Abstract: An acoustic diaphragm is disclosed having a plurality of acoustic elements supported by the diaphragm. In a preferred form, each element is coupled to a driver and extends radially at a uniform acute angle to a normal of the driver. In the preferred embodiment, a plural layer of the elements is arranged so that the direction of each element is out-of-phase relative to each other, preferably in the range of approximately ninety degree. An element is also supplemental to the conventional acoustic diaphragm. The improved acoustic diaphragm is used in electric acoustic and acoustic electric transducer systems having improved performance at wide frequency range.

Abstract: A loudspeaker containing an improved voice drive structure including a convex diaphragm adhered with a voice coil before being mounted to a modified damper integrated with a surround to increase directivity of output of sound effects and effective expand sound field of the loudspeaker.

Abstract: On one surface of a piece of wooden sheet, a cloth or paper is adhered to make an adhered sheet. An approximately V-shaped notch is provided on the adhered sheet, the adhered sheet is wetted to be softened, and a lubricant which acts to keep water is impregnated thereinto. Edge portions of the notch are overlapped, and the adhered sheet is tentatively molded in an approximately horn shape by a first hot press molding. The adhered sheet is then dried, impregnated with thermosetting resin, and half-dried. The adhered sheet is subject to a second hot press molding. A moisture-proof agent is applied on the adhered sheet, a center hole for a voice coil and periphery are removed to make a speaker diaphragm having a predetermined dimension and shape.

Abstract: Provided is a diaphragm edge of a speaker which is formed by compressing a material including silicon rubber and has an emboss portion on a front surface thereof so that sensitivity of sound is improved. Also, a diaphragm edge of a speaker is formed by compressing a material including silicon rubber and powdered viscose rayon and has an emboss on a front surface thereof.

Abstract: A speaker system having a structure in which the room surrounding the first diaphragm and the room adjacent to the second diaphragm are acoustically coupled. The second diaphragm has coating on a surface. Applying the coating to the second diaphragm enhances the reliability and performance of the speaker system. Besides, the diversely definable geometry of the diaphragm allows an electronic device employing the speaker system or the speaker module to have flexibility in design.

Abstract: A substrate (580) made by a thin magnesium plate having a thickness of at most 60 ?m and bent in a predetermined shape is subjected to anodic oxidation using an alkali-mixture aqueous solution containing metallic salt with a pH 12 or more so that porous anodic oxide coatings (571) are formed on the surfaces thereof. A first treated substrate (581) having the anodic oxide coatings (571) is immersed in a bath of a dye (571B), which fills the pores (571A) of the anodic oxide coatings (571) and dyes the substrate, providing a second treated substrate (582). The second treated substrate (582) is subjected to electrodeposition using electrodeposition paint made mainly of acrylic resin, forming electrodeposition coatings (572) on the anodic oxide coatings (571). A magnesium diaphragm is thereby produced, which is thin and has sufficient sensitivity and desired characteristics. The diaphragm thus dyed has metallic gloss and hence acquires a high decorative value.

Abstract: A portable electronic device of the present invention includes a cabinet and a speaker placed inside the cabinet. The cabinet has one or more sound radiating holes in an area opposed to a front face of the speaker. A dustproof plate formed by attaching a dustproof net and a reinforcing sheet to each other is placed on the front face of the speaker or an inner face of the cabinet opposed to the front face. The reinforcing sheet has a plurality of openings formed for passing through sound waves from the speaker.

Abstract: A loudspeaker includes a diaphragm, an edge, and a voice coil. The diaphragm includes a groove having a concave cross section. Also, the diaphragm is in a horizontally or vertically elongated shape. The edge is coupled to an outer circumference of the diaphragm, and has a roughly half-round shaped cross section. The voice coil is bonded to the groove. The voice coil is thicker than a depth of the groove. Also, the voice coil has a cross section in which a dimension in a direction along a plane of the diaphragm is longer than a dimension in a direction perpendicular to the plane of the diaphragm.

