Abstract: An electro-acoustic transducer, such as a speaker device or an earphone device. Includes an electro-acoustic transducing unit, such as a speaker unit, for converting input electrical signals into sound, a casing in which the electro-acoustic transducing unit is arranged and which delimits a back cavity towards the rear side of the electro-acoustic transducing unit, and at least two openings having a sound duct communicating with the back cavity. The sound radiated from the back surface of the electro-acoustic transducing unit is attenuated by being transmitted into the inside of the sound duct to prevent the radiated sound from being re-admitted into the electro-acoustic transducer.

Abstract: This invention provides a system for integrating sound radiation from mid-range and high frequency sources enabling improved control over the radiation of high frequency sound waves. This acts to minimize the distortion, while enabling compression-loading of the mid-range sound waves increasing acoustic energy. To do so, a radiation boundary integrator (“RBI”) having slots is positioned over the mid-range sound sources acting as a smooth sidewall wave-guide thus controlling the high frequency sound waves emanating from the high frequency sound sources. To allow the mid-range frequency sound waves generated from mid-range sound sources to pass through the RBI, slots are formed within the RBI. As such, RBI may have an outer surface area that may form an acoustical barrier to high frequencies radiating across the outer surface, yet be acoustically transparent to mid-range frequencies radiating through slots in the radiation boundary layer.

Abstract: A venturi expander is mounted on a speaker enclosure to receive the rearward-propagated sound waves and to extend the propagation path. The venturi expander's reflective sides direct the rearward sound to the sides or top or bottom of the speaker enclosure to produce a reflected sound surrounding the speaker enclosure and producing sound to the sides of the speaker substantially as projected from the front of the speaker.

Abstract: Disclosed is an improved loudspeaker comprising a pre-stressed cabinet and a loudspeaker unit fixed to the inside of the cabinet. The cabinet comprises a hollow conical assembly including two conical bodies of high-rigidity metal, one press-fitted into the other by applying an increased compressive force. The hollow conical assembly has front and rear plates closing its front and rear openings. These front and rear plates are pulled toward each other by tightening screw rods.

Abstract: An air induction system comprises an air induction body, a speaker with a first diaphragm disposed about the air induction body, and a second diaphragm spaced from the first diaphragm. A signal is generated from the first diaphragm and transmitted to the second diaphragm. The second diaphragm generates a noise attenuating sound.

Abstract: In a speaker unit, a case 40 is formed of a synthetic resin member having a case body 42 and a protective cover 44 integrally molded. Further, an opening portion 48 is formed in a surrounding wall 46 of the case body 42 and a beam 50 is formed inside of the case body 42. In a state where the speaker 20 is inserted into the case body 42 through the opening portion 48, the speaker 20 is held by the beam 50 and the protective cover 44 from its upside and downside.

Abstract: The present invention concerns a watertight apparatus capable of being immersed in a liquid, for example a watertight watch, including a case (1) with an inner chamber (10) communicating with the exterior, the chamber being separated from the exterior by a membrane (17) which can be deformed, defining, on one side, a non-watertight outer zone and, on the other side, a watertight inner zone, in which is housed, in association with the membrane, an acoustic transducer (22), the membrane being fixed by its peripheral edge (17A) in the chamber (10) and applied via elastic memeber (20) towards its periphery, but at a distance from the edge, against a support surface (12) arranged in the inner chamber (10).

Abstract: An acoustic chamber formed in door of a vehicle includes a metal door inner panel having an aperture extending therethrough, and a door module secured in the aperture of the door inner panel. The door module includes an indentation and may be made of a polymer or a fibrous material. An interior door trim panel overlies the door module and a loudspeaker is secured between the interior door trim panel and the door module. The interior door trim panel may include a bulge opposing the indentation in the door module. A sealing element is secured between the door module and the interior door trim panel for defining an acoustic chamber between the door module and the interior door trim panel. The acoustic chamber enhances the performance of the loudspeaker, thereby allowing a smaller loudspeaker to be used.

