Abstract: A device comprising a vibration system having a vibration component capable of vibrating and an electromechanical force transducer mounted to the component to excite vibration in the component. The transducer has an intended operative frequency range and comprises a resonant element having a frequency distribution of modes in the operative frequency range and coupler for mounting the transducer to the component.

Abstract: A method of improving the modal resonance frequency distribution of a panel for a distributed resonant mode bending wave acoustic device. The method involves analysing the distribution of the modal resonance frequencies of the panel, identifying a modal resonance frequency that is non-uniformly spaced relative to adjacent modal resonance frequencies, identifying a location on the panel that exhibits anti-nodal behaviour at the identified modal resonance frequency, and changing the local impedance to bending wave vibration at that location. The method has particular application to distributed mode loudspeakers.

Abstract: At improved loudspeaker system for a passenger vehicle such as an automobile is disclosed. The system comprises a transducer capable of being excited by applied electric potential and electronic means that is electrically connected to the transducer to apply electric potential thereto. It is a feature of the present invention that the diaphragm driven by the excited transducer is comprised of the trim panel of the vehicle.

Abstract: Active acoustic device comprises a panel member (11) having distribution of resonant modes of bending wave action determining acoustic performance in conjunction with a transducer (31-34). The transducer (31-34) is coupled to the panel member (11) at a marginal position. The arrangement is such as to result in acoustically acceptable action dependent on said distribution of active said resonant modes. Methods of selecting the transducer location, or improvement by location of localized marginal clamping, rely on assessing best or better operative interaction of said transducer (31-34) and the panel members (11) according to parameters of acoustic output for the device as an acoustic radiator.

Abstract: A bending wave panel loudspeaker with a bending wave acoustic panel that is capable of supporting bending wave vibration. The panel has a front face and a rear face, and a transducer mounted on the panel to excite bending wave vibration in the panel in response to an electrical signal applied to the transducer so that sound energy is radiated from both the front and the rear faces of the panel. An acoustically porous resistive structure is mounted proximate to one face of the panel to resistively impede sound energy radiated from that one face.

Abstract: A speaker apparatus in which the acoustic sound is radiated by flexural oscillations of a diaphragm in the form of a panel having a substantially flat surface. The speaker apparatus includes a panel-shaped diaphragm the outer rim of which can be oscillated substantially freely at least in the direction along the diaphragm thickness and at least one driver unit constituting an oscillation source secured to the diaphragm surface for imparting oscillations to the diaphragm. The diaphragm is set into flexural oscillations by oscillations applied from the driver unit driven on the basis of the playback input signal. By flexurally oscillating the diaphragm to radiate the acoustic sound, optimum frequency response characteristics can be obtained over a wide frequency range from the low to high frequency range. Moreover, the acoustic sound of optimum sound quality may be radiated in a state of minimum sound pressure level fluctuations over a frequency range from the low to high frequency range.

Abstract: A loudspeaker comprises a panel member (11, 21, 31, 41, 61, 71, 81, 91) as resonant acoustic radiator relying on bending wave action and a driver (12, 22, 32, 42, 62, 72, 82, 92) coupled to the panel member to cause bending waves therein. The panel member has its mass and/or bending capability of the panel member locally altered or otherwise different, particularly locally of the driver as coupled to the panel member. Local holes (16, 26, 36, 46), affixed mass (66) or affixed damping material (76) are effective to reduce high frequency due to drumming effects at the driver coupling (17, 37, 47, 67, 77, 87).

Abstract: A panel-form loudspeaker having a member capable of sustaining and propagating input vibrational energy by bending waves, and a transducer mounted on the member for applying a local couple to the member. The motor coil assembly of the transducer has a surrounding attachment portion rigidly attached to one face of the member in spaced relation to the central attachment portion of the magnet assembly of the transducer. When the transducer is energized, the motor coil assembly and the magnet assembly move in opposite directions to apply a couple to the member through their respective spaced attachment portions to launch bending waves into the member.

Abstract: A portable spa including an audio system designed to use the spa shell as the sound generating device. Transducer devices are mounted within an enclosure which is bonded to the spa shell so as to couple the sound vibration energy to the shell so that sound can be heard when using the spa.