Abstract: A speaker diaphragm which has a high rigidity and can improve sound transmission speed for better sound quality is provided. The speaker diaphragm contains fibers of 3 to 50 mm length mixed in matrix resin. The fibers are oriented radially from center to periphery in surface layers of the diaphragm, while they are oriented in different directions in a middle layer. After setting the resin, these fibers are fixed in the matrix resin with certain tension applied thereto.

Abstract: A high efficiency loudspeaker without a damper is provided. The loudspeaker includes magnetic circuit having a magnetic gap and a voice coil member, which has movable coil, disposed in the magnetic gap of the magnetic circuit. The loudspeaker also includes a diaphragm, whose inner peripheral part is linked with the voice coil member, outside the magnetic gap and a frame linked with an outer peripheral part of the diaphragm via a first edge. An inner peripheral part of a suspension holder is linked with the voice coil member at a linked position which is closer to the magnetic circuit than a linked position of the diaphragm and the voice coil member. An outer peripheral part of the suspension holder is linked with a frame via a second edge. The first edge and the second edge are substantially symmetrical with each other about a median of a first edge and a second edge.

Abstract: A diaphragm in one mode of the present invention comprises an outer shape section having a circle with one diameter, or a shape of a polygon to be inscribed in a circle with the one diameter; an inner shape section protruding in one direction with regard to a plane including the outer shape section, wherein a shape formed by projecting the inner shape section on the plane is rotationally symmetric about the central axis of the circle; and a vibrating face section linking the outer shape section and the inner shape section and having an inclined face inclined to the central axis, wherein any one of cross-sectional shapes of the vibrating face section is rotationally symmetric about an eccentric axis which is eccentric with regard to the central axis, the cross-sectional shapes being defined by a plane intersecting perpendicularly to the central axis. An electroacoustic transducer uses the above diaphragm.

Abstract: A novel shallow speaker has a novel spidercone coaxial with and optionally having a radially inner spidercone flange suspended in a circumferential adhesive well affixed to the former. An inner rearward flange of the flat annular diaphragm is suspended in the circumferential adhesive well and the well is filled with epoxy. The spidercone has a frustroconical portion having a minimum radius smaller than the maximum magnet assembly radius and a maximum radius greater than the maximum magnet assembly radius. The spidercone has a spider portion integral with the larger end of the frustroconical portion and attachable to the basket by a tangential flange. The tinsel is interwoven with the spidercone in a way that reduces the risk of breaking and shorting. The diaphragm is substantially flat and coplanar with the top edge of the narrow surround when at rest.

Abstract: There is disclosed a small-size speaker in which distortion is not easily caused when a diaphragm vertically movers for sound reproduction. The speaker includes: a bottom-equipped cylindrical frame having an opening at the top; a magnetic circuit arranged on the inner bottom of the frame; a voice coil whose coil portion is arranged in a magnetic gap of the magnetic circuit; a diaphragm arranged at the opening of the frame and its inner circumference is fixed to the voice coil while its outer circumference is fixed to the frame via a first edge; and a support body having one end fixed to the side of the diaphragm having the magnetic circuit and the other end fixed to the vicinity of the magnetic circuit via a second edge. The first edge has a shape substantially similar to the shape of the second edge with respect to the boundary between the first edge and the second edge.

Abstract: A suspension with a plurality of roll sections each of which has a semi-cylindrical shape from a cross-section view. The roll sections are disposed side by side based on a straight line connecting two points on an inner periphery or an outer periphery. The roll sections form a closed loop in a manner that a roll section of the roll sections being disposed first adjoins a roll section of the roll sections being disposed last. Adjacent roll sections are coupled with each other through a boundary section forming a continuous three dimensional curved surface. A linearity of compliance improves, and generation of distortion or rolling is restricted using the suspension.

