Abstract: A loudspeaker transducer diaphragm or cone (e.g., 201, 301 or 401) is configured with arcuate protrusions that project distally from the main forward or distal surface 230 to provide stiffening and a break-up of resonant vibration modes when the loudspeaker is in use. The protrusions (e.g., 210, 310 or 410) are convex on one surface 230 and concave on the opposite surface 234, so their average thickness is similar to the frustoconical areas of the cone, i.e. they are shell-like in nature rather than solid mounds or walls. The protrusions 210 are generally curved as they run radially from the inner opening 204 to the outer peripheral edge to encourage modal break-up (suppressing strong vibrational modes, e.g., as in region 155).

Abstract: Electrodynamic drive for a flat loudspeaker having an enclosure where the following components are installed: a magnetic system, a cylindrical coil fixed to the frame, a sound-emitting membrane attached to the cylindrical coil former, a system holding the coil within a magnetic gap, and flexible wires for supplying an electrical signal to the coil. While the magnetic system is made as a cylindrical permanent magnet, a ferrite ring with the above mentioned cylindrical magnet and washers, joining them into a single structure.

Abstract: Circular flat panel loudspeaker comprising a resonant with a rear surface opposite the front surface. An exciter is provided at an axial centre of panel and coupled to the rear surface of the panel to cause the panel to vibrate, on operation of the exciter, to generate sound. A frame is provided for mounting in the surface and having the rear surface of the panel fixed thereto around the whole of the outer boundary of the panel, such that when mounted in the mounting surface and when the panel is caused by the exciter to vibrate on operation of the exciter, the outer boundary of the panel is fixed relative to the mounting surface.

Abstract: Provided are a speaker unit and a speaker device. A main body of the speaker unit is a rectangular bowl-shaped structure, and comprises a suspension system, a magnetic circuit system having an annular magnetic gap, and a bowl-shaped frame connecting the suspension system and the magnetic circuit system. The bowl-shaped frame accommodates the suspension system and the magnetic circuit system. The magnetic circuit system is fixed to the interior of the bowl-shaped frame. The suspension system comprises a diaphragm and at least one voice coil connected to a bottom portion of the diaphragm. The magnetic circuit system comprises at least one magnetic circuit assembly matching the voice coil. One end of the voice coil is connected to the diaphragm by means of a voice coil frame. The other end of the voice coil is suspended within an annular magnetic gap of the magnetic circuit assembly.

Abstract: A method of forming a device having a compliant member includes providing an elastomeric layer in an uncured state. The elastomeric layer is pre-cured to increase its viscosity. Subsequently, a bobbin and housing, each having an end, can be positioned such that their ends extend at least partially into the elastomeric layer. The elastomeric layer is cured to secure it to the bobbin housing. Examples of pre-cure and cure operations include one or more of a thermal cure, evaporative cure and ultraviolet cure, and the application of moisture, microwave energy and chemical additive. Due to the increased viscosity after the pre-cure, the migration of elastomeric material is substantially reduced relative to an uncured elastomeric material. The reduction in elastomeric material migration results in smaller menisci formed along the walls of the housing and bobbin, and reduced thinning of the compliant member formed at their ends.

Abstract: There is provided a diaphragm or a dust cap configured to emit a sound wave and an electrodynamic speaker unit including the diaphragm or the dust cap. The speaker unit is configured so that a great peak dip of sound pressure frequency characteristics due to influence of a divided vibration mode can be prevented and excellent reproduced sound quality can be provided. In the diaphragm or the dust cap, a recessed-raised portion imitating a wing of an insect is formed at least on one surface of a diaphragm portion configured to emit a sound wave. Preferably, the recessed-raised portion is formed based on data obtained by measurement of an actual shape of a wing vein of the insect or data of a Voronoi diagram imitating the wing vein of the insect.

Abstract: An embodiment of an integrated microphone structure. The integrated microphone structure includes a first silicon substrate patterned as a first plate. A silicon oxide layer formed on one side of the first silicon substrate. A second silicon substrate bonded to the first substrate through the silicon oxide layer such that the silicon oxide layer is sandwiched between the first and second silicon substrates. A diaphragm secured on the silicon oxide layer and disposed between the first and second silicon substrates such that the first plate and the diaphragm are configured to form a capacitive microphone.

