Abstract: A diaphragm for a planar speaker and a planar speaker having a long-term stability and a high reliability and exhibiting a flat sound pressure frequency property. The diaphragm for a planar speaker includes a voice coil formed by winding a wire conductor, two adhesive layers sandwiching the voice coil therebetween, and bases bonded to the two adhesive layers on the side opposite to the voice coil. The planar speaker employs the diaphragm.

Abstract: A loudspeaker system for an aircraft cabin for passengers has a support structure, which includes multiple flexible flat elements, forming the internal walls of the cabin, and fastening devices for fastening flat elements to the support structure, so that the flat elements may oscillate. At least one acoustic driver is connected to one or more flat elements, to induce a bending movement in the one or more flat elements. The particular flat element may oscillate as an acoustic diaphragm. The acoustic driver has a film-shaped piezoelectric exciter, which is bonded flatly to the flat element. The flat element bonded to an exciter has a first cover layer, a second cover layer, and a core layer between them. The core layer is subdivided in a plane parallel to the first and second cover layers by a horizontal incision in at least one predefined area.

Abstract: A flat speaker device capable of emitting loud reproduced sound with a relatively simple configuration is provided. The speaker device includes a diaphragm, a frame supporting the diaphragm vibratably in the vibration direction, a magnetic circuit disposed in the frame, and a driving member for driving the diaphragm. The driving member includes a voice coil movably disposed in a magnetic gap of the magnetic circuit, a driving part formed movably in a direction different from the vibration direction of the diaphragm, and an angle conversion and transmission part, one end of which is angle-variably joined to the driving part and another end of which is angle-variably joined to the diaphragm. The angle conversion and transmission part has rigidity and is obliquely disposed with respect to each of the vibration direction of the diaphragm and the moving direction of the driving part.

Abstract: A diaphragm, and a loudspeaker unit using the same, capable of providing better low-tone characteristics than conventional ones. A loudspeaker unit includes a base frame and a cover plate joined to each other to provide a flat casing. Arranged in the casing are a diaphragm and a drive mechanism for vibrating the diaphragm. The diaphragm consists of a rectangular area and a pair of semi-elliptic areas, spreading rightward and leftward from the rectangular area, and has an elliptic central portion having its major axis in the longitudinal direction of the diaphragm and a peripheral portion spreading around the central portion. The central portion includes an adhesive layer for fixing a coil, laid on a central area of a diaphragm body, and is formed thicker than the peripheral portion.

Abstract: A multi-directional flat speaker device is disclosed. By the directional characteristics of a plurality of flat speakers of the flat speaker device, accompanying with mechanism to actuate each of the plurality of flat speakers independently rotating to its desired direction, a composite sound field is generated as desired accordingly. The design makes the applications of the flat speaker device more suitable to meet the requirement of future utilizations. The mechanism to actuate the plurality of flat speakers can be achieved by controlling one or more of the flat speakers to rotate in a unique manner. The mechanism can control a facing angle of any one of the plurality of flat speakers independently. The mechanism can be designed by mechanical or electrical controlling manner.

Abstract: A planar magnetic driver includes covering plates that are maintained under tension to form a buckled or curved surface, thereby providing for a larger magnetic gap, and allowing for a larger excursion of the diaphragm and extended lower frequency response. Another aspect of the driver includes a corrugated region along the periphery of the diaphragm, which provides increased internal dampening.