Abstract: A woofer apparatus having a cabinet defining a chamber, a magnet, a voice coil member positioned to reciprocate in the magnetic field of the magnet, a speaker diaphragm, and a passive radiator diaphragm. The components are arranged so that the maximum box pressure during maximum displacement mode of operation is greater than 0.2 psi. the tuned frequency of the apparatus is, in a preferred mode, at about 35 Hz, so that the passive radiator has substantially greater maximum excursion strokes at maximum displacement than the speaker diaphragm.

Abstract: A method of constructing an acoustic filter incorporates a technique in which the filter is modelled with one or more distributed two port elements. The or each distributed element is defined by a characteristic impedance and length and includes a waveguide filter which does not require damping. The or each filter section is characterized in that it has at least two resonances which are used to shape a specified response for the filter. A substantially reactive acoustic filter constructed according to the method and a loudspeaker system incorporating such an acoustic filter are also disclosed.

Abstract: A thin-type speaker having a secondary diaphragm. The speaker including an enclosure, a diaphragm, a yoke, a sound coil, a magnet, and a washer. The surface of a first diaphragm is covered by a secondary diaphragm. The secondary diaphragm is made of sponge, cloth, paper, cardboard or isolating fabric. A thin-type speaker constructed according to the invention can produce larger tensioning as the power increases so that the speaker has a substantially larger flat effective bandwidth and less vibration noise.

Abstract: To overcome acoustic distortion caused by local resonance in panel core cells, a resonant multi-mode radiator element is provided for a panel form loudspeaker with a functional upper frequency limit ƒmax. The element has skins and a cellular based core, the skins have a thickness h, a Young's modulus &Egr; a Poisson's ratio of &ngr; and a material density &rgr; and the core has a cell size lcell characterized in that the cell size lcell is less than equation (2).

Abstract: An apparatus (1) is constructed for operation in an on-ear mode and an off-ear mode and includes a housing wall (6) having passages (15) to allow useful sound waves to pass through, and additional passages (16) to allow the passage of sound waves which are in phase opposition to the useful sound waves and includes, behind the housing wall (6), an electroacoustic transducer (7) having a diaphragm (12), the transducer (7) being accommodated in an acoustically substantially impervious holder compartment (17). Sound-pressure frequency response influencing structures (18, 19) are arranged both in the sound path between the frontside (13) of the diaphragm (12) and the passages (15), and in the sound path between the rearside (14) of the diaphragm (12) and the additional passages (16).

Abstract: A speaker base, which includes a tweeter holder having a holder base and a bottom mounting holder rod, and withholding ring mounted on the tweeter holder to hold a tweeter, wherein the tweeter holder has an axial center through hole through its holder base and bottom mounting holder rod through which the lead wires of the tweeter pass.

Abstract: The system of the present invention includes, briefly, a point source speaker system, comprising a processor which produces a left minus right (L-R) audio signal, a right plus left (R+L) and a right minus left (R-L) audio signal; left, center and right speakers for audibly transmitting one of the L-R, R+L and R-L audio signals, respectively; left and right acoustically reflective surfaces proximate to the left and right speakers, respectively; and a point source speaker enclosure for housing the three speakers in a single enclosure.

Abstract: A loudspeaker horn has straight wall section and a curved wall section. The straight wall section has diverging walls defining a coverage angle and the curved wall portion is connected to the straight wall portion at a point tangent thereto, and has a proximal end disposed perpendicular to the plane of the throat entrance. At least one coverage angle in orthogonal planes has a common apex in the plane of the throat entrance and along the horn axis.

Abstract: A panel-form loudspeaker has a resonant multi-mode radiator panel which is excited at frequencies above the fundamental frequency and the coincidence frequency of the panel to provide high radiation efficiency through multi-modal motions within the panel, in contrast to the pistonic motions required of conventional loudspeakers. The radiator panel is a skinned composite with a honeycomb or similar core and must be such that it has a ratio of bending stiffness to the third power of panel mass per unit area (in mks units) of at least 10 and preferably at least 100. An aluminum skinned, aluminum honeycomb cored composite can meet this more severe criterion easily.

