Abstract: [PROBLEM] There is provided a diaphragm, and a loudspeaker unit using the same, capable of providing better low-tone characteristics than conventional ones. [SOLUTION] A loudspeaker unit of the present invention includes a base frame and a cover plate joined to each other to provide a flat casing. Arranged in the casing are a diaphragm 3 and a drive mechanism 2 for vibrating the diaphragm 3. The diaphragm 3 consists of a rectangular area 30a and a pair of semielliptic areas 30b, 30b spreading rightward and leftward from the rectangular area 30a, and has an elliptic central portion 31 having its major axis in the longitudinal direction of the diaphragm 3 and a peripheral portion 32 spreading around the central portion 31. The central portion 31 includes an adhesive layer 33 for fixing a coil 21, laid on a central area of a diaphragm body 30, and is formed thicker than the peripheral portion 32.

Abstract: The invention provides, in one aspect, a loudspeaker that has electrodynamically-driven piston mounted in one external wall and that has movable panels in one or more other external walls. Those panels are air-coupled to the piston, e.g., via air within the enclosure, such that vibrational motion of the piston causes the vibration of the panels, thereby, improving the overall air coupling of the piston to the external environment, e.g., the listening room. Further aspects of the invention provide an improved driver for use, e.g., in the aforementioned loudspeaker. The driver comprises a three-part piston having first and second diaphragms coupled back-to-back with one another and having a voice coil face-mounted (or front-mounted) within the second diaphragm.

Abstract: A transducer assembly includes a transducer and a coupler with rheological material. A loudspeaker further includes an acoustic radiator. The coupler is mounted to the transducer and is operatively connected to the acoustic radiator. The transducer excites bending waves in the acoustic radiator to produce an acoustic output. By control of the rheological material, which may include mageto-rheological liquid or electro-rheological liquid, the transducer in various embodiments may selectively be substantially rigidly or substantially flexibly coupled to the acoustic radiator. If flexibly coupled the force experienced by the transducer when the host device is dropped, jarred, or pressured may be reduced from that experienced with a rigid connection. The acoustic radiator may be, for example, a display such as an LCD or a window mounted over a display. A mobile terminal may include such a loudspeaker in accordance with one embodiment.

Abstract: An inventive loudspeaker includes a diaphragm, a first excitation means for generating structure-borne sound in the diaphragm, and a second excitation means, different from the first one, for setting the diaphragm into a longitudinal vibrational motion in a direction perpendicular to the extension of the diaphragm. In accordance with the invention, the problem of insufficient bass reproduction and/or of the magnitude conflicting with invisible integration or installation is solved in that a second exciter system is introduced, which uniformly moves the diaphragm, or the plate serving as the diaphragm, forward and backward in addition to the bending waves of the structure-borne sound. The sound reproduction therefore is possible across the entire audio-frequency range without impeding the goal of invisible integration or installation.

Abstract: An electroacoustic transducer comprising a magnetic circuit of a magnetically conductive material with a pair of opposed surfaces defining a gap therebetween, the magnetic circuit comprising a magnet inducing a magnetic field in the gap, the magnet having a surface constituting one of the opposed surfaces. The magnetic circuit further comprises a diaphragm and a coil having electrically conducting paths secured to the diaphragm. The coil has portions of its paths situated in the gap.

Abstract: An inertial exciter (40) for an acoustic radiator (42), and a loudspeaker incorporating an acoustic radiator and such an exciter. The exciter has a massive member (44); a coupler (56) adapted for attachment to the acoustic radiator (42) and adapted for relative movement with respect to the massive member (44); a motor for effecting relative movement of the coupler with respect to the massive member; and a suspension (60) for supporting the massive member relative to the coupler. The suspension (60) acts in a plane generally passing through the center of mass of the massive member, thereby reducing any moment acting on the suspension. Also disclosed is a loudspeaker exciter assembly (70) that has a base plate (86) for attachment to an acoustic radiator in a non-repeatedly engageable manner, and an exciter (40) attached to the base plate (86) in a repeatedly engageable manner; and a loudspeaker incorporating such an exciter assembly.

