Abstract: The present invention provides a loudspeaker including a case having an inner wall, a front opening, and an edge surrounding the front opening. A diaphragm including a substantially planar front surface, a rear surface, and a periphery is attached to the case with flexible attachment element(s). The attaching means attaches the periphery of the diaphragm to the case in the vicinity of the edge of the front opening. A controller is attached to the case in the vicinity of a central inside portion of the case. An actuator is attached to the diaphragm in the vicinity of a central portion of the diaphragm. The controller and the actuator transform an electric signal provided to the controller into a corresponding vibratory movement of the diaphragm between a high frequency and a low frequency. The diaphragm includes a first area in the vicinity of where the actuator is attached to the diaphragm. The diaphragm also includes a second area between the first area and the periphery of the diaphragm.

Abstract: The cone of a speaker which has fibers perpendicularly fastened thereto by an electrostatic fiber implanting apparatus to eliminate the reflection of transverse waves between the diaphragm and the peripheral flange of the cone.

Abstract: The present invention relates to an apparatus that removes howling phenomena in a video display appliance capable of absorbing and damping vibrations arising from the output of a loudspeaker to remove the howling phenomena produced by the transfer of the vibrations to a cathode-ray tube. The apparatus includes a vibration-absorbing section mounted on the loudspeaker for absorbing vibrations generated and propagated from the loudspeaker due to the output of the loudspeaker, and a vibration-damping section having a predetermined space for receiving the vibration-absorbing section therein. The vibration-damping section disperses and damps the remaining vibrations passing through the vibration-absorbing section in the space.

Abstract: A damper for a loudspeaker has an improved linearity of the amount of strain caused by the vibrational energy to vibrational energy exerted on the damper to enable the loudspeaker to reproduce sounds in a high fidelity. The damper is formed such that the modulus of elasticity with respect to a direction perpendicular to the surface of the damper is uniform on a circle with its center at the center of the damper, and portions respectively on concentric circles with their centers at the center of the damper are different in modulus of elasticity with respect to a direction perpendicular to the surface of the damper from each other.

Abstract: An electroacoustic transducer having a diaphragm and a magnetic driving portion respectively housed in a housing wherein the magnetic driving portion vibrates the diaphragm magnetically in response to an electric signal. A base member for closing an opening at the rear side of the housing is formed of a metallic plate. Lead portions are provided by extending both ends of a coil of the magnetic driving portion. Terminal patterns are formed on a surface of the base member with an insulating film between them. The lead portions of the coil of the magnetic drive portion are connected to the terminal patterns.

Abstract: The invention is intended to improve the durability and durability of a diaphragm of centrally convex form. A diaphragm comprises a substantially circular woven base fabric (1) formed of warp yarns (1a and 1a') radially extending in centrally convex form from the central region and weft yarns (1b) helically interwoven with the warp yarns (1a), and a rubber member (2) of centrally convex membrane form molded integrally with the base fabric (1).

Abstract: A pattern of blocks or other features is formed on the diaphragm of an electro-acoustic transducer. The features in the pattern extend along and adjacent to an edge of the diaphragm. The features in a pattern are preferably arranged along two parallel lines, with a pair of features along one line positioned adjacent to a gap in the other line. Similar patterns may also be formed along a second, opposite edge of the diaphragm, and/or on enclosing surfaces adjacent to a transducer. The diaphragm may further be covered by a conformal coating which allows vibratory energy propagating through the surface to exceed the speed of sound through air.

Abstract: A cone formed from paper such as used in speaker as a diaphragm, wherein the wing portions, which may function to reinforce the cone, are selectively arranged and extending from any point in the periphery of the larger diameter circle to any point in the smaller diameter circle of the cone which has a frusto-conical shape and a coating layer is applied to the entire surface of the cone, and a method for making a cone using a sheet of paper, wherein the method comprises steps of cutting a sheet of paper into a desired pattern simultaneously with seaming at least a pair of folding portions composed of a centeral folding line and two lateral folding lines equi-angularly and symmetricaly displaced to each side of the center line, forming wing portions by folding said lines, honding the facing surfaces of the folded portions and, coating the entire surface of the entire surface of the cone with moisture-proof material.

