Abstract: A method for manufacturing a resonator is presented in the present application. The method includes providing a handle substrate, providing a host substrate, providing a quartz substrate comprising a first surface opposite a second surface, applying interposer film to the first surface of the quartz substrate, bonding the quartz substrate to the handle substrate wherein the interposer film is disposed between the quartz substrate and the handle substrate, thinning the second surface of the quartz substrate, removing a portion of the bonded quartz substrate to expose a portion of the interposer film, bonding the quartz substrate to the host substrate, and removing the handle substrate and the interposer film, thereby releasing the quartz substrate.

Abstract: A linear interleaved magnetic motor in which the B-field flows between a plurality of motor cell elements, creating a long, serpentine gap. The motor is used with at least one flex circuit as a drive coil. The motor can be used as a drive motor for a loudspeaker transducer. Multiple loudspeaker transducers can be connected together to make a loudspeaker frame or system.

Abstract: Disclosed are methods and devices that include a therapeutic fluid dispensing device (10) to deliver a therapeutic fluid into a body of a patient. The device includes a controller to control one or more of fluid delivery operations and notification operations, at least one auditory notifier (800) to produce one or more acoustic signals in response to application of one or more activation signals by the controller and a plurality of electrical contacts coupled to the at least one auditory notifier to enable the application of the one or more activation signals to the at least one auditory notifier. The device also includes at least one housing retaining the at least one auditory notifier therein, the at least one housing being structured to resonate at least one of the one or more acoustic signals produced by the at least one auditory notifier in response to application of at least one of the one or more activation signals.

Abstract: An improved structure for an amplifier comprises: a single member, which at least has a frame, an edge and a membrane; and a positioning shrapnel, which is assembled by an inner frame, an outer frame and a plurality of flexible braces, the outer frame is firmly disposed at the frame of the single member, the plurality of flexible braces is disposed between the inner frame and the outer frame, the inner frame is firmly disposed on the membrane of the single member, wherein the peripheral of the frame has a fillister that can be embedded in by the outer frame, each connection of any of the flexible braces and the inner frame is a curve portion that is to keep the connection of the inner frame and the outer frame while a height difference is existed between the inner frame and the outer frame.

Abstract: A slimline speaker comprises: a magnetic circuit having a magnet and yoke disposed to form a separating space in the horizontal direction; a bobbin on which a voice coil is mounted and of which the lower side is inserted in the separating space between the magnet and yoke; a base frame for mounting the magnetic circuit; a damper having an inside edge coupled to the bobbin and an outside edge coupled to the base frame; and a diaphragm having an inside edge coupled to a point lower down than the point where the damper is coupled on the bobbin, and an outside edge coupled to the base frame.

Abstract: A hearing aid (8) comprises an inlet port (6), a sound tube (12) for conveying sound to the ear piece (13). The invention further provides a component for a hearing aid comprising a slab (26) having an exterior surface, which is super-hydrophobic. The component may be any one of a housing, a casing, a shell, a faceplate, a grid, a hook, a lid, a battery drawer, a button, or a manipulator. The invention also provides a method of manufacturing a component for a hearing aid.

Abstract: Transducers and resonators are embedded in body support structures in contact with a user to for the purpose of conveying musical sound energy to a user's body at selected frequencies and in selected patterns. Body support structures comprise beds, pillows, chairs, and other structures typically used to support people. The sound may be audio tones and/or music. The transducers and resonators may be incorporated into a foam component or in a coil spring component of the body support structure. Latex-type foams and beds made with springs are candidate body support structures for receiving transducer's and resonators. Electro-active polymers are also used as transducers. Floor systems are activated by both mechanical transducers and electro-active polymers.

Abstract: An electric horn (1) has a coil bobbin (4) in a casing (2). A fixed iron core (3) is fixed in a hole (4f) in the coil bobbin (4) and is magnetized to define an exciting coil (C). A moving iron core (10) is at the center of a diaphragm (9) at the open end of the casing (2) and faces the fixed iron core (3). The moving iron core (10) is displaced relative to the fixed iron core (3) by a power supply of the exciting coil (C); thus beeping an alarm. The moving iron core (10) has an end face toward the fixed iron core (3) that strides over a reference position (N) within the amplitude (W) of the moving iron core (10). The end portion on the moving iron core (10) side of the wound portion (4e) of the exciting coil (C) is the reference position (N).

