Abstract: An electromagnetic transducer, such as an audio speaker, includes a return path member which is a pole piece for external magnet geometries or a cup for internal magnet geometries. The magnetic flux return path for the primary drive magnet is through a first portion of the return path member. A first section of a low reluctance magnetic flux return path for a secondary drive magnet is through a second portion of the return path member. A magnetically conductive plate provides a second section of the low reluctance return path from the second portion of the return path member to the secondary drive magnet.

Abstract: A mechanical resonance frequency of vibration section 13 of an electro-acoustic transducer having vibrating function is measured during assembly process and is compared with a predetermined mechanical resonance frequency. Based on a difference obtained by the comparison, one of an weight of weight 14 to be attached and a position for fixing the vibration section to frame 16 is determined. In accordance with the determination, the weight 14 for resonance frequency adjustment is attached to vibration section 13, or suspension 12 and frame 16 which have been provisionally fixed are fixed again. Thus the predetermined mechanical resonance frequency f0 can be obtained steadily. As a result, the rectro-acoustic transducers having vibrating function with stabilized mechanical resonance frequency of the vibration section 13 can be produced.

Abstract: The armature of an electromagnetic transducer, extending through the polarizing flux between opposing permanent magnet pole faces, is snubbed to limit its shock-induced excursions normal to the directions of its extent and of the flux field. Such snubbing helps to protect the armature from plastic damage and accompanying shift of magnetic balance of the transducer upon the occurrence of a strong mechanical shock in an arbitrary direction.

Abstract: A speaker having a generally linear response by configuring two elastic members opposite one another so that any non-linearlity in the spring constant between an outward displacement versus an inward displacement are substantially cancelled. The present invention provides a pseudo linear spring constant throughout the range of travel of the cone and voice coil, or the sound baffle for a passive radiator. This minimizes the flexing of the cone and the wobble of the voice coil tube, or the baffle, as each travels to reproduce the audio waves.

Abstract: A novel electromagnetic acoustic device with twin magnetic loops is disclosed. The electro-acoustic device of the present invention comprises a magnetic transfer, a magnetic column (2), an annular magnet (4), an annular pole piece (5) and a pole piece (3). The magnetic transfer comprises a first, “cup-shaped”, round housing (11, 12) and its flange (13), which is the second annular. The first round housing (11, 12), the magnetic column (2), the pole piece (3) form the first magnetic loop. On the other side of the round housing, the housing flange, the annular magnet (4) and the annular pole piece (5) form the second magnetic loop.

Abstract: A speaker has an annular magnet structure. First and second annular magnets are arranged concentrically with each other and connected by a shunt at one end and a pole-defining structure at the other end to concentrate magnetic flux in a cylindrical voice coil gap. The shunt and pole structure are stacked such that the combined magnetic assembly has an opening extending centrally therethrough. A voice coil rides in the cylindrical magnetic flux gap and its leads are brought out through the opening to the other side of the magnet. When used with an enclosure, the diaphragm of the speaker may communicate through the central opening with the volume of a tuned enclosure extending behind the speaker, or the opening may serve as a port of the enclosure, allowing further degrees of control over total acoustics. In one embodiment, annular magnets of axial polarity are oppositely poled, and are positioned concentrically with a space between them.

Abstract: The present invention relates to an electric-mechanical-acoustic converter used mainly in a mobile telephone and the like, and its objective is to provide a high-quality product in which damage and degradation of performance caused by shock due to a drop are prevented. In order to achieve this objective, the present invention includes at least one suspension (14) supporting a movable portion (19) formed of the magnetic circuit portion (17) and a weight portion (13), and a frame (9) supporting a diaphragm (8) and the suspension (14), a space in an elastic deformation range of the suspension (14) being provided between the outer periphery of the movable portion (19) and the frame (9). Even in the case where a portable terminal apparatus is dropped, and the electric-mechanical-acoustic converter built therein is subjected to shock, the outer periphery of the movable portion (19) is received by the frame (9), whereby the suspension (14) can be prevented from being permanently deformed.

Abstract: A weight is attached to the rear side of a magnetic circuit of a speaker unit. The tip of a boss that projects to the front side from the weight is joined to the rear side of a center pole of the magnetic circuit with a bolt. Even if reactive force that is generated when an electrical signal is converted into mechanical vibration by the magnetic circuit and a voice coil and sound waves are emitted from a vibration plate is transmitted to the magnetic circuit, the vibration of the magnetic circuit is suppressed by the weight. In this manner, sound quality with a good transient characteristic can be obtained.