Abstract: A ribbon transducer has the ends of its ribbon held by end fixings which incorporate damping member. The end fixing may include a resilient support member fixed to the ribbon, with the ribbon overlying a pad of damping material and having its outer end held clamped, or alternatively left free.

Abstract: An improved audio transducer includes a diaphragm having a pair of cylindrically-shaped webs that provide greater bandwidth, reduced distortion and greater horizontal dispersion of sound. The audio output of the transducer is further improved by forming the diaphragm of a polyvinyl fluoride film. Other improvements include the use of damping pads to damp internal sound waves and damping strips on the diaphragm to minimize distortion at the resonant frequency of the transducer. In one alternative embodiment a laminated diaphragm is used to damp resonance in the high-frequency end of the transducer operating range.

Abstract: An active noise reducing headset has a high compliance diaphragm. Structure limits the maximum excursion of the diaphragm so that the voice coil does not escape the air gap. Structure, such as indentations in the diaphragm, prevent unrecoverable diaphragm collapse.

Abstract: A membrane for a loudspeaker is designed so as to facilitate manufacture and to improve the tone of the loudspeaker. The membrane consists of a first plastic film (5a) which serves to retain the shape and a second plastic film (56) laminated to the first film which serves to damper partial oscillations. The membrane is particularly suitable as a conical membrane for a loudspeaker for a television receiver.

Abstract: There is a dynamic microphone comprising: a diaphragm which can vibrate by an acoustic wave and a voice coil which is joined to the diaphragm so as to transverse a magnetic field formed by the magnet and can vibrate integratedly with the diaphragm, wherein a number of peripheral treatment agents for damping are coated in a dot shape or a discontinuous stripe shape at intervals onto either one of the front surface and the back surface of the portion of the diaphragm excluding the center dome. With the above construction, a change in stiffness of the diaphragm by the peripheral treatment agents is extremely reduced, it is prevented that the diaphragm resonates at a special frquency, a sudden attenuation of the low frequency limit is prevented, and a low sound can be also certainly collected.

Abstract: In a speaker system with a speaker unit attached to a baffle board, the frame of the speaker unit vibrates so that the quality of sound transmitted from the speaker is impaired. These vibrations can be attenuated by coating the outer circumferential edge of the frame with an elastic material such as rubber.

Abstract: An improved flat sound transducer including a planar diaphragm having at least one region suited for reproduction of low frequencies and one region suited for reproduction of high frequencies wherein the frame of the flat sound transducer is used to sandwich a foam strip between the frame and the diaphragm in order to dampen low frequency vibrations and substantially isolate the high frequency region from the large amplitude low frequency vibrations while still allowing high frequency vibrations to emanate from the entire sound transducer diaphragm. The dampening strip may used with either a metallic frame or with a unitary plastic frame. A high frequency enhancement coating may be used to increase the frequency response in the high frequency region of the diaphragm.

Abstract: An improved audio transducer includes a diaphragm having a pair of cylindrically-shaped webs that provide greater bandwidth, reduced distortion and greater horizontal dispersion of sound. The audio output of the transducer is further improved by forming the diaphragm of a polyvinyl fluoride film. Other improvements include the use of damping pads to damp internal sound waves and damping strips on the diaphragm to minimize distortion at the resonant frequency of the transducer.

Abstract: An electrodynamic loudspeaker (1) has a diaphragm comprising a central part (2) and a peripheral part (3), and a voice-coil device (9, 10) coupled to the central part (2). The surface ratio S.sub.2 /S.sub.1 complies with the relationship 0.5.ltoreq.S.sub.2 /S.sub.1 .ltoreq.6, where S.sub.1 and S.sub.2 are the surface areas of the central part (2) and the peripheral part (3) respectively. The mass ratio m.sub.2 /m.sub.1 complies with the relationship 0.5.ltoreq.m.sub.2 /m.sub.1 .ltoreq.8 where m.sub.1 and m.sub.2 are the mass of the central part (2) and the voice-coil device (9, 10) and the mass of the peripheral part (3) respectively. Further, the stiffness imposed on the diaphragm by the space (6, 6') defined by the diaphragm (2, 3) and the chassis (4) and/or the magnet system (7) is smaller than the stiffness of the diaphragm itself. Thus it is possible to derive a car loudspeaker which has a specific dip in its frequency response characteristic P (FIG. 2a), measured in an anechoic room.

