Abstract: A frame for a speaker device includes a magnetic circuit housing unit which houses a magnetic circuit, an annular outer peripheral portion which is arranged on an outer side of the magnetic circuit housing unit, and plural arm portions which connect the magnetic circuit housing unit and the outer peripheral portion. The plural arm portions form such plural bridges that a pair of the arm portions are linearly positioned to connect two parts of the outer peripheral portion, and each of the bridges does not pass through a center of the outer peripheral portion.

Abstract: A voice-coil transducer includes two radially concentric magnets, a voice-coil located in the gap between the inner and outer magnets, and a diaphragm coupled to the voice-coil. An audio loudspeaker includes the voice-coil transducer with two radially concentric magnets, a voice-coil located within the gap between the inner and outer magnets, a diaphragm coupled to the voice-coil in order to create sounds from the voice-coil, and a chassis to support the magnets, voice-coil, and diaphragm.

Abstract: An electroacoustic transducer has a magnetic circuit unit including a plate-shaped yoke, first and second magnets juxtaposed on the yoke, and first and second top plates mounted on the respective tops of the first and second magnets. One end of the first magnet is magnetized to one of north and south poles. The other end of the first magnet is opposite in polarity to the one end. The second magnet is magnetized to polarities opposite to those of the first magnet. A magnetic gap is formed between the first and second top plates.

Abstract: A speaker having an improved sound-radiating function to both directions is provided. The speaker includes a magnetic circuit unit, a voice coil, and an auxiliary vibrating plate and a primary vibrating plate sequentially arranged from a forward direction. The voice coil vibrates toward a backward direction and a forward direction due to interaction with the magnetic circuit unit. The auxiliary vibrating plate is cone-shaped and has a damping function. The primary vibrating plate is also cone-shaped. Central necks of the primary vibrating plate and the auxiliary vibrating plate are fixed on the voice coil, respectively. The auxiliary vibrating plate is enlarged toward a forward direction and the primary vibrating plate is enlarged toward a backward direction.

Abstract: Leakage flux is reduced particularly in a magnetic gap of a magnetic circuit to improve the sensitivity of a dynamic microphone. A dynamic microphone including a magnetic circuit unit 20 including a center pole piece 22 connected to one pole of a first permanent magnet 21 and a yoke 23 which is connected to the other pole of the first permanent magnet 21 and is arranged like a ring around the center pole piece 22 via a magnetic gap of a predetermined width, a diaphragm 10 having voice coils 13 disposed in the magnetic gap, and a resonator 40 which has a front acoustic terminal 41 and is disposed at the front of the diaphragm 10, the dynamic microphone further including a second permanent magnet 43 disposed on a part of the resonator 40 so as to face the center pole piece 22, the second permanent magnet 43 being polarized in such a way that the same poles of the first permanent magnet 21 and the second permanent magnet 22 face each other.

Abstract: Improved loudspeakers, systems and components are adapted to interconnect with many forms of communication media. In one embodiment, a speaker is mountable within a receptacle. The speaker includes a magnetic driver and a diaphragm mounted to a frame. The frame includes a mounting member extending from a surface of the frame behind the flange plane. The mounting member is engagable in a notch formed in the receptacle for securing the speaker within the receptacle. In another embodiment, a low-profile loudspeaker has a front-mounted magnetic driver disposed within a cone-shaped acoustic diaphragm. The magnetic driver includes a first rare earth magnet centrally disposed within an electromagnetic shielding material. In another embodiment, a low-profile, two-way loudspeaker includes a cone-shaped diaphragm and a dome-shaped (tweeter) diaphragm. A front-mounted magnetic driver comprises first and second rare earth magnets each centrally disposed within electromagnetic shielding material.

Abstract: A loudspeaker used mainly for mobile communication equipment such as a mobile telephone and having two loudspeaker parts provided in one frame is provided. In the loudspeaker, a yoke has a groove portion and a second voice coil disposed in this groove portion drives a second diaphragm. Since the groove portion functioning as a magnetic gap is formed by processing the yoke, variation in the magnetic gap, which conventionally occurred at the time of incorporation, is eliminated and accuracy is improved, thus stabilizing the sound pressure frequency property.