Abstract: The subject invention relates to a type of multi-functional audio & video control box, comprising such components as an antimagnetic speaker box and several sets of audio/video selector whereby an audio/video connection switch box and an audio input/output speaker switch functions are completely integrated inside an antimagnetic speaker box, so as to very efficiently save space, with possible designing and combination of easily operated switches.

Abstract: An easily-combinable and movable speaker case includes two side boards, a front holed board, a speaker support board, an electric circuit board, a rear control board, a cap board, a bottom board, and a pull member. The two side boards are spaced apart parallel and respectively has a plurality of vertical position grooves and posts spaced apart on an inner surface for inserting the front holes board, the speaker support board, the electric circuit board and the control board in the position grooves of the two side board. Then the cap board and the bottom board are respectively fixed on and under the two side boards with screws. Further two rollers are fixed under the bottom board to permit the speaker case inclinedly move on the ground by pulling the pull member.

Abstract: A loudspeaker enclosure having a constrained layer damping system for minimizing the propagation of vibrations and controlling the resonant modes of the enclosure. The enclosure has a front baffle board on which a plurality of transducers are mounted, and a plurality of other walls mounted to the baffle board to form a cabinet structure. The front baffle board comprises an interior substrate, an exterior substrate, and a constrained layer damping material sandwiched between and bonded to the two substrates. The constrained layer damping material comprises an energy absorbing thermoplastic alloy having a very high material loss factor. The other walls of the enclosure also comprise an interior substrate and an exterior substrate with a constrained layer damping material sandwiched therebetween. An extensional damping material may also be bonded to an interior surface of the interior substrates to further control vibrations in the enclosure.

Abstract: A small, compact subwoofer cabinet; openings in two cabinet walls; first and second cages mounted on respective ones of the walls in alignment with the openings; a voice coil driven driver including an annular magnet weighing approximately 225 oz. affixed to the first cage; a stationary pole piece extending through the magnet and defining a magnetic gap therebetween; a voice coil mounted on a cylindrical voice coil former positioned within the gap; a cone affixed to one end of the former; a first flexible surround secured to the outer end of the cone and to the first cage; a flexible spider secured to the former and to the first cage; a mass driven driver including a mass aggregating about 2 lbs.; a second flexible surround secured to the mass and to the second cage; a flexible spider attached to the second cage and to the mass; both surrounds having a thickness of about 0.1", an edgeroll having a diameter of about 1.5", and capable of standing off internal pressures up to about 3 lbs./in.sup.

Abstract: Loudspeaker improvements are disclosed to add versatility and economy, particularly for multimedia applications. These improvements include: (1) the printing of voice coil conductors, (2) adding conductive elements to the sound driver surface, (3) using multiple coil paths around a single voice coil former to drive the overall sound driver surface, (4) creating a simple digital loudspeaker with multiple coil paths, (5) implementing multiple functions in the multiple coil loudspeaker/transducer, (6) creating integrated systems with a series of multiple function, multiple coil loudspeakers/transducers and (7) providing a novel subwoofer loudspeaker housed in a cylinder.

Abstract: A speaker enclosure with at least one woofer and one mid-range speaker with associated parallel sound channels and ports for direction of the back waves generated by the speakers. The woofer and mid-range speaker are in a spaced relationship with the sound channel ports for the woofer speaker in close proximity to the mid-range speaker and the mid-range sound channel port in close proximity to the woofer speaker. The sound channels for the mid-range and woofer speakers are adjacent and parallel to each other. The back waves generated by the speakers travel along the sound channels which form a sound traveling path. The ports are located at a distance from the speakers generating the sound waves, but adjacent to other speakers, resulting in a life-like and rich sound.

Abstract: A television receiver has a subwoofer box situated inside the cabinet of the television receiver. The subwoofer box has a loudspeaker arranged in a chamber and mounted in such a manner that it is situated outside the space enclosed by the subwoofer box. The chamber is dimensioned so as to accommodate the loudspeaker. This enables the volume of the subwoofer box to be optimized in view of the space available inside the cabinet of the television receiver. Moreover, mounting of the loudspeaker and the wiring thereof is simplified considerably.

