cone of the woofer. Since the squawker, the tweeter, and the super tweeter are positioned at different distances from the axis of the assembly rotation, it is possible to design the system such that the speaker which reproduces relatively directional sound, such the tweeter or the super tweeter takes an elevated position as compared to the squawker when the assembly is rotated within the woofer cone.

Abstract: A planar loudspeaker system having an elongated and substantially planar enclosure, configured to house tweeter, midrange, and a pair of upper and lower woofer diaphragms in its median, longitudinal section. A pair of woofer labyrinths, acting as quarter-wave transmission lines, extends throughout the remainder of the enclosure's volume. The labyrinths vent the substantially in-phase backwaves forwardly, toward the listener, through a pair of shared ports in the mid-frontal region of the enclosure. An electro-magnetic drive unit, employing bar magnets, pole pieces and thin encapsulated moving coils, all of elongated and symmetrical configuration, is also disclosed. Three versions of the drive unit are shown, each being adapted to provide a distributive driving force to the planar diaphragms of the loudspeaker.

Abstract: The disklike diaphragm is made up of an essentially conical plastic film provided with vacuum-formed supporting members which extend up to the disklike radiating layer.

Abstract: A speaker system and assembly achieves a high fidelity sound reproduction by causing acoustical waves emanating from juxtaposed and co-axially positioned first and second speakers, which produce respective mid-range and treble frequencies, to reach a listener simultaneously.