Abstract: A loudspeaker is made of a panel supporting bending waves and a transducer covering a substantial portion of the panel surface. At least one constraint, for example a clamp or a mass, is fixed to the panel. Each constraint reduces the mobility of a small area of the panel. Excitation of the transducer excites bending waves in the panel; the constraints discourage simple motion and encourage the production of a plurality of bending waves instead. The constraints can constrain the panel to be excited to produce a good distribution of resonant bending wave modes.

Abstract: A speaker mounting apparatus is provided which facilitates pivoting of the speaker to a desired angular position, while providing increased thermal mass for the speaker assembly. For preferred embodiments, the speaker is mounted in a cup of a thermally conductive material, which cup has a surface which mates with a corresponding surface of a mount in a manner so as to permit the speaker to be pivoted to a desired angular position, to be held in such position and, for preferred embodiments, to permit heat transfer from the cup to the mount, which is also of a thermally conductive material, further increasing the thermal mass of the apparatus.

Abstract: The present invention relates to a LCD display that has a thin depth, rigid enclosure and includes a thin speaker so that the depth of the enclosure does not have to be increased to accommodate the speaker. The speaker is used to generate audio output that may correlate to the graphical information displayed on the LCD display. The enclosure has an opening for inclusion of a semi-rigid lens for viewing of an internal LCD module that is also used as a planar surface for the thin speaker. In order to provide a thin device in the enclosure that is driven by a driver to move air to generate sound, the driver is attached to the semi-rigid lens.

Abstract: A speaker system for an electronic device includes a keypad with keys, a housing with first spaces for receiving respective ones of the keys, and a flat speaker located under the keypad. The keys and the first spaces are sized such that there are gaps between the keys and the housing when the keys are received within the first spaces. The speaker is co-planar with the keypad and when sound is projected from the speaker, it is emitted through the gaps between the keys and the housing.

Abstract: A thin, lightweight electroacoustic actuator device covering a large surface area providing a high piston-like output over the frequency range of from at least 30 to in excess of 500 Hz comprising a stiff, lightweight face plate; a backing structure disposed below the face plate; at least one driver structure disposed between the face plate and the backing structure; and flexible structure flexibly connecting the at least one driver to the face plate.

Abstract: A system responsive to acoustic waves includes a resonator having a bottom plate, side walls secured to the bottom plate, and a top plate disposed on top of the side walls. The top plate includes an orifice. The bottom plate or side walls of the resonator include at least one compliant portion. A reciprocal electromechanical transducer is coupled to the compliant portion of the resonator to form a transducer/compliant composite, wherein the transducer/compliant composite has an open circuit acoustic impedance. An electrical network is coupled to the transducer/compliant composite. The acoustic impedance of the transducer/compliant composite copied to the electrical network is different as compared to the open circuit impedance which perm its the frequency response of the system to be varied over a large range of frequencies.

Abstract: A fire protective flat panel radiator assembly for installation in a suspended ceiling grid is provided. The assembly includes a flat panel radiator having a frame that supports a sonic diaphragm, which is driven by a transducer to reproduce an audio program. A back box is mounted to the radiator and the back box covers and encloses the diaphragm and other fire susceptible components of the radiator. The back box is provided with a cut-out portion that is covered with an air pervious panel, which is resistant to fire hazards but that allows air flow in and out of the back box. In one embodiment, the radiator has a bridge and the back box is formed by a pair of shells mounted on each side of the bridge to enclose and protect the diaphragm. The result is a fire protected flat panel radiator assembly that meets the fire performance requirements for air handling plenums while retaining the sonic fidelity of a flat panel sound radiator without a fire protective back box.

Abstract: A method of improving the modal resonance frequency distribution of a panel (2) for a distribution resonant mode bending wave acoustic device 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 said panel that exhibits anti-nodal behaviour at said modal resonance frequency and changing the local impedance to bending wave vibration at said location (6). The method has particular application to distributed mode loudspeakers (1).