Abstract: A stepped frequency microphone particularly adapted to a hearing aid application provides a stepped frequency response characteristic relative to frequency, and has a low-pass sonic attenuator for providing to the undriven side of the microphone diaphragm a sonic counterpressure which at low frequencies substantially cancels ambient sound pressure delivered to the drive side of the diaphragm, the attenuator reducing this counterpressure at elevated frequencies to provide accentuated high frequency response.

Abstract: An installation of sound converters (e.g., speakers) in an enclosure having mechanical fasteners such that the transmission of solid-borne sound from the speakers to the enclosure is prevented.

Abstract: A speaker system comprises a housing and at least one speaker mounted in said housing. An acoustical filter for intercepting and reradiating sound waves is mounted in front of the cone of the speaker. The acoustical filter includes a frame having a central aperture and at least one membrane mounted to the frame covering the aperture and having a resonant frequency of vibration. A plurality of slots are formed in the frame adjacent the aperture. A dispersion grid for increasing the spacial angular dispersion of sound waves generated by the speaker is mounted in front of the frame.

Abstract: The present invention relates to acoustic filters for use in combination with a multiple transducer system which includes a low frequency transducer subsystem and a high frequency transducer subsystem each mounted with respect to an axis directed towards the listening environment so as to function acoustically as though having coaxial acoustic centers. Preferably, the acoustic filter is constructed from one or more acoustical elements such as small tubes, narrow slits, perforated baffles, enclosed cavities, and the like combined so as to provide an acoustical impedance which is relatively low for the frequencies produced by the low frequency transducer but which is relatively high for the frequencies associated with the high frequency transducer.

Abstract: A circular diaphragm typically edge mounted to the housing of an electroacoustic transducer includes a plurality of inwardly curved slots isolated by a circular ridge formed in the diaphragm to thereby increase the compliance of the diaphragm at the center of the circular ridge. Portions of the slots are overlapped to maintain a substantially rectangular section of the diaphragm between the slots. The slotting and rectangular sections of the diaphragm allow the center of the circular ridge to flex in a piston-like manner whereby higher frequency flexural modes of the diaphragm are either reduced or completely eliminated.

Abstract: A speaker provided with a diaphragm having a foamed resin body of relatively low density on its front surface includes a thin sheet of foamed resin applied to its surface. The thin sheet of foamed resin has relatively high flexural rigidity and is impermeable to air, to enable the surface of the foamed resin body to be protected against damage or indentation that might otherwise be caused. The thin sheet of foamed resin may be coated with a paint or have a foil applied to its surface. The speaker has improved electroacoustic transducing efficiency.

Abstract: An improved ribbon-type speaker having an independent magnetic circuit unit and vibration system assembly to thereby reduce second harmonic wave distortion and to provide a speaker which is easy to assemble and disassemble. The case of the magnetic circuit unit can be used as a jig in assembling the magnetic circuit thereby largely reducing the number of steps and the number of tools needed in assembly. The ribbon-type speaker further incorporates advantageously recess portions in a supporting frame of the vibration system assembly together with semicircular cut-out portions provided at both ends of long sides of the opening in the supporting frame. The rigidity of the vibrating plate is thus enhanced and the deformation and elongation of the damper member of the vibration system assembly is reduced.

Abstract: A microphone, particularly for hearing aid application, said microphone providing a stepped response characteristic relative to frequency wherein low frequency sounds will couple to the associated hearing aid with a restricted amount of amplification, while providing an emphasis or higher amplification for the higher frequencies in the bandwidth of interest.

