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.

Abstract: An active noise insulation wall includes an active sound reduction apparatus disposed on an upper end surface of a noise insulation wall. The active sound reduction apparatus comprises a combination of an active acoustic control cell and a sound tube. The active acoustic control cell controls a coming noise such that a diffracted sound pressure component of the coming noise at the upper end surface of the noise insulation wall is actively reduced. The sound tube decreases a sound wave of a frequency different from a target frequency of the active acoustic control cell. Thus, the active noise insulation wall can effectively reduce noises including many frequency components.

Abstract: A vehicle having a passenger compartment (102) characterised by a loudspeaker (81) in the passenger compartment comprising a distributed mode acoustic radiator (2) and a transducer (9) mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.

Abstract: A panel-shaped loudspeaker comprising a panel (1) having a first main surface (1A) and a second main surface (1B) parallel to the first main surface and further comprising an exciter (3) positioned at the first main surface. When the exciter is energized the panel is capable of sustaining bending waves and has a distribution of resonant modes of its natural bending wave vibration, which results in an acoustic radiation. The loudspeaker has a tuning element (17) extending near the second main surface of the panel and positioned opposite the exciter so as to form a resonant cavity (18) between the panel and the exciter.

Abstract: A compound driver acoustic transducer. A frame supports a motion generator to one side of two diaphragms. An intermediate diaphragm is continuous and is driven by the motion generator. The intermediate diaphragm forms a closed volume with a solid portion of the frame that opens into a central opening through the other, open diaphragm. An axially rigid coupling connects the two diaphragms so they operate in unison.

Abstract: A transducer (14) for producing a force which excites an acoustic radiator, e.g. a panel (12) to produce an acoustic output. The transducer (14) has an intended operative frequency range and comprises a resonant element which has a distribution of modes and which is modal in the operative frequency range. Parameters of the transducer (14) may be adjusted to improve the modality of the resonant element. A loudspeaker (10) or a microphone may incorporate the transducer.

Abstract: A low profile speaker enclosure for mounting on a structure including a speaker housing and an electroacoustical transducer is disclosed. The speaker housing has a front face and a back each defining a length and a width, and a plurality of sides substantially separating the front face and the back and defining a thickness of the speaker housing. In the preferred embodiment, the front face and the back are substantially parallel. The front face, the back, and the plurality of sides of the speaker housing substantially define a chamber. The front face defines a speaker aperture opening into the chamber. The electroacoustical transducer is mounted in the speaker aperture. At least one of the sides defines a side aperture. The back of the low profile speaker enclosure defines a channel and defines a back aperture providing an opening between the channel and the chamber. The side aperture is also defined by the channel.

Abstract: A panel-form microphone characterised by a distributed mode acoustic member (12) and a transducer (63) coupled wholly and exclusively to the member to produce a signal in response to resonance of the member due to incident acoustic energy.

Abstract: An electroacoustic transducer to be mounted on a board of a device, includes an anode conductive part which is in press contact with the board of the device, and a cathode conductive part which is in press contact with the board of the device, wherein the anode conductive part and the cathode conductive part are respectively placed at an axial center position or at predetermined positions in a radial direction to eliminate directionality in a circumferential direction.

Abstract: A loudspeaker system is disclosed for active noise reduction. The loudspeaker has a substantially flat or planar diaphragm which is vibrated by an appropriate driver to generate a cancelling signal to cancel noise in the vicinity of the loudspeaker. The loudspeaker includes an input transducer such as a microphone which detects the ambient noise. The microphone is preferably incorporated in the panel structure of the loudspeaker in such a way that the ambient noise information can be captured and presented to active noise cancelling circuitry. The circuitry then provides an appropriate signal to the loudspeaker driver so that the cancelling sound source is provided by the loudspeaker. The use of flat panel loudspeaker technology has been found to provide effective noise reduction and is very appropriate for circumstances in which noise reduction is desirable, for example in aircraft, bus or vehicle seats or telephone kiosks.

Abstract: A panel-form loudspeaker (81) comprising a resonant distributed mode acoustic radiator having a periphery, a transducer (9) mounted to the radiator to excite distributed mode resonance in the radiator, and a frame (1) supporting the radiator, the transducer being coupled between the radiator and the frame to vibrate the panel to cause it to resonate to produce an acoustic output, characterized in that frame supports the radiator round its periphery and by resilient suspension means coupled between the frame and the radiator periphery.

Abstract: A loudspeaker drive unit comprising a visual display screen, a resonant panel-form member positioned adjacent to the display screen and at least a portion of which is transparent and through which the display screen is visible, and vibration exciting means to cause the panel-form member to resonate to act as an acoustic radiator.

Abstract: An electroacoustic transducer with attenuated effective output irregularities caused by intrinsic normal modes of oscillation. What stands out, as a structural property of a preferred embodiment, is a sandwich assembly, having an oscillating medium of layered components suspended between two rigid baffles, with a hinged baffle extension supporting the device in upright position. An opening, asymmetrically positioned in each of said two rigid baffles, exposes to the ambient medium a driven and asymmetrically positioned antinode belonging to a predetermined mode pattern of the oscillating medium. The resulting asymmetrical and partial coupling of the oscillating medium with the ambient medium limits occurrences of irregularities in effective output. Similarly, the asymmetrical and partial driving of the oscillating medium leads to a relatively high number of normal modes simultaneously excited.