Abstract: An improved structure of a picture-frame type loudspeaker is disclosed. The loudspeaker structure having a magnetic core is mounted on a housing body adhered to the rear side of a picture frame, and the circumferential edge of the magnetic core is mounted with a conduit containing a voice coil, and the end section of the conduit, close to the magnetic core is connected together with a corrugation portion which is combined with the housing body, the middle section of the conduit is connected to a diaphragm and the other end of the conduit is connected to a vibration board within the picture frame via a medium. By means of the reaction to the signal current by the voice coil, a magnetic field is produced and a relative motion is formed with the magnetic core, such that the vibration board vibrates to produce sound from the picture frame.

Abstract: An acoustic device having a panel-form member adapted to support bending wave vibration and having a frequency distribution of resonant bending wave modes. The member is of substantially triangular form with the parameters of the member being selected to provide a desired frequency distribution of resonant modes. At least one of the parameters is selected from the ratio of the effective lengths of two of the sides of the triangular form, the effective angle between at least two of the sides of the triangular form, and the curvature of at least one side.

Abstract: Active acoustic device comprises a panel member (11) having distribution of resonant modes of bending wave action determining acoustic performance in conjunction with transducer means (31-34). The transducer means (31-34) is coupled to the panel member (11) at a marginal position. The arrangement is such as to result in acoustically acceptable action dependent on said distribution of active said resonant modes. Methods of selecting the transducer location, or improvement by location of localised marginal clamping, rely on assessing best or better operative interaction of said transducer means (31-34) and the panel members (11) according to parameters of acoustic output for the device as an acoustic radiator.

Abstract: Acoustic device comprising a member relying on bending wave action with beneficial distribution of resonant modes thereof, wherein the member has its acoustically active area at least partly bounded by means having a substantially restraining nature in relation to bending wave vibration. Operation can be below coincidence, or above if desired for active acoustic device further having beneficial location of bending wave transducer means determined with reference to and taking account of such bounding means.

Abstract: A diaphragmatic (planar) electrocoustic transducer forms a complete sound radiating transducer, with high efficiency and linearity. An easily exchangeable and rectangular in shape diaphragm, of very thin polyamide film is made with a plurality of aluminum conductors formed on one side of said diaphragm. The diaphragm with the plurality of conductors form two identical and symmetrical coils which are the one, inside the other, in an order, that conductors of each coil are interlaced. The two sections of the coils are disposed in dense air-gaps of the magnet system, which comprises a plurality of high (BHmax) Neodymium magnets. The binary interlaced coils can be utilized in a number of modes, for the purpose of accomplishing a variety of operating modes, such as: 1. A series connection provides a higher sensitivity compared to single coil (2). A parallel connection converts the transducer to a higher power standing devise (3).

Abstract: A piezoelectric transceiver comprises a piezoelectric ceramic piece which is provided in two sides with an electrode layer and a bonding wire guided out of the electrode layer. One of the two sides is attached to a vibration piece which is made of a high molecular material having an excellent rigidity as compared with the metal vibration piece of the prior art transceiver. The present invention has a wider volume frequency and a more gentle sound. The present invention is lighter in weight and more energy-efficient.

Abstract: A speaker apparatus in which the acoustic sound is radiated by flexural oscillations of a diaphragm in the form of a panel having a substantially flat surface. The speaker apparatus includes a panel-shaped diaphragm the outer rim of which can be oscillated substantially freely at least in the direction along the diaphragm thickness and at least one driver unit constituting an oscillation source secured to the diaphragm surface for imparting oscillations to the diaphragm. The diaphragm is set into flexural oscillations by oscillations applied from the driver unit driven on the basis of the playback input signal. By flexurally oscillating the diaphragm to radiate the acoustic sound, optimum frequency response characteristics can be obtained over a wide frequency range from the low to high frequency range. Moreover, the acoustic sound of optimum sound quality may be radiated in a state of minimum sound pressure level fluctuations over a frequency range from the low to high frequency range.

