Abstract: A speaker diaphragm which has a high rigidity and can improve sound transmission speed for better sound quality is provided. The speaker diaphragm contains fibers of 3 to 50 mm length mixed in matrix resin. The fibers are oriented radially from center to periphery in surface layers of the diaphragm, while they are oriented in different directions in a middle layer. After setting the resin, these fibers are fixed in the matrix resin with certain tension applied thereto.

Abstract: An electricity-to-sound transducer has a diaphragm having an asymmetric shape which is flat when viewed from a direction of vibration, with major and minor axes, having continuous curvatures of concavity and convexity in a direction of sound irradiation, provided with a slot formed almost at a center of the diaphragm in a direction perpendicular to a longitudinal direction of the diaphragm. An edge portion is formed as surrounding an outer periphery of the diaphragm, an inner section of the edge portion being connected to the outer periphery, the edge portion sustaining the diaphragm so that it can vibrate. A voice coil bobbin has a winding portion around which a voice coil is wound split into two portions in the longitudinal direction of the diaphragm, the bobbin being attached to a rear surface of the diaphragm while the two portions are joined to each other, the joined portions forming a reinforcing beam that reaches a rear surface of a bottom of the slot of the diaphragm.

Abstract: A loudspeaker of the present invention includes a diaphragm; a voice coil for driving the diaphragm; and a magnetic circuit including a yoke, a magnet provided on the yoke, and an upper plate provided on the magnet, for producing a magnet field that is perpendicular to the voice coil. The upper plate has a surface configuration such that when reflecting sound waves created by the diaphragm, the upper plate diffuses the sound waves.

Abstract: An ultra low frequency transducer or subwoofer for automotive speaker systems with a rectangular or square, concave diaphragm. The square periphery preferably is sized to be substantially coextensive with the front of the speaker housing or cabinet. In this way, air displacement in the subwoofer is maximized for a given size of enclosure, and thus so is the loudness of the speaker. The transducer typically includes a frame or basket with a square front for supporting the periphery of the diaphragm. The preferred diaphragm includes a convex surround with pleated corners. For increased durability, trusses are formed in the diaphragm.

Abstract: A speaker capable to playback in wide frequency range by means of reducing peak values of amplitude of resonance frequencies in frequency characteristics is provided by means of differing a radius of curvature R1 of an inner diaphragm 10a and a radius of curvature R2 of an outer diaphragm 10b to differ resonance frequencies of the inner diaphragm 10a and the outer diaphragm 10b. Furthermore, by means of equalizing an area S1 of the inner diaphragm 10a and an area S2 of the outer diaphragm 10b, sound pressure levels of the inner and outer diaphragms 10a, 10b are equalized with each other.

Abstract: A high efficiency loudspeaker without a damper is provided. The loudspeaker includes magnetic circuit 9 having magnetic gap 14 and voice coil member 15, which has movable coil 16, disposed in magnetic gap 14 of magnetic circuit 9. The loudspeaker also includes diaphragm 17, whose inner peripheral part is linked with voice coil member 15, outside magnetic gap 14 and frame 19 linked with an outer peripheral part of diaphragm 17 via first edge 18. An inner peripheral part of suspension holder 20 is linked with voice coil member 15 at a linked position, which is nearer to magnetic circuit 9 than a linked position of diaphragm 17 and voice coil member 15. An outer peripheral part of suspension holder 20 is linked with frame 19 via second edge 21. First edge 18 and second edge 21 are substantially symmetrical analog each other about a median of first edge 18 and second edge 21.

Abstract: The invention relates to an acoustic transducer for broad-band loudspeakers or magnet-free, electrodynamic head-phones for generating sound, especially for the use in the homogenous and/or inhomogeneous magnetic field of a magnetic resonance tomograph. According to the advantages of the invention, sound having defined characteristics can be generated in such a way that said sound is provided with good quality and high effectiveness within the strong magnetic field of a magnetic resonance tomograph. In addition to music and voice, this comprises the generation of sound for actively controlling noise by generating sound by means of one or several membranes (1) that form air pockets. Said membranes (1) consist of elastic, non-magnetic or slightly magnetic material and are connected to strip conductors (2) in a two-dimensional and solid manner. A Lorentz force which is caused by the magnetic field of the magnetic resonance tomograph is exerted on said strip conductors as the driving power when current flows.