Abstract: Diaphragm (9) has through-hole (10) for fixing a voice coil at its center part, and has a fixing part of edge (12) at its outer periphery whose shape is substantially circular. The shape of the outer periphery of diaphragm (9) is formed as follows: first circle and second circle (9A, 9B) are overlapped each other with their center points (9a, 9b) displaced in such a manner that at least one part of an outer periphery of first circle and second circle (9A, 9B) forms a part of the substantially circular outer periphery of an entire shape. Signal reproduction characteristics can be flattened as much as possible by reducing a resonance level.

Abstract: A preferably elongated loudspeaker (LS), which preferably comprises a cylindrical moving coil (SP) and an elongated diaphragm (M) with an elongated fastening part (B) and an annular retaining part (H) lying within the fastening part (B), and with corrugations (S1) extending in radial directions, wherein the diaphragm (M) comprises an arrangement for reducing its stiffness in at least one narrow region (SM1, SM2), which arrangement is present between the fastening part (B) and the retaining part (H). In a preferred embodiment comprising an arrangement of the corrugations (S1) in the at least one narrow region (SM1, SM2) the corrugation density is smaller than the corrugation density in at least one wide region (BM1, BM2). Preferably, the diaphragm (M) furthermore comprises an additional corrugation (S2) in the at least one narrow region (SM1, SM2), which additional corrugation (S2) extends transversely to radial directions.

Abstract: A diaphragm (1) of a light sound converter which has a high performance, is suitable for mass-production and has a slit (1s) formed therein. A light emitting element and a light receiving element are disposed at positions opposed to a reflective part (1a) of the diaphragm (1) having a pressure receiving surface part (1d) and the reflective part (1a), and light is radiated from the light emitting element to the reflective part (1a) of the diaphragm (1) and the reflected light from the reflective part (1a) is received by the light receiving element, whereby the position of the diaphragm (1) can be detected.

Abstract: A loudspeaker arrangement in a motor vehicle includes at least one loudspeaker, which is able to be driven by an audio processor, the loudspeaker being arranged as at least one electrostatic planar loudspeaker.

Abstract: A loudspeaker in which the voice coil diameter is so large that the voice coil is axially beneath the suspension roll of the surround. The surround has an overlapping suspension roll such that the inner portion of the surround is coupled to the diaphragm well inward of the bobbin. Such a transducer having greatly extended low frequency abilities by virtue of its wider, softer suspension roll enabling a much lower resonant frequency, and by virtue of its maximum sized magnet and voice coil yielding increased motor strength and power handling. Additionally, the dome diaphragm can now be vented through the portion of the dome that is beneath the surround roll, releasing the trapped back pressure below the diaphragm, thereby further lowering the resonant frequency.

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

Abstract: A loudspeaker is provided that satisfies requirements for both a small size and a high sound pressure. In addition, the heat capacity of the magnetic circuit and the heat dissipation of the voice coil are improved in this loudspeaker. Using at least two pieces of bar magnets (21), an outer magnet type magnetic circuit is structured in which the magnetic gap comprising an upper plate (22) and a lower plate (23) has a straight section. Also, the configuration of the voice coil (28) is that of a track.

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 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: A liquefied paper material is used as raw materials. A paper frame member 1 supporting a vibrating plate is paper-skimmed and formed. On paper-skimming and forming, a central hole for use in voice coils, air-release hole 1a releasing air pressure in a rear of the vibrating plate to outside due to vibration of the vibrating plate. A loudspeaker system is manufactured using the paper frame member 1.

Abstract: A linkage assembly is used for mechanically coupling an armature and a diaphragm of a balanced receiver, the linkage assembly formed from a first linkage member displaced from a strip of stock material relative to the plane of the stock material and a second linkage member displaced from the strip relative to the plane. The first and second linkage members are then joined while secured to the strip. At least one severable connecting member securing the linkage member to the strip is severed to release the linkage member from the strip for assembly of the linkage member into the receiver. A method of forming a three-dimensional structure from flat stock is used to form the linkage assembly.

