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.

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: 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 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: 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: 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: 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: 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: 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 display screen (32), e.g., a projection screen comprising a panel having a light reflective surface, characterised in that the screen is a distributed mode acoustic radiator loudspeaker having a transducer (9) mounted wholly and exclusively thereon to vibrate the radiator to cause it to resonate to provide an acoustic output.

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 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 loudspeaker (81) comprises an enclosure, an acoustic radiator (2) in the enclosure, a compliant suspension (3) mounting the radiator in the enclosure for pistonic movement relative thereto, and a first transducer (9) for driving the radiator pistonically. The radiator is also excited by a bending wave transducer mounted on the radiator which vibrates the radiator to cause it to resonate. The first transducer varies the air pressure in the enclosure to cause the radiator to move pistonically.

Abstract: A vibration exciter adapted for location in a cavity in a member to be vibrated. A motor coil assembly (6) has a coil rigidly fixed to a tubular member, the motor coil assembly having an outer peripheral face, and a magnet assembly (3-5) is disposed concentrically of the motor coil assembly and arranged for axial movement relative thereto. The magnet assembly has opposed generally disc-like pole pieces (4, 5), the periphery of one of which is disposed within and adjacent to the motor coil assembly, and the periphery of the other (5) of which pole pieces is formed with a flange (8) arranged to lie adjacent to and to surround the motor coil assembly. The flange has aperture portions (11) through which the outer peripheral face of motor coil assembly is adapted to be fixed directly to the cavity wall in the member to be vibrated.

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.

Abstract: A panel-form loudspeaker (81) comprising a resonant distributed mode acoustic radiator (2), and drive means (9) mounted to the radiator to excite multi-mode resonance in the radiator, characterised by a baffle (6, 8) surrounding and supporting the radiator.