Abstract: An electro-acoustic product, and more particularly to a metal diaphragm and a speaker. The metal diaphragm includes a hemispherical diaphragm portion that is provided with a central convex, a hemispherical diaphragm portion periphery is extended in a horizontal direction and configured to form an annular flat diaphragm portion, a annular flat diaphragm portion periphery is folded toward the convex direction of the hemispherical diaphragm portion and configured to extend away from the hemispherical diaphragm portion to form a trumpet-shaped diaphragm portion; a height of a trumpet-shaped diaphragm outer periphery portion away from the hemispherical diaphragm portion is greater than a height of a top portion of the hemispherical diaphragm portion. Thereby the split distortion of the speaker at high-frequency is reduced to ensure that the metal diaphragm can be normally vibrated to produce sound.

Abstract: A method of forming a device having a compliant member includes providing an elastomeric layer in an uncured state. The elastomeric layer is pre-cured to increase its viscosity. Subsequently, a bobbin and housing, each having an end, can be positioned such that their ends extend at least partially into the elastomeric layer. The elastomeric layer is cured to secure it to the bobbin housing. Examples of pre-cure and cure operations include one or more of a thermal cure, evaporative cure and ultraviolet cure, and the application of moisture, microwave energy and chemical additive. Due to the increased viscosity after the pre-cure, the migration of elastomeric material is substantially reduced relative to an uncured elastomeric material. The reduction in elastomeric material migration results in smaller menisci formed along the walls of the housing and bobbin, and reduced thinning of the compliant member formed at their ends.

Abstract: Circumferential mode vibrations, in a diaphragm of an acoustic transducer, are damped by defining at least one elongated opening extending radially along a portion of a length from the central area to the outer perimeter being covered by a material having higher damping properties than the material of the cone.

Abstract: Circumferential mode vibrations, in a diaphragm of an acoustic transducer, are damped by defining at least one elongated opening extending radially along a portion of a length from the central area to the outer perimeter being covered by a material having higher damping properties than the material of the cone.

Abstract: A method of forming a device having a compliant member includes applying heat to a thermoplastic elastomer to maintain the thermoplastic elastomer in a softened state. The thermoplastic elastomer is extruded in the softened state as a film of thermoplastic elastomer. One or more of a bobbin and a housing, each having and end, is positioned such that the end extends at least partially into the film of thermoplastic elastomer. The positioning occurs when the thermoplastic elastomer is in the softened state and/or the bobbin and/or housing is at a temperature that is greater than a temperature of the film of thermoplastic elastomer. The film is cooled so that the bobbin and/or housing are secured to the film and so that the thermoplastic elastomer is in a state that exhibits rubber-like properties.

Abstract: A space frame reinforced tweeter dome is disclosed. The tweeter dome includes a space frame and a convex diaphragm attached to the space frame. The space frame can include a crown portion in the form of a triangular frame and three leg portions each extending from a corresponding vertex of the triangular frame. Each leg portion has a distal foot adapted for connection to a voice coil former for movement therewith. The convex diaphragm can be comprised of a soft, e.g., textile, material while the space frame is comprised of rigid material such as metal. The space frame reinforced tweeter dome is free from ringing while being sufficiently rigid to follow the enormous accelerations of a music signal at high frequencies.

Abstract: The present invention relates to a loudspeaker which can be arranged to minimise its overall depth while also increasing the breakup frequency and reducing potential rocking vibrations.

Abstract: Acoustic transducer systems involving position sensing, and methods of operating and providing the acoustic transducer systems, are described herein. The described systems include a driver motor with a voice coil structure coupled to a diaphragm, the voice coil structure movable within an air gap in response to a magnetic flux; a position sensor to generate a position signal to represent a displacement of the diaphragm; and a system controller to modify an input signal based on the position signal and transmit the modified input signal to a voice coil so the voice coil can move in response to the modified input signal. The position sensor can generate the position signal based on optical sensing or strain measurements.

Abstract: A sound output device which can be fitted flush to match shape and contour of a desired housing device includes an arc-shaped shell as the housing, a mainboard, at least one first sound output unit, at least one second output unit, and at least one conductive distance piece. The arc-shaped shell defines sound output holes. The first sound output unit is located on one side of the mainboard close to the at least two sound output holes. The at least one second output unit is located above the conductive distance piece on the side of the mainboard close to the sound output holes. The conductive distance piece elevates the at least one second sound output unit to the same level as that of the first sound output unit, or to some other level required for the particular shape of the arc-shaped shell.

Abstract: This invention relates to the field of silicon microphone technology, more specifically, to a method for fabricating a MEMS microphone using multi-cavity SOT wafer by Si—Si fusion bonding technology, which comprises a multi-cavity silicon backplate and a monocrystalline silicon diaphragm, both are separated with a layer of silicon dioxide to form the capacitor of the MEMS microphone. The monocrystalline silicon diaphragm has advantages such as low residual stress and good uniformity, which increase the yield and sensitivity of MEMS silicon microphone; the diaphragm comprises tiny release-assistant holes, spring structures with anchors and bumps which can quickly release the residual stress and reduce the probability of stiction between the backplate and the silicon diaphragm. This structure will further improve yield and reliability of MEMS microphone.

