Abstract: An electro-dynamic loudspeaker is provided with dampening arrangements that contribute to improved acoustical properties for the electro-dynamic planar loudspeaker. The dampening arrangements include providing a frame having a curved sidewall surface for reducing standing waves. Another design provides for a ferrofluid being disposed between the diaphragm and magnets of the electro-dynamic loudspeaker in order to dampen the resonance frequency of the device. In addition, a diaphragm of an electro-dynamic loudspeaker is provided with a short turn of conductor disposed along a fringe zone at an edge of the diaphragm in order to electro-dynamically dampen the edge resonance of the film.

Abstract: A bending wave panel-form acoustic radiator formed from sheet material to define an acoustically active area and having at least one integral stiffening member in the form of a corrugation extending out of the plane of the sheet and at least partially across the acoustically active area of the radiator, which stiffening member is of substantially U-shaped cross section. Also disclosed is a method of making a bending wave panel-form acoustic radiator, comprising forming a sheet into a panel having at least one integral corrugation member extending out of the plane of the sheet and at least partly across the sheet and of substantially U-shape cross-section, to stiffen the sheet to have a desired ability to support and propagate bending waves.

Abstract: There is provided a speaker unit comprising: an elliptical vibrating diaphragm; a cylindrical voice coil secured at one end thereof on the center of the elliptical vibrating diaphragm; a frame structure for movably supporting the vibrating diaphragm, said frame structure being formed into a rectangular or elliptical shape and having a through hole in the center thereof; a magnetic circuit formed by (1) a top plate having a rectangular shape and having a through hole in the center thereof, (2) a plate-shaped magnet having a rectangular shape and having a through hole in the center thereof, (3) a back plate having a rectangular shape and having an upright pole on the center thereof. In this speaker unit, the top plate, the plate-shaped magnet and the back plate each has a width which is narrower than that of the frame structure in its shorter axis.

Abstract: The present invention relates to a multifunctional device, which is particularly applicable to a twin magnet loop (called TML) transducer with both vibrating and sound functions. The present invention integrates an inner and an outer magnet loop of TML into one device, which can be used as a vibrator and a speaker. A disc-shaped pole core, a flange bowl-shaped magnetic transfer, an annular pole piece, a cylindrical magnet and an annular magnet constitute the inner and outer magnetic loops; wherein the disc-shaped pole core is placed on the cylindrical magnet and centered with the flange bowl-shaped magnetic transfer; the annular magnet and the annular pole piece are overlaid together under the ring of the flange bowl-shaped magnetic transfer; the entire of the TML assembly is connected with a housing base via a resilient plate.

Abstract: Trace runs for Planar Line Source Transducers (or speakers) are separated into multiple trace circuits which are electrically isolated but occupy the same area on the planar film. The separate trace runs are then driven with different electrical signals with tailored spectral content in order to achieve an overall acoustical frequency response. By having the separate trace runs occupy the same area, the line source nature of the transducer is preserved over the entire intended spectral response of the transducer and the mechanical structure is also kept simple. External spectral filtering circuits are used to pre-shape the spectral signal into each individual trace run and in most cases, the filtering components are passive and inexpensive.

Abstract: The invention provides a continuous layer of polymer that is shaped to act as the suspension, the former, and an attachment to the diaphragm. The coil may be located within the pocket providing insulation to the coil thus preventing electrical short circuiting of the voice coil as the voice coil expands or contracts based on its operating temperature. The invention also provides an inner flange area of a suspension that may act as a spring generating additional acoustic energy from the compression driver. The inner flange area may also be tuned to vibrate at a predetermined high frequency. Thus, in certain applications, where more acoustic energy is desired at high frequency, the inner flange area may be tuned to provide that extra acoustic energy. To further increase the high frequency energy generated by the compression driver, the diaphragm may be coupled to the bottom side of the inner flange area.

Abstract: A molten resin is injected into a cavity together with long fibers. Opposite surfaces of the resin are solidified as a fiber-resin mixture temperature drops. These surface layers become non-foam layers. A foam layer is created between the non-foam layers. A pressure reduction process is applied to cause a spring back effect when the foam layer is created. A diaphragm having these three layers can be manufactured in an inexpensive process, but physical characteristics and appearances of the diaphragm are not sacrificed.