Abstract: Flat subwoofer (1) comprising a driver (10) in which a coil (2) is arranged in an air gap (3) in said driver, which coil is connected to a membrane (4,5), where said driver (10) is arranged on a chassis (11), characterised in that the membrane comprises two interconnected parts, a forward membrane part (4) and rear membrane part (5), where both membrane parts (4,5) are substantially mmetrical around an axis (9) perpendicular to the membranes plane, where each membrane part has an outer and an inner periphery where said forward membrane part (4) along an outer periphery is connected to the chassis (11) by means of a surround (8), and where said rear membrane part (5) is connected to a spring member (15) which spring member at least partly surrounds the driver (10), and where the coil (2) is arranged on a coil cylinder (16), which cylinder is connected either to the inner periphery (13) of the rear membrane part (5) or to the inner periphery of the forward membrane part (4) in which case the forward and rear me

Abstract: A vehicle audio device includes a vibrator (30), a first threaded member (20), a second threaded member (32), and a ring-shaped resilient member (25). The first threaded member (20) includes a tubular portion (22), an external thread (22m) formed on an outer surface of the tubular portion (22), and a flange (24) formed on one end of the tubular portion (22). The resilient member (25) is fitted around the tubular portion (22) of the first threaded member (20) so as to axially oppose the flange (24) of the first threaded member (20). The second threaded member (32) includes a ring-shaped portion (32f) axially opposing the resilient member (25) from the side of the resilient member (25) not opposing the flange (24) of the first threaded member (20). Internal threads (32w) are formed on an inner surface of the ring-shaped portion (32f) and are engageable with the external threads (22m) of the first threaded member (20). The vibrator (30) is mounted to one of the first and second threaded members (20, 32).

Abstract: A method of mounting a flat panel speaker is provided which is capable of reliably preventing entry of dust and of shortening assembling time. By bonding a gasket member to a diaphragm, by pasting a separator to a gasket member side opposite to the diaphragm and, by sandwiching the diaphragm and the gasket member from both sides, a gasket-attached diaphragm is fabricated. After peeling off a protecting sheet on a rear side of the gasket-attached diaphragm, the actuator module is bonded to the diaphragm. Then, after peeling the separator from the gasket-attached diaphragm, positioning is performed on the diaphragm and the gasket member is bonded to a putting-face of the front case. The entry of dust into a region corresponding to a liquid crystal display panel is blocked by a partitioning portion of the gasket member.

Abstract: The planar speaker contains a frame, a diaphragm, a driver, a surround, and a number of flexible suspension elements. The diaphragm is suspended in a front opening of the frame by the surround. The driver is positioned at the center of the frame and a voice coil of the driver is attached to a back surface of the diaphragm. Two beams are arranged in parallel between two opposing longer wall segments of the frame on either side of the driver. The suspension elements are supported by the two beams, respectively, and attached to a back surface of the diaphragm. The symmetric deformation of the diaphragm along its longer side is thereby constrained by the suspension elements and the deformations at the two end zones of the diaphragm vibrating at a phase opposite to that of the center of the diaphragm would be suppressed.

Abstract: A transducer including a frame and a panel disposed within the frame and coupled to the frame such that the panel may rotate relative to the frame about a rotational axis. The transducer includes an actuator positioned to engage the panel such that the panel rotates about the rotational axis.

Abstract: A speaker includes a sound source, a rod-like member whose base end is in contact with the sound source, and a pair of flexible wing members whose ends are attached to the tip of the rod shape member, and whose other ends are free.

Abstract: An audio output apparatus for converting an input audio signal into audio and outputting the audio includes a first oscillation enhancing panel for outputting the audio as a result of being oscillated; a second oscillation enhancing panel for outputting the audio as a result of being oscillated; a first transducer for allowing the first oscillation enhancing panel to oscillate on the basis of an audio signal, the first transducer being disposed in the first oscillation enhancing panel; and a second transducer for allowing the second oscillation enhancing panel to oscillate on the basis of an audio signal, the second transducer being disposed at a position on the second oscillation enhancing panel, the position on the second oscillation enhancing panel differing from the position corresponding to the position of the first transducer in the first oscillation enhancing panel.

Abstract: A loudspeaker comprises a diaphragm, an edge operable to support, on a frame, the diaphragm in such a manner that enables vibration thereof, and a voice coil operable to generate a driving force. The voice coil is of an approximate rectangular shape, and a length of a long axis direction of the voice coil is no less than 60% of a length of a long axis direction of the diaphragm. Positions of long sides of the voice coil to be fixed on the diaphragm are positions corresponding to nodes of a primary resonance mode in a short axis direction of the diaphragm, or in the respective vicinities thereof. Accordingly, it is possible to realize a high sound quality loudspeaker having a narrow width (elongated structure), but not easily causing resonance, thereby obtaining a flat frequency characteristic.