Abstract: A loudspeaker has a diaphragm with a voice coil disposed about its perimeter and extending in a gap into which the flux of an annular rare earth magnet is focused. An opening behind the diaphragm communicates through the speaker frame. The voice coil may have two or more windings that are connected in parallel, and may, e.g., be layered on top of one another, so that the impedance of the coil, as well as its depth in the front/back direction of motion, are low. The voice coil is preferably implemented using a polyimide form or bobbin, which has patterned lead-in conductors embedded therein to bring power to wire windings on the perimeter of the coil. The lead-in conductors extend to, or through, the central opening of a ring magnet, providing a robust ribbon input connection. The ribbon lead-in may be symmetrical, and the central opening further provides an air channel that couples to an auxiliary chamber for enhanced sound.

Abstract: A dual magnetic loop type receiver is composed of a yoke molding, a yoke piece, an annular magnet, a magnetic pole member, a pressure plate, a circular plate, and a vibration panel. While the receiver is operated, the annular magnet and the yoke piece cause the receiver to produce an inner magnetic loop that interacts with the inner voice coil and an outer magnetic loop that interacts with the outer voice coil such that the receiver generates vibration and sound.

Abstract: A loudspeaker having an annular speaker cone with a central orifice, a voice coil bobbin attached to the annular speaker cone and a permanent magnet for producing a magnetic field in an air gap. A dust barrier blocks the transfer of material, such as magnetically attracted dust, through the central orifice into the air gap.

Abstract: An actuator is provided in which one or more separate compensating coils are employed to alter the distribution of the magnetic flux density in the air gap to produce a substantially constant force throughout the stroke; and in which current in the separate compensating coils can be adjusted with the stroke using separate power supplies and position feedback.

Abstract: A back plate having a stationary back electrode is secured to a substrate. A diaphragm electrode is mounted on the back plate interposing a spacer. A frame having a sound collecting hole is mounted on the diaphragm electrode.

Abstract: A multifunction acoustic device has a rotor rotatably supported in a frame, a stator provided in the frame. A permanent magnet is provided on the rotor, a coil is provided for forming magnetic fluxes between the rotor and the stator. Voltage detecting means is provided for detecting a voltage generating at the coil. A voltage detected by the voltage detecting means in the operation of the acoustic device is compared with a reference voltage which corresponds to a voltage generating at abnormal rotation of the rotor and for producing an abnormal signal when the detected voltage is equal or higher than the reference voltage. In response to the abnormal signal, the rotor is rotated from a low speed.

Abstract: A magnetic circuit for a speaker comprises: a bottom yoke including a center pole; a ring magnet; a top plate; and a short-circuiting ring shaped like a hollow cylinder. The short-circuiting ring is disposed close and parallel to a voice coil and attached to the inner portion of the bottom of the top plate.

Abstract: The speaker disclosed in this invention comprises: (a) a central cap fixed on voice coil bobbin; (b) a shaft fixed in the center of the central cap; and (c) a bearing filled with lubricating fluid and fixed in a through-hole disposed in the center of a magnetic circuit. The speaker has excellent characteristics without sliding noise or harmful rolling phenomena but with reduced harmonic distortion due to the introduction of a magnetic fluid or a lubricant used as a lubricating fluid.

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 case comprises an upper case and a lower case. A vibrating plate is secured to the upper case, a voice coil is secured to an underside of the vibrating plate. Each end portion of the voice coil is engaged in a groove formed in the upper case.

Abstract: An electronic linear motor particularly for use with loudspeakers includes first and second structures that define first and second annular counterfacing air gaps centered on a motor axis. An armature carries first and second voice coils in the first and second annular air gaps, respectively. A spider acts as a centering structure and attaches to the armature and the motor frame to center the armature radially on and longitudinally along the motor axis. A rigid link connects the armature and an output device whereby the armature is constrained to motion along the motor axis without radial displacement with respect to the motor axis.

Abstract: An electromechanical and electroacoustic transducer is compact and has a simple drive circuit. Two independent magnetic circuits share a single permanent magnet. A voice coil is placed in one of the magnetic circuits, and a magnetic weight is placed in the other magnetic circuit. A switching element is turned on and off upon movements of the magnetic weight.

Abstract: A structure of a rectangular transducer is provided. The structure includes a magnet assembly, a voice coil assembly and a positioning assembly. The magnet assembly has a pair of magnetic units with a gap therebetween for generating two magnetic fields having magnetic fluxes in opposite direction within the gap. The voice coil assembly includes a slab, a coil and a suspension unit, wherein the slab is used for being attached to a panel and the coil is immersed within the gap. The positioning assembly is used for supporting and positioning the magnet assembly and the voice coil assembly. When electric current flows through the coil, the voice coil assembly generates a motion in a direction vertical to the magnetic fluxes so as to excite the panel to generate flexural vibration and radiate sound.