Abstract: A ceiling panel speaker 100 comprises ceiling panel vibrating plates 110 and exciter units 200 mounted on said vibrating plates 110, each exciter unit 200 connected via line 270 to an amplifier not shown. The ceiling panel vibrating plates 110 are aligned to form a longitudinal size L1 extending above one or more aisles within the cabin, so that the ceiling panel speaker 100 realizes a long surface sound source. The sound waves output from the ceiling panel speaker 100 are transmitted along inner wall panels 12 etc. and spread throughout the closed space of the passenger cabin 50.

Abstract: A small-sized, light-weight display device having an audio output circuit is provided. A display device of the present invention has a flat speaker and an audio signal processing device is constructed from thin film semiconductor elements, typically, thin film transistors, on the display device. The speaker is driven by BTL driving, thereby reducing the power supply voltage and preventing degradation of the thin film transistors. A display device with a built-in audio signal processing circuit is thus reduced in size and weight.

Abstract: A vehicle headliner includes electromagnetic drivers for sonically driving a member or a layer of the headliner. A foam beam is shaped around a driver transducer connection area that holds one or more driver connectors. A cover may be maintained over the shaped foam beam to protect against entry of dust and other debris into the driver and the transducer connection area that receives the driver.

Abstract: Arrangement of a sound reproduction system (1), including at least one input (2), a sound field generator (4), a loudspeaker panel (10); the at least one input (2) connected to the sound filed generator (4), and the sound filed (4) connected to the loudspeaker panel (10); the at least one input (2) arranged for generating and audio signal; the sound filed generator (4) including a wave field synthesiser (6) arranged for generating a spatially perceptible sound field for the audio signal and for outputting the spatially perceptible sound field to the loudspeaker panel (10) consisting of a plate (12) and a plurality of transducers (16), arranged within an array (14) on the large plate (12) for reproducing the spatially perceptible sound field from the wave field synthesiser (6) by exciting bending waves in the plate (12).

Abstract: An inertial vibration transducer for exciting bending waves in a sound-radiating member has a motor coil assembly with a tubular member adapted to be rigidly mounted directly to the sound-radiating member by adhesive means. The transducer has a magnet assembly supported on a resilient suspension, and the magnet of the magnet assembly may be disposed within the tubular member of the motor coil assembly. Loudspeakers incorporating such transducers also are disclosed.

Abstract: The present invention relates to an electromagnetic vibrator of variable reluctance type, according to a new principle which provides higher efficiency, smaller dimension, and higher reliability compared to known technology. This has been obtained by the magnetic signal flux around the coil is closed through a bobbin body and a yoke and through air gaps formed between bobbin body and yoke(s) where a static flux from one or more of the permanent magnets and the signal flux cooperates so that static forces are outbalanced and so that axial signal forces are generated. The new vibrator principle has been names: Balanced Electromagnetic Separation Transducer (BEST).

Abstract: The invention relates to a system with multi-mode radiator panels used to reproduce sound. The multi-mode radiator panels include at least one driver, a core layer and two cover layers connected to the core layer. The panels are typically mounted in a frame with attachments providing a connection between the frame and the unit formed of the core layer and the cover layers. To protect the system against overload and damage, the entire driver electronics is housed in a hermetically sealed air space located between the frame, the core layer and the attachments. The driver electronics includes a power amplifier powered by low-voltage power supply. The voltage supply may be buffered by a battery to keep the average power supplied to the electronics small, while still being able to reproduce infrequently occurring peak power events.

Abstract: A planar type speaker keeps its diaphragm (2) free from any distortion in operation, thus providing high fidelity sound reproduction. The diaphragm (2) is of a planar type and surrounded by a flexible edge member (3). This member (3) is constructed of an inner edge piece (3a) and an outer edge piece (3b) each of which has a semicircular shape in cross section to provide a convex surface and a concave surface. These edge pieces (3a, 3b) are the same in construction, but are inverted in arrangement to have the concave surfaces thereof face to each other to sandwich the diaphragm (2) between the concave surfaces of the edge pieces (3a, 3b); and, the outer edge piece (3b) is provided with a plurality of notched holes (7) which are symmetrically arranged in the outer edge piece (3b).