Abstract: A loudspeaker includes a frame, a magnet coupled to the frame and a diaphragm secured to the frame. An acoustic lens may be positioned in front of the diaphragm. An aperture extends through the acoustic lens. The acoustical directivity pattern of the loudspeaker may be modified by the acoustic lens to improve the uniformity of the off axis vs. on axis sound pressure level.

Abstract: A sound-damping structure is provided for use as part of a sound-directing component of a loudspeaker. The structure includes a first structural layer, a second structural layer, and a core layer enclosed between the first and second structural layers. The first and second structural layers include a generally rigid material, and the core layer includes a sound-damping material. The first structural layer includes an outside surface facing an exterior of the sound-directing component. The second structural layer includes an inside surface having an interior of the sound-directing component through which sound energy is directed.

Abstract: A membrane (20) has a membrane axis (5) and a middle area (50), a central cup-shaped depression (52) being provided around said membrane axis (5), which depression (52) preferably has a connecting channel (53), wherein the middle area (50) comprises groups of stiffening grooves (54, 55, 56, 57) which extend parallel to radial directions and of which a first group of long stiffening grooves (54, 55, 56) extends up to the depression (52), said connecting channel (53) issuing into two of the long stiffening grooves (55, 56), thus interconnecting these two long stiffening grooves (55, 56).

Abstract: The invention relates to an electromagnetic driver comprising a soft magnetic core in the form of an E with three legs and a back, an alternating field driver, magnetically coupled to the soft magnetic core, for generating an alternating magnetic field in the soft magnetic core, depending upon a sound signal, a constant field driver magnetically coupled to the soft magnetic core for generation of a constant magnetic field in the soft magnetic core, a soft magnetic element for coupling to the plate of the planar diaphragm loudspeaker, lying opposite the back and magnetically closing the legs across at least one small induction gap, whereby the constant field and the alternating field are asymmetrically superimposed such that a resulting force, or a resulting torque on the soft magnetic element, is proportional to the sound signal.

Abstract: The present invention provides a planer acoustic transducer including a vibrating diaphragm including a spiral voice coil provided on both surfaces or on one surface of an insulating base film; and a permanent magnet corresponding to the voice coil, wherein, in the vibrating diaphragm, the spiral voice coil is formed by applying a wire conductor, in a coil pattern, onto a sheet-like substrate having an adhesive layer on at least one surface thereof. Alternatively, at least a portion of the vibrating diaphragm, which portion corresponds to the loop of a first or second vibration mode, is reinforced with a rigidity-imparting member; the substrate of the vibrating diaphragm is formed of a resin foam; or the voice coil is formed three-dimensionally.

Abstract: An exciting device capable of producing sound by sound-producing vibration body of a main body of an apparatus is provided. An exciting member 32A thin and long in the direction X is provided on a vibration substrate 31 thin and long in the direction X. Both ends of the exciting member 32A are fixed to the vibration substrate 31. Further, a piezoelectric element 33 that functions as vibration generating means is provided in the middle in the direction X of the exciting member 32A. The vibration substrate 31 is directly or indirectly fixed to the sound-producing vibration body. Vibration of the exciting member 32A is transmitted to the sound-producing vibration body through the vibration substrate 31 so that the sound-producing vibration body produces sound.

Abstract: Electro-dynamic loudspeakers typically include a diaphragm having a conductor applied to one of its surfaces. The diaphragm is secured to a frame. The conductor is connected to a power supply for providing electrical current through linear traces of the conductor that interact with magnetic fields generated by magnets that are mounted to the frame. The diaphragm is driven by a motive force created when current passes through the conductor within the magnetic field. The electrical current is varied to create an acoustical output from the electro-dynamic loudspeaker. Different methods of tensioning the diaphragm are provided for simplifying the manufacturing process and for assuring proper diaphragm tension.