Abstract: A magnetic core for speaker is constructed to include an annular magnet connectable to the body of the speaker, a center magnet mounted in the center of the annular magnet and connectable to the body of the speaker, an annular magnetically conducting plate mounted on the topmost edge of the annular magnet, and a center magnetically conducting plate mounted on the topmost edge of the center magnet for producing a magnetic loop with the annular magnetically conducting plate.

Abstract: A dipole radiating dynamic speaker design comprises a diaphragm (32) providing a surface for radiating acoustic output, a voice coil assembly (36) for driving the diaphragm, and a magnet system for providing magnetic flux across the voice coil assembly. The speaker incorporates a vented pole flux conductor (42) and a vent adjacent to the diaphragm permitting the rearward acoustic output to propagate away from the diaphragm producing acoustic output as a dipole radiator.

Abstract: A magnetic core for speaker is constructed to include an annular magnet connectable to the body of the speaker, a center magnet mounted in the center of the annular magnet and connectable to the body of the speaker, an annular magnetically conducting plate mounted on the topmost edge of the annular magnet, and a center magnetically conducting plate mounted on the topmost edge of the center magnet for producing a magnetic loop with the annular magnetically conducting plate.

Abstract: A loudspeaker having an improved air cooling system. The loudspeaker includes a speaker frame, a diaphragm connected to the speaker frame, a voice coil which is formed on a voice coil bobbin and is connected to the diaphragm for vibrating the diaphragm, a permanent magnet having a central opening, a pole piece disposed coaxially within the central opening of the permanent magnet to form an air gap into which the voice coil is disposed, and a heat transfer plate disposed over the permanent magnet. The heat transfer plate has a plurality of cooling fins which are radially outwardly extending toward an outer rim thereof and inner and outer air openings on the outer rim. The outer rim has a step like shape in cross section and has a flat upper surface which is higher than top ends of the cooling fins. The vibration of the diaphragm produces air flows through air passages on the heat transfer plate between the inside and outside of the loudspeaker.

Abstract: An internal magnetic circuit is formed by a plate forming a pole piece, a vertically magnetized magnet attached to a bottom face of the plate, and a yoke attached to a bottom face of the magnet. A magnetic gap is formed between the plate and the yoke. The yoke includes a bottom part attached to the bottom face of the magnet, a side part standing on the side of the plate, and a folded-back part folding downwards over the side part to face the magnetic gap. Thus, the internal magnetic circuit having a uniform magnetic flux density inside the magnetic gap along the direction of its length is provided.

Abstract: An electromagnetic transducer, includes: a first diaphragm disposed in a vibratile manner; a second diaphragm provided in a central portion of the first diaphragm, the second diaphragm being formed of a magnetic material; a yoke disposed in a position opposing the first diaphragm; a center pole provided on a face of the yoke that opposes the first diaphragm; a coil substantially surrounding the center pole; a magnet substantially surrounding the coil; and a thin magnetic plate provided between the magnet and the first diaphragm, an inner periphery of the thin magnetic plate being in overlapping relation to an outer periphery of the second diaphragm.

Abstract: A loudspeaker includes a magnetic circuit comprising a center plate, first and second magnets disposed respectively on a lower surface and an upper surface of the center plate and magnetized to be repulsive to each other, an under plate disposed at a lower surface of the first magnet, and a yoke. The loudspeaker further comprises a voice coil, a diaphragm, an edge coupled with the outer circumferential edge of the diaphragm, and a frame. The above-described magnetic circuit further comprises a top plate disposed on an upper surface of the second magnet. Both of the second magnet and the top plate have a ring shape, the inner and the outer diameters of the second magnet and the top plate being substantially the same. Outer diameters of the second magnet and the top plate are smaller than that of the center plate, and the center plate is provided on its upper surface with a protrusion for positioning of the second magnet.

Abstract: A speaker system and a cooling device therefor is provided which is capable of effectively dissipating heat generated by a voice coil. The cooling device is formed as a unitary member having a first member having a hollow cylindrical shape which is integrally formed with a second member having a hollow cylindrical shape which is concentric thereto and has a larger diameter than the first member, and a plurality of third members each in the form of a plate and radially arranged between the first member and the second member for connecting the members. The first member is arranged adjacent to the voice coil and at the same time inside a magnetic flux loop generated by a magnetic circuit, and the second member is arranged outside the magnetic flux loop, so that heat generated by the voice coil can be efficiently dissipated from the second member.