Abstract: The disclosed transducer the can transfer an audio signal into a full-spectrum tactile wave over a frequency of 10 Hz-2 KHz. Upper and lower springs of the transducer produce vibrations via a coil/magnet in a manner similar to a conventional speaker, but the transducer uses a novel arrangement of elements, such as two south-to-south coils and carbon fiber springs, so as to produce the vibrations tactilely. The transducers can be tuned for specific applications and can be attached or formed integrally with a support surface. When attached or incorporated into a chair, massage table or other human-support structure, the transducer creates a sonic environment that surrounds and permeates the body with vibration, providing a direct experience of mental desired states. When connected to any full fidelity sound system, a support structure, a full frequency response process promotes a state of relaxation in the listener.

Abstract: A driver for a speaker including: an upper housing, a lower housing and a vibration device, wherein said upper housing combines with said lower housing to form a chamber therein. The vibration device is received in the chamber. The vibration device is basically constituted with an acoustic phase equalizer, a diaphragm, a flux guiding plate, a magnet and a yoke. By the design of the flux guiding plate, the magnet and the yoke in present invention, the disadvantage of highly concentrated heat in prior art can be improved and extends the operation period.

Abstract: A driver for a speaker including: an upper housing, a lower housing and a vibration device, wherein said upper housing combines with said lower housing to form a chamber therein. The vibration device is received in the chamber. The vibration device is basically constituted with an acoustic phase equalizer, a diaphragm, a flux guiding plate, a magnet and a yoke. By the design of present invention, the disadvantage of poor radiation efficiency in prior art can be improved and extends the operation period.

Abstract: An electromagnetic transducer such as an audio loudspeaker, whose diaphragm assembly and motor both have a highly elongated shape in which the long dimension is at least 3× greater than the short dimension. The diaphragm may be obround, and the motor's magnetic air gap may comprise a pair of elongated, parallel, linear gaps. A novel “boxcar” device is used to hold the bobbin and voice coil in an obround shape, maintaining the parallel, linear shape of their elongated sides. The lower suspension may be disposed only at the ends of the motor, enabling the narrowest possible configuration.

Abstract: An electro-acoustic transducer includes a tone generator, a vibrator, and a case. The tone generator includes a diaphragm, and a voice coil joined to the diaphragm. The vibrator includes a magnetic circuit having a magnetic gap at which the voice coil is positioned, and a suspension made of metal and having a first end joined to the magnetic circuit to suspend the magnetic circuit for allowing the magnetic circuit to vibrate. The case is joined to a periphery of the diaphragm, and includes a metal plate joined to a second end of the suspension. The metal plate is joined to the suspensions reliably, hence allowing the electro-acoustic transducer to be manufactured stably.

Abstract: A loudspeaker of improved construction includes a frame and a toroidal magnet that is affixed to the rear of the frame. The toroidal magnet has a central passageway that opens into the frame. A cap is affixed to the rear of the magnet and closes the central passageway. A guide rod is affixed to the cap and projects forwardly from the cap into the central passageway. A tubular former is slidably positioned upon the guide rod. A voice coil is wound about, and is affixed to, the tubular former. A forward cone has a narrow, rear end that is affixed to the tubular former and a wide, front end that is affixed to the front of the frame. A rearward cone has a narrow, rearward end with a central opening that loosely receives the tubular former between the rear of the frame and the rear end of the forward cone. The rearward cone also has a wide, forward end that is affixed to the frame rearwardly of the front end of the forward cone.

Abstract: The invention relates to a moving-coil electrodynamic motor and a loudspeaker. A moving-coil includes a winding with a given number of turns. A motor comprises a magnet arranged between a front pole piece and a rear pole piece. The front pole piece and the rear pole piece enclose a magnetic field in a gap and the moving coil is arranged in the gap. The gap may include a groove arranged essentially parallel to the turns. The coil has a height less than or equal to the height of the gap and the groove forms a recessed zone with an internal ring made from electrically conducting material.

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 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: A magnet assembly having inner and outer yokes of magnetic flux conductive material which together define an annular air gap and a radially oriented magnet sandwiched between the inner and outer yokes such that a first face of a first magnetic polarity contacts the inner yoke and a second face of a second opposite magnetic polarity contacts the outer yoke, characterised by an axially oriented magnet forming part of the magnet assembly, and wherein the radially oriented magnet is annular and has opposed axial ends, and the inner and outer yokes are annular and together enclose one axial end of radially oriented magnet to define the air gap, and wherein the axially oriented magnet is disposed adjacent to the other axial end of the radially oriented magnet, whereby the inner and outer yokes and the axially oriented magnet together reduce flux leakage from the magnet assembly.