Abstract: An electroacoustic transducer comprising a magnetic circuit of a magnetically conductive material with a pair of opposed surfaces defining a gap there between, the magnetic circuit comprising one magnet. The magnet can either be positioned in the center of the magnetically conductive material so as to form two gaps. In an alternative embodiment the magnet is attached to the magnetic conductive material forming only one gap. The transducer further comprises a diaphragm and a coil system having electrically conducting paths fastened to the diaphragm. The coil system has portions of its paths situated in the gap. The transducer may be supplied with an additional diaphragm and coil system positioned on the opposite side of the magnetic circuit. In a preferred embodiment the transducer is rectangular. The transducer is suited for integration into miniature components such as mobile communication equipment and hearing aids.

Abstract: A single end planar magnetic speaker system having at least one thin film, flexible diaphragm (72, 90) having a front side and a rear side for converting an input electrical signal into a corresponding acoustic output, the at least one diaphragm including a predetermined conductive region (76) and a predetermined non-conductive region; a magnetic structure (92) utilizing nonferite high energy magnets of a predetermined thickness wherein the magnets are each at least as wide as they are deep; the magnets having a magnetic strength wherein when compared to magnets of a ferrite type of same width as the nonferite high energy magnets but which have increased depth to yield at least nearly the same magnetic strength as the high energy magnets in the magnetic structure, doubling the depth of the high energy magnets in the magnetic structure, doubling the depth of the high energy magnets in the magnetic structure yields an increase in speaker sensitivity of at least 3 dB while the doubling the depth of the ferrite t

Abstract: The invention relates to so-called panel loudspeakers (11) working according to the multiresonance principle. Said loudspeakers are generally formed by a core layer (13) and at least one outer layer (14.o, 14.u). The outer layers (14.o, 14.u) are connected to the core layer (13). A periphery is also provided (12) enclosing the panel loudspeaker (11) at a lateral distance (A). The panel loudspeaker is connected to the periphery (12) by means of connecting elements (17, 17?). Although good reproduction results can be obtained in the mid and high audio frequencies with the panel loudspeakers (11) described above, undesired large panel surfaces are known to be required for good low frequency reproduction. When such panel surfaces are not used, the lowest panel resonances ensuring bass reproduction are shifted towards the midfrequencies. Hence, the invention aims at providing a panel loudspeaker (11) exhibiting improved acoustic reproduction in the low frequency range despite a relatively smaller panel surface.

Abstract: The invention relates to a method for sound reproduction and a loudspeaker, in which a vibrating diaphragm controlled by an operating device produces sound in the air surrounding it on the first side, and in which acoustic feedback is prevented by preventing the passage of the air over the edge of the diaphragm to its other side, and in which the air transports the sound to the surrounding free space. The diaphragm is formed as a uniformly vibrating, essentially straight and high element, so that the height H of the diaphragm is at least three times, and preferably at least five times its width W. Preferably, an essentially closed chamber is formed in front of the diaphragm, except for a narrow opening arrangement, in which one or more narrow openings essentially corresponding to the height of the diaphragm permit the passage of air and thus of sound from the enclosure to the free space.

Abstract: A speaker module includes a first diaphragm and a second diaphragm acoustically coupled with each other as a part of a wall forming a hermetic space with a panel. A light emitting section emits light to the panel, and the panel transmits the light to a side of the second diaphragm. The speaker module is configured to emit sound and light.

Abstract: A multi-resonator-based system responsive to acoustic waves includes at least two resonators, each including a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice so that a portion of an incident acoustical wave compresses gas in the resonators. The bottom plate or the side walls include at least one compliant portion. A reciprocal electromechanical transducer coupled to the compliant portion of each of the resonators forms a first and second transducer/compliant composite. An electrical network is disposed between the reciprocal electromechanical transducer of the first and second resonator.

Abstract: A sound-driving loudspeaker system is achieved with a simple structure and is capable of easily improving acoustic characteristics. The loudspeaker system emits sound by driving a diaphragm panel by an electromechanical acoustic transducer. The loudspeaker system includes a board, the diaphragm panel whose rim is fixedly attached to the board so as to form a space and which has a stiffness lower than that of the board, and the electromechanical acoustic transducer for emitting sound into the space. With this structure, the diaphragm panel is flexed to be vibrated by the sound emitted from the electromechanical acoustic transducer.