Abstract: A speaker frame, including: a vibration support portion supporting a vibrating body of a speaker; a magnet support portion arranged inside of said vibration support portion and supporting a magnetic circuit portion of said speaker; and a plurality of connection beams connecting said vibration support portion and said magnet support portion, wherein in a cross-section passing through a central axis of said speaker, an inclination angle of one connection beam of said connection beams to said central axis is different from an inclination angle of other connection beam to said central axis.

Abstract: A speaker unit performing sound output in proportion to electric current by current driving includes: a frame having an opening; a magnet arranged inside the frame and formed in an annular shape; a yoke including a shaft-shaped insertion arrangement portion which is inserted into a center of the magnet; a coil bobbin formed in a cylindrical shape; a coil wound around an outer peripheral surface of the coil bobbin; a damper having elasticity and connected between the frame and the coil bobbin; a cone connected to the coil bobbin at an inner peripheral portion and fixed to an opening edge of the opening of the frame at an outer peripheral portion, which vibrates with movement of the coil bobbin; and a sound absorbing material arranged inside the coil bobbin.

Abstract: A loudspeaker, which includes a ferrite core, a voice coil, and a movable membrane. The voice coil is wound around the core and cooperatively defining an exciting device. The movable membrane is disposed in close proximity to the exciting device with a gap formed thereinbetween. The loudspeaker is constructed without permanent magnets.

Abstract: A method for fabricating a speaker is disclosed. The speaker is equipped with a case having a through cavity, an inner surface forming the cavity and an outer surface, a magnetic bowl coupled to the case, a magnet positioned in the magnetic bowl, a pole plate covering the magnet, a magnetic gap formed by the magnet and the magnetic bowl, a diaphragm supported by the case and vibrating along a vibrating direction, a voice coil connected to the diaphragm, and a hearing aid coil formed on the case. The method includes the steps of: providing a case made of thermoplastic doped with organometallic additive; activating the organometallic additive in the case by a laser beam for forming initial pattern of the hearing aid coil in the inner surface of the case; and bathing the case in copper solution for providing the initial pattern with copper plating layer.

Abstract: An apparatus including an electromagnetic coil and a magnet system. The electromagnetic coil includes electrical leads. The magnet system forms electrical conductors connected to the electrical leads of the coil. The magnet system is configured to provide an electrical interface.

Abstract: Disclosed is a vibration module for a portable terminal that includes a housing, a magnetic moving part movable in a first direction within the housing; an elastic member supported between the opposite ends of the magnetic moving part and inner walls of the housing, and a solenoid coil provided in the housing. The vibration module is positioned at one end of the moving section by the magnetic force of the magnetic moving part and an object around the magnetic moving part, allowing the vibration module to provide a user with a feeling similar to a click feeling via the acceleration produced at a stopping instant. In addition, when vibrating, the vibration module generates sufficient vibration power through acceleration at the instant of changing moving direction at the ends of the moving section, to provide an alarm function, such as an incoming call notification.

Abstract: In one embodiment, a mobile device including a magnet unit that is thermally coupled to the heat sink portion of a housing of the mobile device is disclosed. The mobile device comprises a speaker driver that includes a magnet unit, a housing having a heat sink portion that is made of a material having a high thermal conductivity, and a thermal component. The heat sink portion has a first face that is coupled to the speaker driver and a second face that is exposed to the exterior of the mobile device. The thermal component binds the speaker driver to the first face of the heat sink portion to create a cooling path from the magnet unit to the exterior of the mobile device. Other embodiments are also described.

Abstract: A loudspeaker includes: a frame; a yoke fixed to the frame; a magnet fixed to the yoke; a plate fixed to an upper surface of the magnet which is opposite to a surface of the magnet which is fixed to the yoke; a vibratable voice coil arranged in a first magnetic gap formed between the yoke and the plate; a diaphragm having an outer-edge portion joined to the voice coil; and a support member supporting the diaphragm in a vibratable manner, and composed of edges, one end of each edge being fixed to the frame. The plate is composed of: a flat-plate part fixed to the upper surface of the magnet, and having, at an upper surface thereof, a planar portion extending from the outer-edge portion up to a predetermined distance; and a protruding part disposed on the flat-plate part excluding the planar portion, and protruding toward the diaphragm.