Abstract: A miniaturized electro-dynamic sound transducer has a housing made of deep drawn sheet metal. A magnet system with a magnet is arranged in the housing. A diaphragm provided with a coil is arranged in the housing, and wires extend from the coil to contacts. The housing has an outer diameter of maximally 20 mm. The thin sheet metal of the housing has an average thickness of maximally 0.2 mm. The magnet system has a lower pole piece and an upper pole piece, wherein the pole upper and lower pieces are made of sheet steel having a thickness of at least 1.5 times an average thickness of the bottom of the housing.

Abstract: A magnetic circuit of the present invention uses a yoke, wherein a thickness of a bottom portion 10b of the yoke 10 is thicker than a thickness of a cylindrical peripheral portion 10a of the yoke 10. The magnetic circuit of the present invention includes the yoke, a magnet 2 bonded to the bottom portion of the yoke, and a top plate 3 bonded to the magnet, the top plate forming a magnetic gap with the cylindrical peripheral portion in between. According to a configuration of the present invention, it is possible to reduce the magnetic saturation in the bottom portion of the yoke and to improve the efficiency of the magnetic circuit. As a result, the configuration contributes to improve the performance and efficiency of a loudspeaker using the magnetic circuit of the present invention.

Abstract: A speaker comprising: a magnetic circuit provided with a through hole, and a recess formed around the through hole for retaining a magnetic fluid. The speaker further comprises a bearing provided in the through hole and a shaft supported by the bearing to be movable up and down and fixed to a center cap fixed to a voice coil. A gap between the bearing and the shaft is filled with the magnetic fluid. The speaker eliminates a damper, and realizes a very low f0 which has not been obtained before. Furthermore, the magnetic fluid absorbs friction and resonance between the bearing and the shaft, and the magnetic fluid is kept in the recess and is supplied smoothly into the gap between the shaft and the bearing. Thus, generation of abnormal sounds is suppressed and a large amplitude operation is realized in the speakers of the present invention.

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: A loudspeaker has a magnetic circuit, a plastic frame to be coupled with the magnetic circuit, a voice coil disposed in a magnetic gap of the magnetic circuit, and a diaphragm connected with the voice coil. The frame and the magnetic circuit are coupled together by an elastic fastener provided on the frame. The frame and yoke are coupled together by fitting a plurality of elastic fasteners provided on a circle on a bottom surface of the frame with a yoke of the magnetic circuit. The elastic fastener can also be a clip section provided on a circle on the bottom surface of the frame. The frame and magnetic circuit are coupled together by the clip section and an extension provided along an outer circumference of the magnetic circuit.

Abstract: To realize a speaker device capable of significantly improving sound quality with a simple construction. The speaker device applies electromagnetic force to a voice coil based on a supplied audio signal, and generates a sound wave according to the audio signal by vibrating a vibratory plate fixed to the voice coil.

Abstract: An electromagnetic drive motor assembly (EDMA) has at least one bridge that extends along a radial direction to conduct heat away from the magnetic gap and towards the outer surface of the EDMA. The EDMA includes a conductive ring between a first plate and a second plate. The conductive ring has an inner ring, an outer ring, and at least one bridge between the inner and outer rings. The inner ring is adapted to receive a voice coil such that the heat generated by the voice coil conducts through the inner ring, the bridge, and then to the outer ring. As such, a heat conducting path is provided within the EDMA to remove the heat away from the voice coil. This allows the EDMA to operate more efficiently. The EDMA may also include a flux return having a pole piece that protrudes from the first plate. The inner ring of the conducting ring may receive the pole piece to form an intermediate gap between the pole piece and the inner ring.

Abstract: An electromagnetic transducer is described including a magnet assembly (50) and a conductive drive coil (52). The magnet assembly provides an emanating magnetic field within which the drive coil is located. The drive coil is a flat ring coil having a width that is equal to or greater than its height. As assembled, the drive coil is mounted in close proximity to the magnet assembly such that relative axial motion may occur between them during use. In one embodiment, the magnet assembly includes two permanent disc magnets (64), (66) having axial magnetizations and being oriented with like poles facing one another to produce a radially emanating magnetic field. In another embodiment, the magnet assembly includes a pair of axially magnetized permanent ring magnets (64), (66) also oriented with like poles facing one another.