Abstract: The present invention provides an acoustic display device for displaying modal patterns in response to sound from a sound source. The display device (10) has a substantially circular housing (12), which housing (12) includes a continuous curved side wall (13a), a substantially flat base wall (13b), and open end (13c). The open end (13c) is closed by diaphragm (14), thereby forming closed chamber (15). Excitation of the diaphragm can be effected by introducing vocal sounds to the underside of the diaphragm via one of a plurality of sound connecting means (22) that include a flexible tubular section (30), which terminates in a mouthpiece (32). A user can place the mouthpiece over their mouth and nose and make vocal sounds, which are delivered to the interior of the chamber (15). The mouthpiece (32) can be substituted with a sound collector (60) having a “horn” shape and an annular flange for engagement with a loudspeaker.

Abstract: A loudspeaker comprising a magnet unit that generates a magnetic field, and a membrane which is mounted in a frame and which is provided with an electrical conductor arranged in a pattern on the membrane, which membrane is positioned in the magnetic field in such a manner that a force is exerted when current is fed through the conductor pattern on the membrane, which force is capable of setting the membrane in motion so as to produce sound, the frame being provided with metallic cooling members that partially cover the conductor pattern, wherein said cooling members are mounted in a metal housing, making contact with said housing over the larger part of their surface area, or are integral with such a metal housing.

Abstract: A planar diaphragm acoustic loudspeaker having a planar diaphragm biased with a high magnetic flux density magnetic circuit which feeds an acoustic waveguide. The apparatus provides high fidelity and efficient acoustic reproduction of high frequency alternating current signals with a minimum of diaphragm resonance and with a substantially flat electrical input impedance versus frequency. The diaphragm has a substantially uniform drive across an acoustically active portion and is held in three dimensional space whereby any mass or diaphragm resonances are controlled and minimized. The acoustic waveguide mates with said diaphragm and ensures a uniform acoustic phase field and an optimal diaphragm acoustic impedance match with atmosphere.

Abstract: An acoustic apparatus has permanent magnets 2 and 3, which have north poles and south poles magnetized alternately in a stripe-like fashion, at the front and back of a diaphragm 1, respectively; and has a conductor circuit 4 wired on the diaphragm 1 along the stripe-like poles of the permanent magnets 2 and 3. This offers an advantage of being able to prevent an echo. The diaphragm 1, permanent magnets 2 and 3, conductor circuit 4, spacer 5, and iron plates 6 and 7 are installed in a baffle 8.

Abstract: An acoustic device comprising a diaphragm (10) having an area and having an operating frequency range and the diaphragm (10) being such that it has resonant modes in the operating frequency range, an electromechanical transducer having a drive part coupled to the diaphragm (10) and adapted to exchange energy with the diaphragm, and at least one mechanical impedance means (20,22,24) coupled to or integral with the diaphragm, the positioning and mass of the drive part (26) of the transducer and of the at least one mechanical impedance means (20,22,24) being such that the net transverse modal velocity over the area of the diaphragm (10) tends to zero.

Abstract: A push-pull magnetic-planar acoustic transducer provides easy field replacement of a diaphragm. Push-pull magnetic-planar acoustic transducers are known for the relative vulnerability of their diaphragms to damage. Replacement of the transducers in the field as been problematic because of the high repulsive force between the front and back panels and the need to obtain even tension across the diaphragm. The push-pull transducer assembly incorporates an edge hinge on which the panels can be pivoted to bring the panels into facing positions and a plurality of set screws to be fitted around the perimeter of the panels allowing essentially flat closure of the panels on one another to a working spacing engaging the diaphragm.