Abstract: A low cost sound recording and playback device and a low cost method for wirelessly communicating with, and recharging of, the device. The device utilizes commonly available electronic components generally included in electronic sound producing devices thereby allowing for lowest cost of manufacture. The device includes a low cost low-power processor, general purpose low-cost loudspeaker, and a power source. The method incorporates inductive coupling between an external communication and recharging device, and the internal loudspeakers voice coil of the device. Substantial reductions in cost and space savings are realized by utilizing the internal loudspeaker's voice coil for multiple purposes.

Abstract: A method for manufacturing a spiral coil, the method including: forming a solenoid having a diameter larger than a length by spirally winding an insulated electric wire; forming a spiral coil having folded corners by folding four corners in a circumference direction with respect to the solenoid; fixing the folded corners of the spiral coil; and fixing two terminal portions corresponding to start and end points of the spiral coil to a fixing module. According to the method, a thin and long spiral coil having folded corners is easily manufactured by using a general insulated electric wire. In addition, the spiral coil manufactured by using such a method is applicable to a surface radio frequency (RF) coil optimized for various applications of an electro-magnetic acoustic transducer (EMAT) and enables easy access to an optimized transducer.

Abstract: A multifunctional vibrator includes a frame, a vibrating unit receiving in the frame and including a magnetic circuit part with a magnetic gap, a plurality of elastic members connecting the vibrating unit and the frame, and a voice coil partially inserted into the magnetic gap. Each elastic member includes a retaining portion assembling to an inner face of the frame, a connecting portion attached to the vibrating unit, and an elastic portion extending from the retaining portion to the connecting portion along a devious way. The elastic portion of elastic members includes a first arm capable of generating elastic deformation along a short axis direction of the vibrating unit and a second arm capable of generating elastic deformation along a long axis direction of the vibrating unit.

Abstract: An improved electrically conductive membrane pump/transducer, such as a graphene membrane transducer.

Abstract: An apparatus including a housing having a sound hole; a sound transducer in the housing; and a dust barrier in the housing between the sound hole and the sound transducer. The dust barrier has a deck located in a path between the sound hole and the sound transducer. The deck comprises a dust collection pocket configured to accumulate dust therein and prevent dust from passing through the deck at the dust collection pocket. A sound aperture is provided between the sound hole and the sound transducer such that sound passes by the dust collection pocket between the sound hole and the sound transducer.

Abstract: An electrostatic speaker including a frame; a first electrode installed at a first end of the frame; a second electrode installed at a second end of the frame to be at a predetermined distance apart from the first electrode; a suspension which is arranged between the second electrode and the first electrode and is elastically installed inside the frame; and a diaphragm assembly which is supported by the suspension and has a multilayer structure. The electrostatic speaker adopts a dual electrode structure, has the multilayer structure formed inside the diaphragm assembly, and is provided with a driving chip that applies a bias voltage to the diaphragm assembly by rectifying an audio signal after applying a driving signal that has amplified the audio signal to the dual electrodes. Thus, the invention does not require any external power, and is also capable of maintaining relatively high sensitivity by enhancing the charge density.

Abstract: A speaker includes a base having a groove, a tube received in the groove, a magnet disposed in the tube, a first ring-shaped body and a washer mounted, from top to bottom, on an outer side of the tube sequentially, and a second ring-shaped body connected to an edge of the first ring-shaped body and installed around a wall surface of a rim of the groove. The second ring-shaped body has an inner ring-shaped plate, an outer ring-shaped plate, and a connection segment connected between the inner ring-shaped plate and the outer ring-shaped plate. Therefore, a low-frequency effect thus generated is greatly improved.

Abstract: A speaker device has a magnet, outer yokes, and inner yokes which are assembled so that a magnetic gap is formed between the outer yoke and inner yokes over which a magnetic flux which is generated from the magnet cuts across. A voice coil unit which is linked to a diaphragm is disposed within the magnetic gap, and positioning members determine the positions of the inner yokes and the outer yokes which attach magnetically to the magnet such that a magnetic gap is formed. The speaker device has a magnetic circuit of which the construction facilitates assembly, and recycling of various individual parts is relatively easy.

Abstract: A portable electronic device includes a housing. An opening is formed on the housing and a containing space is formed inside the housing. The portable electronic device further includes a speaker installed inside the containing space in a rotatable manner, a first magnetic component installed on a side of the speaker, a second magnetic component installed inside the housing and disposed on a side of the containing space for attracting the first magnetic component so as to position the first magnetic component on a first location, and a restoring component connected to the speaker for driving the speaker to rotate to a second location so as to expose the speaker outside the opening on the housing when magnetic attractive force between the first magnetic component and the second magnetic component disappears.