Abstract: A planar-magnetic electro-acoustic transducer including a support structure and a magnetic structure carried by the support structure, the magnetic structure comprising a multiplicity of high-energy magnets configured so as to have shared loop field maxima and local loop field maxima, and a diaphragm carried by the support structure, comprising a plurality of conductors carried by and coupled to the diaphragm, said conductors being disposed in relation to local loop maxima and configured to exploit the energy of local loop maxima, as well as the energy of shared loop maxima in driving the diaphragm to produce an acoustic output; and the magnetic structure can be configured so that it includes magnet rows, and the transverse cross-sectional width of the magnets does not exceed their transverse cross-sectional height, and the distance between adjacent elongated magnet rows is greater than one half the width of either of the magnets of the adjacent magnet rows.

Abstract: A speaker apparatus in which the acoustic sound is radiated by flexural oscillations of a diaphragm in the form of a panel having a substantially flat surface. The speaker apparatus includes a panel-shaped diaphragm the outer rim of which can be oscillated substantially freely at least in the direction along the diaphragm thickness and at least one driver unit constituting an oscillation source secured to the diaphragm surface for imparting oscillations to the diaphragm. The diaphragm is set into flexural oscillations by oscillations applied from the driver unit driven on the basis of the playback input signal. By flexurally oscillating the diaphragm to radiate the acoustic sound, optimum frequency response characteristics can be obtained over a wide frequency range from the low to high frequency range. Moreover, the acoustic sound of optinum sound quality may be radiated in a state of minimum sound pressure level fluctuations over a frequency range from the low to high frequency range.

Abstract: A thin loudspeaker is provided that produces a superior frequency response and a diffuse acoustical pattern using magnetic drivers, acoustical plates, or a combination of magnetic drivers and acoustical plates. The invention contains a specially designed crossover network and a novel enclosure design. The novel enclosure includes a septum and cross bracing which enables the invention to realize superior performance in a thin loudspeaker design. The invention encompasses methods for improving the performance of an acoustical plate which include (1) placing acoustical plate motor elements on the plate in a manner that avoids rotational, mirror, and translational symmetry, (2) using acoustical plate motor elements of different shapes and sizes to stimulate the plate, and (3) using an acoustical plate that has an asymmetric shape. All of the embodiments of the invention may be covered with a decorative cover and hung on a wall like a picture or used to form a panel in a home entertainment center.

Abstract: An acoustic actuator comprises a radially poled piezoelectric or electrostrictive drive element which is electroded on its inner and outer faces, and an acoustic diaphragm coupled to the upper surface of the piezoelectric drive element. As a voltage is applied to the electrodes, the piezoelectric drive element expands and contracts in the radial direction and the acoustic diaphragm displaces upward or downward, generating a sound wave. In an alternative embodiment, the piezoelectric or electrostrictive drive element is comprised of several subelements laid end to end and radially poled. In another embodiment, the piezoelectric or electrostrictive drive element is comprised of several subelements laid end to end which are thickness-poled reduced and internally biased oxide wafers of piezoelectric material.

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

Abstract: A bending wave panel-form acoustic radiator formed from sheet material to define an acoustically active area and having at least one integral stiffening member in the form of a corrugation extending out of the plane of the sheet and at least partially across the acoustically active area of the radiator, which stiffening member is of substantially U-shaped cross section. Also disclosed is a method of making a bending wave panel-form acoustic radiator, comprising forming a sheet into a panel having at least one integral corrugation member extending out of the plane of the sheet and at least partly across the sheet and of substantially U-shape cross-section, to stiffen the sheet to have a desired ability to support and propagate bending waves.

Abstract: An acoustic device has a plurality of resonant bending wave modes along the length of a member. The fundamental frequency of resonant bending wave modes in directions perpendicular to the length is much higher, so that the lower frequency resonant bending wave modes are substantially one directional. A plurality of transducers may be spaced across the width of the member at a preferred position along the length of the panel.

Abstract: An acoustic diaphragm arranged to face a driving device of a loudspeaker is disclosed. The acoustic diaphragm comprises at least one laminated structure, one of which includes a first carbon fiber layer, a glue layer formed on the first carbon fiber layer, and a second carbon fiber layer formed on the glue layer. The acoustic diaphragm of the present invention has small distortion of sound, less deformation by external force, better stereo, and sound quality, as compared with a conventional diaphragm.