Abstract: A speaker is provided that is operable to reproduce ultrahigh frequencies. Specifically, the speaker outputs ultrahigh frequencies up to 100 kHz with stable sound pressure. The speaker may include a disk-shaped piezoelectric ceramic vibrator wherein a piezoelectric ceramic and a metal substrate are bonded; a dome-shaped diaphragm attached to the piezoelectric ceramic vibrator; and a panel that fixes an outer peripheral part of the piezoelectric ceramic vibrator.

Abstract: A meshed etching tunnel made of aluminum is disposed inside a cylindrical quartz reactive chamber, and speaker diaphragms are aligned inside the tunnel at a certain interval. Opposing electrodes are disposed outside the reactive chamber. Plasma is applied at low temperature to prevent heat deformation. Uniform wettability is also assured by the use of the meshed etching tunnel, achieving high productivity. Uniform wettability further stabilizes bonding and improves bonding strength of the speaker diaphragm onto the voice coil and edge, offering a speaker with improved input power durability.

Abstract: A method of improving the modal resonance frequency distribution of a panel (2) for a distribution resonant mode bending wave acoustic device involves analysing the distribution of the modal resonance frequencies of the panel, identifying a modal resonance frequency that is non-uniformly spaced relative to adjacent modal resonance frequencies, identifying a location on said panel that exhibits anti-nodal behaviour at said modal resonance frequency and changing the local impedance to bending wave vibration at said location (6). The method has particular application to distributed mode loudspeakers (1).

Abstract: A speaker system includes a display panel for displaying an image; a transparent panel provided such that the image displayed in the display panel is viewed through the transparent panel; an electric-mechanical-acoustic-transducer having a diaphragm for outputting a sound by vibrating the diaphragm in accordance with an electric signal; and an acoustic signal transfer member for transferring the sound output from the electric-mechanical-acoustic-transducer to a space provided between the display panel and the transparent panel. The transparent panel is allowed to be vibrated by the sound transferred to the space from the electric-mechanical-acoustic-transducer via the acoustic signal transfer member.

Abstract: A displacement/quantity of light converter in which sensitivity to a micro displacement due to sound of a diaphragm, or the like, can be enhanced easily. In the displacement/quantity of light converter where a light emitting part (2) and a light receiving part (3) are disposed oppositely to a diaphragm (1), light emitted from the light emitting part (2) and reflected off the diaphragm (1) is received at the light receiving part (3), and a displacement of the diaphragm (1) is converted into an output from the light receiving part (3), a concave diaphragm is used and the concave face is directed toward the light emitting part (2) and the light receiving part (3). According to the arrangement, light emitted from the light emitting part (2) and reflected off the diaphragm (1) impinges efficiently on the light receiving part (3) in the form of focused light.

Abstract: An edge damper frame 18b is disposed in between a part of an outer peripheral surface 20a of a frame-cover 20 and a leveling surface 14c-1 of a frame 14. A slope 18e of a diaphragm 15 is extended from the edge damper frame 18b toward the frame 14 and provided alongside an outer side surface 14c-2 of a convex portion 14c of the frame 14.

Abstract: In an electroacoustic transducer (21) with a stationary transducer part (23) and with a membrane configuration (17) comprising a membrane (15) and a handling ring (1) for the membrane (15) connected with the membrane (15), the membrane configuration (17) is connected with the stationary transducer part (23) via the handling ring (1), and the handling ring (1) and membrane (15) are connected together via an interlocking connection.

Abstract: An acoustical transducer such as an audio loudspeaker or a microphone, having a suspension component whose outermost edge extends axially rather than radially and couples with an axial mounting surface in the transducer's frame rather than with a radial flat surface of the frame. The suspension component may be a surround or a spider. Eliminating the radial portions of the suspension component and the frame enables the use of a larger diaphragm within a transducer of unchanged outer dimensions, increasing the amount of air moved by or moving the diaphragm. It also enables closer on-center packing of multiple transducers onto the same baffle such as the front baffle of a speaker enclosure, or, put another way, it enables a higher percentage of the mounting baffle's front surface area to be covered with moving diaphragm area. Radial mounting flanges and their mounting holes are limited to portions of the frame which will not increase the gap space between adjacent transducers or other boundaries.