Abstract: A power efficient, acoustical Helmholtz resonator foghorn including a plurality of electrical emitters, some of which are redundant, arrayed at one end of a blocked tube with a plurality of exhaust ports located therein surrounded by a standoff tubular member. The foghorn tuned to provide a high pitch thus providing a compact horn having an acoustical path capable of producing an exceptional wavelength in a generally concentric horizontal sound propagation the horn configurable for use as either a one-half mile or two mile marine navigational aid for offshore structures, buoys, and the like.

Abstract: A planar magnetic driver includes covering plates that are maintained under tension to form a buckled or curved surface, thereby providing for a larger magnetic gap, and allowing for a larger excursion of the diaphragm and extended lower frequency response. Another aspect of the driver includes a corrugated region along the periphery of the diaphragm, which provides increased internal dampening.

Abstract: A planar magnetic driver includes covering plates that are maintained under tension to form a buckled or curved surface, thereby providing for a larger magnetic gap, and allowing for a larger excursion of the diaphragm and extended lower frequency response. Another aspect of the driver includes a corrugated region along the periphery of the diaphragm, which provides increased internal dampening.

Abstract: A magnetic circuit includes a cylindrical yoke member having an inner circumferential surface and a collar formed at one end thereof and turned back substantially at right angles, and a plurality of permanent magnet segments of a partially circular arc in cross section having respective outer surfaces attracted magnetically to the inner circumferential surface of the cylindrical yoke member and respective one end faces attracted magnetically to the collar of the cylindrical yoke member. The magnetic circuit is manufactured by a method including the steps of magnetically attracting the permanent magnet segments to an outer peripheral surface of a center rod, causing the magnet segments in a magnetically attracted state to face the yoke member, using a nonmagnetic supporter to regulate the magnet segments in position, extracting the center rod from the magnet segments in a position-regulated state, and magnetically attracting and fixing the magnet segments to the yoke member.

Abstract: A speaker device for improving mid/high-range frequencies includes a magnetic base, a frame annularly mounted to the magnetic base, a cone mounted to an inner side of the frame, a voice coil mounted to the cone and suspended in a gap of the magnetic base, and a deadening phase plug mounted on a central portion of the magnetic base. The magnetic base includes a T-iron, a magnet, and a pole plate. The deadening phase plug is made of a sound-absorbing material for absorbing and eliminating sound waves generated by the voice coil and the cone.

Abstract: An improved in-wall speaker assembly providing better performance and less intrusion than prior art speakers. The speaker assembly is oriented such that the driver fires vertically, parallel to the wall studs, rather than horizontally and perpendicular to the wall studs. The cone and surround of the speaker assembly are generally rectangular and/or conform to the area available between studs. Additionally, the cone is not attached to the voice coil, but is connected to the voice coil by a shaft which transmits the energy from the voice coil to the cone. In another aspect of the invention, the cabinet or housing includes two housings.

Abstract: A 4? steradian omni directional tweeter has a closed hollow body acting as a dynamic reflector connected at the center topside of a diaphragm. A piezoelectric element or a voice coil drives the diaphragm. The closed hollow body can be sphere, spheroid, prolate spheroid, ellipse, ellipsoid, prolate ellipsoid, cylindrical, oblate shape, egg shape. In one embodiment, the closed hollow body is made of substance that has a light, rigid, seamless and uniform thickness similar to a bird or chicken egg. The dynamic reflector in the present invention moves simultaneously with its diaphragm to produce an omni directional radiation pattern. Compared with a static reflection system, the dynamic reflection system provides better phase response. Hence the reproduced sound is more realistic, has better precision, clarity and staging.

Abstract: The present invention provides a diaphragm for a loudspeaker which suppresses divided resonance and shows a stable sound-pressure-frequency characteristic, and a loudspeaker using the diaphragm. The diaphragm includes three or more thick parts (11c) of odd numbers formed radially from a center part to an outer periphery, and semi thick part (11d) formed between the thick parts so as to become thinner gradually from the outer periphery to the center part. Web shaped thin part (11e) is formed at an inner part of the semi thick part.