Abstract: An ultra low frequency transducer or subwoofer for automotive speaker systems with a rectangular or square, concave diaphragm. The square periphery preferably is sized to be substantially coextensive with the front of the speaker housing or cabinet. In this way, air displacement in the subwoofer is maximized for a given size of enclosure, and thus so is the loudness of the speaker. The transducer typically includes a frame or basket with a square front for supporting the periphery of the diaphragm. The preferred diaphragm includes a convex surround with pleated corners. For increased durability, trusses are formed in the diaphragm.

Abstract: An acoustic pressure type sensor fabricated on a supporting substrate is disclosed. The acoustic sensor is fabricated by depositing and etching a number of thin films on the supporting substrate and by machining the supporting substrate. The resulting structure contains a pressure sensitive, electrically conductive diaphragm positioned at a distance from an electrically conductive fixed electrode. In operation, the diaphragm deflects in response to an acoustic pressure and the corresponding change of electrical capacitance between the diaphragm and the fixed electrode is detected using an electrical circuit. Two or more such acoustic sensors are combined on the same supporting substrate with an interaural flexible mechanical connection, to form a directional sensor with a small surface area.

Abstract: An electroacoustic transducer has a diaphragm having an asymmetric shape, having a flat vibrating surface with major and minor axes when viewed from a direction of vibration, having continuous curvatures of concavity and convexity in a direction of the major axis. The diaphragm is provided with a slot formed almost at the center of the vibrating surface in a direction perpendicular to the major-axis direction and a groove provided along the periphery of the vibrating surface. A fringe is connected to the groove as surrounding the groove, for sustaining the diaphragm against vibration. A voice-coil bobbin is connected to the diaphragm. A voice coil is wound around the voice-coil bobbin. Hook suspensions are provided at both ends of the voice coil in the major-axis direction to support the voice coil against vibration occurring when a magnetic circuit applies fluxes to the voice coil.

Abstract: An acoustic- to-electrical transducer for sensing body sounds is disclosed. The transducer comprises a diaphragm that can be placed in direct contact with a body, whereby the diaphragm motion directly affects an electromagnetic sensing signal, which is then converted to an electrical signal representation of the diaphragm motion. Such sensing means allows the diaphragm to move freely without mechanical coupling to a secondary transducer, while providing a direct and efficient acoustic to electrical conversion means. The transducer further provides a means for using static diaphragm pressure to control gain and frequency characteristics of the electrical signal. The sensor, circuitry, manufacturing methods and improvements are disclosed.

Abstract: A panel-shaped loudspeaker includes a panel (1) and an exciter coupled to the panel. The panel is provided with two parallel extending thin walls (1a, 1b) which are interconnected by a structure of thin strip-shaped partitions (1c) situated between the walls. The longitudinal axes of all partitions extend parallel to each other and give the panel an anisotropic bending stiffness. The material of the walls and the partitions of the panel has an internal damping which is at least 2.5% of the critical damping of the relevant material, used in the panel.

Abstract: A loudspeaker with independent magnetic dampening and excursion control includes at least two magnets for dampening the axial movement of a voice coil. The dampening magnets substantially reduce/prevent fatigue of the component parts of the loudspeaker and detrimental contact between the voice coil and its supporting parts, and the remaining component parts of the loudspeaker. A pole yoke supported by a backplate defines the inner diameter of an annular gap within which the voice coil moves and a top plate defines the outer diameter of the gap. A first dampening magnet is statically supported by the pole yoke. A second dampening magnet is supported by and moves in concert with the voice coil. As the voice coil and second magnet move within the gap, the repelling forces of the magnets provide the desired dampening effect, thus limiting or reducing the movement in one direction.

Abstract: An electroacoustic transducer operating in accordance with the electrodynamic principle include a diaphragm which has in the region of the coil an annular protrusion which is integrally connected to the diaphragm, wherein the coil is attached, preferably glued, to the annular protrusion at a desired distance from the diaphragm. The attachment can be end face against end face. The diaphragm may in the area of the coil have an annular reinforcing corrugation which is attached to the coil in an appropriate manner, preferably by gluing.