Abstract: A transducer includes a motor assembly for providing a magnetic field across an air gap, a voice coil supported in the air gap, a diaphragm coupled to the voice coil for reciprocation with the voice coil, and conductors for coupling opposite ends of the voice coil to a source of alternating current to cause the voice coil to reciprocate in the air gap. At least some portion of the length of at least one of the conductors is fusible when exposed to a direct current having a magnitude greater than the maximum desired magnitude of direct current to which it is desired to expose the voice coil.

Abstract: Disclosed is a speaker with a built-in direct current motor for selectively generating sound and vibration, which includes: a speaker part, a direct current motor part, and a frame. The speaker part has a yoke having a hole formed at the center thereof, a first ring-shaped magnet mounted on the top surface of the peripheral portion of the yoke, a ring-shaped upper plate mounted on the top surface of the first magnet, a vibration plate fixedly mounted to the top surface of the upper plate at the circumferential end thereof, and a generally cylindrical voice coil attached to the bottom surface of the vibration plate.

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: Disclosed is a speaker with a built-in direct current motor for selectively generating sound and vibration, which includes: a speaker part, a direct current motor part, and a frame. The speaker part has a yoke having a hole formed at the center thereof, a first ring-shaped magnet mounted on the top surface of the peripheral portion of the yoke, a ring-shaped upper plate mounted on the top surface of the first magnet, a vibration plate fixedly mounted to the top surface of the upper plate at the circumferential end thereof, and a generally cylindrical voice coil attached to the bottom surface of the vibration plate.

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

Abstract: A receiver for converting electrical energy to acoustical energy, and a method of manufacturing the receiver, are disclosed. The receiver comprises an armature having a peripheral edge, a magnet stack and a weld joint for attaching the armature to the magnet stack at the peripheral edge of said armature. The method comprises providing an armature having a peripheral edge, providing a magnet stack adjacent said armature, and welding said armature to the magnet stack at the peripheral edge of said armature.

Abstract: A pole piece 31 is placed on a lower case 21. A pole piece 31 has a core 32 and a base 33. The bobbin portion 24 extends from the lower case 21 toward the internal space of a case 1 so as to surround the outer periphery of the core 32. The bobbin portion 24 is divided into a plurality of portions along the circumferential direction of the core 32. The bobbin portion 24 has basal parts 26 and elongated parts 27. The pole piece 31 is pressed from the above of the lower case 21 in a state where the bobbin portion 24 is passed through holes 35 of the base 33, to be positioned on the outer periphery of the core 32, so that the pole piece is fitted and placed into the lower case 21. A coil 41 is configured by winding a conductor wire 42 around the elongated parts 27 of the bobbin portion 24.

Abstract: A loudspeaker has a diaphragm with a voice coil disposed about its perimeter and extending in a gap into which the flux of an annular rare earth magnet is focused. An opening behind the diaphragm communicates through the speaker frame. The voice coil may have two or more windings that are connected in parallel, and may, e.g., be layered on top of one another, so that the impedance of the coil, as well as its depth in the front/back direction of motion, are low. The voice coil is preferably implemented using a polyimide form or bobbin, which has patterned lead-in conductors embedded therein to bring power to wire windings on the perimeter of the coil. The lead-in conductors extend to, or through, the central opening of a ring magnet, providing a robust ribbon input connection. The ribbon lead-in may be symmetrical, and the central opening further provides an air channel that couples to an auxiliary chamber for enhanced sound.

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

Abstract: The invention comprises a supporting stand provided with an enlarged opening in a front and a damper in a rear for adhering to the sound coil. A magnetic circuit supported by a cylinder and connecting to the supporting stand and both ends of the magnetic circuit are provided with movement-accommodating space; first sound coil provided in the movement-accommodating space on one end of the space on the other end of the magnetic circuit; first diaphragm provided in an inner rim of the enlarged opening and adhering to the first sound coil; and second diaphragm provided in the inner rim of magnetic circuit; first diaphragm provided in an inner sound coil. Thereby allowing the magnetic circuit to be installed in front of the supporting stand; and thus high-pitch sound and low-pitch sound simultaneously output from a single device.

Abstract: A sound quality improving mechanism for a loudspeaker is proposed, in which a hollow annular component is deposited with a vibration-absorbing material therein. A plurality of conductive components are each disposed in a manner as to penetrate the hollow annular component in a diametrical direction, for allowing the hollow annular component to be held in place at a back end of a loudspeaker in a manner that the conductive components abut a peripheral surface of the back end of the loudspeaker, and for conducting vibration at the back end of the loudspeaker in a diametrical direction to the hollow annular component to be absorbed by the vibration-absorbing material, so as to improve the sound quality of the loudspeaker.