Abstract: The present invention relates to an miniature actuator especially suitable for hearing aid applications. The actuator according to the present invention operates according to the change in reluctance principle. In particular, the actuator according to the present invention operates in a balanced configuration comprising two planar coils, two magnets, a membrane and a spacer chip providing the necessary back chamber volume.

Abstract: A loudspeaker for generating sound from an electrical current provided by an external source may include an adapter and/or a guide for supporting, directing and routing lead wires carrying the electrical current from the external source. The lead wires may be routed through a guide supported by a pole assembly in the center of the loudspeaker in order to keep the mass associated with the lead wires as near as possible to a moving voice coil former. In this manner, detrimental effects of premature failures and undesirable noise caused by movement of loudspeaker components during operation may be significantly reduced. The guide may include apertures for supporting the lead wires at a desired angle and directing the lead wires toward the external source. Alternatively, or in combination with the aforementioned guide, the lead wires may be routed through an adapter attached to the voice coil former.

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: A loudspeaker comprising at least one magnet 27, a yoke 24 fixed to a bottom surface of the magnet, a flat plate 26 fixed on an upper surface of the magnet, a magnetic circuit 29 having a magnetic gap 28 formed between the plate and the yoke, and a flat diaphragm 23 provided with a coil 21 disposed above the magnetic gap. The magnet has a width greater than that of the plate, and at least a part of the upper surface of the magnet is exposed so that it directly faces the diaphragm. According to the structure of the present invention, a larger volume magnet can be used without increasing the size of the magnetic circuit. Furthermore, as magnetic flux can be concentrated in an upper region of the magnetic gap, the magnetic circuit becomes efficient and compact. Thus a compact and high-efficiency loudspeaker for high frequency sound reproduction can be provided.

Abstract: The present invention provides an electromagnetic drive motor assembly (EDMA) that has an inner flux return assembly formed from an upper pole piece and a lower pole piece oppositely disposed relative to each other along the center of the EDMA. An annularly positioned conductive ring (or flux stabilization ring) encircles the inner flux return assembly, concentrically in contact with the outside of the inner flux return assembly. Along the exterior side of the flux return pieces, is a magnet that is between a top plate and a bottom plate. Each plate contacts with the magnet to form a magnetically conductive system. A magnetic gap is formed in between the inner flux return assembly and the top and bottom plates. Disposed within the magnetic gap is a dual coil wound around a cylinder. The dual coil includes a first coil portion and a second coil portion. To minimize the modulation, the top and bottom plates may be saturated and plate tips may be provided near the magnetic gap.

Abstract: A vented tweeter with a low profile particularly suited for automotive applications where the mounting depth is limited. The tweeter comprises a motor with a central air passage extending through it and a lateral air chamber formed around it. Radial channels on the top of the motor connect the air gap in the motor with the central air passage, and radial channels under the motor connect the central air passage with the lateral air chamber. As the diaphragm oscillates, air can move back and forth between the air gap around the magnet and lateral space outside the motor. This configuration substantially increases the volume of air that can be acted on by the diaphragm without significantly increasing the length of the assembled tweeter or compromising the power of the motor. To enhance the power of the motor, a secondary magnet can be included above the top plate.

Abstract: The present invention discloses an improved single magnetic circuit dual output speaker, comprising a support retainer with an expanded opening at its front end, a bridge disposed across the opening, a magnetic circuit wound and fixed inwardly in the middle of the bridge, a vibrating space disposed on each of both sides of the magnetic circuit, a first voice coil disposed in the vibrating space on one side of the magnetic circuit, a second voice coil disposed in the vibrating space on the other side of the magnetic circuit, a first diaphragm disposed on the expanded opening of the support retainer and having its internal diameter stuck with the first voice coil, a second diaphragm disposed on the expanded opening of the support retainer and having its internal diameter stuck with the second voice coil, and a damper disposed at the back of the support retainer and stuck with the first voice coil, such that the magnetic circuit is mounted at the front of the support retainer by the bridge to provide the dual ou

Abstract: A compound loudspeaker drive unit comprising a first drive unit and a second drive unit arranged co-axial with respect to the center axis of the loudspeaker, and each drive unit comprises permanent magnet means and pole piece means together forming a magnetic circuit with a pole gap for exciting a voice coil assembly, each pole gap providing magnetic field directed radially with respect to a center axis of the loudspeaker. At least one of the permanent magnet means has a radially extending magnetization direction with respect to said center axis of the loudspeaker and the acoustic centers of said drive units substantially coincide.