Abstract: A super tweeter includes a magnetic base, a voice coil, a frame annularly mounted to the magnetic base, a central supporting member mounted on a central portion of the magnetic base, a diaphragm, an annular inner supporting member, and an annular outer supporting member. The diaphragm is connected between an annular outer side of the annular inner supporting member and an annular inner side of the annular outer supporting member. An annular inner side of the annular inner supporting member is engaged with the central supporting member. An annular outer side of the annular outer supporting member is engaged with the frame. The annular inner supporting member and the annular outer supporting member cause the diaphragm to vibrate in a balanced manner, generating super high frequency range of sound waves.

Abstract: A diaphragm for a speaker comprises a metal cone 2 and a paper auxiliary cone 4 bonded integrally to the center portion of the metal cone 2.

Abstract: A loudspeaker comprising an enclosure 31 provided with a second diaphragm disposed at an opening, and at least one sound generator 40 coupled acoustically with the enclosure. The sound generator is provided with a first diaphragm 27, wherein the second diaphragm has an area greater than an area of the first diaphragm. In the present invention, the shape of the enclosure, and the positioning and shape of the first and the second diaphragms can be designed at a designer's option. Thus a small-sized electronic apparatus can be obtained with a greater designing freedom, while a large-sized diaphragm prevents a decrease of generated sound pressure.

Abstract: A structure of a rectangular panel-form loudspeaker is provided. The structure includes a radiating panel, a transducer, a frame and a suspending unit. The radiating panel includes a rectangular laminated composite plate with length b and width a, and the laminated composite plate includes an intermediate core layer sandwiched between two fiber-reinforced polymeric layers. The transducer is used for exciting the radiating panel to produce flexural vibration. The transducer includes a voice coil assembly and a magnet assembly, wherein the voice coil assembly is coupled to a first side of the laminated composite plate at a first specified location. The frame is used for positioning the laminated composite plate and the magnet assembly. The suspending unit is made of a soft material and disposed between peripheral edges of the laminated composite plate and the frame.

Abstract: A speaker apparatus is provided. A frame has a projecting portion projecting toward a diaphragm at the periphery of the frame. The diaphragm has a rising portion extending opposite to the frame from the periphery of the diaphragm and having an outside surface along an inside surface of the frame projecting portion. The outside surface of the rising portion is adhered to the inside surface of the frame projecting portion.

Abstract: A speaker comprises: a magnetic circuit composed of a pot yoke, a magnet, and a pole piece; a diaphragm shaped conical, defining an outer periphery and an inner periphery, and having a surround half-rolled and fixedly disposed at the outer periphery and a voice coil bobbin with a voice coil wound thereon fixedly disposed at the inner periphery; a spider having an outer diameter equal to or larger than the outer diameter of the surround; a frame having the magnetic circuit fixedly disposed at its central opening; and a spacer ring fixedly disposed inside the frame, and having a surround edge receiving portion adapted to fixedly receive the entire outer edge of the surround thereon.

Abstract: A speaker includes: a frame; a magnetic circuit fixed to the frame; a diaphragm fixed to the frame so as to be capable of vibrating in a predetermined direction; a driving force transmitting member connected to the diaphragm; and a damper for supporting the driving force transmitting member, wherein the magnetic circuit is positioned between a first plane and a second plane, the first plane being parallel to the diaphragm and defined as a plane with which at least a portion of the magnetic circuit is in contact, and the second plane being parallel to the diaphragm and defined as a plane with which at least a portion of the magnetic circuit is in contact, and one end of the damper is connected at a position between the first and second planes, and the other end of the damper is connected at another position between the first and second planes.

Abstract: The present invention relates a speaker having a diaphragm around the rim of a frame on the speaker for disposing a magnetic member at the center of the diaphragm along the direction of a resonant space enclosed by the diaphragm and the frame. When a winding in the center of the frame is excited, the resonant space generates varying magnetic lines and an attraction-repulsion effect is generated in the center of the winding or a reserved space at the position of the periphery to vertically slide the magnetic member and cause the diaphragm to vibrate and generate sound. The present invention can effectively reduce the space occupied by the components such as the seat, core, and magnetic member, and greatly reduce the thickness of the speaker.

Abstract: A loudspeaker drive unit comprising a resonant acoustic radiator, an exciter on the radiator to apply bending wave energy to the radiator to cause it to resonate, a support for the loudspeaker drive unit, and means resiliently coupling the exciter to the support.