Abstract: This invention has a cup-shaped external case 15 with a rising tube 15b in the center of the closed face 15c, the external case 15 accommodating the stator and rotor and the end of the shaft 1 opposite that where the brush seat 10 is assembled, such that by fitting the end of the shaft 1 into the rising tube from the inside of the external case 15, the external case 15 is held in a position parallel to the shaft 1, and such that by fitting the brush seat 10 into the open end of the external case 15, the external case 15 is held in place by the shaft 1 and the brush seat 10.

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 for vehicles having cabins, the loudspeaker including a diaphragm including a first, planar portion for radiating acoustic energy and a second, planar portion for transmitting vibrational energy from a voice coil driver to the first portion. The first portion is incorporated into an inner surface of the vehicle's cabin. The second portion extends from the first portion to a location outside of the cabin, where the voice coil driver is located.

Abstract: A thin, lightweight electroacoustic actuator device covering a large surface area providing a high piston-like output over the frequency range of from at least 30 to in excess of 500 Hz comprising a stiff, lightweight face plate; a backing structure disposed below the face plate; at least one driver structure disposed between the face plate and the backing structure; and flexible structure flexibly connecting the at least one driver to the face plate.

Abstract: A micro-mechanical pressure transducer is disclosed in which a capacitive transducer structure is integrated with an inductor coil to form a LC tank circuit, resonance frequency of which may be detected remotely by imposing an electromagnetic field on the transducer. The capacitive transducer structure comprises a conductive movable diaphragm, a fixed counter electrode, and a predetermined air gap between said diaphragm and electrode. The diaphragm deflects in response to an applied pressure differential, leading to a change of capacitance in the structure and hence a shift of resonance frequency of the LC tank circuit. The resonance frequency of the LC circuit can be remotely detected by measuring and determining the corresponding peak in electromagnetic impedance of the transducer.

Abstract: The present invention relates to a LCD display that has a thin depth, rigid enclosure and includes a thin speaker so that the depth of the enclosure does not have to be increased to accommodate the speaker. The speaker is used to generate audio output that may correlate to the graphical information displayed on the LCD display. The enclosure has an opening for inclusion of a semi-rigid lens for viewing of an internal LCD module that is also used as a planar surface for the thin speaker. In order to provide a thin device in the enclosure that is driven by a driver to move air to generate sound, the driver is attached to the semi-rigid lens.

Abstract: A panel form loudspeaker comprises a resonant multi-mode radiator (11) which in turn comprises a plurality of substantially concentric sub-panels (20, 21, 22, 23). A plurality of analogue drivers (10) drive the radiator (11), one or more of the drivers being operational at any time. A signal level measured at the input to the loudspeaker determines the operational state of each of the drivers (10). The concentric sub-panels may take various shapes and have different areas.

Abstract: A fire protective flat panel radiator assembly for installation in a suspended ceiling grid is provided. The assembly includes a flat panel radiator having a frame that supports a sonic diaphragm, which is driven by a transducer to reproduce an audio program. A back box is mounted to the radiator and the back box covers and encloses the diaphragm and other fire susceptible components of the radiator. The back box is provided with a cut-out portion that is covered with an air pervious panel, which is resistant to fire hazards but that allows air flow in and out of the back box. In one embodiment, the radiator has a bridge and the back box is formed by a pair of shells mounted on each side of the bridge to enclose and protect the diaphragm. The result is a fire protected flat panel radiator assembly that meets the fire performance requirements for air handling plenums while retaining the sonic fidelity of a flat panel sound radiator without a fire protective back box.

Abstract: A structure of a rectangular panel-form loudspeaker is provided. The structure includes a radiating panel, a transducer, a frame and a suspending unit. The radiating panel includes a rectangular laminated composite plate with length b and width a, and the laminated composite plate includes an intermediate core layer sandwiched between two fiber-reinforced polymeric layers. The transducer is used for exciting the radiating panel to produce flexural vibration. The transducer includes a voice coil assembly and a magnet assembly, wherein the voice coil assembly is coupled to a first side of the laminated composite plate at a first specified location. The frame is used for positioning the laminated composite plate and the magnet assembly. The suspending unit is made of a soft material and disposed between peripheral edges of the laminated composite plate and the frame.