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

Abstract: A squeeze-stretch (also called, herein push-pull) loudspeaker or driver, such as an electret, can operate in an active noise reduction (ANR) earplug application. Other embodiments of a squeeze-stretch loudspeaker, such as piezoelectric bimorph and balanced armature, operate in a similar way, although they will differ in detail. Other applications, such as earphones for communication and entertainment, will benefit from the compact arrangement of components in a squeeze-stretch design. The advantages are a greater sound output from a smaller package, a smooth frequency response, and because of the diaphragm arrangement, less sensitivity to vibration.

Abstract: A sound hole is provided in a silicon substrate. A diaphragm electrode is secured to the upper surface of the silicon substrate via at least one fixed end so as to cover the sound hole of the silicon substrate. The diaphragm electrode is provided with four projections extending in respective directions of diameter orthogonal to each other. The fixed end is provided in one of the four projections. Hinge shafts are provided in the other three projections. A backplate electrode is provided above the diaphragm electrode so as to form a capacitor.

Abstract: A loudspeaker device 1 includes an acoustic diaphragm 5 composed of a domed diaphragm 11, an edge-like diaphragm 13, and a junctional flat portion 12 which joins those domed and edge-like diaphragms, and a joined portion 23 where an end surface of a bobbin 4 of a voice coil or of a conductive 1-turn ring 3 is stuck and fixed to the junctional flat portion 12 or a reinforcement ring 15; and the reinforcement ring 15 is stuck and fixed to the junctional flat portion 12 from above or from under, thereby increasing the mechanical strength of the junctional flat portion 12 of the acoustic diaphragm 5. A loudspeaker device in which unnecessary vibrations are removed and also the quality of acoustic signals is excellent up to high range is provided.

Abstract: A speaker cabinet including at least one bass speaker having a voice coil aligned by a magnetic fluid without a ‘spider’ and having an anodised metal cone, and at least one further speaker having a thin conductive membrane, and having integrated preamplifiers and at least one power amplifier, for use with musical instruments, for playing small to medium sized venues and/or for use as a personal monitor speaker on a performance stage for playing medium to large venues. Multiple channels are provided to amplify more than one instrument, and microphone inputs are provided for acoustic instruments and/or voice amplification. A line level input is also provided for external signal sources. An auxiliary input is provided to facilitate the monitoring of accompanying musicians, thus permitting the loudspeaker system to also function as a stage monitor. Reverberation and notch filtering, as well as tone control, may also be provided.

Abstract: In manufacturing a speaker, ultrasonic complex vibration welding is applied at least to: a process of fixedly putting together a magnet, a pot yoke a the pole piece; a process of fixing, to a portion of an inner circumference of a frame, an outer periphery of a spider, which has its periphery fixed to a bobbin; a process of fixing to a portion of the frame an outer circumferential edge of a surround, which has its inner circumferential edge fixed to an outer periphery of a diaphragm whose inner periphery is fixed to the bobbin; and a process of fixedly connecting both ends of each of tinsel leads respectively to terminations of a voice coil and to terminals.

Abstract: A loudspeaker includes a box-form structure made from stiff lightweight sheet material to define a plurality of faces, at least one face of the structure forming a panel-form bending wave acoustic radiator, and an electro-acoustic vibration transducer coupled thereto to apply bending wave energy to the radiator to cause it to radiate an acoustic output when an input signal is applied to the transducer. The box-form structure is collapsible, so that the box-form structure can be stored and transported in a flat form and erected as a box when required as a loudspeaker.

Abstract: A device is provided for actuating a membrane arranged in an opening to a space, and a vehicle having such a device. The membrane has a first surface and a second opposite surface, and is limited by an edge area. The device includes a first strip to be attached to the second surface of the membrane in the edge area, and a second strip to be attached to a surface of a frame portion extending around the opening. An exchanging member is arranged between and connecting the first strip and the second strip. An actuating member is arranged to transfer a reciprocating primary movement to the exchanging member converting the primary movement to a reciprocating secondary movement, which has a longer length of stroke than the primary movement and acts on the strips to move towards and away from each other.