Abstract: In one embodiment, a loudspeaker system is provided comprising a motor assembly for driving a diaphragm assembly, where the motor assembly includes a pole piece configured to receive an inductance sleeve. The motor assembly also comprises a permanent magnet, a first shorting ring, and a second shorting ring, with the first and second shorting ring being positioned at least partially within an air gap adjacent the pole piece, and with the first ring positioned adjacent a first side of the permanent magnet and the second shorting ring positioned adjacent a second side of the permanent magnet. The permanent magnet preferably is preferably coated with an insulative material, and may also comprise a plurality of arcuate segments.

Abstract: A loudspeaker includes a movable diaphragm, a resilient centering device for centering and guiding the movement of the diaphragm, and a magnet system for controlling the movement of the diaphragm, where the diaphragm is positioned between the magnet system and the resilient centering device.

Abstract: A transducer magnet for a low profile loudspeaker transducer is provided having a voice coil, surround suspension, diaphragm, and top plate. The transducer magnet may include a first magnet assembly, including an annular outer magnet having an outer perimeter, an outer diameter and an inner diameter. The inner diameter defines a vacant circular center within the annular outer magnet, and the difference in length between the diameter of the circular inner magnet and the inner diameter of annular outer magnet define an annular first magnet assembly air gap. The annular outer magnet includes one or more channels extending inwardly from the outer perimeter of the annular outer magnet to the first magnet assembly air gap, which is configured to receive the voice coil. The channels are configured to pass hookup wires from the voice coil to an external device from the transducer magnet.

Abstract: A composite speaker is provided capable of obtaining larger sound output than that of a conventional flat panel speaker and flat speaker when input with an audio signal of the same strength.

Abstract: A flat acoustic transducer (100) includes a permanent magnet (10) and a magnetic member (20), which are arranged adjacent to each other with a predetermined interval, a flat vibrating membrane (30), provided facing the permanent magnet (10) and the magnetic member (20), and at least one coil (40), fixed to the vibrating membrane (30). In the flat acoustic transducer (100), an electrical signal is applied to the coil (40), to obtain vibration force (F) on the vibrating membrane (30) by way of a magnetic flux ? generated between a magnetic pole face (12) of the permanent magnet (10) and the magnetic member (20), a step (50) is provided between the magnetic pole face (12) and the upper face (22) of the magnetic member (20), while at least part of a winding (42) of the coil (40) at the time of no application of an electrical signal is arranged inside the step (50).

Abstract: The present disclosure relates to a voice coil lead wire and a loudspeaker using the same. The voice coil lead wire includes a lead wire structure and a core wire structure. The lead wire structure includes at least one lead wire. The core wire structure includes at least one carbon nanotube wire structure. The carbon nanotube wire structure includes a plurality of carbon nanotubes. The at least one lead wire winds around the at least one carbon nanotube wire structure in a helix manner or a twisted manner.

Abstract: An earphone includes an earphone casing inside which a sound path that guides sound to a sound discharging hole is formed, and an acoustic transducer disposed inside the earphone casing. The acoustic transducer includes an accommodation casing having accommodated therein a yoke on which paired magnets disposed so as to face each other are mounted, a coil to which a driving current is supplied, an armature provided with a vibrating part vibrating when the driving current is supplied to the coil, the vibrating part being disposed between the paired magnets, and a diaphragm coupled to the vibrating part of the armature, a sound output hole is formed on a surface that faces a vibration surface of the diaphragm in the accommodation casing, and the acoustic transducer has the sound output hole disposed in the earphone casing so that the sound output hole is acoustically coupled to the sound path.

Abstract: A composite speaker is disclosed that can more easily be made thin and small, and is configured so that the assembly process of the speaker is easy. A first space that opens to the rear is formed in a main yoke that forms a magnetic field emitter, and a magnetic gap is formed in the first space. A first voice coil, connected to an inner peripheral end of a first diaphragm whose surface area is large, is inserted into the first magnetic gap toward the front direction. A second space that passes through from front to back is provided in the main yoke, a second magnetic field emitter is mounted therein, and a second diaphragm whose surface area is small is provided in front thereof. Because of the structure in which the second magnetic field emitter is housed within the first magnetic field emitter, the front-to-back dimension of the speaker can be reduced.