Abstract: The present invention relates to an electret condenser microphone including the vibratory diaphragm which is comprised of an electret film into which an electric charge is charged; a conductive film formed on one side of the electret film and a polar ring disposed at a peripheral edge of the underside of the conductive film. Also, this microphone includes a vibratory diaphragm support member which is disposed on the vibratory diaphragm and has a concave groove and a concave portion. On the vibratory diaphragm support member is attached an integrated circuit serving to receive and amplify a transformed electrical signal from the vibratory diaphragm.

Abstract: A panel form acoustic member capable of supporting bending wave vibration has the bending wave velocity varied in the region of coincidence to provide a range of coincidence frequencies, for causing the acoustic coupling of the bending waves in the panel to occur over a broader range of angles or for making the coupling more uniform. The member may be incorporated in a loudspeaker having a panel member (1) and an exciter (3) fixed to the panel member to excite bending waves in the loudspeaker to cause an acoustic output.

Abstract: A dynamic electroacoustic transducer adapted to be surface-mounted on a printed circuit board comprises a diaphragm, a synthetic resin frame for supporting the diaphragm at the periphery thereof, a surface-mounting terminal member mounted on the frame, and a synthetic resin cover with a sound emitting hole fixed to the frame so as to cover the diaphragm. Since the frame and the cover are made of synthetic resin of lower heat conductivity, the electroacoustic transducer is allowed to be subject to reflow soldering when it is surface-mounted on a printed circuit board without a damage to the diaphragm and the magnet.

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: An electro-dynamic inertial vibration exciter (1), for exciting a member (2) having capability to sustain and propagate input vibrational energy comprising a motor coil assembly (3, 4) having a coil (3) rigidly fixed to a tubular coil former member (4), a magnet assembly (5, 6, 7) disposed concentrically with respect to the motor coil assembly, and means (11) suspending the magnet assembly for axial movement relative to the motor coil assembly, characterized by a carrier (9) supporting the motor coil assembly (3, 4) and adapted for connection to the member (2) to be excited.

Abstract: A speaker enclosure (10) comprising a speaker box (12) having an opening (27) and adapted for mounting within a wall (20) upon a wall stud (22); a compressible gasket (14) affixed about the box opening (27); a faceplate (16); and a plurality of independently adjustable coupling mechanisms (18) for coupling the faceplate (16) with the box (12). The protruding, uncompressed gasket (14) is compressed by the faceplate (16) and the coupling mechanisms (18), which may be independently adjusted to provide an optimum and substantially uniform degree of separation between faceplate (16) and wall (20), thereby reducing distortion, vibration, and damage due to undesirable contact therebetween. A spring (160) is provided to prevent over-compression of the gasket (14) due to heavy or low frequency speakers, thereby facilitating maintaining the uniform degree of separation; and a spacer (162) is provided to maintain the spring (160) in its operating position.

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: A panel loudspeaker with a low mass panel, a holder for retaining the panel and at least one driver with a vibrating connection to the panel for producing mechanical vibrations as a function of electrical drive signals, where the panel is bent at least in one dimension.

Abstract: A loudspeaker assembly comprises at least one mid-range speaker with a substantially planar diaphragm comprised of a lightweight material. The diaphragm can include a support shield to prolong the operating lifetime of the loudspeaker assembly. The loudspeaker assembly further comprises at least one high-range speaker. The loudspeaker assembly further comprises two posts. The at least one mid-range speaker and the at least one high-range speaker can be positioned between the two posts during assembly. The relative positions of the at least one mid-range speaker, and the at least one high-range speaker are adjustable.

Abstract: The problem of providing an electroacoustic converter for wide-band loudspeakers or magnetless electrodynamic headphones for generating sound, in particular for application in the homogeneous and/or nonhomogeneous magnetic field of a magnetic resonance tomograph, an electroacoustic converter avoiding the drawbacks of the prior art, is essentially resolved in that the electroacoustic converter for generating sound comprises an elastically suspended oscillating body, whereby the oscillating body consists of a non-elastic or low-elastic, non-magnetic or only weakly magnetic material and is flatly and in a fixed manner connected with conductor paths, on which a Lorentz force is acting as the driving force when current is flowing. The Lorentz force is supplied by the magnetic field of the magnetic resonance tomograph.