Abstract: A flat speaker comprising a vibrating plate including a spiral voice coil, a lead portion extracted from the vice coil and reinforced by the reinforcing member, and an electric supply line; an edge portion supporting the vibrating plate; and a yoke, supporting the edge portion, on which the permanent magnet arranged to face the voice coil. The flat speaker 1 of the invention includes a vibrating membrane 2 of an insulating base film 3 with a spiral or meandering voice coil 4 formed on one or both faces thereof, a permanent magnet 5 arranged on corresponding location facing the voice coil 4; and a yoke 6 on which the permanent magnet 5 is arranged. The vibrating membrane 2 is avoided from hitting the permanent magnet by providing a perforated sheet on the back face of the yoke to control acoustic resistance.

Abstract: A curve fitted planar loudspeaker minimizes variation and dead zones in the sound field propagated by an array of the loudspeakers. The curve fitted loudspeaker provides a plurality of sound generating transducers. The diaphragm is curved and each adjacent section fits as a section into a larger curve, eliminating or minimizing breaks in the propagated sound filed at the target distance to the target.

Abstract: An improved driver assembly for a panel loudspeaker includes a retaining element for locating the voice coil with respect to the magnet assembly and forming a surface for removable attachment of the driving assembly to a radiating member. In a preferred embodiment, the retaining element is injection moulded from a hydrogel material with Shore A hardness in the range 0 to 20.

Abstract: A flat loudspeaker structure is provided. A conductive electrode of a vibrating membrane of a flat speaker unit is disposed on both utmost sides of the flat speaker unit, so as to improve reliability of the flat speaker unit. The utmost conductive electrodes of the flat speaker unit are further grounded to achieve the EMI preventing function and/or thereby prevent a user from a risk of contacting high voltages. The flat speaker unit at least includes a pair of vibrating membranes each having the conductive electrode, a plurality of supporting members, a perforated electrode structure with a plurality of holes, and an insulator layer.

Abstract: A flat panel speaker system is provided. The system includes, a modified panel having a front surface and a rear surface, wherein the modified panel acts as a diaphragm for the flat panel speaker system; a supporting member coupled to the rear surface of the modified panel; and a detachable driver operationally coupled to the supporting member.

Abstract: According to the invention, a whole-surface driven, flat thin loudspeaker that brings about smooth frequency characteristics with split vibration hardly caused is realized, and a voice coil assembly that has high reproduction efficiency and fewer operation failures, and brings about favorable work efficiency in manufacturing and further reduced manufacturing cost, and a loudspeaker using the same are manufactured.

Abstract: The design of a diaphragm for a rotary loudspeaker driver that eliminates phase cancellation and therefore eliminates the necessity of a box to acoustically isolate the front sound from the back. The key element of the design of the diaphragm is to use a cross section of at least three equal sides. This allows for the long sides of the diaphragm to create essentially positive pressure only as it rotates and creates a very rigid structure. Further by sizing the cross section to the width of the highest frequency to be produced you allow for a nearly perfect 360 degree radiation at all frequencies.

Abstract: An acoustic assembly for use in a transducer includes a multi-layer structure. A first layer member includes a first center portion, a first edge portion and a first aperture separating the first center portion and the first edge portion. A second layer member includes a second center portion, a second edge portion and a second aperture separating the second center portion and the second edge portion such that the second center portion is free to move relative to the second edge portion. The first and second layers are formed into an assembly wherein the first center portion and the second center portion are coupled, the first edge portion and the second edge portion are coupled, and the first aperture and the second aperture are substantially aligned to define a passageway. The assembly has an assembly stiffness that is greater than the stiffness of either the first or second layer members.