Abstract: In a loud speaker, the diaphragm has a protruded part protruding on a yoke side on the inside and in the vicinity of an inner coupling part as a coupled portion to a voice coil. The loud speaker can be manufactured with the voice coil accurately positioned with respect to a diaphragm, and the voice coil is accurately vibrated vertically inside a magnetic gap. The possibility of the voice coil coming into contact with a plate and a yoke as a magnetic circuit body of the loud speaker can be reduced, thereby to improve production efficiency and a yield at the time of manufacturing the loud speaker.

Abstract: Apparatus, methods and computer program products are provided to produce tactile feedback from sound. The apparatus is a sound cavity apparatus for a portable communication device and includes: at least one loudspeaker; and at least one cavity. At least one surface of the at least one cavity is configured to vibrate. The sound cavity apparatus is attached to the portable communication device and the sound cavity apparatus is configured to transmit vibration to the portable communication device.

Abstract: Disclosed herein is a method of manufacturing an inertial sensor. The method of manufacturing an inertial sensor 100 includes (A) applying a polymer 120 to a base substrate 110, (B) patterning the polymer 120 so as to form an opening part 125 in the polymer 120, (C) completing a cap 130 by forming a cavity 115 on the base substrate 110 exposed fro the opening part 125 through an etching process in a thickness direction, and (D) bonding the cap 130 to a device substrate 140 by using a polymer 120, whereby the polymer 120 is applied to the base substrate 110 in a constant thickness D3, such that the cap 130 may be easily bonded to the device substrate 140 by using the polymer 120.

Abstract: The instant disclosure relates to a loudspeaker, which includes a ferrite core, a voice coil, and a movable membrane. The voice coil is wound around the core and cooperatively defining an exciting device. The movable membrane is disposed in close proximity to the exciting device with a gap formed thereinbetween. The loudspeaker constructed without permanent magnets takes up less space and is more cost effective. Thus, the loudspeaker has a broader application range.

Abstract: An inertial vibration exciter having a magnet assembly defining an annular gap, a coil assembly disposed in the annular gap, suspension means mounting the coil assembly for reciprocating movement in the gap, means coupling the coil assembly to a member to be vibrated, and a hermetically sealed housing in which the magnet assembly, the coil assembly, the suspension means and the coupling means are disposed. The housing may comprise a heat sink thermally coupled to the magnet assembly and the heat sink may be resiliently coupled to the housing. The coupling means may comprise a plate-like member to which the coil is rigidly attached and of a size substantially greater than the diameter of the coil. The plate-like member may be resiliently coupled to the housing.

Abstract: Improved approaches for providing a speaker within a housing of a portable electronic device are disclosed. The housing of the portable electronic device can be compact, such as a low profile housing. In one embodiment, an acoustic chamber for a speaker can be formed internal to a housing for a portable electronic device using non-dedicated space. In another embodiment, irregular surfaces can be sealed so that an acoustic chamber for a speaker can be formed internal to a housing for a portable electronic device.

Abstract: In one embodiment, a loudspeaker system is provided comprising a motor assembly for driving a diaphragm assembly, where the motor assembly includes a pole piece configured to receive an inductance sleeve. The motor assembly also comprises a permanent magnet, a first shorting ring, and a second shorting ring, with the first and second shorting ring being positioned at least partially within an air gap adjacent the pole piece, and with the first ring positioned adjacent a first side of the permanent magnet and the second shorting ring positioned adjacent a second side of the permanent magnet. The permanent magnet preferably is preferably coated with an insulative material, and may also comprise a plurality of arcuate segments.

Abstract: An electro-acoustic transducer includes an insulative flexible substrate, a base, and a magnetic field generator. The base includes a cavity and a magnetic portion disposed below the cavity. The insulative flexible substrate is configured to cover the cavity. The magnetic field generator can be disposed on the insulative flexible substrate and corresponds to the cavity. The magnetic field generator can produce a magnetic field and a reverse magnetic field to cause the magnetic field generator and the magnetic portion of the base to attract and repel each other, thereby vibrating the insulative flexible substrate.

Abstract: Said electrodynamic speaker structure having MEMS technology, comprising a stator-forming means (2), diaphragm-forming means (3), and resiliently shape-changing means (4) for connecting all of said means, is characterized in that the stator-forming means (2), diaphragm-forming means (3), and connecting means (4) are made of a single part by machining a silicon chip.