Abstract: A speaker for a portable phone capable of being assembled without bonding by adhesives is disclosed. The speaker has a protector having a plurality of sound holes, and having an annular tension extension formed at a periphery thereof and extended upwardly and outwardly; a frame having a stepped portion and a cylindrical wall extended upwardly from the periphery of the stepped portion and having locking means; a diaphragm seated on the stepped portion of the frame and intended to generate sound; a voice coil attached to a lower surface of the diaphragm and adapted to vibrate; a top plate disposed in the voice coil; and a magnet fixedly disposed between the top plate and the frame and adapted to generate a predetermined magnetic field.

Abstract: A loudspeaker has a magnetic flux assembly that has a pole piece and a plate and magnet structure for co-operating with a voice coil. The plate structure includes a top plate which is mounted adjacent to the diaphragm assembly of the loudspeaker. There is a cavity within the voice coil and between the diaphragm membrane and the top of the pole piece. A fluid flow passage is provide to permit air displaced to and from the cavity during movement of the diaphragm assembly to flow through the top plate and to encourage cooling of the assembly.

Abstract: A fluid cooled speaker having a T-yoke with a pole piece, a magnet surrounding the pole piece, a voice coil positioned between the pole piece and the magnet, and a cone connected to the voice coil. The T-yoke includes a body having a base and a pole piece with a sealed cavity formed within the pole piece. The T-yoke also has a fluid inlet and outlet formed in the body and communicating between the cavity and an area outside the body of the T-yoke.

Abstract: An amount of movement of an air passing through a clearance G2 is adjusted by adjusting the clearance G2 by placing an outer shape surface 35 of a yoke 3 in proximity of an inner side surface of a housing 1. Accordingly, a vibration characteristic having a wide frequency bandwidth can be obtained, thereby improving stability and convenience of body-sensible vibration characteristic of a multifunctional vibration actuator.

Abstract: A loudspeaker includes a bobbin, a coil, a magnetic circuit having a magnetic gap, a first cylinder fixed to the outer surface of the bobbin, a second cylinder connected with the first cylinder, a diaphragm and a damper coupled to the outer circumferential surface of the second cylinder, an edge coupled to the diaphragm, a frame, and terminals. The outer circumference of a yoke constituting the magnetic circuit has a plurality of slits, while the first cylinder and the second cylinder are connected together by a plurality of radially-disposed joints. The loudspeaker has a flat profile yet is compatible with large amplitude and high output power, and capable of reproducing a wide range of sounds from a low tone to a high tone.

Abstract: A loudspeaker includes: a bottom plate; a center pole provided upwardly from the bottom plate; a yoke surrounding the center pole and having a plurality of slits; a magnet for providing a magnetic flux for the center pole and the yoke; a coil provided between the center pole and the yoke; a first annular member for supporting the coil; a plurality of support members for supporting the first annular member, the plurality of support members being inserted into the plurality of slits; and a diaphragm supported by the plurality of support members, wherein upper faces of the plurality of support members gradually decrease in height in a direction away from the first annular member, and wherein a lower face of the coil is located below a position at which the diaphragm is supported by the plurality of support members.

Abstract: An electromagnetic transducer such as an audio speaker having at least one of the soft magnetic components of its motor assembly constructed as a laminated structure of electrically insulated magnetically conductive sections. Eddy currents, which would have been induced in a monolithic component in response to an electrical signal applied to the voice coil, are prevented or significantly reduced by the electrical insulation material between the sections of the laminated component. The transducer produces less heat, is less susceptible to flux modulation, and has increased power handling and reduced distortion.

Abstract: This invention concerns an electromagnetic induction actuator to be mounted in small equipment such as portable telephones and pagers; also concerns such portable telecommunications equipment. The electromagnetic induction actuator, as well as the portable telecommunications equipment in which it is mounted, can be assembled in a thin and small package even though there are tabs as shock resistance stoppers, and has good acoustical characteristics. In the electromagnetic induction actuator there is a yoke that has tabs as stoppers to provide shock resistance, and there are springs that have inner rings, outer rings, bridge arms that connect the inner and outer rings and recesses that correspond to the tabs of the yoke.