Abstract: A technique and apparatus for integrating a speaker with button (or keyboard) components such as a tactile membrane and/or PCB. The tactile membrane conventionally used between buttons and switch mechanisms to provide tactile feedback to a user upon depression of the button is extended to form a vibrating portion of a speaker. The vibrating portion is doped with or otherwise includes an activating material (e.g., copper) which will be physically affected by a magnetic field. The activating material may be adhered to the upper and/or lower side of the vibrating portion, or doped therein. A coil for the speaker is formed with a coil tracing pattern formed on one or more layers of a PCB. One or more amplifier circuits may be included to drive one or more coil patterns, to cause a fluctuating magnetic field in the direction perpendicular to the vibrating portion of the tactile membrane.

Abstract: A low frequency loudspeaker driver has polygonal diaphragm surfaces. In a first embodiment, the peripheral edge of a loudspeaker driver diaphragm is polygonal, preferably hexagonal or six sided, wherein each of the six peripheral sides are of equal length and meet in radiused or rounded corners. The hexagonal loudspeaker driver is supported within a matching hexagonal section truncated pyramid shaped basket having a hexagonal peripheral mounting flange. The hexagonal woofer of a first embodiment is adapted to be mounted on a planar baffle in a variety of densely packed arrays such that virtually no wasted baffle space is visible between the driver basket peripheral edges. The faceted hexagonal diaphragm shape provides an increase in cone surface area of approximately ten percent as compared to conventional frustoconical woofers having circular peripheral edges.

Abstract: A diaphragm includes a vibratory membrane and at least one nickel titanium memory metal member having a shape that can be mechanically adjusted with a heating signal. The mechanical adjustment of the at least one nickel titanium memory metal member tunes the frequency response of the vibratory membrane in the diaphragm. The at least one nickel titanium memory metal member can be a sheet providing a vibratory membrane, or sheet sections or wire made of nickel titanium memory metal bonded to a vibratory membrane.

Abstract: Acoustic device comprising a member relying on bending wave action with beneficial distribution of resonant modes thereof, wherein the member has its acoustically active area at least partly bounded by means having a substantially restraining nature in relation to bending wave vibration. Operation can be below coincidence, or above if desired for active acoustic device further having beneficial location of bending wave transducer means determined with reference to and taking account of such bounding means.

Abstract: An outer end portion 21A of an edge 21, which is formed at an interior of an outer periphery thereof, is mounted on an attaching surface 10b which is formed inside an outer peripheral rim 10a of a speaker frame 10. An outer peripheral surface 21a of the outer end portion 21A is allowed to abut on the outer peripheral rim 10a of the speaker frame 10. Also, an attaching screw section 14 of the speaker frame is provided on the attaching surface 10b. The outer end portion 21A has a wall thickness thicker than the thickness of a screw head of the attaching screw section, and is provided with a notch 21b to avoid the attaching screw section 14. Therefore, the inside area of the speaker frame can be effectively utilized to obtain enough level of outputted sound pressure. Further, since a gasket is unnecessary for positioning and attaching the edge, the number of parts can be reduced to lead cost-down.

Abstract: An electroacoustic transducer which has at least one stator member with an operating surface and a suspended emitter diaphragm spaced from the operating surface of the stator member to enable the diaphragm to oscillate in response to an applied signal voltage. The diaphragm has increased stiffness in a direction along the diaphragm and within the emitter section to enable the emitter diaphragm to oscillate without applying tension in the direction of stiffness. A clamp member secures the diaphragm to maintain the diaphragm in a fixed position relative to the stator to minimize distortion. The clamp member is positioned to define at least two isolated emitter sections for enhancing the frequency response of the transducer. A method is also provided for generating audio output from an electroacoustic transducer.

