Abstract: An electroacoustic diaphragm comprises a membrane, and an electrically conductive circuit carried by the membrane, such that a segment of the electrically conductive circuit is divided into two or more separate subcircuits. An electroacoustic transducer assembly comprises a frame, the novel diaphragm supported on the frame, and a magnetic element disposed adjacent the novel diaphragm whereby the transducer achieves uniform force distribution across the novel diaphragm. An audio device comprises a housing having an acoustic opening and the electroacoustic transducer including the novel diaphragm. Methods for constructing a transducer comprises determining the flux density of a magnetic field and configuring a diaphragm with separate subcircuits to correlate or inversely correlate to the flux density.

Abstract: The present application discloses a speaker having a vibrating system and a flexible circuit board. The vibrating system has a lower vibrating diaphragm with a first fastening portion, a second fastening portion, and a vibrating portion having a first connecting portion and a second connecting portion and a middle portion. A vertical distance between a tangent line along a vibrating direction at first end of the first connecting portion and another tangent line along the vibrating direction at the second end of the first connecting portion is a first distance; another vertical distance between a tangent line along the vibrating direction at third end and another tangent line along the vibrating direction at the fourth end is a second distance. The first distance is shorter than the second distance. The acoustic quality of speaker can be improved.

Abstract: A system, method and computer program for predictive maintenance on natural gas compressors through auditory detection. Using one or multiple microphones, a system will collect and evaluate sound waves for the purpose of predicting and detecting failures and alert conditions in mechanical and process equipment. The system will collect sound which is used in a machine learning environment to utilize supervised training as well as unsupervised training, to produce a normal baseline and detect abnormal operations. Additionally, abnormal operations are categorized against known conditions. For uncategorized and unknown conditions, a workflow is in place to allow for the retraining and learning” of new conditions which are then published to the entire network of devices.

Abstract: A wearable audio device including a magnetic device and a docking or parking magnet that has opposed first and second sides and produces a magnetic field, wherein the flux of the magnetic field from the first side has a greater magnitude than the flux of the magnetic field from the second side, and wherein the second side is closer to the magnetic device than is the first side.

Abstract: The present disclosure provides a speaker. The speaker includes a basket having an accommodating space, a vibration system and a magnetic circuit system which are accommodated in the accommodating space. The magnetic circuit system includes a yoke fixedly connected to the basket, a main magnetic steel assembled to the middle of the yoke, and a main pole core attached to a surface of the magnet away from the yoke. The main magnetic steel has a first leakage hole formed in a vibration direction of the vibration system, and the main pole core has a second leakage hole formed at a position corresponding to the first leakage hole. The first leakage hole and the second leakage hole are in communication with each other.

Abstract: The present disclosure provides a speaker, including a flexible circuit board, a holder, a diaphragm received in the holder, and a voice coil received in the holder and configured to drive the diaphragm to vibrate. The voice coil is electrically connected to the flexible circuit board, and includes an upper surface close to the diaphragm, a lower surface facing away from the diaphragm, and a side surface connecting the upper surface with the lower surface. The flexible circuit board includes a body portion supporting the voice coil. The body portion includes a bottom wall that abuts against the lower surface of the voice coil and an extension portion extending from the bottom wall while being bent towards the diaphragm. The extension portion is attached to and fixed to the side surface.

Abstract: An isomagnetic speaker comprising a diaphragm and an interference-free magnet structure is described herein. The interference-free magnet structure comprises a magnet array disposed to correspond with a predetermined region of the diaphragm and comprising a plurality of permanent magnets disposed at equal intervals along at least one direction. A plurality of bottoms of the plurality of permanent magnets are arranged on a same plane and oriented toward the diaphragm. A magnetic field direction of each permanent magnet is perpendicular to a corresponding bottom. A maximum size of a length of each permanent magnet along a direction parallel to the diaphragm is smaller than or equal to c/2?fmin, wherein c is a sound wave speed, and fmin is a minimum output audio frequency of the isomagnetic speaker.

Abstract: The present application discloses a speaker assembly. The speaker assembly includes a sound generator having a sound radiation surface and a back surface opposite to the sound radiation surface; at least one leakage area formed on the back surface; at least one leakage controller corresponding to the leakage area and covering the leakage area; a damping element disposed on a plane on which the leakage controller is disposed. The damping element is arranged between adjacent two leakage areas. By the configuration, the height of the speaker assembly is reduced.