Abstract: System and method for audio transducer stabilization comprising providing a sound generation panel for transmission of audio sound waves in response to a plurality of force inputs received from three or more audio transducers, providing a mounting frame for coupling to the sound generation panel, the mounting frame having three or more predefined locations for receiving audio transducers, placing the three or more audio transducers in the predefined locations, the predefined locations optimized to reduce a plurality of force moments when the audio transducers are driven using an input drive signal, connecting a coupler ring on each of the audio transducers placed in the predefined locations on the mounting frame to an outer surface of the sound generation panel, and driving each of the audio transducers using the input drive signal from an audio amplifier.

Abstract: One embodiment of the invention discloses an acoustic device having a housing having an accommodating space with a sound hole formed thereon and communicating with the accommodating space; a speaker unit received in the accommodating space having a diaphragm including a first area away from the sound hole and a second area close to the through window; wherein, the diaphragm has a plurality of corrugations formed on the first area and the second area, respectively, and the amount of the corrugations on the first area is less than that on the second area.

Abstract: Driver for an acoustic transducer having a moving coil of substantially equal length to the air gap. The air gap may itself be extended in length using an upper or lower lip, or both. A stationary coil is also provided. The moving and stationary coils can be controlled by suitable control blocks to form an electromagnet-based transducer with reduced distortion. The acoustic transducer may be a hybrid acoustic transducer.

Abstract: The present invention relates to a sound converter, and, more particularly, to a sound converter which can solve a problem in that a vibration space decreases in the sound converter requiring high outputs, as the overall height of a voice coil increases.

Abstract: There is provided a dynamic sound transducer having a diaphragm system (10) which has at least a first and second metallized surface (11) which are separated from each other by an insulating surface (12). The dynamic sound transducer further has a moving coil (20) with a coil wire (25). An end of the coil wire is electrically conductingly connected to the first metallized surface (11) and the other end of the coil wire is electrically conductingly connected to the second metallized surface (11).

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

Abstract: An object of the present invention is to provide an electroacoustic transducer having a multi-channel diaphragm, and a hearing aid using the electroacoustic transducer, in which a plurality of channels having different resonant frequencies is formed in the diaphragm using MEMS technology, thus more closely approximating the different audible frequency characteristics of respective persons. The present invention provides an electroacoustic transducer provided with a multi-channel diaphragm. The electroacoustic transducer includes a diaphragm (110) and signal conversion units (120). The diaphragm is provided with respective channels having different resonant frequencies.

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

Abstract: A membrane for an electroacoustic transducer is disclosed having a first area, a second area, which is arranged for translatory movement in relation to said first area, and a third area, which connects said first area and said second area, wherein local, planar spring constants along a closed line within said third area encompassing said second area, are determined in such a way that local, translatory spring constants along said line in a direction of said translatory movement are substantially constant or exclusively have substantially flat, mutual changes.

Abstract: A diaphragm of an electro-acoustic transducer is provided. The diaphragm of the electro-acoustic transducer includes a central portion and a peripheral portion. The rigidity of the central portion is greater than the peripheral portion, such that the diaphragm has different rigidity characteristics, and thus gets better high-frequency performance and better sensitivity.

Abstract: A diaphragm for use in a speaker is manufactured using a plurality of thin wooden boards having flat rectangular shapes. The thin wooden boards are impregnated with a resin; then, a plurality of cutouts, which are elongated along wooden fiber directions or which are elongated in directions crossing wooden fiber directions, are formed in the thin wooden boards. Instead of the cutouts, it is possible to form a plurality of folded portions elongated in directions crossing wooden fiber directions. The thin wooden boards are integrally laminated together in such a way that the wooden fiber directions thereof mutually cross with a prescribed angle therebetween. The thin wooden boards integrally laminated together are subjected to thermal pressing so as to form a wooden vibrator serving as the diaphragm. Thus, it is possible to easily produce the diaphragm having a high strength and superior acoustic characteristics without causing defects.

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

Abstract: It is an object of the present invention to provide a vibrating plate of a dynamic microphone and a method of manufacturing the vibrating plate. The vibrating plate includes a center dome and a sub-dome which includes a damping thin film having stable quality. Referring to FIG.