Abstract: An electroacoustic transducer adapted to be mounted on a printed circuit board in which a coil spring is accommodated and supported in a cylindrical recess of a frame while it is fixed to neither a terminal plate nor the frame. Particularly, a protruding pin of the coil spring is passed through a though hole of the terminal plate to allow a leading portion of the protruding pin to be hooked thereon. When the electroacoustic transducer is mounted on the printed circuit board, any horizontal displacement between the compressed spring and the printed circuit board would not cause stress concentration on the coil spring since the coil spring is onlly horizontally shifted in the cylindrical recess until a coil portion of the coil spring hits against the wall of the cylindrical recess.

Abstract: A keyboard (40) having a bending wave loudspeaker (46) comprising an acoustic radiator capable of supporting bending waves and a transducer (48) mounted on the acoustic radiator to excite bending waves in the acoustic radiator to produce an acoustic output. The keyboard comprises a housing (38) having a lid (36) supporting individual keys (14) or a touchpad. The loudspeaker (46) may be integrally formed with the base (42) of the housing of the loudspeaker, or, if a touchpad is used, may be integral with the touchpad. The acoustic radiator may be a resonant mode bending wave radiator.

Abstract: The invention relates to a vehicle (1) having a sound-radiating element (10) for emitting sound waves into a passenger compartment (2) and having an air duct (6) for the air conditioning of the passenger compartment (2), the air duct (6) having an air duct inner wall (7) facing the passenger compartment (2). In order to reduce the installation space for the sound-radiating element and to simplify the assembly, the invention proposes that the sound-radiating element (10) has the air duct inner wall (7) and an oscillation exciter (9) arranged on the air duct inner wall (7), for exciting oscillation of the air duct inner wall (7).

Abstract: An economical and compact flat panel loudspeaker is disclosed that effectively dampens undesirable standing waves that form in the diaphragm without adversely affecting the frequency response. The diaphragm is preferably anisotropic, and has at least one compliant compressed dampening member transposed between it and a substantially planar support. The dampening member is preferably positioned at or near at least one mode of constructive or destructive interference on the diaphragm, and urges the diaphragm away from the planar support, thereby placing as light bending force on the diaphragm, and a slight compression force on the dampening member. Accordingly, the dampening member serves as a sink for transferring undesirable standing waves from the diaphragm to the planar support. In a preferred embodiment, the dampening member is an elongated strip of compliant foam rigidly secured to the diaphragm and planar support and extending through a plurality of modes on the diaphragm.

Abstract: The invention proposes a contact connection for sound reproduction devices according to the flexural wave principle. Since the drive systems 21 of such installations require high current intensities and such current intensities could only be properly transmitted by massive contact connections which however hinder the flexural wave propagation, the object of the invention is to propose a contact connection which eliminates the problems of the state of the art, and which is also very easy to implement. To that end it is proposed that at least one of the two cover layers 12 and/or the core layer 11 contain conductive areas 17 which are connected to the lines 32 of a sound signal source. It is particularly advantageous if the conductive areas 17 can be manufactured together with the components that are also used to manufacture the core layer 11.

Abstract: An improved flat panel sound radiator assembly is provided for reproducing high quality sound at volume levels substantially higher than existing flat panel sound radiator systems. The assembly includes a flat panel radiator having a core sandwiched between facing skins. The core, which preferably is a honeycomb core, and the skins are made of materials that result in a substantially enhanced signal-to-noise ratio and enhanced bass response when reproducing sound. The flat panel radiator is disposed within a frame and the peripheral edges of the radiator are movably coupled to the frame with a compliant surround. An exciter, which may be a traditional magnet structure, is mounted on and supported by a bridge structure spaced from the inside face of the radiator and is coupled to the radiator only through a voice coil assembly. In use, the radiator produces sound through distributed mode reproduction below a sound level threshold.