Abstract: A transparent panel-form loudspeaker consists of a transparent sound radiation panel that can radiate sound with desired pressure level over a specific frequency range when subjected to the flexural vibration induced by a preselected number of transducers located at specific positions on the peripheral edge of the transparent sound radiation panel and a rigid frame carrying a flexible suspension device which supports the periphery of the transparent sound radiation panel. The transparent sound radiation panel is made of a kind of transparent materials with the ratio of elastic modulus to density in the range from 3 to 180 GPa/(g/cm3) and the ratio of length to thickness of the transparent sound radiation panel in the range from 80 to 600.

Abstract: Acoustic devices have members extending transversely of thickness and capable of sustaining bending waves causing consequential acoustic action by reason of areal distribution of resonant modes of natural bending wave vibration consonant with required achievable acoustic action of said member over a desired operative acoustic frequency range, Areal distribution of stiffness including variation(s) therein is used to get desired locations for bending wave transducers and/or good resonant mode acoustic action from inherently unfavourable shapes of members. Members with combined pistonic active drive and bending wave excitement at centers of mass and geometry are featured.

Abstract: An electroacoustic capsule or electroacoustic transducer for an electroacoustic device has electrostrictive or magnetostrictive elements connected to a controllable power supply. Dimensional changes of the electrostrictive or magnetostrictive elements cause changes of the inner geometry of the electroacoustic capsule or electroacoustic transducer. This allows the adjustment of the capsule or transducer to the electroacoustic device in which it is mounted so that individual and dynamic adjustments are possible.

Abstract: Acoustic devices rely on bending wave action in a panel member, particularly distribution of resonant modes of such bending wave action and related acoustically significant surface vibration over area of said panel member favourable to desired or at least acceptable acoustic device performance. The devices comply with selecting parameters of said panel member affecting said distribution, including configuration/geometry and/or bending stiffness(es), and/or location(s) of bending wave transducer(s) in said area of said panel member; the selecting being in accordance with analytical assessment of power transfer related characteristic(s) of said panel member thus said acoustic device concerned and desiderata therefor correlating with achieving said acoustic device performance.

Abstract: A speaker assembly comprising a speaker housing, a speaker mounted in the housing, and at least two threaded studs connected to the housing and speaker and extending away from the external surface of the housing. The studs have an unthreaded, pointed end that is particularly suitable for piercing a ceiling tile with little effort or mess. There are at least two nuts for threading over the studs to secure the studs to a ceiling tile after the studs pierce the tile to attach the housing to the tile, and at least two wire nuts to connect amplifier wires to the tip of the studs. The speaker is mounted to a ceiling tile by piercing the tile with the studs and securing the studs to the other side of the tile with the nuts. The amplifier wires are then connected to the tips of the studs via the wire nuts.

Abstract: A loudspeaker comprising a panel-form acoustic member adapted for operation as a bending wave radiator and an electrodynamic moving coil transducer having a voice coil mounted to the acoustic member to excite bending wave vibration in the acoustic member. The junction between the voice coil and the acoustic member is of sufficient length in relation to the size of the acoustic member to represent a line drive such that the acoustic member has a mechanical impedance which has a rising trend with bending wave frequency.

Abstract: A pole piece 31 is placed on a lower case 21. A pole piece 31 has a core 32 and a base 33. The bobbin portion 24 extends from the lower case 21 toward the internal space of a case 1 so as to surround the outer periphery of the core 32. The bobbin portion 24 is divided into a plurality of portions along the circumferential direction of the core 32. The bobbin portion 24 has basal parts 26 and elongated parts 27. The pole piece 31 is pressed from the above of the lower case 21 in a state where the bobbin portion 24 is passed through holes 35 of the base 33, to be positioned on the outer periphery of the core 32, so that the pole piece is fitted and placed into the lower case 21. A coil 41 is configured by winding a conductor wire 42 around the elongated parts 27 of the bobbin portion 24.

Abstract: Packaging comprises a loudspeaker which has a board component that forms a part of the packaging and acts as a distributed mode bending wave acoustic radiator. A transducer is mounted wholly and exclusively on the radiator to vibrate it and cause it to resonate.