Abstract: A planar diaphragm loudspeaker for use in a suspended ceiling grid and related methods of manufacturing are provided. The loudspeaker includes a rectangular, planar diaphragm of polymer material sized to fill an opening of the ceiling grid. The front surface of the diaphragm defines a three-dimensional, textured pattern formed by a secondary operation, such as, etching, perforating, and adhesion of granular or fiber material. The diaphragm may include an outer region about the periphery of the diaphragm having a density of at least 5 pcf and an inner region circumscribed by the outer region, thereby providing sufficient structural stiffness to the outside perimeter of the diaphragm and eliminating the need of an outer frame. The density of the inner region is at or below about 3 pcf throughout the inner region. Also, a shroud may secured to the diaphragm, in which the shroud and the diaphragm are securable in a first orientation for flush mounting or in a second orientation for tegular-drop mounting.

Abstract: The present invention relates to an electro-acoustic transducer suitable for applications within mobile communication equipment and hearing aids. The transducer comprises two diaphragms positioned on opposite sides of a magnetic circuit having two magnetic gaps. When used as a microphone the transducer is substantially insensitive to vibrations, and when used as a speaker the transducer generates only very low vibration levels. The magnetic circuit has a number of advantages compared to conventional transducers with circular magnetic. The transducer can be made lightweight and with very compact dimensions compared to conventional designs. In a preferred embodiment the diaphragms are rectangular. The transducer may additionally be used as a vibration generator for silent alarm signals.

Abstract: A loudspeaker having a back plate, a driver attached to the back plate, the driver being responsive to an electrical signal, an enhancer having a neck and a mouth, the neck attached to the driver and movable in accordance with the movement of the driver, a thin film membrane, the membrane attached to the enhancer, the membrane stretched over the frame, a frame for supporting the membrane and maintaining it in a taut state, and a rubber type adhesive for dampening the membrane resonances and for adhering the membrane to the frame. Clarity of sound can be further improved by including a plurality of sound breathers in the back plate of the speaker. For improved sound radiation capability, the size and the shape of the enhancer can be modified in various ways, including a frustoconical, parabolic, or bell-shaped enhancer.

Abstract: A loudspeaker diaphragm affixed with a coil includes an edge portion located outside of a portion affixed with the coil and a center portion located inside of the portion affixed with the coil. The center portion is provided thereon with ribs. With these ribs, the height of the center portion can be limited to the height of the ribs. Therefore, it is possible to save a space of a loudspeaker where the loudspeaker diaphragm is placed, thereby slimming down the loudspeaker. Furthermore, with these ribs, the rigidity of the center portion can be improved without using a conventional solution of forming, for example, a dome shape on the center portion.

Abstract: A piezoelectric film loudspeaker comprising a diaphragm having a flexible piezoelectric film and electrodes formed on the both surfaces of the flexible piezoelectric film and a frame for supporting a side of the diaphragm, wherein said respective electrodes disposed on the both surfaces are divided into a plurality of sections. Each area of the divided electrodes is formed differently from one another, and each curvature of the film in the divided section also is formed differently from one another. Thus, the piezoelectric film loudspeaker having a predetermined area can have a broad band.

Abstract: A planar type speaker keeps its diaphragm (2) free from any distortion in operation, thus providing high fidelity sound reproduction. The diaphragm (2) is of a planar type and surrounded by a flexible edge member (3). This member (3) is constructed of an inner edge piece (3a) and an outer edge piece (3b) each of which has a semicircular shape in cross section to provide a convex surface and a concave surface. These edge pieces (3a, 3b) are the same in construction, but are inverted in arrangement to have the concave surfaces thereof face to each other to sandwich the diaphragm (2) between the concave surfaces of the edge pieces (3a, 3b); and, the outer edge piece (3b) is provided with a plurality of notched holes (7) which are symmetrically arranged in the outer edge piece (3b).

Abstract: A piezoelectric electroacoustic transducer includes a substantially rectangular piezoelectric diaphragm having an internal electrode, a plurality of laminated piezoelectric ceramic layers having the internal electrode interposed between two of the piezoelectric ceramic layers, principal-surface electrodes disposed on top and bottom principal surfaces of the piezoelectric diaphragm, the piezoelectric diaphragm generating surface bending-vibrations in response to application of an alternating signal between the principal-surface electrodes and the internal electrode, a resin film that is larger than the piezoelectric diaphragm and having the piezoelectric diaphragm affixed onto substantially a central portion of a front surface thereof, and a housing having a support for supporting the outer periphery of the resin film.