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 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: A microphone sensing element and a method for making the same are disclosed. The sensing element has a diaphragm and an attached electrical lead-out arm preferably made of polysilicon that are separated by an air gap from an underlying backplate region created on a conductive silicon substrate. The backplate region has acoustic holes created by removing an oxide filling in a continuous trench that surrounds hole edges and by removing oxide to form the air gap. The diaphragm is softly constrained along its edge by an elastic element that connects to a surrounding rigid polysilicon layer. The elastic element is typically a polymer such as parylene having a Young's modulus substantially less than that of the diaphragm. First and second electrodes are connected to the diaphragm through the lead-out arm and to the substrate through polysilicon via fillings, respectively, and thereby establish a variable capacitor circuit for acoustic sensing.

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: An electromagnetic transducer includes: a first diaphragm; a second diaphragm provided in a central portion of the first diaphragm, the second diaphragm comprising a magnetic material having a first opening in a central portion thereof; a yoke disposed so as to oppose the first diaphragm; a center pole disposed between the yoke and the first diaphragm, wherein the center pole has a shape which allows insertion into the first opening; a coil disposed so as to surround the center pole; and a first magnet disposed so as to surround the coil.

Abstract: A micromachined acoustic transducer comprising a parylene diaphragm piezoelectric transducer. The parylene diaphragm has far lower stiffness than the silicon nitride. The method for fabricating the parylene diaphragm acoustic transducer utilizes a prestructured disphragm layer utilizing silicon nitride which is compatible with high temperature semiconductor process. A silicon nitride layer is patterned and partially removed after forming the parylene diaphragm layer in order to enhance the structural qualities of the parylene diaphragm. The diaphragm may be flat or dome-shaped.

Abstract: A mid-frequency loudspeaker drive unit includes a substantially conical diaphragm having a forward periphery and a surround connected to and extending from the forward periphery of the diaphragm to form a substantially smooth transition from the diaphragm to the surround, the diaphragm and the surround presenting a substantially smoothly continuous outwardly facing surface. The drive unit can be part of a compound loudspeaker drive unit including a high-frequency drive unit coaxially disposed within the diaphragm and a chassis encompassing the mid-frequency drive unit with the surround being secured to the chassis to form the smooth transition from the diaphragm to the surround.

Abstract: In a speaker including a voice coil which is wound on a voice coil bobbin and is inserted into a magnetic circuit gap of a magnetic circuit, and a cone which is coupled to the voice coil bobbin for vibration, the cone (16) is constructed of two divided cones: a drive cone (16A) linked to the voice coil bobbin (14) and a cone paper (16B) linked through an edge (17) to a frame (F).

Abstract: A kind of vibrating diaphragm of false speaker structure which includes a center piece with integrated formation directly on a larger outer diameter surface layer body, a connected suspended edge provided at the side way of the surface layer body in circle, and the hardness of the center piece is greater than the surface layer body and a gap reserved at the separation of the formation of the surface layer body and the suspended edge; with this provision, it provides aesthetic and consistence in appearance to the vibrating diaphragm formation, and save the adhesion of the suspended edge and the center piece which reduce the process and lower cost and make the center piece embedded with the product firmly without loosen, meeting various test condition and prolong the service life of the structure in practice.

Abstract: A speaker apparatus which can remove undesirable vibrations and can produce sounds of excellent quality of acoustic signals having high audio frequencies is presented by increasing a strength of a flat joint portion and by properly setting a mass ratio between a central dome-like diaphragm and an edge-like diaphragm of a speaker diaphragm. This speaker apparatus includes a diaphragm portion in which a mass ratio of the edge-like diaphragm relative to the dome-like diaphragm falls within a predetermined range near 1 and a fixed portion at which a bobbin of a voice coil or an end face of a conductive one turn ring is bonded to and fixed to a flat portion for joining the dome-like diaphragm and the edge-like diaphragm so that mechanical strength of a joint flat portion of the diaphragms can be increased.

Abstract: A frame (14) supporting a diaphragm (12) by its outer periphery is constructed by a connecting ring (30) and a base (28) which comprises a bottomed cylinder portion (28A) and a mounting portion (28B) which extends radially outward from the bottomed cylinder portion (28A) which is a part of the magnetic circuit unit (18). The connection is achieved by the caulking of the ring (30) and the mounting portion (28B) with the diaphragm (12) clamped therebetween.