Abstract: An electrodynamic loudspeaker which comprises a generally rectangular flat vibrating plate, and first and second magnetic drives for driving the vibrating plate to produce vibrations. The first magnetic drive is so positioned as to drive the vibrating plate at a first location corresponding to one of two line nodes m.sub.1 and m.sub.2 of vibration of a first predetermined frequency f.sub.1 which would be produced when the vibrating plate is driven at the center thereof, whereas the second magnetic drive is so positioned as to drive the vibrating plate at a second location corresponding to one of four line nodes n.sub.1, n.sub.2, n.sub.3 and n.sub.4 of vibration of a second predetermined frequency f.sub.3 which would be produced when the vibrating plate is driven at the center thereof. Each of all of the line nodes extends in parallel to the shorter sides of the rectangular shape of the vibrating plate.

Abstract: A speaker enclosure with a pentagonal cross section and sloping sides contains a dynamic damping system located in the lower portion of the enclosure. Speakers mounted in the side walls are always positioned opposite a corner to prevent the production of standing waves. The rearward projection from the speaker and reflections from the walls are directed downward to the dynamic damping system, eliminating the absorptive padding used in prior systems and its inherent loss.

Abstract: An improved acoustic impedance for a direct radiating dynamic loudspeaker having a natural Q greater than about 1.2, is substantially planar and is positioned in front of and covers the projected frontal radiation area of the diaphragm or cone of the loudspeaker. The acoustic impedance element is supported about its periphery and comprises a fibrous felt material having an air flow resistance in the range of about 50-100 cu. ft. per min. at 0.5 p.s.i. pressure drop, a density in the range of about 6-12 oz. per sq. yd. and a thickness in the range of 0.03-0.09 in. The acoustic impedance element is an air permeable continuous sheet and is comprised substantially entirely of fibers of synthetic materials, such as, for example, polyester, which are relatively impervious to moisture. The Q of the speaker including the damping element is in the range of about 0.75-1.0.

Abstract: A speaker in which a voice coil bobbin (4) is connected through a mechanical filter to vibrating members (11, 14) for limiting the reproducing frequency band in predetermined range by the mechanical filter, and a speaker system employing the speaker. A pneumatic suspension V is used as the mechanical filter to eliminate the variations in the reproducing frequency band even for long term usage.

Abstract: An improved loudspeaker cone construction and method of improving performance comprises the use of one or more stiffener columns positioned across and attached to a loudspeaker cone at points intermediate small and large ends of the cone. A plurality of stiffener columns may be arranged in one or more cross shaped arrays or one or more polygon shapes, and attached to the cone in a plane perpendicular to a central axis of the cone. The stiffener rods reduce self-resonances within the cone and improve stiffness to generally improve performance.

Abstract: Provided is an electro-dynamic speaker having a unique damper extending between a coil bobbin carried by the inner periphery of a diaphragm and a frame carrying the outer periphery of the diaphragm. Due to the provision of the unique damper, a satisfactory compliance along the axis of the bobbin and a favorable regulating force against radial deforming force are obtained, to ensure a good linearility of the force-displacement characteristics of the speaker in the low frequency range even during vibration at a large amplitude.

Abstract: A decorative light flashing apparatus employs a mass-damped dynamic microphone which preferentially responds to impulse-type sounds to trigger a timing circuit. The timing circuit produces pulses in response to the impulse-type sounds which drive a commutating circuit for sequentially illuminating a plurality of light sources in time to the impulse-type sounds.

Abstract: The periphery of the diaphragm of a loudspeaker is mechanically connected to a diaphragm support or basket by a layer of acoustic dampening-adhesive material. The layer of acoustic dampening-adhesive material covers a sufficient portion of the surfaces of the diaphragm to dampen standing waves which would otherwise reflect from the periphery of the diaphragm. Thus, a unitary diaphragm mechanical termination-acoustic termination structure is formed.

Abstract: The present invention is an acoustic filter for use in combination with a coaxial loudspeaker system which includes a low frequency loudspeaker and a high frequency speaker which is axially aligned with the low frequency loudspeaker. The acoustic filter includes a pair of parallel, perforated sheets which are separated from each other a suitable distance and which are joined together at their peripheries in any appropriate manner so that they enclose an airspace therebetween in order to form a single section filter. The acoustic filter is disposed between the low frequency loudspeaker and the high frequency loudspeaker so the acoustic filter inhibits the high frequency sounds of the high frequency loudspeaker from interacting with the internal sidewall of the conically shaped diaphragm of the low frequency loudspeaker.