Abstract: A speaker is provided in the present disclosure. The speaker includes a shell, a magnetic system received in the shell for providing a magnetic gap, and a vibrating system. The vibrating system includes a membrane, a voice coil arranged in the magnetic gap for driving the membrane to vibrate, and a coil support for supporting the voice coil. The coil support includes a first connecting member and a second connecting member parallel to each other and connected to the membrane, the voice coil is fixed between the first connecting member and the second connecting member.

Abstract: A method of and a system for generating an acoustic wave representing reverberations from a desired acoustic environment are described including having a recording surface (11) defined by a spatial distribution of recording transducers (o) and an emitting surface defined by a spatial distribution of emitting transducers (x), wherein the emitting surface (12) defines a volume within which the recording surface (11) is located, recording an acoustic wave (14) originating from within a volume defined by the recording surface (11) using the recording transducers (x), extrapolating the recorded wave (14) to the emitting surface using wavefield propagator system (IS) representing the desired acoustic environment, and emitting the extrapolated wave from the emitting transducers (o).

Abstract: An audio output circuit of a condenser microphone includes a condenser microphone unit, first and second impedance conversion circuits that receive a positive phase output signal and a reverse phase output signal from the condenser microphone unit, first and second output circuits that output an audio signal from the condenser microphone unit in a balanced line to a balanced output terminals upon receipt of outputs of the first and second impedance conversion circuits. First and second impedance conversion circuits respectively use FETs as source follower circuits and supply first and second impedance conversion outputs generated across source resistors to the first and second output circuits. A voltage regulating device that generates a constant voltage is connected in series to the source resistors. With this configuration, an audio output circuit of a condenser microphone is provided, which solves a problem of operation instability caused by variation of Idss's of the FETs.

Abstract: An energy converter includes a permanent magnet and a diaphragm. The permanent magnet is fixed to a predetermined area. The diaphragm is disposed on the permanent magnet and has a coil formed of a conductor pattern.

Abstract: A miniature speaker includes a frame having a sidewall including a first upper thinner portion and a first lower thicker portion, a magnetic circuit unit, a voice coil having a lead wire, and a diaphragm driven by the voice coil. The magnetic circuit unit has a yoke, a magnet mounted on the yoke, a pole plate attached to the magnet, and a magnetic gap. The yoke further includes a lower plate and a side extending from the lower plate, the side including a second thinner portion and a second lower thicker portion. A recess is accordingly formed by the thinner portions and the thicker portions for accommodating the lead wire of the voice coil. The recess defines a bottom formed by the thicker portions and an opening formed by the thinner portions thereby providing an enlarged space to the lead wire.

Abstract: An anti-diffraction plate for including in a planar magnetic transducer. The anti-diffraction plate includes anti-diffraction structures for positioning adjacent to magnets of the planar magnetic transducer. By introducing a shape over top surface of the magnets, the anti-diffraction structures cause the elimination of diffraction patterns as a main audio wavefront passes by the magnets from a diaphragm. A diffusion structure for diffusing reflected sound waves, the diffusion structures reducing or eliminating the power and capacity of the reflected sound waves to create interference patterns with oncoming sound waves.

Abstract: An acoustic transducer (104) is shown, which may be configured as either a loudspeaker or a microphone. The acoustic transducer includes a magnet system (401), and a diaphragm (303) having a conductive element (402) disposed on it. The conductive element has a first outer conductive portion (405) and a second outer conductive portion (407) for generating force parallel to the magnet system. It also has a central conductive portion (406) for generating force normal to the magnet system. In this way, application of an audio frequency signal to the conductive element, possibly via positive and negative input terminals (202, 203), causes oscillation of the diaphragm.

Abstract: An ultrasonic audio speaker includes a backing plate comprising a first major surface and a conductive region, the backing plate further comprising a plurality of textural elements disposed on the first major surface. A flexible layer disposed adjacent the first major surface of the backing plate includes a conductive region and an insulative region, wherein the flexible layer is disposed adjacent the backing plate such that the insulative region is positioned between the backing plate and the conductive region of the flexible layer, and such that there is a volume of air between the flexible layer and surfaces of the textural elements.