Abstract: A loudspeaker may include a baffle, a planar diaphragm transducer carried by the baffle and having a front surface for radiating acoustic energy therefrom, and a slotted waveguide adjacent the front surface of the planar diaphragm transducer. The planar diaphragm transducer may be operable to a desired high frequency, and the slotted opening may have a width not substantially greater than a wavelength corresponding to the desired high frequency. For example, for a desired high frequency of about 20 KHz, the slotted opening may have a width not greater than about two-thirds of an inch. Accordingly, the loudspeaker including the slotted waveguide may provide nearly constant horizontal directivity over a large angle. In another embodiment, the loudspeaker may include a conical diaphragm transducer with a slotted waveguide adjacent its front surface.

Abstract: A structure and method for mounting a flat panel speaker are provided which are capable of reliably and accurately positioning a diaphragm in a cabinet and of improving an acoustic characteristic of the flat panel speaker. At least one first protruding portion formed in rectangular portions strikes a first side wall face of a corresponding corner portion of two side walls making up a front case and at least one second protruding portion formed in rectangular portions strikes a second side wall face of a corresponding corner portion of another side wall face of the front case, thus making it possible to properly position the diaphragm relative to the front case and, with the diaphragm being properly positioned, the diaphragm is attached to the front case with the gasket member bonded to the putting-face interposed between the diaphragm and the front case. The diaphragm comes into close contact with the front case in a manner to form a line-like boundary in a contacted portion.

Abstract: A flat panel display with detachable anti-vibrate speaker includes a speaker body with a front bezel attached at least one speaker driver, a rear bezel and a middle frame. The middle frame with a bottom positioning hole is made of an elastic material and situated between the front bezel and the rear bezel, and an elastic rib is formed on an inner surface of the middle frame to separate and to be against the front bezel and the rear bezel. A stand includes a positioning structure and a top surface groove. The positioning structure is assembled inside the top surface groove and is blocked by a blocking member fixed on an upper surface of the top surface groove. An elastic member is situated in the bottom of the top surface groove and a positioning member with a round top is located between the blocking member and the elastic member and is pushed to fit the positioning hole by the elastic member.

Abstract: Loudspeakers optimized for use in array environments are described herein. In one embodiment, a system includes a transducer-array module having a plurality of piston-based transducers. Each transducer is configured to drive a particular one of a plurality of discrete non-concentric acoustic-radiating diaphragms. A frame is positioned around an outermost boundary of a plurality of the discrete non-concentric acoustic-radiating diaphragms, which are adjacent to the outermost boundary. The transducer-array module may be used in array configurations, including, but not necessarily limited to: line, planar, and phased arrays.

Abstract: The present invention provides electroactive polymer transducers that produce out-of-plane deflections. The transducers form a set of surface features based on deflection of an electroactive polymer. The set of surface features may include elevated polymer surface features and/or depressed electrode surface features. Actuation of an active area may produce the polymer deflection that creates one or more surface features. A passive layer may operably connect to a polymer. The passive layer may comprise a thicker and softer material to amplify polymer thickness changes and increase surface feature visibility.

Abstract: A diaphragm for use in a speaker is manufactured using a plurality of thin wooden boards having flat rectangular shapes. The thin wooden boards are impregnated with a resin; then, a plurality of cutouts, which are elongated along wooden fiber directions or which are elongated in directions crossing wooden fiber directions, are formed in the thin wooden boards. Instead of the cutouts, it is possible to form a plurality of folded portions elongated in directions crossing wooden fiber directions. The thin wooden boards are integrally laminated together in such a way that the wooden fiber directions thereof mutually cross with a prescribed angle therebetween. The thin wooden boards integrally laminated together are subjected to thermal pressing so as to form a wooden vibrator serving as the diaphragm. Thus, it is possible to easily produce the diaphragm having a high strength and superior acoustic characteristics without causing defects.

Abstract: A flat panel audio output apparatus including a plurality of flat panels; and one or more vibrators respectively provided to each of the flat panels to vibrate the flat panels to make a sound; wherein the one or more vibrators of each one of the respective flat panels receives audio signals of a different channel and/or a different frequency band than those received by the one or more vibrators of at least one of the remaining flat panels.