Abstract: In an electro-acoustic transducer having a magnetic circuit and a vibrative member disposed in an air gap formed in the magnetic circuit, the vibrative member having a frame with an opening, a membrane mounted on the frame, an acoustic transparent member mounted on the frame so as to define a space between the membrane and the acoustic transparent member, and an acoustic damping material disposed in the space.

Abstract: A diaphragm for a loudspeaker includes a core member having a flat front surface from which a frustum-shaped side surface extends to a back portion, a cover member secured to the back portion and adapted to be connected to a voice coil bobbin of the loudspeaker, an outer radiation layer mounted on the front surface and having a relatively high resonance sharpness, and an intermediate layer laminated between the front surface and the outer radiation layer and having a resonance sharpness lower than that of the outer radiation layer.

Abstract: A loudspeaker having a framework with a plurality of openings therein is fitted with an elastic body of a bitumen-containing urethane foam over the rearside of the framework to absorb the acoustic energy transmitted rearwardly from the speaker.

Abstract: A loudspeaker includes a flat plate diaphragm mounted in a speaker frame and which is driven by a plurality of magnetic drivers each having a magnetic gap, a voice coil bobbin connected to the diaphragm at a respective node portion of the divided vibration mode and a voice coil in the respective magnetic gap and being wound around the voice coil bobbin therein. Rotational vibration of the diaphragm is prevented by a pole member which is connected from the center of the diaphragm to a damper supported behind the speaker frame on a damper supporting frame. The leverage due to the longer length of the pole member makes the damper member more effective in resisting rotational vibration. The damper supporting frame is mechanically connected to the speaker frame and/or magnetic drivers to add stiffness to the structure.

Abstract: A loudspeaker system embodies an enclosure defining a sound chamber having a front wall with a sound emitting opening therein. An outwardly and forwardly flaring speaker cone is mounted within the enclosure and adjacent the opening therein with the innermost portion of the speaker cone emitting more distorted sound than the outermost portion thereof. At least one reflector is mounted outwardly of the enclosure and forwardly of an outer portion of the speaker cone with the innermost edge of the reflector being located at least 15 per cent of the radial distance measured outwardly from the outer edge of the loudspeaker voice coil to the outer edge of the cone diaphragm with the sound being reflected by the reflector being directed outwardly of the enclosure at least 90.degree. from a line extending forwardly along the axis of the loudspeaker cone.

Abstract: A drone acoustical transducer for a loudspeaker system has an improved means of interconnecting the generally conical speaker diaphragm and supporting basket. In conventional fashion, the acoustical transducer includes a generally conical speaker diaphragm supported within a vented basket having an open front and a rear wall. The large, front end of the diaphragm is flexibly connected to the front of the basket by means of a supple annulus. The basket has a rear wall having an upstanding boss which is coaxial with the diaphragm and smaller in diameter than the small end of the diaphragm. A flexible spider interconnects the small end of the diaphragm with the boss, allowing full excursion of the vibrating speaker diaphragm. To allow for maximum excursion of the diaphragm, the rear wall of the basket may be concave as viewed from the rear.

Abstract: An acoustic diaphragm has a substrate of either a hard resin film or cloth of an organic material, and at least one side of the substrate is laid with a polyurethane elastomer layer. In the case of a cloth substrate, the cloth is optionally metallized by evaporation deposition of Al or Ti and/or impregnated with a thermosetting resin. The elastomer is a copolymer given by condensation of bifunctional polymeric alcohol and a glycol with a diisocyanate. This diaphragm features a flat response curve at medium to high frequencies on account of its relatively large value for Young's modulus and adequately great internal loss, and accordingly is particularly useful for tweeters.

Abstract: The invention relates to an electroacoustic transducer for the sound reproduction, comprising a substantially olive-shaped diaphragm body formed of a plurality of convexly pre-curved diaphragm segments capable of bending, damping material accommodated within the diaphragm body, at least one oscillation generator provided on one end of the diaphragm body and having its moving coil connected to the diaphragm body, and means for rigidly connecting the other end of the diaphragm body to the housing of the oscillation generator.