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

Abstract: A converter with two coils and two magnetic gaps of which the upper and lower yokes of are two innerwardly concave plates or round plates. 3 set or more than 3 sets of axially magnetized permanent magnets are provided. Said permanent magnets are directly engaged with pole faces of said plates. Two magnetic gaps are formed between the vertical peripheric faces of said plates and the outer peripheric faces of a coaxial mounted annular or cylindrical magnetic body. Coils are inserted into said magnetic gap, while wound direction of two coils and the direction of current are decided to produce an electrodynamic force in the coils to the same direction. Said converter possesses resistance load characteristics by setting the values of the inductance of the two coils equal to each other in case that said converter are provided with two magnetic paths and coil circuits completely symmetric in their magnetic characteristics.

Abstract: A dual magnetic loop type receiver is composed of a yoke molding, a ferrite yoke, an annular magnet, a magnetic pole member, a vibration panel, a ferrite core, and a circular plate. While the receiver is operated, the annular magnet and the ferrite core and the ferrite yoke 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 speaker with enhanced magnetic flux loop includes a core magnet (12) installed inside hollow space of a bottom yoke (11), and a ring-shape magnet (13) with opposing polarity placed on the outer periphery of the core magnet (12). The ring-shape magnet (13) acts as an induction medium in a magnetic flux loop flowing across the core magnet (12), thus bottom yoke the magnetic flux within the boundary of the yoke (11) and preventing loss of magnetic flux. The dual magnet architecture brings about increased sensitivity to sound and output volume for the speaker, whilst the external dimensions of the conventional speaker can be scaled down as a result of smaller yoke (11).

Abstract: A loudspeaker has first and second diaphragms provided in a case. A first voice coil is provided for vibrating the first diaphragm, and a second voice coil is provided for vibrating the second diaphragm. A first permanent magnet is provided for applying a magnetic flux to the first voice coil, and a second permanent magnet is provided for applying a magnetic flux to the second voice coil.

Abstract: In a speaker, a magnet 23 is disposed at a mid position of a voice coil bobbin 25 mounted on a cone 34. A couple of voice coils 28 and 29 are put around the circumferential outer surface of the voice coil bobbin 25 at the positions thereof facing one end and the other end of the magnet 23. A magnet 32 is disposed within the voice coil bobbin 25, and develops two magnetic fields in a state that the first and second voice coils 28 and 29 are located between the one and other ends of the first magnet 23. Dampers 26 and 27 support the voice coil bobbin 25 at positions such that the voice coil bobbin 25 is axially vibratory. Those positions are located on both sides of and symmetrical with respect to those portions of the voice coil bobbin 25 which are respectively wound with the voice coils 28 and 29.

Abstract: A magnetic circuit of the present invention uses a yoke, wherein a thickness of a bottom portion 10b of the yoke 10 is thicker than a thickness of an outer cylindrical portion 10a. The magnetic circuit of the present invention comprises the yoke, a magnet 2 bonded to the bottom portion of the yoke, and a top plate 3 bonded to the magnet, a magnetic gap being formed between the top plate and the outer cylindrical portion. According to a configuration of the present invention, it is possible to reduce the magnetic saturation in the bottom portion of the yoke and to improve the efficiency of the magnetic circuit. As a result, the configuration contributes to improve the performance and efficiency of a loudspeaker using the magnetic circuit of the present invention.

Abstract: A speaker with a replaceable cone assembly. The motor assembly has its own basket, which is mounted in the enclosure. The cone assembly also has its own basket, which fits inside the motor basket. In the event of damage or malfunction in the cone or coil, the entire cone assembly is easily removed and replaced, while the motor assembly and the main basket remain undisturbed in the enclosure. Preferably, the speaker includes a pole with additional vents to improve heat dissipation. The pole has a pole cap with vent openings aligned with the secondary vent passages in the pole. The pole cap has a plug to occlude the front end opening of the central or primary vent passage in the pole. The top of the cap is domed to provide a guide surface for the former as the replacement cone assembly is inserted in the motor assembly.

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.