Abstract: A loudspeaker having a diaphragm with a fixed edge and a free edge, and a multiplicity of conductors running parallel to its length and adjacent to the free edge.

Abstract: There is provided an acoustic vibratory plate having at least first to third laminated bodies layered. In the acoustic vibratory plate, the first and third laminated bodies are formed of a polymer material, and the second laminated body is formed of a polymer material different from the polymer material forming the first and third laminated bodies in dynamic internal loss.

Abstract: A flat speaker includes a casing with a display window, a vibratory sound panel mounted to the display window and having a display region and an exciter mount region, a display screen disposed internally of the display region, and an exciter mounted to the inner surface of the exciter mount region. A dust barrier is disposed to isolate a first space defined between the display region and the display screen from a second space surrounding the first space. The dust barrier has a dust barrier member disposed between the display region and the exciter mount region and extending across the vibratory sound panel to inhibit dust particles from moving from said exciter mount region to said display region within said casing. The dust barrier member is yieldingly deformable in response to vibration of said vibratory sound panel.

Abstract: A flat panel speaker. The speaker includes a drive unit made up of a signal oscillation radiator the winding of which promotes oscillating rather than translational movement of the radiator. Such a configuration allows the speaker to operate at a broad range of frequencies. In one form, the radiator includes a magnet, a coil former and a coil winding formed around the coil former in such a way that a magnetic field produced in the magnet can cooperate with a magnetic field induced by a current that corresponds to an audio signal flowing in the winding to produce an oscillating force in the radiator that can be converted into the oscillating movement imparted to the panel.

Abstract: From one aspect, the invention is a method of making a bending wave panel loudspeaker, comprising rigidly coupling a lever to a panel edge or marginal portion such that the lever extends at an angle to the plane of the panel, coupling a bending wave exciter to the lever whereby bending wave energy is coupled to the panel to produce an acoustic output when the exciter is fed with a signal and supporting the panel on a suspension positioned outboard of the lever. From another aspect the invention is a bending wave panel-form loudspeaker having a lever rigidly coupled to a marginal portion or edge of the panel, a vibration exciter coupled to the lever to apply bending wave energy to the panel to produce an acoustic output and a panel suspension positioned outboard of the lever. From a further aspect, the invention is a small electronic device, e.g.

Abstract: The invention refers to a device (3) for actuating a membrane arranged in an opening to a space, and a vehicle having such a device. The membrane (1) has a first surface (1?) and a second opposite surface (1?), and is limited by an edge area. The device includes a first strip (5) to be attached to the first surface of the membrane in the edge area, and a second strip (6) to be attached to a surface of a frame portion extending around the opening. An exchanging number (8) is arranged between and connecting the first strip with the second strip. An actuating member (20) is arranged to transfer a reciprocating primary movement to the exchanging member converting the primary movement to a reciprocating secondary movement, which has a longer length of stroke than the primary movement and acts on the strips to move towards and away from each other.

Abstract: Improved transducer for reproducing and/or recording sound, comprising a membrane onto which is provided a one-piece or multipart piezo-electric element, characterized in that the membrane is composed of two or several layers of which at least one layer is made of polymer, and the shape of the perimeter of the piezo-electric element differs from the shape of the perimeter of the membrane.

Abstract: The present invention provides electroactive polymer transducers that produce out-of-plane deflections. The transducers form a set of surface features based on deflection of an electroactive polymer. The set of surface features may include elevated polymer surface features and/or depressed electrode surface features. Actuation of an active area may produce the polymer deflection that creates one or more surface features. A passive layer may operably connect to a polymer. The passive layer may comprise a thicker and softer material to amplify polymer thickness changes and increase surface feature visibility.

Abstract: A bending wave loudspeaker having an operating frequency range and a coincidence frequency which is above the operating frequency range, comprising a resonant panel having two generally orthogonal axes, vibration exciting means coupled to the panel to excite the panel into resonance along the one axis of the panel, and means restraining or preventing resonance along the other axis of the panel whereby the panel radiates an acoustic output which is of wide directivity along the one axis and of narrow directivity along the other axis of the panel.