Abstract: A piezoelectric film loudspeaker comprising a diaphragm having a flexible piezoelectric film and electrodes formed on the both surfaces of the flexible piezoelectric film and a frame for supporting a side of the diaphragm, wherein said respective electrodes disposed on the both surfaces are divided into a plurality of sections. Each area of the divided electrodes is formed differently from one another, and each curvature of the film in the divided section also is formed differently from one another. Thus, the piezoelectric film loudspeaker having a predetermined area can have a broad band.

Abstract: A flat panel sound radiator having improved audio performance is provided. The sound radiator has a panel to which is coupled a traditional electromechanical exciter for imparting audio frequency vibrational energy to the panel. The panel has a honeycomb core made of Kraft paper, which is flexible, has a low self noise, and high noise damping characteristics. The core is sandwiched between facing skins made of a material with a high Young's modulus, a high tan delta, a high tensile strength, and low self noise. Preferably, this material is an aramid polyamide such as Kevlar®, Nomex®, Conex®, or Technora®, all of which exhibit these properties. The facing skins are fixed to the core with an adhesive that is flexible and has high acoustic damping qualities and high shock resistance, such as rubber cements, silicone adhesives, and water-based acrylic adhesives.

Abstract: A speaker enclosure (10) comprising a speaker box (12) having an opening (27) and adapted for mounting within a wall (20) upon a wall stud (22); a compressible gasket (14) affixed about the box opening (27); a faceplate (16); and a plurality of independently adjustable coupling mechanisms (18) for coupling the faceplate (16) with the box (12). The uncompressed gasket (14) protrudes beyond the wall surface (26) until the faceplate (16) is brought into contact with and compresses the gasket (14) by the coupling mechanisms (18) which may be independently adjusted to provide an optimum and substantially uniform degree of separation between faceplate (16) and wall (20), thereby reducing distortion, vibration, and damage due to undesirable contact therebetween.

Abstract: A first conductor and a second conductor are provided at a diaphragm. The first and second conductors intersect magnetic force lines between north poles and south poles of permanent magnets M which are adjacent to one another. When electricity passes through the conductors, a direction in which a force from the magnetic field acts on the current is substantially orthogonal to a surface of the diaphragm. Therefore, the diaphragm can be oscillated in the direction orthogonal to the diaphragm surface. The conductors have widths of from 1000 &mgr;m to 2000 &mgr;m. Therefore, relative errors in the widths caused by etching can be greatly reduced compared to the prior art, and etching is easier. Moreover, the conductors are arranged in a zigzag pattern. Because the conductors do not have a coil form, a large number of through-holes is not required as in conventional products.

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 bending wave loudspeaker includes a transparent acoustic radiator capable of supporting bending wave vibration and an electromechanical force transducer mounted to the acoustic radiator to excite bending waves in the acoustic radiator to produce an acoustic output. The transducer has an intended operative frequency range and includes a resonant element having a frequency distribution of modes in the operative frequency range and a coupler for mounting the transducer to the acoustic radiator. The loudspeaker may be incorporated in a telephone handset or a visual display unit.

Abstract: A compound speaker has first and second sound production devices provided in a case. First and second sound discharge holes are formed in the case for discharging sounds produced by the first and second sound production devices, respectively. The first sound discharge hole is formed in a peripheral side wall of the case so as to discharge sounds in a lateral direction.

Abstract: A touch pad assembly for use in an electronic article. The assembly comprises a touch pad, a coupler for mechanically coupling the touch pad to casing of the electronic article and a transducer which is mounted by coupling means on the coupler or the touch pad to drive the casing as an acoustic radiator. An electronic article can incorporate the same. An electronic article comprises a body in or on which a bending wave loudspeaker is mounted. The loudspeaker comprises a bending wave acoustic radiator and an electromechanical force transducer mounted to the radiator to vibrate the radiator to produce an acoustic output. 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 coupling means for mounting the transducer to the radiator.

Abstract: A vehicle component for mounting in a passenger compartment of a vehicle, the component comprising a loudspeaker having an acoustic radiator capable of supporting bending wave vibration and an electromechanical force transducer mounted to the acoustic radiator to excite bending waves in the acoustic radiator to produce an acoustic output, characterized in that 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 a coupler on the resonant element for mounting the transducer to the acoustic radiator.