Abstract: A novel ribbon microphone incorporates rounded-edge magnet motor assembly, a backwave chamber, and a phantom-powered JFET circuit. In one embodiment of the invention, one or more novel rounded-edge magnets may be placed close to a ribbon of the ribbon microphone, wherein the one or more novel rounded-edge magnets reduce or minimize reflected sound wave interferences with the vibration of the ribbon during an operation of the ribbon microphone. Furthermore, in one embodiment of the invention, a novel backwave chamber operatively connected to a backside of the ribbon can minimize acoustic pressure, anomalies in frequency responses, and undesirable phase cancellation and doubling effects. Moreover, in one embodiment of the invention, a novel phantom-powered JFET preamplifier gain circuit can minimize undesirable sound distortions and reduce the cost of producing a conventional preamplifier gain circuit.

Abstract: A ribbon microphone circuit includes a ribbon microphone unit; a step-up transformer; buffer amplifier circuits connected to a secondary winding of the step-up transformer; an external power supply circuit as a power source for driving the buffer amplifier circuits; and a switch circuit including photo-relays having lights that are turned on while the external power source is being supplied and having contacts operating depending on states of the respective lights, wherein signals output from the ribbon microphone unit are sent through the buffer amplifier circuits while the external power source is being supplied, and sent without passing through the buffer amplifier circuits while the external power source is being not supplied.

Abstract: A single-ended planar transducer device for generating a sound signal based on an electrical signal comprising at least two primary rows of primary magnets, at least one return row of at least one return structure, a diaphragm, a conductive trace formed on the diaphragm, and a frame. The frame supports two primary rows to define at least one core set comprising no more than two primary rows. A primary magnetic field is established between the primary rows in the at least one core set. The frame supports at least one return row adjacent to the at least one core set. A return magnetic field is established between each return row and any primary row adjacent thereto. A first portion of the trace is arranged at least partly within each primary magnetic field and a second portion of the trace is arranged at least partly within each return magnetic field.

Abstract: An acoustic transducer (104) is shown, which may be configured as either a loudspeaker or a microphone. The acoustic transducer includes a magnet system (401), and a diaphragm (303) having a conductive element (402) disposed on it. The conductive element has a first outer conductive portion (405) and a second outer conductive portion (407) for generating force parallel to the magnet system. It also has a central conductive portion (406) for generating force normal to the magnet system. In this way, application of an audio frequency signal to the conductive element, possibly via positive and negative input terminals (202, 203), causes oscillation of the diaphragm.

Abstract: A loudspeaker comprises a voice coil and a diaphragm attached to the voice coil. The diaphragm has a generally rectangular outer shape, and comprises an outer rim (A1) having an outer edge at which the diaphragm is fixed in position and an inner section (A0) within the outer rim. The inner section (A0) comprises: an outermost area (A00) which is coupled to the voice coil and having the same generally rectangular outer shape; and an inner area (A01) comprising a periodic rib structure (A01p), with the ribs running parallel to the shorter side of the rectangular outer shape, and two lateral transition areas (A01c) between the edges of the periodic rib structure (A01p) and the shorter side edges of outermost area (A00).

Abstract: The present invention relates to a voice film having a multi-layered structure for a flat panel speaker, including a PCB configured to have permanent magnets disposed on the left and right sides thereof, to have a voice coil patterned therein and disposed between the permanent magnets on the left and right sides so that the voice coil is vibrated up and down, and to have a PCB structure of a stack structure and coil patterns formed on surfaces of the highest PCB, one or more intermediate layer PCBs, and the lowest PCB in the form of a consecutive spiral track, wherein the start points of coil patterns of adjacent PCBs formed in layers, from among the coil patterns, are shorted through a via hole and are bonded to the respective end points of the coil patterns of the adjacent PCBs at the end points of the coil patterns.

Abstract: An acoustic apparatus includes a first acoustic element, a second acoustic element, and a registration portion. The first acoustic element and the second acoustic element are elements such as a coil, a reed, or a yoke. The registration portion is configured to register the first acoustic element with respect to the second acoustic element such that an exact and relative alignment and positioning between the first acoustic element and second acoustic element is provided and ensured.