Abstract: Synchronous dustproof cover structure for sound membrane. The dustproof cover structure being made of a light and rigid material. Multiple reinforcing ribs are perpendicularly disposed on one face of the dustproof cover at equal intervals. Bottom ends of the multiple reinforcing ribs are connected with adjoining sections of the sound basin and the sound ring. The circumference of the dustproof body is connected on the sound basin, whereby the dustproof cover, the sound basin and the sound ring are connected into an integral body and the sound basin and the dustproof cover are synchronously vibrated with the sound ring to emit sound. The multiple reinforcing ribs are connected with the sound basin and the sound ring at multiple points so as to enhance the rigidity and strength of the sound basin. Therefore, the distortion of the sound basin at high volume can be reduced and a good quality of sound can be achieved.

Abstract: A frame 14 supporting a diaphragm 12 by its outer periphery is constructed by a connecting ring 30—which is formed in an annulus following the shape of the outer periphery of diaphragm 12—to base 28 which comprises a bottomed cylinder portion 28A and a mounting portion 28B which extends radially outward from the bottomed cylinder portion 28A which is a part of the magnetic circuit unit 18. The connection is achieved by the caulking of the ring 30 and the mounting portion 28B with the diaphragm 12 clamped therebetween.

Abstract: The invention herein of a standard-sized Vibrating Diaphragm speaker structure, primarily includes a stand with an enlarged opening in the front and a magnetic element in the rear, a cylinder inside a magnetic element, a spring panel sticking with a cylinder, and a Vibrating Diaphragm located on the enlarged opening of the stand. The inner face of Vibrating Diaphragm sticks with cylinder. The improved structure of the invention is characterized as that the surface of Vibrating Diaphragm is free of end fixture and it sticks with a foam washer, which is located at the lower portion of Vibrating Diaphragm and is stuck with an enlarged opening of a stand. Thus, the effective vibration area for a Vibrating Diaphragm is maximized and the output of sound magnitude for a speaker is enhanced. A foam washer substitutes the function of flexible movement for an end fixture of the invention of prior art to achieve normal sound output of a speaker.

Abstract: A loudspeaker has a frame, a magnetic circuit formed on the frame, a voice coil bobbin disposed in a magnetic gap of the magnetic circuit, and a diaphragm connected to the voice coil bobbin at an inner periphery and to the frame at an outer periphery thereof. The diaphragm is folded at a position between the inner and outer peripheries to form an annular ridge. The ridge is projected in an axially inner direction of the loudspeaker.

Abstract: An electroacoustic transducer (1) having a voice coil (17) and having a diaphragm (19) with an annular intermediate zone (22) for securing the voice coil (17), the intermediate zone (22) having angularly spaced-apart trough portions (29) which are each bounded by a trough bottom wall (30) and two trough side walls (31, 32), and the voice coil (17) being secured to the trough bottom walls (30).

Abstract: In a loudspeaker, a diaphragm is equally divided circumferentially into a plurality of regions which have the same shape with each other. Each of the divided regions is formed by a hyperbolic paraboloid. The hyperbolic paraboloid is obtained by moving a straight line connecting between two segments along these two segments. The hyperbolic paraboloid is large in strength and can suppress generation of the dividing vibration of the diaphragm.

Abstract: The present invention is directed to an improved high frequency acoustic speaker center cone, which may be located at a speaker coil tubular support, tube wherein the cone has a plurality of thin, pie-shaped segments radiating outwardly with each of the segments having an arcuated cross-section, so as to create a convex shape towards its center. The segments are highly concave toward the center and less concave with increasing radial distance away from the center. The width of the segments may increase linearly with radial distance so as to create a constant acoustical resistance radially. The center cone also has a thickness gradient with increasing thickness radially towards its center. In another embodiment, the present invention is directed to a system containing both the aforesaid center cone, an outer cone with similar radial characteristics but being concave towards its center. The segments of the outer cone preferably terminate at a flexible, high sound absorption ring.

Abstract: Acoustic speaker cones have a plurality of thin, pie-shaped segments radiating outwardly from their center with each of the segments having an arcuated cross-section. The cones are made of polycarbonate plastic and take the form of being convex towards the center for high frequency cones or of being concave towards its center for larger broad range cones. The present invention is also directed to a system containing both the aforesaid high frequency cone, and an outer broad range cone with similar radial characteristics The segments of the outer cone preferably terminate at a flexible, high sound absorption ring. The center cone fits within a central orifice at the center of the outer cone. The polycarbonate cones have a specific gravity of about 1.10 and about 1.40, having an electrical dissipation factor of about 0.05 to about 0.30 at 60 Hertz, having an electrical dissipation factor of about 1.00 to about 1.25 at 10.sup.6 Hertz, and having a thermal condutivity of at least 1.2 BTU/hr/ft.sup.2 /.degree.F.