Abstract: Active acoustic device comprises a panel member (11) having distribution of resonant modes of bending wave action determining acoustic performance in conjunction with a transducer (31-34). The transducer (31-34) is coupled to the panel member (11) at a marginal position. The arrangement is such as to result in acoustically acceptable action dependent on said distribution of active said resonant modes. Methods of selecting the transducer location, or improvement by location of localized marginal clamping, rely on assessing best or better operative interaction of said transducer (31-34) and the panel members (11) according to parameters of acoustic output for the device as an acoustic radiator.

Abstract: An improved structure of a picture-frame type loudspeaker is disclosed. The loudspeaker structure having a magnetic core is mounted on a housing body adhered to the rear side of a picture frame, and the circumferential edge of the magnetic core is mounted with a conduit containing a voice coil, and the end section of the conduit, close to the magnetic core is connected together with a corrugation portion which is combined with the housing body, the middle section of the conduit is connected to a diaphragm and the other end of the conduit is connected to a vibration board within the picture frame via a medium. By means of the reaction to the signal current by the voice coil, a magnetic field is produced and a relative motion is formed with the magnetic core, such that the vibration board vibrates to produce sound from the picture frame.

Abstract: A diaphragm of electroacoustic transducer has an edge formed with alternately up-rolled and down-rolled portions with respect to vibration plane of the diaphragm and disposed at regular intervals in circumferential direction and with sloped-plane portions respectively connecting rims opposing above and below of adjacent ones of the up-rolled and down-rolled portions, the sloped-plane portions extending in respective tangential lines with respect to an inner periphery of the edge and intersecting the circumferential direction at an alternately opposite angle with respect to the vibration plane.

Abstract: A laminated aluminum polypropylene (refers to LAP hereinafter) multi-layers loudspeaker diaphragm comprises different material layers to exploit the appearance feature and mechanical properties from different material. LAP diaphragm contains (1) the front layer which is made of formed aluminum foil, (2) the second layer which is injected polypropylene and (3) a bonding adhesive layer lying between the aluminum and polypropylene layers to bond two different material layers tightly and also enhance the property of internal loss. The loudspeaker with this multi layers vibrating diaphragm posses the advantages of the metal glaring appearance and mechanical properties good for quality sound reproduction and environmental resistance.

Abstract: A flat panel sound radiator system for installation in a suspended ceiling is disclosed. The system is capable of concealing a modular sound radiator so that it appears substantially the same as surrounding ceiling panels. In this way the monolithic appearance of the ceiling is not interrupted. The assembly comprises a frame and a radiating panel resting within the frame and an acoustic facing covering the panel that is substantially indistinguishable from surrounding ceiling panels. Additionally disclosed is a ceiling system including a grid, a plurality of ceiling panels and an acoustical radiator having an acoustical visually matched exposed layer.

Abstract: An electroacoustic transducer (1) has a magnet system (7) and a moving coil (15), which is disposed in the air gap (14) of the magnet system (7), and a diaphragm (17) attached to the moving coil (15). The diaphragm (17) has a mounting zone (24) for mounting the moving coil (15), and projections (25) in the mounting zone (24). The diaphragm (17) also has an interspace between every two projections (25), and two stabilizing walls (32, 33), which are inclined with respect to the diaphragm axis (18), are arranged in each interspace and are arranged so as to form a roof shape and are formed so as to project beyond the mounting zone (24) in radial directions.

Abstract: A diaphragmatic (planar) electrocoustic transducer forms a complete sound radiating transducer, with high efficiency and linearity. An easily exchangeable and rectangular in shape diaphragm, of very thin polyamide film is made with a plurality of aluminum conductors formed on one side of said diaphragm. The diaphragm with the plurality of conductors form two identical and symmetrical coils which are the one, inside the other, in an order, that conductors of each coil are interlaced. The two sections of the coils are disposed in dense air-gaps of the magnet system, which comprises a plurality of high (BHmax) Neodymium magnets. The binary interlaced coils can be utilized in a number of modes, for the purpose of accomplishing a variety of operating modes, such as: 1. A series connection provides a higher sensitivity compared to single coil (2). A parallel connection converts the transducer to a higher power standing devise (3).