Abstract: A speaker system comprising a speaker unit, a drone cone driven by the speaker unit; and a removable weight loaded on the front of the drone cone which can be exchanged from the front of the drone cone.

Abstract: An improved lightweight, stiff member for use as a speaker diaphram is formed from a porous layer of high stiffness fibers. The fibers are randomly oriented, spaced-apart, and crossover each other at given points to form a porous layer with a given thickness. The fibers are bonded to each other at the given crossover points. A gastight film is also bonded to the layer of fibers thereby providing a gastight member having high flexural stiffness.A method for making a lightweight, stiff member by the application of a dilute solution of an epoxy resin and a solvent to a porous layer of randomly oriented, spaced-apart, high stiffness fibers. The solvent is removed, leaving a thin layer of epoxy resin on the fibers. The porous layer of fibers and a gastight overlying sheet are pneumatically formed into a predetermined configuration.

Abstract: A loudspeaker including a porous diaphragm having an outside edge, an electromagnetic drive means mounted on a central area of the diaphragm for displacing the diaphragm and a hard ring forming a junction between the diaphragm and the drive means with the diaphragm being totally permeated with a stiffening material in the area between the ring and the outer edge without increasing the thickness of the diaphragm thereby improving the acoustic characteristics of the loudspeaker as compared with an equivalent unstiffened diaphragm.

Abstract: This invention relates to loudspeaker diaphragms and methods of making such diaphragms. It is an object of the invention to improve damping of standing waves formed in a loudspeaker diaphragm. To this end a diaphragm in accordance with the invention is made of textile material impregnated with a stiffening material which does not completely fill the spaces between the threads of the textile material, said spaces being partially filled with damping material. The textile material is preferably a woven glass-fiber fabric or a fabric woven or knitted from an aramid fiber. The stiffening material is preferably a synthetic resin, for example, a phenolic, epoxy or melamine resin and the damping material is preferably a polyvinyl-acetate emulsion or a vinyl resin-based thermoplastic material of the kind used as a cone edge dampener.

Abstract: A disposable noise reducing hearing attachment provided for covering the sound inlet of a hearing aid to reduce the amplitude of random noises such as wind noises and to prevent dirt and moisture from entering the sound inlet. The attachment includes a flexible open cellular noise filter that is covered by a thin sheet of tightly woven material to form a wind and dust screen on the top surface of the noise filter. A stretchable bottom ring layer of nonporous sheet material is attached to the bottom surface of the noise filter in which the bottom ring layer has an aperture that is greater than the cross section of the sound inlet. The top wind screen layer and the bottom ring layer are secured to opposite sides of the noise filter layer by rings of adhesive that have diameters greater than the cross-sectional diameter of the sound inlet of the hearing aid so that adhesive does not interfere with the sound transmission through the attachment and into the hearing aid through the sound inlet.

Abstract: A loudspeaker of the well known conical diaphragm moving coil type is provided with an annular, frusto-conical, cellular damping/deflection element on the magnet or magnet housing thereof. This element interferes with the rearward radiation of sound from the diaphragm and is of particular value when the loudspeaker is housed in a cabinet since it acts to inhibit the formation of standing waves due to reflection at the rear wall of the cabinet of the rearwardly directed radiation; this reduces the distortion of the forwardly radiated sound, caused by the rearwardly directed radiation reflected from the rear wall of the cabinet. A further cellular element, of generally cylindrical form, may be attached to the rim of the diaphragm so as to project rearwardly therefrom and surround the loudspeaker back to a line defined by the forwardmost part of the frusto-conical annular cellular element on the magnet or magnet housing.

Abstract: A loud speaker having air communicating holes within the rear portion of the frame and facing the diaphragm is provided with regularly woven wire gauze formed of warp and weft wire threads of different diameter, which gauze covers the communicating holes to obtain a stable vibration damping effect.

Abstract: A diaphragm having a flat multi-layer body with at least one layer of viscoelastic material.