Abstract: A micromachined microphone or speaker embedded within, or positioned on top of, a substrate suitable for carrying microelectronic chips and components. The acoustic element converts sound energy into electrical energy which is then amplified by electronic components positioned on the surface of the substrate. Alternatively, the acoustic element may be driven by electronics to produce sound. The substrate can be used in standard microelectronic packaging applications.

Abstract: A ribbon transducer comprising a ribbon made of conductive material, two rigid supports where the ends of the ribbon are fixed, and a tensioning and damping system provided at least at one end of the conductive ribbon to tension the ribbon and damp its movements. The tensioning and damping system comprises a leaf spring comprising a first end section to which said ribbon is fixed and a second end section fixed to said rigid support, in such a way to exert a tensile force in the tensioning direction of the ribbon.

Abstract: A battery compartment for a condenser microphone includes a battery space configured to hold a battery; a battery outlet open to a portion of a peripheral wall of the battery space and allowing removal of the battery in the battery space; a lid covering the battery outlet; and a ribbon having one end portion fixed to an internal wall of the battery space and the other end portion disposed to be pulled out from the battery outlet and wrapping around an external periphery of the battery. The ribbon is conductive and the fixed end portion is grounded.

Abstract: A ribbon transducer (101) is disclosed, comprising: a ribbon made of conductive material (2), a damping system (4) arranged at least at one end of the conductive ribbon (2), and two rigid supports (103) where the ends of the ribbon (2) are fixed. The damping system (104) comprises a suspension composed of at least one wire (105), anchoring means (107) to connect said ribbon (2) to said wire (105), and elastic means (150) operatively connected to said wire to generate mechanical stress.

Abstract: An electromagnetic converter includes a magnetic circuit having permanent magnets, a lower frame for fixing magnetic pole faces of these permanent magnets thereto, an upper frame having an opening formed therein on a side of the other magnetic pole faces of the permanent magnets and plates fixed to the other magnetic pole faces, and a diaphragm having a voice coil pattern arranged on side portions thereof in a direction of the length thereof and on a top portion thereof in a direction of the width thereof. Protruding portions join between these side portions. The periphery of the top portion is joined to the periphery of the opening of the upper frame via an upper gasket. A flange at the edges of the four side portions is joined to an inner surface of the upper frame, i.e., an inner portion of the magnetic circuit via a lower gasket.

Abstract: An electronic device is provided. The electronic device includes a housing and an electro-acoustic transducer disposed on the inner surface of the housing. The electro-acoustic transducer includes an electret diaphragm, a conductive plate and at least one spacer. The electret diaphragm is positioned on the inner surface of the housing and has a film body and an electrode layer. The film body has static charges and the electrode layer is formed on the lower surface of the film body. The conductive plate has a plurality of openings and is stacked on the upper surface of the film body. The spacer is positioned between the electret diaphragm and the conductive plate to keep a predetermined distance therebetween.

Abstract: There is provided a capacitive electro-acoustic transducer comprising an active diaphragm (20) and a first and a second diaphragm carrier (60). The active diaphragm (20) is accommodated between the first and second diaphragm carriers (60). The first and second diaphragm carriers (60) each have a respective flat electrode (30). The diaphragm carrier and the electrode are connected together in such a way that the diaphragm carrier projects beyond the electrode by a predetermined amount.

Abstract: There is provided: first to fourth magnetic pole yokes 13-16 magnetized by the magnets 11, 12 having both poles on these opposite faces to establish a magnetic pole; and a vibrating membrane 17 disposed between the magnets 11, 12 and electromagnetically coupled to the yokes 13-16 by energizing a meandering coil pattern 17b thereon to vibrate in a predetermined direction. The yokes 13-16 include: abutting sections 13a-16a to be magnetized with abutting against the magnets 11, 12, and magnetic pole sections 13b-16b establishing the magnetic pole in a band shape. The sections 13b-16b each are disposed on the upper and lower sides of the vibrating membrane 17, and disposed with a gap (sound emitting hole 19) such that the magnetic poles different in magnetic polarity are positioned alternately in the lateral direction of the membrane 17 to form magnetic pole faces on the upper and lower sides thereof.