Abstract: An electroacoustical transducing system for exchanging pressure wave energy with a medium that propagates pressure waves includes an electroacoustical transducer having a vibratile surface. At least one low-loss pressure waveguide has one end adjacent to the vibratile surface and the other end adjacent to the medium. At least one acoustic immittance element is imposed in the length of the waveguide dimensioned and positioned to alter the transfer characteristic of the waveguide between the vibratile surface and the medium at the other end.

Abstract: A speaker mounting system wherein the speaker is mounted to a support surface indirectly by a compliant gasket with no rigid mechanical coupling between the speaker and the surface. Accordingly, mechanical transmission of vibrations from the speaker to the surface is greatly reduced. The gasket has a cross-section configured as a curved beam with one end secured to the support surface and the other end terminated by a thickened portion having an interior annular groove receiving the open end edge of the rigid outer basket of the speaker.

Abstract: A speaker system includes a vertically oriented elongated tube supported on a ground surface, and open at upper and lower ends thereof; a woofer, mid-range speaker and tweeter mounted at a lower end of the tube, the woofer having a front driving face with an effective driving area, the woofer providing an in-phase audio signal directed upwardly through the tube and an out-of-phase ground wave audio signal directed in an opposite direction therefrom; an enclosure enclosing the woofer and mounting the tube on the ground surface; a restricted open area formed between a lower edge of the enclosure and the ground surface and being less than the effective driving area, the restricted open area being arranged to transmit the out-of-phase ground wave audio signal from the woofer in a direction transverse to the axial direction; and a driving circuit for driving the woofer and including a power amplifier for amplifying an input signal with a variable gain and supplying the amplified input signal to the woofer, a circu

Abstract: Disclosed is a sub-woofer module which has a simple construction and provides a good low-frequency bass in compliance with an audience's taste. The sub-woofer module has an enclosure, a baffle board which separates the enclosure into first and second chambers, and a speaker coupled to the baffle board. The baffle board is engaged with a screw shaft and moves upward and backward along the screw shaft to vary the volume of the first and second chambers. A reverse-conical cap is disposed above the enclosure to permit the upwardly projected sound to be projected in 360 degrees, and a conical base is disposed below the enclosure to permit the downwardly projected sound to be projected in 360 degrees. The audience can listen to sound of the same quality regardless their position in relation to the sub-woofer module.

Abstract: A loudspeaker enclosure has an inside volume. At least one port characterized by predetermined mass intercouples the inside volume and the region outside the enclosure. Each port has a smoothly flared input end within the inside volume and smoothly flared output end adjacent to the region outside the inside volume. The port defines a boundary between the acoustic mass therein and the inside volume, the boundary typically being defined by an ellipse, and in a particular form by the rotation of an ellipse about the axis of a port. Typically, the length of the port corresponds substantially to the major diameter of the ellipse.

Abstract: It is an object of the present invention to provide a loudspeaker structure suitable for use in almost full range in relation to a reproduction frequency band of a conventional ultrathin-type loudspeaker by resolving the defects of the loudspeaker and expanding the frequency band. A multipoint driving loudspeaker in which a single diaphragm is driven by a plurality of voice coils, having a plurality of holes 11a for connection with voice coils 12 at arbitrary positions on the diaphragm 11, an outer periphery of each voice coil or each voice coil bobbin 12a constituting the voice coil being joined to an inner periphery of each hole, each magnetic circuit for driving the voice coil being placed at an inner periphery of the voice coil or of the voice coil bobbin correspondingly to each voice coil, and the magnetic circuit including two magnets 82 with the same poles positioned at opposite side each other and being used as a repulsion magnetic circuit with a center plate 81 grasped between the magnets.

Abstract: The purpose of the invention is to direct, in a coherent fashion, audible frequencies, particularly, low frequencies and especially those below 90 cycles. The advantage to directing low frequencies to acute projection patterns previously thought impossible is to reduce low frequency feedback in live performance applications and to reduce low frequency room reverberation in all applications which results in a faster decay time of the low frequency produced. Acute directivity of low frequencies is achieved by using a rectangular enclosure in the vertical axis and by placing a rectangular port on the horizontal axis centrally located between two transducers. The three-point projection pattern is established so that the three points of projection can act to set up a carrier wave and side band waves effect. Alternatively, one transducer can be centrally located between two rectangular ports.