Abstract: A loudspeaker and method of assembling same is disclosed in which the motor structure and frame are interconnected, the voice coil is initially secured within the magnetic gap of the motor by the lower suspension and then the diaphragm and surround are installed by first affixing the surround to a flange at the upper end of the frame so that the outer diameter of the surround is concentric to its inner diameter, and then inserting the lower end of the diaphragm within a pool of adhesive carried by a well structure mounted to the exterior surface of the voice coil such that the diaphragm is allowed to move in both a lateral direction and a vertical direction within the well structure while the adhesive cures, thus maintaining the original shape of the surround and substantially preventing misalignment of the voice coil within the magnetic gap of the motor during operation of the loudspeaker.

Abstract: A planar-magnetic electro-acoustic transducer including a support structure and a magnetic structure carried by the support structure, the magnetic structure comprising a multiplicity of high-energy magnets configured so as to have shared loop field maxima and local loop field maxima, and a diaphragm carried by the support structure, comprising a plurality of conductors carried by and coupled to the diaphragm, said conductors being disposed in relation to local loop maxima and configured to exploit the energy of local loop maxima, as well as the energy of shared loop maxima in driving the diaphragm to produce an acoustic output; and the magnetic structure can be configured so that it includes magnet rows, and the transverse cross-sectional width of the magnets does not exceed their transverse cross-sectional height, and the distance between adjacent elongated magnet rows is greater than one half the width of either of the magnets of the adjacent magnet rows.

Abstract: The invention relates to the embodiment of panel loudspeakers 10 working according to the bending wave principle. Such loudspeakers 10 generally consist of an acoustic panel 11 and drivers 12, whereby the drivers 12 are connected to the acoustic panel 11. For the formation of bending waves in the acoustic panel 11, it is essentially important that the drivers 12 do not unnecessarily rigidize the acoustic panel 11. This has led to the arrangement of the drivers 12 at a distance from the acoustic panel 11 in a separate frame. In view of the complexity of such an arrangement, the invention aims at providing a connection between the drivers 12 and the acoustic panel 11 that can be supported directly on the acoustic panel 11 and which does not impede the propagation of the bending waves. This is achieved by connecting the drivers to the acoustic panel only at very few points 24 or by providing elastic member 25 in the fixing area of the drivers. A combination of both embodiments is also described.

Abstract: A loudspeaker comprises a motor structure including a voice coil with a hollow former, a frame having an upper end and a lower end connected to the motor structure, an upper suspension mounted to the upper end of the frame, and, a two part diaphragm structure which includes an upper diaphragm connected to the upper suspension and a lower diaphragm extending between the upper suspension and the voice coil in position to overlie the hollow former of the voice coil.

Abstract: A speaker unit includes a woofer having a diaphragm with an ellipse shape sound emitting opening, and a separate speaker having an ellipse shape diaphragm with an area smaller than that of the diaphragm of the woofer, located in front of the diaphragm of the woofer, attached to a center axis of the ellipse shape of the woofer coincident with that of the ellipse shape of the separate speaker, and emitting a sound higher in frequency than that of the woofer.

Abstract: A butterfly damper for supporting a voice coil bobbin of a speaker on a frame in a state that the damper is vibrative. The butterfly damper is made of olefinic resin material having an internal loss of 0.045 or greater, a tensile elongation of 200% or greater, and a flexural modulus of 300 MPa or greater.

Abstract: Permanent magnets m18, m28 and m38 each of which is formed in a flat and rectangular shape are disposed on a yoke 20 with the magnetic pole surfaces facing upwardly so that the magnetic pole surfaces whose polarities are different are disposed alternately. A vibrating diaphragm 26 is disposed on the top surface of the yoke 20 so as to be in parallel with the magnetic pole surfaces of the permanent magnets. Pairs of coils L18, L28 and L38 which are wound in a swirled shape and are disposed at the top and rear surfaces of the vibrating diaphragm are disposed on the vibrating diaphragm 26 so as to correspond to the permanent magnets m28 and m38, respectively. Each of the pairs of coils L18, L28 and L38 is wound in a swirled shape so as to be substantially analogous with the external edge of the magnetic pole surface of each of the permanent magnets m18, m28 and m38.