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 at least part of the membrane in motion so as to produce sound, wherein a part of the conductor pattern extends beyond the plane of the aforesaid movable part of the membrane near at least one end of the membrane. Preferably, the aforesaid part of the conductor pattern makes an angle of about 90 degrees with the aforesaid movable part of the membrane.

Abstract: A sound producing system includes an electro-acoustic transducer having an electromagnetic motor for moving a diaphragm of the transducer back and forth to create acoustic waves. The diaphragm has a surface that includes one or more of a surface of a dust cap of the diaphragm, a surface of a cone of the diaphragm, and a portion of a surface of a surround of the diaphragm. A solid gas impermeable cover faces the diaphragm surface and has a surface which faces the diaphragm surface. At least a portion of the cover surface has a contour which is substantially the same as a contour of the diaphragm surface. The system includes an asymmetric exit for the acoustic waves to leave a volume defined between the diaphragm surface and the cover surface.

Abstract: An electrostatic speaker system including at least one electrostatic speaker element having a pair of stators and a diaphragm therebetween, each of the stators and the diaphragm having an least one electrically conductive portion. The conductive portion of the diaphragm is patterned as a mesh, which may include gaps, and a conforming layer overlying the conducting portion of the diaphragm and disposed so as to cover gaps in the mesh. A speaker drive circuit provides soft clipping of the audio input signal so that the audio signal applied between the diaphragm and the stators does not exceed the maximum acceptable level that can be applied between the diaphragm and the stators of at least one speaker element.

Abstract: A microelectromechanical system diaphragm is provided. The microelectromechanical system diaphragm includes a substrate, a first conductive layer, a second conductive layer, a first dielectric layer, and a second dielectric layer. The first conductive layer is disposed on the substrate. The first conductive layer has a flexible portion in which a plurality of trenches is formed. The second conductive layer is disposed between the first conductive layer and the substrate, in which the flexible portion is located above the second conductive layer. The first dielectric layer is disposed between the second conductive layer and the substrate. The second dielectric layer is disposed between the substrate and a portion of the first conductive layer so as to suspend the flexible portion. Furthermore, at least one first opening is formed in the first conductive layer.

Abstract: A geometrically shaped acoustic polymer ribbon with shape memory, high conductivity, high toughness. A method of manufacturing the ribbon comprises: forming a sized, elongated, coated or coatable polymeric substrate film between a pair of opposed, geometrically shaped dies, pinching the dies about the polymeric substrate film to form an assembly, heating the dies and the pinched die and polymeric film assembly to a temperature of at about 300 degrees F. for a period of about 15 minutes to set the elongated film into a predetermined geometric pattern, cooling the assembly, removing the film from the dies; and if not already coated, coating the geometrically formed, set, elongated film with a conductive coating.

Abstract: A speaker device which can form an ideal cylindrical wave as sound traveling nondirectionally in a horizontal direction toward a listener. A vibration transmitting member is supported at one end thereof to the vertex of a conical diaphragm, and vibration generated by a vibrating element according to an acoustic signal is applied to the other end of the vibration transmitting member. The angle ? between the perpendicular dropped from the vertex of the conical diaphragm to the base thereof and the side surface of the conical diaphragm is set according to the sound velocity in the air and the sound velocity in the conical diaphragm so that the distance traveled by a sound radiated from the vertex is equal to the distance traveled by a sound radiated from an end of the side surface of the conical diaphragm farthest from the vertex.

Abstract: An electro-acoustic transducer includes a diaphragm, a casing which is formed with an opening for directly or indirectly supporting the diaphragm, a first magnetic pole section provided on a side of the opening with respect to the diaphragm and having a magnetic pole at a surface which faces the diaphragm, a second magnetic pole section provided on a side of an inner bottom surface of the casing with respect to the diaphragm and having a magnetic pole at least a part of a surface which faces the first magnetic pole section through the diaphragm, and a drive coil provided on the diaphragm and located in a magnetic gap formed by the first and second magnetic pole sections. The magnetic poles of the first and second magnetic pole sections which face each other through the diaphragm have the same polarity. An outer shape of the surface of the first magnetic pole section which faces the diaphragm is smaller than that of the surface of the second magnetic pole section which faces the diaphragm.