Abstract: A tweeter with a light, thin sandwich plate which can be excited into multiple reflected bending waves, and a driver which makes a vibrating contact and excites the sandwich plate, where the driver is designed for higher sound frequencies and the sandwich plate for propagating bending waves with low damping. The sandwich plate is freely carried with low damping by holding elements, where the latter are designed to be low damping at higher sound frequencies.

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 a cylindrical flange extending from its peripheral edges axially in the direction of the motor. The termination of said cylindrical flange provides an attachment for an annular rear flexible suspension member that, in turn, attaches to the frame.

Abstract: A micromachined acoustic transducer comprising a parylene diaphragm piezoelectric transducer. The parylene diaphragm has far lower stiffness than the silicon nitride. The method for fabricating the parylene diaphragm acoustic transducer utilizes a prestructured disphragm layer utilizing silicon nitride which is compatible with high temperature semiconductor process. A silicon nitride layer is patterned and partially removed after forming the parylene diaphragm layer in order to enhance the structural qualities of the parylene diaphragm. The diaphragm may be flat or dome-shaped.

Abstract: The invention is a suspension element having an outer edge and an inner edge. The suspension element, such as a spider or surround, varies in shape along at least a portion of the suspension element to help relieve both the radial and tangential stress placed on the suspension element when it is stretched. The shape employed in the suspension element allows the suspension element to stretch more easily, creating a higher performance speaker of the same size by increasing the diaphragm excursion and voice coil movement.

Abstract: A loudspeaker comprising a panel-form acoustic member adapted for operation as a bending wave radiator and an electrodynamic moving coil transducer having a voice coil mounted to the acoustic member to excite bending wave vibration in the acoustic member. The junction between the voice coil and the acoustic member is of sufficient length in relation to the size of the acoustic member to represent a line drive such that the acoustic member has a mechanical impedance which has a rising trend with bending wave frequency.

Abstract: This invention provides a speaker apparatus that outputs sound having smooth frequency characteristics. To solve the inconvenience with the prior art, this invention is a speaker apparatus comprising a diaphragm and a cylindrical-shaped coil bobbin, and not comprising a center cap that covers the coil bobbin, and where the diaphragm is located such that it rests on the coil bobbin, and the coil bobbin and diaphragm are located such that sound from the coil bobbin and diaphragm is not reflected.

Abstract: The invention relates to the embodiment of so-called panel loudspeakers working according to the bending wave principle. Said panels are generally formed by a panel (11), at least one driver (12) and a frame (13), the panel (11) being connected to the frame (13). In order to achieve appropriate bending wave induction in the panel (11), very complicated assessments must be made in order to determine the corresponding positioning areas (15) in which the driver (12) excites the panel (11) or is connected to the latter. Furthermore, the size of the panels (11) can change considerably depending on the application so that assessments must only be made repeatedly in the case of panels that can be easily modified. The invention aims at providing general positioning areas (15) for the driver (12) in or on the panels (11) so that no further assessments need to be carried out regarding the positioning area (15).

Abstract: A compact lightweight speaker system without a resonance box that can reproduce the original sound with high fidelity. A speaker unit is located on a baffle board with a vibration absorbing member between a frame of the speaker unit and the baffle board. Furthermore, an acoustic resonance reflecting board of a vertical flat board type based on the operating principle of a passive radiator is formed by the baffle board and a flat board being similar to the baffle board. As a result, a compact smart design will be produced. It is applicable to an electric or electronic apparatus which produces sound.

Abstract: A diaphragm for electroacoustic transducers including loudspeakers as formed substantially in a dome shape having an outer periphery of a circular shape and made excellent in tone quality is provided. The dome shape of the diaphragm has an irregular section with a central arcuate edge line of a radius of curvature across the circular outer periphery and passing through an apex of the dome shape, and side surfaces formed on both sides of the central edge line respectively to have side edge lines intersecting at right angles the central edge line and having a radius of curvature larger than that of the central edge line. The side edge lines of both side surfaces are of constant radius of curvature at least in one of the surfaces or of mutually equal radius of curvature at all positions intersecting the central edge line, to be mutually asymmetric or symmetric for dispersing resonating portions over the whole area of the dome shape.