Abstract: An inductive electroacoustic transducer which includes a yoke, a magnetic circuit system disposing in the yoke, a vibration membrane which is driven by the magnetic circuit system, a cover coupled on one side of the yoke and it has a plurality of sound holes, and a circuit board which has a positive pole and a negative pole for importing acoustic electrical signals. The circuit board also has an inductive soldering disc and it is coupled to another side of the yoke. A portion of the yoke is connected to the inductive soldering disc with which it is conducted.

Abstract: A speaker includes a base having a groove, a tube received in the groove, a magnet disposed in the tube, a first ring-shaped body and a washer mounted, from top to bottom, on an outer side of the tube sequentially, and a second ring-shaped body connected to an edge of the first ring-shaped body and installed around a wall surface of a rim of the groove. The second ring-shaped body has an inner ring-shaped plate, an outer ring-shaped plate, and a connection segment connected between the inner ring-shaped plate and the outer ring-shaped plate. Therefore, a low-frequency effect thus generated is greatly improved.

Abstract: Actuator apparatus for generating a physical effect, at least one attribute of which corresponds to at least one characteristic of a digital input signal sampled periodically in accordance with a clock, the apparatus comprising at least one array of moving elements each constrained to travel alternately back and forth along a respective axis in response to an alternating electromagnetic force applied to the array of moving elements, at least one latch operative to selectively latch at least one subset of said moving elements in at least one latching position thereby to prevent the individual moving elements from responding to the electromagnetic force, an electromagnetic field control system operative to receive the clock and, accordingly, to control application of the electromagnetic force to the array of moving elements, and a latch controller operative to receive the digital input signal and to control the latch accordingly.

Abstract: An edge portion includes a center portion, one end and an other end. As seen in a cross section of a vibration plate in the radial direction, the center portion, the one end and the other end each are formed in a circular arc such that the edge portion forms a convex so as to protrude in a direction in which the protruding shape protrudes. The radius of curvature of the circular arc of the center portion is not less than the radius of curvature of the circular arc of each of the one end and the other end. Accordingly, a vibration plate allowing a decrease in the lowest resonance frequency while suppressing the edge portion from being brought into a tensioned state, a speaker unit provided with the vibration plate and a portable information terminal can be provided.

Abstract: There is provided a linear vibrator including: a housing having an internal space formed therein; a magnetic field unit including a yoke disposed in the internal space and having a magnet and a magnet insertion part formed therein, and interacting with a coil to which power is applied to linearly move in the internal space, the magnet insertion part determining an insertion position of the magnet; and an elastic member disposed in a space between the housing and the magnetic field unit and elastically supporting linear movement of the magnetic field unit.

Abstract: A flat thin dynamic speaker which includes a motor unit, a suspension unit, a radiating unit and a frame arranged in such a manner that the motor unit and the suspension unit are at the same plane while the radiating unit is on top of the motor unit such that the thickness of the speaker assembly is reduced while the performance of the speaker assembly is maintained or even improved. Also, the speaker can be made into a quadrangular, polygon or a spherical structure. The speaker further has a surround at a level lower than the radiating unit without utilizing the radiating surface of the radiating unit such as a maximized radiating surface is provided, and includes a dual side voice-coil actuation to the radiator unit, thereby providing a slim and flat speaker assembly with high power output.

Abstract: A manufacturing method of a paper making part for a loudspeaker has freedom of adjusting a characteristic and a sound quality, and has a higher productivity. Accordingly, a fibrillating step of a paper making material is achieved by an explosive crushing step. Alternatively, the step is achieved by a mixing step of a paper making material and a liquid, a material micro-fabricating step of applying a pressure to a mixed solution obtained by the mixing step so as to pass through an orifice and thereafter run into a device wall, and a paper making step including the micro-fabricated material.

Abstract: An elongated loudspeaker having high sound quality includes an elongated flat-plate-shaped diaphragm, a frame having an opening portion larger than the diaphragm, an edge placed between an inner periphery of the frame around the opening portion and an outer periphery of the diaphragm allowing the diaphragm to vibrate, a coupling cone extending from a rear surface of the diaphragm and including two elongated portions arranged parallel to a longitudinal direction of the diaphragm, a voice coil wound around at least the two elongated portions, and a magnetic circuit that imparts, to the voice coil, a driving force for generating sound. A distance between the two elongated portions of the coupling cone is smaller at end positions than at root positions. The elongated portions are shaped/sized such that the entire two elongated portions are included within magnetic gaps of the magnetic circuit when the coupling cone vibrates along with the diaphragm.