Abstract: A capacitive sound transducer provided with a perforated attenuation disk. The invention further relates to a capacitive sound transducer and a condenser microphone having such a sound transducer. The sound transducer comprises a diaphragm and a counterelectrode which is disposed at a short distance from the diaphragm and provided with first perforations. In order to attenuate natural oscillations of the diaphragm at high frequencies, a capacitive sound transducer is proposed in which a sound-permeable attenuation disk provided with second perforations is disposed at a short distance from the diaphragm and opposite the counterelectrode. In this arrangement, the first perforations and the second perforations are also offset in relation to each other.

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: A ribbon for a ribbon microphone having a magnet forming a magnetic gap, the ribbon which is arranged in the magnetic gap and is vibrated by a sound wave, an electrode for outputting an electric signal which is generated when the ribbon vibrates in the magnetic gap, and a frame for holding the magnet and the electrode; the ribbon has patterns of a large waveform which are formed so as to progress in a longitudinal direction of the ribbon and are formed so that ridge lines face a direction which perpendicularly crosses the longitudinal direction of the ribbon, and small patterns which are smaller than the patterns of the waveform and are formed along the longitudinal direction of the ribbon.

Abstract: A diaphragm unit is arranged to be used in a loudspeaker including a frame. The diaphragm includes a diaphragm and an edge joined to an outer periphery of the diaphragm. The diaphragm extends in a longitudinal direction and has a first center line extends along the longitudinal direction. The edge has an outer periphery being arranged to join to the frame, and an inner periphery joined to the outer periphery of the diaphragm. The edge has a convex surface having substantially a semi-circular cross section. The convex surface of the edge has grooves provided therein. The grooves extend from the inner periphery of the edge to the outer periphery of the edge. The grooves have cross sections each having a U-shape or a V-shape, and are arranged symmetrically about the first center line of the diaphragm. This diaphragm unit provides an elongated loudspeaker reproducing bass sounds with small distortions.

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: Contemplated planar magnetic microphones have a magnet and diaphragm arrangement such that substantially homogenous vertical and high horizontal magnetic flux density is realized in the inter-magnet space. Most preferably, the diaphragm is disposed in the inter-magnet space and includes a voice coil covering a significant fraction of the active portion of the membrane. In further especially preferred aspects, the membrane is sufficiently strong and tensioned to allow a large elastic excursion in the inter-magnet space. Consequently, contemplated planar magnetic microphones provide exceptionally large dynamic range without compression and/or distortion and can be easily configured to operate in an environment that is subject to moisture, rain, or to even operate in a submerged environment. Moreover, contemplated microphones can be used as speakers at even high SPL without reconfiguration.

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: An acoustoelectric transformation chip for a ribbon microphone includes a diaphragm that has a vibrating region and two fixing regions disposed on two opposite sides of the vibrating region, and a voice coil film formed on the diaphragm. The voice coil film includes two rectangular voice coils, each of which has a plurality of first and second connection segments parallel to a direction of a magnetic field. A plurality of first and second transverse segments are perpendicular to the first and second connection segments and are connected between the first and second connection segments. The second transverse segments of each voice coil are disposed on one of the fixing regions. The first transverse segments of the two voice coils are disposed in the vibrating region.

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: A microphone unit (1) has a first vibration plate. A support member (6) supports the microphone unit (1). A second vibration plate (5) is fixed to the support member (6) at a predetermined distance from the first vibration plate. An armoring body (2) covers the microphone unit (1), the support member (6) and the second vibration plate (5). A space surrounded by the support member (6), the first vibration plate and the second vibration plate (5) is a closed space (S1) with air kept therein.

Abstract: A loudspeaker includes a frame, a yoke physically associated with the frame and a sheet attached to an outer surface of the yoke. The sheet is made of an electrically conductive material. An electronic device incorporating the loudspeaker is also provided.

Abstract: A composite membrane acoustic transducer structure comprising a magnet assembly is arranged adjacent the composite membrane material. The magnet assembly is arranged to produce a flux field. A first layer of thin, elongate composite membrane material is held under tension. A second conductive layer is attached to the first layer of composite membrane material wherein the first and second layers of membrane material are arranged adjacent, generally parallel and offset from the magnet assembly. The assembly is arranged to produce the flux field through at least part of the first layer and the second layer.