Abstract: A loudspeaker comprising a resonant panel-form member adapted to produce an acoustic output and a vibration exciting system on the panel-form member and adapted to apply bending wave energy thereto, characterised in that the vibration exciting system is adapted to apply a bending couple to the panel-form member.

Abstract: An electronic musical instrument having a keyboard and a loudspeaker, wherein the loudspeaker comprises a resonant distributed mode acoustic radiator having a stiff lightweight member having capability to sustain and propagate input vibrational energy by bending waves in at least one operative area extending transversely of thickness, and a transducer mounted wholly and exclusively on the member at a predetermined location or site within the operative area.

Abstract: A loudspeaker/visual display combination comprises a visual display module and a transducer attached to the display module to apply bending wave energy thereto to cause the display module to radiate an acoustic output. Attachment of a transducer directly to the visual display module dispenses with the need for a separate bending wave speaker whilst application of bending wave energy to the module allows satisfactory acoustic performance to be obtained.

Abstract: An apparatus for mounting a flat panel radiator into a ceiling grid. The ceiling grid system includes openings defined by main beams and crossbeams. The main beams are secured through hanger wires to a hard ceiling. The main beams and the crossbeams have flanges with the crossbeams resting on the flanges of the main beams. The mounting apparatus has a frame including a top plate, a side plate, and a bottom plate, containment elements and isolation elements attached to the frame, and an acoustically transparent scrim attached to the bottom of the frame. The flat panel radiator is mounted between containment elements and isolation elements. The radiator panel can be fabricated from a honeycomb core. The containment elements may be made from a stiff to resilient material, whereas the isolation element will always be resilient to vibration isolate the radiator panel from the ceiling grid system both mechanically and acoustically. The flat panel sound radiator assembly can also be installed in wall partitions.

Abstract: An inertial exciter (40) for an acoustic radiator (42), and a loudspeaker incorporating an acoustic radiator and such an exciter. The exciter has a massive member (44); a coupler (56) adapted for attachment to the acoustic radiator (42) and adapted for relative movement with respect to the massive member (44); a motor for effecting relative movement of the coupler with respect to the massive member; and a suspension (60) for supporting the massive member relative to the coupler. The suspension (60) acts in a plane generally passing through the center of mass of the massive member, thereby reducing any moment acting on the suspension.

Abstract: A trim panel, e.g., a roof lining for a vehicle passenger compartment, characterized in that the trim panel comprises an integral acoustic radiator and a vibration exciter mounted on the radiator to launch bending waves into the radiator to cause it to resonate to produce an acoustic output. The acoustic radiator has a periphery which is integral with the radiator and the trim panel.

Abstract: A loudspeaker comprising a panel which is sufficiently stiff to support bending waves, the panel having a boundary, a transducer mounted to the panel to apply bending wave energy in the form of dispersive travelling waves thereto at a first location in response to an electrical signal applied to the transducer to cause the panel to vibrate and radiate an acoustic output, the loudspeaker having a frequency range extending from a lower frequency to a higher frequency and the panel having a stiffness giving a coincidence frequency above the lower frequency. Means on or associated with the panel at a second location attenuates travelling bending waves in the panel to prevent or at least substantially to moderate panel resonance.

Abstract: A drive module for attachment to a rigid panel and adapted to apply bending wave energy at audio frequencies to the panel whereby the panel can radiate an audio output. The drive module has a housing adapted to be secured to the panel, at least one foot on the housing and adapted to fix the housing securely to the panel, an electromechanical transducer in the housing, a support for the transducer in the housing, the transducer being adapted to contact the panel to apply bending wave energy thereto when energized with an electrical audio signal, and an audio signal amplifier in the housing.

Abstract: A greetings or the like card (144), characterised by a board (2) forming at least part of the card and in that the board is a distributed mode acoustic radiator having a transducer (9) mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.

Abstract: Acoustic device including a member extending transversely of its thickness and capable of sustaining bending waves at least over an intendedly consequentially acoustically active area of the transverse extent of said member, the member having, by reason of orderly design methodology disclosed and claimed, a distribution of resonant modes of its natural bending wave vibration at least over said area that is dependent on values of particular parameters of said members, including geometrical configuration and directional bending stiffness(es), which values have been selected to predetermine said distribution of natural resonant modes being consonant with required achievable acoustic action of said member for operation of said device over a desired operative acoustic frequency range.