Abstract: A diaphragm for a speaker and a speaker device, a frequency characteristic as well as the endurance against input of which are improved, have been provided. A convexo-concave portion is radially formed at a neck of the diaphragm, which is stuck to a voice coil bobbin, to increase an adhesion area of the neck itself, thereby the endurance against input is improved. In addition, the neck is stuck to the voice coil bobbin by an adhesive to increase the mechanical strength of the neck itself, thereby a frequency characteristic as well as the endurance against input are improved.

Abstract: An audio speaker including a chassis and a diaphragm defining an axis. A suspension movably interconnects the diaphragm and the chassis for reciprocating movement of the diaphragm along the axis. A motor is operably connected to the diaphragm for powered movement thereof. The diaphragm includes front and rear skins, and at least a portion of the skins have a generally conical shape. The skins define outer peripheral edges, and are interconnected at the outer peripheral edges with the conical shapes oriented in opposing directions to form a cavity between the skins having an enlarged central portion tapering to a thinner peripheral portion adjacent the outer peripheral edges. The cavity is at least partially filled with a lightweight core material to support the front and rear skins.

Abstract: An electro-acoustic converter, comprising a barrel shaped diaphragm (2) formed about a longitudinal axis (3) and comprising first and second annular opposed ends (4, 5), and a first electrically driven vibration generator (6-11) for inducing a vibrational movement in the first annular end in the direction of the longitudinal axis.

Abstract: A passive radiator and method is disclosed which improves frequency response linearity and greatly reduces the possibility that wobble of a passive radiator which will occur without the displacement limitations of a spider containing speaker structure. Two substantially fiat surfaced speaker diaphragms are tied together and supported by two sets of surrounds oriented in opposite directions to reduce the non-linearity in the surround spring rate Hand improve low frequency sound generation. A vent (pressure relief system is provided to improve the frequency response and range of motion of the passive speaker system. A progressive surround roll arrangement provides for improved sound quality by utilizing localized position based extension while maintaining the range of maximum travel during resonance.

Abstract: A receiver, such as for use in a hearing aid, is disclosed. The receiver comprises a housing and a diaphragm assembly disposed within the housing. The diaphragm assembly acoustically divides the housing into a front volume and a back volume. The diaphragm assembly comprises a paddle having a perimeter, a flexible annulus connected to the paddle, and a diaphragm support, wherein the diaphragm support secures the perimeter of the annulus to the housing. The receiver further comprises a plurality of apertures in the diaphragm assembly, wherein the plurality of apertures provides an acoustic distortion of no greater than 2% THD.

Abstract: An electromagnetic transducer includes: a first diaphragm; a second diaphragm provided in a central portion of the first diaphragm, the second diaphragm comprising a magnetic material having a first opening in a central portion thereof; a yoke disposed so as to oppose the first diaphragm; a center pole disposed between the yoke and the first diaphragm, wherein the center pole has a shape which allows insertion into the first opening; a coil disposed so as to surround the center pole; and a first magnet disposed so as to surround the coil.

Abstract: A planar-type loudspeaker is provided which includes at least two separate, substantially flat, substantially coplanar diaphragms driven by a common drive mechanism. The diaphragms are each of a material and are dimensioned so that each has only a limited number of natural modes of vibration in the frequency band in which it is to operate and that corresponding natural modes for the diaphragms are close enough to achieve beneficial mechanical coupling and acoustics interference so as to provide a generally uniform acoustic pressure response over the selected frequency band. The diaphragms are preferably coupled only through the drive mechanism and it is preferable that each diaphragm have only two natural modes of vibration in the selected frequency band.

Abstract: The present invention relates to an improved speaker which includes at least one radiating surface configured to vibrate to produce sound waves, and an existing speaker cone configured to vibrate to produce sound waves, wherein said at least one radiating surface is adapted to fit over or onto the existing speaker cone, the said at least one radiating surface having a direct or indirect airtight attachment to the existing speaker cone to provide a hermetically sealed cavity between the existing speaker cone and said at least one radiating surface.