Abstract: Electro-dynamic loudspeakers typically include a diaphragm that is secured to a frame and has a conductor applied to at least one surface of the diaphragm. The conductor is connected to a power amplifier for providing electric current through the linear traces of the conductor that interact with magnetic fields generated by magnets that are mounted to the frame. The interaction between the current passing through the conductor and the magnetic fields cause vibration in the diaphragm that creates the sound that is heard from the electro-dynamic loudspeaker. Different methodologies of forming the conductor are provided for simplifying the manufacturing process and for locating the conductor closer to the magnetic field generated by the magnets.

Abstract: An electromagnetic transducer such as an audio speaker which includes an asymmetric diaphragm to deliver smooth frequency response with reduced distortion by reduction of common modes in the diaphragm. Other benefits such as asymmetric directivity patterns can be realized. The asymmetric cone has a perimeter OD at which a surround may be coupled, and an ID at which a bobbin or spacer may be coupled. The center of the ID is not coincident with the center of the OD. The transducer further includes a stabilization mechanism for reducing rocking of the diaphragm assembly. The stabilization mechanism may include mass balancing of the diaphragm and/or adjustments to the location or symmetry of the suspension components.

Abstract: A piezo-electric speaker capable of easily ensuring a uniform broad-band sound pressure and reproducing a large acoustic signal has a piezo-electric member (10) to generate vibration in accordance with an applied electric signal. A piezo-electric vibration plate (15) is adhered to the piezo-electric member (10). The piezo-electric vibration plate (15) converts the vibration to sound. The thickness of the piezo-electric vibration plate (15) is formed so as to be different in accordance with the distance from the vibration center of the piezo-electric member (10).

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

Abstract: This invention provides a speaker apparatus that outputs sound having smooth frequency characteristics. To solve the inconvenience with the prior art, this invention is a speaker apparatus comprising a diaphragm and a cylindrical-shaped coil bobbin, and not comprising a center cap that covers the coil bobbin, and where the diaphragm is located such that it rests on the coil bobbin, and the coil bobbin and diaphragm are located such that sound from the coil bobbin and diaphragm is not reflected.

Abstract: The invention is a suspension element having an outer edge and an inner edge. The suspension element, such as a spider or surround, varies in shape along at least a portion of the suspension element to help relieve both the radial and tangential stress placed on the suspension element when it is stretched. The shape employed in the suspension element allows the suspension element to stretch more easily, creating a higher performance speaker of the same size by increasing the diaphragm excursion and voice coil movement.

Abstract: An electromagnetic transducer such as an audio speaker which includes an asymmetric diaphragm to deliver smooth frequency response with reduced distortion by reduction of common modes in the diaphragm. Other benefits such as asymmetric directivity patterns can be realized. The asymmetric cone has a perimeter OD at which a surround may be coupled, and an ID at which a bobbin or spacer may be coupled. The center of the ID is not coincident with the center of the OD. The transducer further includes a stabilization mechanism for reducing rocking of the diaphragm assembly. The stabilization mechanism may include mass balancing of the diaphragm and/or adjustments to the location or symmetry of the suspension components.

Abstract: A panel-shaped loudspeaker comprising a panel (1) having a first main surface (1A) and a second main surface (1B) parallel to the first main surface and further comprising an exciter (3) positioned at the first main surface. When the exciter is energized the panel is capable of sustaining bending waves and has a distribution of resonant modes of its natural bending wave vibration, which results in an acoustic radiation. The loudspeaker has a tuning element (17) extending near the second main surface of the panel and positioned opposite the exciter so as to form a resonant cavity (18) between the panel and the exciter.

Abstract: A speaker cone is provided that contains a base portion, and the base portion has a front end and a rear end. The front end contains a plurality of discontinuities such that a first distance from a reference point on a longitudinal axis of the base portion to a first point on the front end is different than a second distance from the reference point to a second point on the front end. By creating the plurality of discontinuities in the front end of the base portion, the distortion or reduction in the amplitude of a flexural wave generated by the speaker cone is dramatically reduced.