Abstract: Disclosed is a concentric magnetic configuration for a speaker system which can produce a full range of frequency sounds from a single source magnet. The magnetic configuration of the present invention includes a high frequency pole plate and one or more middle yoke iron plate placed directly on a cylindrical permanent magnet wherein at least one magnetic flux controlling slot is formed beneath the high frequency pole plate and the middle yoke plate. The multiple air gaps defined by the pole plate and middle yoke iron produce a full range of frequency magnetic fields which can drive the high, medium, and low frequency voice coils.

Abstract: The invention provides a speaker having a number of features that cooperate to provide a small speaker 10 having a high sound pressure level output capability (volume), a wide frequency range, in particular from below 200 Hz to 20,000 Hz, low distortion, and that is magnetically shielded. The speaker 10 is suitable for mounting in, for example, a television where spaces are confined and stray magnetic fields are undesirable, yet high output is desirable and a wide frequency range is desirable to avoid the need for separate middle frequency (midrange) and high frequency (tweeter) speakers.

Abstract: The method of assembling a speaker includes disposing a quantity of volatile magnetic fluid containing a pre-determined amount of lubricating oil into a radial gap of a driver unit, aligning a vibration system having a diaphragm and a voice coil to the driver unit such that the voice coil is movably mounted into the radial gap, fixing the vibration system to the driver unit, and removing the volatile component of the volatile magnetic fluid. The speaker includes a driver unit having a magnetic pole case defining a radial gap, a vibration system having a diaphragm and a voice coil where the vibration system is fixed to the drive unit and the voice coil is movably mounted into the radial gap, and a residual magnetic fluid layer disposed on the surfaces of one or more of the magnetic pole case and the voice coil where an air gap exists between the voice coil and the magnetic pole case.

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

Abstract: Loudspeaker and other transducers of the dual-voice-coil/dual-magnetic-gap type can be improved by the addition of one or more annular shorting rings strategically located in the vicinity of the two magnetic gaps. The shorting rings have no effect on a steady state magnetic field but act in opposition to any change in flux density or any displacement of the flux lines such as those that occur under the loading imposed when the voice coils are driven hard with audio frequency current. The location of the shorting rings determines their effect: location close to a voice coil reduces the voice coil inductance, location entirely within the magnetic flux loop centerline favors reduction of second harmonic distortion and higher order even harmonic distortion, a centered location on the flux loop centerline, i.e.

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: An electroacoustic transducer 1 is constituted by a base 24 formed of magnetic material; a magnetic core 22 formed of magnetic material and provided erectly on the base 24; a diaphragm 20 formed of magnetic material and supported with an air gap between the diaphragm and a forward end of the magnetic core; a magnet 25 constituting a magnetic circuit together with the base 24, the magnetic core 22 and the diaphragm 20 so as to provide a magnetostatic field; a coil 23 disposed around the magnetic core 22 for applying an oscillating magnetic field to the magnetic circuit; a housing 30 molded integrally with the base 24 and the magnet 25, and so on. The housing 30 has notch holes 38 extending from a bottom surface thereof to the magnet 25.

Abstract: A diaphragm for an electroacoustic transducer, the diaphragm comprising a flexible sheet comprising first and second sheet sections, each of the first and second sheet sections defining a substantially plane surface, and one or more electrically conductive coils, wherein each of the one or more coils is defined as an electrically conductive path on the substantially plane surfaces of first and second sheet sections so as to form, for each coil, first and second coil sections, respectively. The flexible diaphragm may be implemented using a single-sided or a double-sided flexprint. An integrated diaphragm and coil system may be formed by a monolithic flexprint. The diaphragm may be used for microphones or loudspeakers.

Abstract: A speaker has an annular magnet structure. First and second annular magnets are arranged concentrically with each other and connected by a shunt at one end and a pole-defining structure at the other end to concentrate magnetic flux in a cylindrical voice coil gap. The shunt and pole structure are stacked such that the combined magnetic assembly has an opening extending centrally therethrough. A voice coil rides in the cylindrical magnetic flux gap and its leads are brought out through the opening to the other side of the magnet. When used with an enclosure, the diaphragm of the speaker may communicate through the central opening with the volume of a tuned enclosure extending behind the speaker, or the opening may serve as a port of the enclosure, allowing further degrees of control over total acoustics. In one embodiment, annular magnets of axial polarity are oppositely poled, and are positioned concentrically with a space between them.

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