Abstract: Acoustic device including a member extending transversely of its thickness and capable of sustaining bending waves at least over an intendedly consequentially acoustically active area of the transverse extent of said member, the member having, by reason of orderly design methodology disclosed and claimed, a distribution of resonant modes of its natural bending wave vibration at least over said area that is dependent on values of particular parameters of said members, including geometrical configuration and directional bending stiffness(es), which values have been selected to predetermine said distribution of natural resonant modes being consonant with required achievable acoustic action of said member for operation of said device over a desired operative acoustic frequency range.

Abstract: The invention relates to a planar loudspeaker comprising a light, thin soundboard (2) which may be energized to produce multiply-reflected bending waves, a surrounding frame (3) holding the soundboard (2) in an articulated, shear-resistant manner; at least one driver (6, 7, 9, 10) connected to the soundboard (2) to energize the soundboard (2); and at least one bridge (13, 16, 18, 20, 22, 25), rigidly connecting the at least one driver (6, 7, 9, 10) to the frame (3), wherein the bridge or at least one of the bridges (13, 16, 18, 20, 22, 25) is connected to the damping board (14).

Abstract: An electro-acoustic transducer for driving a large surface is used to convert electrical signals into sound. The transducer has a housing with a cast aluminum bottom and a molded plastic top. The top and bottom are fastened together by screws with a gasket in between the contacting surfaces to form a housing for a high power electromagnetic voice coil driver mechanism. The top has an opening to allow the voice coil to be centered in its gap by a centering gauge during assembly of the driver. A cap closes the opening once the voice coil is fixed in place in the housing. The op is hexagonal and flat with circular rings in the top surface to allow the top to flex in a controlled manner while supporting the bottom which remains stationary.

Abstract: Ring magnets (5) are concentrically placed with certain spacings (6) on a magnetic frame (4). The magnetic members on the magnets (5) are removed, and the magnets are arranged so that the polarities of adjacent magnets (5)are alternately opposite to each other, thus forming a magnetic circuit. Ribs (7) are provided to a planar vibrating plate (1) and a voice coil (2) fabricated by vertically stacking conductive wires annularly is attached to the planar vibrating plate (1). The planar vibrating plate (1) is secured to a frame (4) through a gasket (3). The voice coil (2) is inserted into magnetic gaps of spacings (6). Since no magnetic body is placed over the magnets (5), the height of the magnetic circuit can be low, and an increase of the reactance due to provision of the magnetic body of the voice coil (2) does not occur. Since the rigidity of the planar vibrating plate (1) is high, it is unnecessary to secure the planar vibrating plate (1) to the frame (4) while applying a tension.

Abstract: An edge-driven diaphragm loudspeaker driver is configured such that the suspension system of the driver is connected to the voice coil rather than to the diaphragm. Thus, the diaphragm in the loudspeaker is free of suspension systems connected to or extending from the diaphragm. By attaching the surround suspension to the voice coil rather than to the diaphragm, the diaphragm is isolated from the influence of spurious high frequency vibrations in the suspension system, thereby increasing the performance of the loudspeaker at high frequencies. The loudspeaker driver configuration also provides for a longer excursion range for the voice coil/diaphragm assembly, which allows for the driver components to be more accurately aligned during manufacturing, thereby enabling the loudspeaker driver to operate as a full range unit by producing low output frequencies.

Abstract: Acoustic device including a member extending transversely of its thickness and capable of sustaining bending waves at least over an intendedly consequentially acoustically active area of the transverse extent of said member, the member having, by reason of orderly design methodology disclosed and claimed, a distribution of resonant modes of its natural bending wave vibration at least over said area that is dependent on values of particular parameters of said members, including geometrical configuration and directional bending stiffness(es), which values have been selected to predetermine said distribution of natural resonant modes being consonant with required achievable acoustic action of said member for operation of said device over a desired operative acoustic frequency range.