Abstract: A vehicle windscreen accessory comprising a body member, an adjustable support structure for the body member whereby the position of the body member can be adjusted, the body member comprising a mirror member and a loudspeaker having a bending wave panel-form acoustic member, the mirror member and panel-form member being integral. The accessory can be in the form of, e.g., a sun visor or a rear view mirror.

Abstract: A loudspeaker comprising a panel capable of supporting bending waves and at least two exciters mounted to the panel for exciting bending waves in the panel to produce an acoustic output, each of the exciters being adapted for connection to respective independent sources of drive signals. A loudspeaker system and a method for operating it also are disclosed. The loudspeaker and system are useful, e.g., as a sound-generating ceiling tile.

Abstract: An electroacoustic transducer 1 is provided with a diaphragm 20 which is made of a magnetic material, and to which a magnetic piece 21 is fixed; a magnetic core 22 which is placed in proximity to the diaphragm 20; a coil 23 which supplies an oscillating magnetic field to the magnetic core 22; a housing 10 which accommodates the diaphragm 20, the magnetic core 22, and the coil 23, and which has a sound release opening 11 in a top plate opposed to the diaphragm 20, the sound release opening being larger than the magnetic piece 21. A beam portion 12 is formed integrally with the housing 10 which extends from a peripheral portion of the sound release opening 11 to another peripheral portion passing above the magnetic piece 21. A gap Ga between the diaphragm 20 and the magnetic core 22, and a gap Gb between the magnetic piece 21 and the beam portion 12 satisfy relationships of Ga≦Gb≦5Ga.

Abstract: A loudspeaker and method of driving it, the loudspeaker having a panel capable of supporting bending waves, a low frequency transducer mounted to the panel for exciting bending waves in the panel at frequencies below a predetermined frequency, a high-frequency transducer mounted to the panel for exciting bending waves in the panel at frequencies above the predetermined frequency, and crossover circuitry for supplying a signal to the low-frequency transducer at frequencies below the predetermined frequency and to the high-frequency transducer for frequencies above the predetermined frequency. The predetermined frequency is substantially equal to the coincidence frequency.

Abstract: A loudspeaker comprising a panel adapted to support bending waves and an exciter for exciting said bending waves employs an exciter having an effective size with which it acts on said panel, the effective size varying in dependence on the frequency with which the exciter acts on the panel. Exciters suitable for use in such a loudspeaker are also disclosed.

Abstract: A mid/high frequency loudspeaker comprising a stiff lightweight resonant panel form member, a housing in which the panel form member is mounted, a suspension connected between the edges of the panel-form member and the housing and by means of which the panel edges are restrained against movement, the arrangement being such that the housing and the panel-form member together define a cavity, and an electrodynamic exciter for applying bending wave energy to the panel-form member to cause it to resonate to produce an acoustic output, the exciter comprising a magnet assembly rigidly fixed to the housing and defining an annular gap, and a voice coil and coil former assembly disposed in the annular gap and rigidly fixed to the panel-form member near to the geometric center thereof, wherein only said panel suspension centers the voice coil and coil former assembly in the annular gap.

Abstract: Acoustic devices have members extending transversely of thickness and capable of sustaining bending waves causing consequential acoustic action by reason of areal distribution of resonant modes of natural bending wave vibration consonant with required achievable acoustic action of said member over a desired operative acoustic frequency range, Areal distribution of stiffness including variation(s) therein is used to get desired locations for bending wave transducers and/or good resonant mode acoustic action from inherently unfavourable shapes of members. Members with combined pistonic active drive and bending wave excitement at centres of mass and geometry are featured.

Abstract: Acoustic device including a member extending transversely of its thickness and capable of sustaining bending waves at least over an intendedly consequentially acoustically active area of the transverse extent of said member, the member having, by reason of orderly design methodology disclosed and claimed, a distribution of resonant modes of its natural bending wave vibration at least over said area that is dependent on values of particular parameters of said members, including geometrical configuration and directional bending stiffness(es), which values have been selected to predetermine said distribution of natural resonant modes being consonant with required achievable acoustic action of said member for operation of said device over a desired operative acoustic frequency range.