Abstract: An electro-acoustic device for creating patterns of particulate matter comprises a housing (2) one end of which is closed and the other end of which is open, a diaphragm (10) extending across the housing (2) at or adjacent the open end of the housing to define and close a hollow interior to the housing, a mass of particulate matter (34) located on the diaphragm (10), and, within the hollow interior of the housing (2), an electro-acoustic transducer (26), the arrangement being such that, in use with the diaphragm (10) extending horizontally and on activation of the transducer (26) by an audio signal, the acoustic output therefrom excites the diaphragm (10) and creates a pattern in the particulate matter (34) thereon representative of the audio signal.

Abstract: A loudspeaker comprising a housing provided with a magnet unit that generates a magnetic field and a membrane which is mounted in a frame and which is provided with an electrical conductor arranged in a pattern on the membrane, which membrane is positioned in the magnetic field in such a manner that a force is exerted when current is fed through the conductor pattern on the membrane, which force is capable of setting the membrane in motion so as to produce sound, wherein the conductor pattern is provided on the membrane in at least two spaced-apart vibrating regions, wherein the loudspeaker is provided with at least two sound channels extending between the two vibrating regions and the outer side of the housing, and wherein the central axes of the two sound channels, which are located between the outer wall and the inner wall of each channel, incline towards each other over a particular distance from the membrane.

Abstract: This invention discloses a loudspeaker 100 that includes a casing 110, a drive assembly 111 with a magnetic core 112, and an induction (voice) coil 113 attached to a first rigid plate 114 for the transmission of vibrations to a support 300. The first rigid plate 114 is attached to the casing 110 by a second plate 115 used for the suspension and the radial positioning of the voice coil 113, and elastic studs 116, used for the elastic suspension of the first rigid plate 114 in relation to the casing 110. By virtue of the invention a room can be transformed easily into an auditorium.

Abstract: A complex speaker edge and asymmetric resonator panel in which the acoustic vibration damping capacity of the speaker edge varies longitudinally around the speaker edge. The resonator panel has an aspect ratio of approximately 1.3:1 or more, and is composed of top and bottom panels held in spaced apart relationship by a plurality of longitudinally extending ribs extending therebetween. The ribs extend at an angle of from approximately 5 to 35 degrees to the longitudinal axis of the panel. The angle is acoustically matched to the complex speaker edge to improve the accuracy with which said acoustic vibration is reproduced. The effectiveness of the differential damping capacity of the edge in improving the quality of sound output from a speaker assembly is determined by observing the average magnitude of the excursions of the sound level pressure versus frequency curves for comparable complex and single speaker edges, particularly in the 200 to 10,000 Hertz range.

Abstract: The present invention relates to a plate type speaker with a planar diaphragm. The plate type speaker of the present invention comprises a base frame; at least one magnetic body coupled to the base frame such that opposite polarities are provided at adjacent lateral positions and are spaced apart by a predetermined distance from each other; a diaphragm; at least one coil plate that is formed with a voice coil wound on either or both of sides thereof, and is inserted vertically into spaces between the opposite polarities of the magnetic body and connected to the diaphragm; and a coil plate guide means coupled to the coil plate for guiding the position and vibration direction of the coil plate such that the coil plate is spaced from the magnetic bodies and vibrates vertically.

Abstract: An electrostatic transducer, such as a loudspeaker or microphone, comprises a multi-layer panel (1) incorporating an electrically insulating middle layer (2) sandwiched between first and second electrically conducting outer layers (3, 4). At least one of the layers has a profiled surface (6) where it contacts the surface of another of the layers. Furthermore a signal generator is provided for applying an alternating electrical voltage across the first and second layers (3, 4) to initiate vibration due to variation of the electrostatic forces acting between the layers, thereby serving as a loudspeaker (or for detecting variation of such electrostatic forces due to received vibration in the case of a microphone).