Abstract: The invention relates to an electromagnetic driver comprising a soft magnetic core in the form of an E with three legs and a back, an alternating field driver, magnetically coupled to the soft magnetic core, for generating an alternating magnetic field in the soft magnetic core, depending upon a sound signal, a constant field driver magnetically coupled to the soft magnetic core for generation of a constant magnetic field in the soft magnetic core, a soft magnetic element for coupling to the plate of the planar diaphragm loudspeaker, lying opposite the back and magnetically closing the legs across at least one small induction gap, whereby the constant field and the alternating field are asymmetrically superimposed such that a resulting force, or a resulting torque on the soft magnetic element, is proportional to the sound signal.

Abstract: A mounting bracket may be used to attach a device or component at a mounting location. The mounting bracket may comprise a an attachment portion having at least one tab portion that further comprises generally parallel first and second surfaces extending along a curved path. The tab portion may be designed so that the slot may be received at the mounting location so that, when installed, the first and second surfaces contact the interior and exterior surfaces, respectively. The tab portion, in cooperation with the slot, may accurately position and securely retain the mounting bracket at the mounting location.

Abstract: A bending wave loudspeaker includes a transparent acoustic radiator capable of supporting bending wave vibration and an electromechanical force transducer mounted to the acoustic radiator to excite bending waves in the acoustic radiator to produce an acoustic output. The transducer has an intended operative frequency range and includes a resonant element having a frequency distribution of modes in the operative frequency range and a coupler for mounting the transducer to the acoustic radiator. The loudspeaker may be incorporated in a telephone handset or a visual display unit.

Abstract: A transducer (14) for producing a force which excites an acoustic radiator, e.g. a panel (12) to produce an acoustic output. The transducer (14) has an intended operative frequency range and comprises a resonant element which has a distribution of modes and which is modal in the operative frequency range. Parameters of the transducer (14) may be adjusted to improve the modality of the resonant element. A loudspeaker (10) or a microphone may incorporate the transducer.

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: A new type of diaphragm transducer comprising magnets to provide magnetic field strength in a planar region and a planar diaphragm located in the said planar region. The diaphragm has a plurality of conductors on its planar surface for inducing electromagnetic forces acting on theses conductors in said planar region when current flows through said conductors. The magnets are arranged in magnetic interaction with a magnetically conducting material, preferably soft iron, to conduct magnetic field from said magnets to said planar region.

Abstract: A transparent panel-form loudspeaker consists of a transparent sound radiation panel that can radiate sound with desired pressure level over a specific frequency range when subjected to the flexural vibration induced by a preselected number of transducers located at specific positions on the peripheral edge of the transparent sound radiation panel and a rigid frame carrying a flexible suspension device which supports the periphery of the transparent sound radiation panel. The transparent sound radiation panel is made of a kind of transparent materials with the ratio of elastic modulus to density in the range from 3 to 180 GPa/(g/cm3) and the ratio of length to thickness of the transparent sound radiation panel in the range from 80 to 600.

Abstract: A loudspeaker module in the form of a ribbon element, where the module can be equipped with a membrane, 50 millimeters in width or narrower, and with any length from 50 millimeters to 2500 millimeters. The magnet system is equipped with so called booster-magnets in order to reduce loss of magnetic flow in the soft iron pole pieces and in order to equalize and in order to even the magnetic flow at the magnet ends. The signal-feed is designed in the form of passive current-feeding, whereby the inductance's negative impact of the frequency response up to the 1/f point is eliminated. Above the 1/f point, the ribbon membrane is compensation fed from a separate circuit consisting of R and C, whose values have been chosen in such a way that the resulting frequency response is flat over the whole operating area.

Abstract: An acoustic device has a suspended sheet of a thin flexible material having a rigid rod secured along one edge. An audio frequency actuator, which is preferably a magnetostrictive actuator, is acoustically coupled to an end face of the rod. The audiofrequency actuator is supplied with an audio signal from an audio source such as player device selected from the group which includes a recording tape player, a CD player, a DVD player, and a solid state memory device.