Abstract: Acoustic devices have members extending transversely of thickness and capable of sustaining bending waves causing consequential acoustic action by reason of areal distribution of resonant modes of natural bending wave vibration consonant with required achievable acoustic action of said member over a desired operative acoustic frequency range, Areal distribution of stiffness including variation(s) therein is used to get desired locations for bending wave transducers and/or good resonant mode acoustic action from inherently unfavourable shapes of members. Members with combined pistonic active drive and bending wave excitement at centers of mass and geometry are featured.

Abstract: An apparatus is disclosed comprising a diaphragm for use in a loudspeaker or a microphone. The diaphragm may be constructed as a sealed structure which forms two chambers. A vacuum can be formed in the two chambers. A gas can be added to each of the chambers. The gas may be an inert gas such as neon or krypton. The diaphragm may be comprised of a material having a low density to stiffness ratio. The diaphragm may be comprised of diamond, beryllium, magnesium, or carbon fiber. The structure of the diaphragm may include two portions. The first portion may be in the shape of an indented donut having a cross section of two partial ellipses. The second portion may have an extended oval cross section. The two portions of the diaphragm may alternatively be comprised of a substantially egg shaped portion and a substantially cylindrical portion with a cone portion. The diaphragm may be constructed by a process such as physical vapor deposition or the like.

Abstract: A planar loudspeaker is disclosed having a unique multi-layered sound resonator plate. The resonator has an upper layer and a lower layer maintained in a flat spaced-apart relationship. Divider walls or ribs are present to maintain the upper and lower layers spaced-apart, and in a self-taut state with internal chambers. The resonator layers and divider walls establish a plurality of internal passages or chambers that may or may not be sealed. The planar speaker includes a frame assembly having a mount plate and a resonator driver attached to the mount plate. The driver being responsive to an electrical signal and attached to a radiator that is movable in accordance with the movement of the driver. The flat spaced-apart resonator is attached to the radiator and frame, which produces sound when vibrated. The aspect ratio of the planar loudspeaker is preferably at least about 1.3 to 1 or greater.

Abstract: A flat panel rectangular or elliptical loudspeaker has one or more anisotropic diaphragms 14, 15, made of double skinned fluted polypropylene copolymer (core flute) or corrugated cardboards having a longitudinal bending strength greater than the transverse bending strength. The diaphragm is vibrated by a driver unit 16 which comprises a magnet 17 and voice coil 18. In this version the magnet 17 is mounted on the rear diaphragm 15 and the voice coil 18 is mounted on the front diaphragm 14. The two diaphragms 14, 15 are mounted at their edges to a frame 11 with the driver unit 16 mounted in the space enclosed by the frame and the diaphragms.

Abstract: A loudspeaker comprises a motor structure including a voice coil with a hollow former, a frame having an upper end and a lower end connected to the motor structure, an upper suspension mounted to the upper end of the frame, and, a two part diaphragm structure which includes an upper diaphragm connected to the upper suspension and a lower diaphragm extending between the upper suspension and the voice coil in position to overlie the hollow former of the voice coil.

Abstract: An electronic musical instrument having a keyboard and a loudspeaker, wherein the loudspeaker comprises a resonant distributed mode acoustic radiator having a stiff lightweight member having capability to sustain and propagate input vibrational energy by bending waves in at least one operative area extending transversely of thickness, and a transducer mounted wholly and exclusively on the member at a predetermined location or site within the operative area.

Abstract: A loudspeaker comprising a bending wave panel, an enclosure in which the bending wave panel is mounted to enclose one face of the panel, a compliant suspension between the panel and the enclosure by which the panel is supported in the enclosure, a vibration exciter attached to the panel to apply bending wave energy thereto, and an acoustic absorber in the enclosure to reduce standing waves in the enclosure, wherein the compliant suspension and the acoustic absorber are integral. A method of making such a loudspeaker is also disclosed.

Abstract: A speaker apparatus includes a frame having a magnetic circuit, a voice coil bobbin installed in the frame to be magnetically coupled to the magnetic circuit, and a diaphragm movably installed in the frame and fixed to the voice coil bobbin so as to be driven by activating the magnetic circuit. The diaphragm has a positioning portion that had been used for securing the diaphragm relative to the magnetic circuit during an installation of the diaphragm in the frame.