Abstract: This application outlines several applications of a piezoelectric materials invention to produce quality loudspeakers in applications where coil driven dynamic speakers are difficult or impossible to implement with an appreciable degree of sound quality. This invention includes a series of modifications to a laptop computer such as the IBM 750c. The modifications to the computer consist of placing piezoelectric patches behind the LCD and directly to the back wall of the laptop lid. Damping materials and stiffeners are also added to the back wall to reduce structural resonance. A system consisting of an audio amplifier and transformer is used to drive the piezo speaker.

Abstract: A vehicular loud speaker cabinet assembly (20) attaches beneath the headliner portion (180) of the vehicular roof and is supported thereagainst in various ways. The vehicle (24) may include a structural roof member (22) interconnecting the respective B pillars (54) such as common in small recreational vehicles. The cabinet assembly (20) for this vehicle (24) includes forward and rearward edge rims (36, 38) which are received along the pinch weld portions (60) of the structural roof member (22) and are functionally and decoratively secured thereto by a moisture seal (62). Alternatively, the cabinet assembly (120, 220) may be provided with threaded fasteners (184, 284) which extend upwardly through the cabinet assembly (120, 220) for anchorage above the headliner portion (180) of the vehicular roof. The threaded fasteners (178) may be used to secure the original equipment dome/cargo light assembly (170) in place.

Abstract: Method and apparatus for obtaining curved array performance from an array of loudspeakers suspended within a simple vertical framework in which each loudspeaker system is suspended within a separate frame structure with a tilting mechanism that allows the loudspeaker sound-emitting access to be changed in a vertical plane to a desired position.

Abstract: A mount for mounting a loudspeaker in a room boundary structure having an outside surface away from the inside of the room includes a frame constructed and arranged to rest on the outside surface. A spring has a first end attached to the frame and a free second end. The spring is constructed and arranged to exert a unidirectional force toward the outside surface whenever the second end of the spring is displaced from the outside surface toward the inside of the room.

Abstract: A mechanism for a speaker assembly utilizing a brace for confining a speaker cone in a particular orientation. The brace is provided with at least first and second feet which append therefrom. At least one of the feet is fastened to a permanent magnet associated with the cone to isolate vibrations originating in the permanent magnet. In this regard, a plate is employed in conjunction with an elastomeric member such that the elastomeric member is interposed the foot and the plate. The elastomeric member is held to the plate and the first foot. The elastomeric member is sized to create a bias for movement of the brace only in a shear direction relative to the plate and the first foot. A fastener is also employed to support the first and second feet to the permanent magnet at predetermined distances from the permanent magnet.

Abstract: A loudspeaker assembly for low frequency reproduction having a good vibration efficiency for a large vibration amplitude and a small magnetic distortion. Two magnets magnetized in the direction of thickness have the magnetic poles of the same polarity disposed facing each other with a center plate made of soft magnetic material being interposed therebetween. Magnetic fluxes extend from the outer periphery (positive side) of the center plate and return to the top and bottom surfaces (negative side) of the two magnets. The winding width of a voice coil is set equal to or greater than a width between two transition points of the magnetic flux distribution from the positive side to the negative side.

Abstract: In accordance with the invention, a new type of microphone utilizes a magnetoresistive sensing element. Specifically, acoustical energy causes vibrations between a magnetoresistive element and a magnet, producing a variation in the resistance which can be used to convert an acoustical signal into a corresponding electrical signal.

Abstract: An apparatus for generating acoustic pressure pulses in an acoustic medium has a membrane that can be driven which adjoins the acoustic medium and which is driven in an impact-producing manner. The membrane is mechanically pre-stressed so that it returns into its initial position after a pressure pulse is generated.