Abstract: A panel form loudspeaker comprises a resonant multi-mode radiator (11) which in turn comprises a plurality of substantially concentric sub-panels (20, 21, 22, 23). A plurality of analogue drivers (10) drive the radiator (11), one or more of the drivers being operational at any time. A signal level measured at the input to the loudspeaker determines the operational state of each of the drivers (10). The concentric sub-panels may take various shapes and have different areas.

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).

Abstract: A first magnet is provided in an upper case and a second magnet is provided in a lower case so that these magnets face each other. These magnets are magnetized in opposite directions. A diaphragm having a drive coil is placed between these magnets. Thus, magnetic flux emitted from the respective magnets bends in a direction approximately perpendicular to the initial direction of emission of the flux. In the magnetic field, the component of the magnetic flux in the direction of radiation proportional to the driving force is dominant, and is symmetrical relative to the direction of vibration. Therefore, the sound pressure of the reproduced sound is increased and the secondary harmonic distortion caused by asymmetry of the driving force can be reduced.

Abstract: An electroacoustic transducer includes a magnetic circuit of a magnetically conductive material with a pair of opposed surfaces defining a gap therebetween. The magnetic circuit includes a magnet inducing a magnetic field in the gap, the magnet having a surface constituting one of the opposed surfaces. The magnetic circuit further includes a diaphragm and a coil having electrically conducting paths secured to the diaphragm. The coil has portions of its paths situated in the gap.

Abstract: A flat panel loudspeaker arrangement with several panel loudspeakers of similar construction is disclosed. The panel loudspeakers are arranged seamlessly side-by-side and are rigidly connected with one another along their respective edges with a high shear strength. The panel loudspeakers can be supported by an existing stable wall.

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: In an electro-dynamic loudspeaker, vent holes are optimized to provide improved the magnetic flux characteristics while maintaining sufficient ventilation. In addition, ported and unported enclosures may be utilized with the electro-dynamic loudspeakers to enhance low frequency performance.

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 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: Electro-acoustic device which when installed in continuous ceiling, partition or wall panels available in the market made of mineral fibre, plasterboard, multi-laminated wood, etc. converts them into flat, invisible radiators of high-fidelity sound by its special characteristic of being equalizable for each type of panel at the time of manufacture and assembly.

Abstract: The invention features a miniature, second-order, microcrystalline silicon microphone diaphragm formed using silicon microfabrication techniques. The diaphragm is composed of two or more rigid diaphragm elements hinged to one another providing second- or higher-order response depending on the number of diaphragm elements used. The response of the differential diaphragm has a response that is highly dependent on the direction of the incident sound. The diaphragms are useful for constructing highly innovative microphones that have far greater directionality, better sensitivity, wider frequency response, and lower noise than is achievable with current technology.

Abstract: A first conductor and a second conductor are provided at a diaphragm. The first and second conductors intersect magnetic force lines between north poles and south poles of permanent magnets M which are adjacent to one another. When electricity passes through the conductors, a direction in which a force from the magnetic field acts on the current is substantially orthogonal to a surface of the diaphragm. Therefore, the diaphragm can be oscillated in the direction orthogonal to the diaphragm surface. The conductors have widths of from 1000 ?m to 2000 ?m. Therefore, relative errors in the widths caused by etching can be greatly reduced compared to the prior art, and etching is easier. Moreover, the conductors are arranged in a zigzag pattern. Because the conductors do not have a coil form, a large number of through-holes is not required as in conventional products.

Abstract: The present invention is directed to a diaphragmatic (planar) electroacoustic transducer that forms a complete sound radiating transducer and provides high efficiency and linearity. The diaphragm is easily exchangeable and rectangular in shape, and may be made of very thin polyamide film with a plurality of aluminum conductors formed on one side of the diaphragm. The plurality of conductors form two identical and symmetrical coils such 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.

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.