Abstract: The present invention relates to a process for producing a shaped diaphragm for electroacoustic transducers which comprises a core layer comprising poly(meth)acrylimide foam and at least one covering layer, which is characterized in that

Abstract: An electro-acoustic transducer (1) is proposed for a component operating with surface waves, in particular for a surface wave filter, in which, to suppress interfering excitation ensuing in the gap region, a variation of the gaps (4) is implemented with regard to at least one feature selected from transversal arrangement, size and shape. Due to the slight dimension change (&Dgr;D) in comparison to the finger length, the desired primary excitation in the transducer remains approximately unchanged, however the interfering excitation is displaced or divided, and therewith made ineffectual.

Abstract: A lead wire of a voice coil is wired along the surface of a diaphragm. The lead wire is bent toward a reverse side of the diaphragm at a peripheral edge portion of the diaphragm. The lead wire is led to the interior of a frame. An external terminal is provided to extend from outside to inside the frame. In addition, a connecting portion for connecting the lead wire and the external terminal is provided inside the frame. The connecting portion is prevented from coming into contact with another part and becoming short-circuited.

Abstract: A diaphragm (1) of a light sound converter which has a high performance, is suitable for mass-production and has a slit (1s) formed therein. A light emitting element and a light receiving element are disposed at positions opposed to a reflective part (1a) of the diaphragm (1) having a pressure receiving surface part (1d) and the reflective part (1a), and light is radiated from the light emitting element to the reflective part (1a) of the diaphragm (1) and the reflected light from the reflective part (1a) is received by the light receiving element, whereby the position of the diaphragm (1) can be detected.

Abstract: An audio speaker having a removable voice coil, which may be a part of a voice coil assembly. The voice coil may be user-removable to facilitate replacement of a damaged voice coil or reconfiguration of a speaker system. Properly positioning the voice coil assembly may provide a solder-free electrical connection between the voice coil and leads that provide current to the voice coil. In some embodiments, the voice coil is user-removably attached to an inner circumferential surface of a diaphragm. In other embodiments, the voice coil is connected to the diaphragm, and the voice coil assembly and the diaphragm are both user-removably attached to a frame.

Abstract: The micro-speaker includes a driver unit having a housing, a magnet disposed within the housing forming a radial gap between the magnet and the circumferential walls of the housing, and a magnetic plate disposed on the magnet, a vibration system having a diaphragm and a voice coil where the vibration system is fixed to the drive unit and the voice coil protrudes into the radial gap, and a volatile magnetic fluid in the radial gap about the voice coil.

Abstract: A sound reproducing apparatus includes a display unit, a board 22, a diaphragm panel 23, and an electroacoustic transducer 26. The display unit displays an image on a display surface. The board 22 is composed of a material which transmits visible light and arranged such that a first space is provided between the display surface of the display unit and the board 22. The diaphragm panel 23 is composed of a material which transmits visible light and arranged on the opposite side of the board 22 from the display unit such that a second space is provided between the board 22 and the diaphragm panel 23. The electroacoustic transducer 26 emits sound into the second space.

Abstract: An electro-dynamic loudspeaker includes a chassis (2), a three-dimensional diaphragm (8) and an electromagnetic actuator (6). The diaphragm is connected to the chassis by a first flexible connection (18) provided near a front part (8a) of the diaphragm and by a second flexible connection (20) provided near a back part (8b) of the diaphragm. The actuator includes a stationary actuator element (6a) fixed to the chassis and a translatable actuator element (6b) fixed to the diaphragm. When energized, both actuator elements magnetically co-operate with one another over an air gap (16). In order to realize a flat but powerful speaker, the device as such and the air gap are outside the area (26) enclosed by the diaphragm but within the space (24) between the first and second flexible connections.

Abstract: Provided is a diaphragm edge of a speaker which is formed by compressing a material including silicon rubber and has an emboss portion on a front surface thereof so that sensitivity of sound is improved. Also, a diaphragm edge of a speaker is formed by compressing a material including silicon rubber and powdered viscose rayon and has an emboss on a front surface thereof.

Abstract: A loudspeaker includes an assembly of at least two bending wave panel-form acoustic members each having a set of modes which are distributed in frequency. The parameters of at least two of the acoustic members are selected so that the modal distributions of each acoustic member are substantially different. The arrangement is such that the modal distributions of the assembly of acoustic members are interleaved constructively in frequency. A transducer applies bending wave energy to the acoustic members to cause them to resonate to produce an acoustic output. A method of making such a loudspeaker is also provided.