Abstract: The present invention involves a moving-coil electrodynamic electroacoustical transducer, comprising a disk made of a hard, nonmagnetic material (12), which is superimposed on the diaphragm (11) and has openings for the output of sound, a power-factor-improvement device/super charger (13) made of a nonmagnetic material which is placed in the concavity of the diaphragm (11) and which has annular, concentric ducts (13') having a conical shape, and a cover (14) made of a nonmagnetic material serving as the lid in both configurations of the transducer, the said cover being applied to the body facing the concavity of the said diaphragm in a direct-radiation transducer, while it is applied to the body facing the convexity of the said magnetic disk (12) in an indirect-radiation transducer.

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 loudspeaker cabinet cluster comprises a plurality of loudspeaker cabinets which are pivotally connected with each other to adjust their splay angles vertically or horizontally and also to face the baffle boards of the loudspeaker cabinets axially to the desired listener. The single loudspeaker cabinet includes an ordinary audio input for a single channel electrical audio signal. Each loudspeaker cabinet is a hollow quadrangular pyramidal body made of fibrous glass reinforced plastics and a baffle board is fitted integrally into a front opening of the loudspeaker cabinet.

Abstract: A hearing aid is disclosed in which the outside sound collected by a microphone is amplified and radiated from the earphone unit so as to be conducted to the user's external auditory meatus. The auditory tube is of an inside diameter approximately equal to that of the user's external auditory meatus and has one end arranged as a section for attachment to the user's auricle and the other end arranged as a reflectionless terminal. The earphone unit is mounted on the peripheral surface of the auditory tube with the sound radiating surface facing the inside of the tube.

Abstract: A vehicle loudspeaker system includes a vehicle body having inside surfaces enclosing a passenger compartment. At least one elongated conduit has a proximal portion and a distal portion. A loudspeaker driver is disposed in the vehicle body outside the passenger compartment. The loudspeaker driver has a vibratile surface for generating sound pressure waves in response to electrical stimulation. The proximal portion of the elongated conduit is open to one side of the vibratile surface. The distal portion is open to the passenger compartment. The elongated conduit extends from the vibratile surface into the passenger compartment with an effective length corresponding substantially to a quarter wavelength at the lowest frequency of sound pressure waves to be transmitted between the vibratile surface and the passenger compartment. The loudspeaker driver is characterized by moving mass and an unloaded natural resonant frequency at a first bass frequency.

Abstract: A transducer and tone generator embodying the same and method of assembling the transducer components with the use of an assembly fixture. The transducer components include a rigid annular structure, a pole piece, an electromagnetic coil assembly, and a diaphragm.

Abstract: A loudspeaker system including a cabinet and at least one loudspeaker mounted on the cabinet which includes a movable speaker element for directing acoustical wave energy to the ambient atmosphere and to the interior of the cabinet. A passive radiator is mounted on the cabinet at a location spaced from the loudspeaker. A panel mounted within the cabinet interior vibrates at a free end when impacted by the acoustical wave energy from the loudspeaker. The panel generates acoustical wave energy which is directed to the passive radiator and causes the passive radiator to move and to direct sound externally of the cabinet.

Abstract: A low sound loudspeaker system is constructed of an acoustic pipe extending from the back side of a loudspeaker unit, an air chamber provided at the front side of the loudspeaker unit, and a bass reflex port provided within the air chamber. The acoustic pipe communicates with the air chamber via the aperture of the acoustic pipe.

Abstract: An audio loudspeaker enclosure is presented. The enclosure has surfaces which resonate across a broad band of low frequencies produced by the loudspeaker, thus enhancing the quality of low frequency sound reproduction.

Abstract: A compact acoustic apparatus in which a vibrator is arranged in a Helmholtz resonator having a resonance port, and is driven to radiate a resonant acoustic wave so as to perform lower bass sound reproduction, is characterized in that a cabinet is reduced in size by externally projecting the resonance port from the cabinet, and/or a boundary condition change buffer means is arranged at an opening portion of the resonance port to prevent noise caused by an air flow flowing through the resonance port.

Abstract: In a speaker system, the rearward area of a diaphragm is separated into two acoustic regions. One of the two acoustic regions is a rear opening type and the other is a base-reflex type. An acoustic mass, such as a port or a passive radiator, is located between the first and second acoustic regions for providing a phase inversion characteristic.