Abstract: A method of making an acoustic device in the form of a loudspeaker drive unit having a resonant panel-form member adapted to provide an acoustic output when excited with bending wave energy, comprising forming a resilient suspension for the panel-form member by moulding and simultaneously fixing the resilient suspension to the panel-form member.

Abstract: Visual display apparatus comprising a notice board in the form of a distributed mode acoustic radiator having a transducer (9) mounted thereon at a preferential location or site for coupling to resonant bending wave modes to vibrate the radiator to cause it to resonate.

Abstract: A mid/high frequency loudspeaker drive unit comprising a stiff lightweight resonant panel form member, a housing to which the panel fog member is mounted, a resilient suspension connected between the edges of the panel form member and the housing, the arrangement being such that the housing and the panel for member together define a closed 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 the resilient suspension centers the voice coil and coil former assembly in the annular gap.

Abstract: A visual display unit having a display screen, a housing in which the display screen is mounted, and a loudspeaker in the housing comprising a member capable of sustaining and propagating input vibrational energy by a plurality of resonant bending wave modes in an operative area, the frequencies of the resonant bending wave modes being interleaved so that resonant bending wave modes are evenly distributed. A transducer is mounted wholly and exclusively on the operative area of the member at a preferential location which substantially maximizes acoustic coupling to the resonant bending wave modes in the member, the resonant bending wave modes in turn producing an acoustic output.

Abstract: A panel-form bending wave loudspeaker comprising a panel (30) having a neutral plane (50) and a displacement transducer (46, 48) coupled the panel at a position displaced from the neutral plane (50). A pair of such displacement transducers (46, 48) may be oppositely disposed about the neutral plane and may be embedded in the panel (30). The displacement transducers (46, 48) induce local bending in the panel by inducing extension and compression on opposite sides of the neutral plane (50).

Abstract: A lap-top computer (128) comprising a combined keyboard (137) and display screen (129), characterised by an opposed pair of loudspeakers (39, 40) attached to the computer, and in that each loudspeaker comprises a distributed mode acoustic radiator having a transducer (9) wholly and exclusively mounted thereon to vibrate the radiator to cause it to resonate.

Abstract: A loudspeaker is superior in space saving ability for enabling down-sizing of a device, to which the loudspeaker is employed, and has frequency characteristics easily designed and adjusted. The loudspeaker includes a vibration plate formed with a plurality of heat radiating through openings, and a vibrating portion responsive to an input electrical signal and driving the vibration plate for generating an acoustic vibration.

Abstract: A ceiling tile adapted to be supported in an overhead opening and function as a loudspeaker. The tile is in the form of a distributed mode acoustic radiator with a transducer mounted wholly and exclusively on the radiator at a location for coupling to resonant bending wave modes so as to vibrate the radiator and cause it to resonate.

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: A greetings or the like card (144), characterized 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: A visual display unit having a display screen, a housing in which the display screen is mounted, and a loudspeaker in the housing comprising a member capable of sustaining and propagating input vibrational energy by a plurality of resonant bending wave modes in an operative area, the frequencies of the resonant bending wave modes being interleaved so that resonant bending wave modes are evenly distributed. A transducer is mounted wholly and exclusively on the operative area of the member at a preferential location which substantially maximizes acoustic coupling to the resonant bending wave modes in the member, the resonant bending wave modes in turn producing an acoustic output.

Abstract: A vibration transducer adapted to be mounted on and launch bending waves into a member having opposed faces by applying a localized couple to the member. Also disclosed is a loudspeaker having such a transducer mounted on a member which acts as an acoustic resonator by sustaining resonant mode bending wave vibrations. The transducer comprises a motor coil assembly having a coil rigidly fixed to a tubular member, and a magnet assembly comprising opposed pole pieces, the periphery of one pole piece being disposed within and adjacent to the motor coil assembly, and the periphery of the other pole piece being disposed outside of and adjacent to the outside of the motor coil assembly. The magnet assembly has a central attachment portion adapted to be rigidly attached to the member to be vibrated.

Abstract: A panel-form loudspeaker (81) comprising a resonant distributed mode acoustic radiator having a periphery, a transducer (9) mounted to the radiator to excite distributed mode resonance in the radiator, and a frame (1) supporting the radiator, the transducer being coupled between the radiator and the frame to vibrate the panel to cause it to resonate to produce an acoustic output, characterized in that frame supports the radiator round its periphery and by resilient suspension means coupled between the frame and the radiator periphery.

Abstract: A speaker has a substantially reduced overall size while producing a complete low frequency sound range at high output amplitude. The speaker includes a main body having open sections at both ends thereof. A sounding body pinched by ringed first dampers is secured to each of the open sections of the main body so that the inside of the main body is kept air-tight except for one opening. A first opening is provided at the middle part of the side of the main body. Lid members are secured on the outside of the two sounding bodies via a ringed second damper so as to keep the inside of the lid member air-tight. A second opening is created around the middle of the bottom of each of the lid members.

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 present invention provides a speaker mounted within a speaker enclosure. The speaker enclosure provides a sidewall defining an interior space sufficient for enclosing the speaker, and a grille is mounted on an open end of the speaker enclosure. A pair of electrically conducting wires connect a speaker electrode to an electrical binding post mounted on an enclosing back wall of the speaker enclosure, providing an electrical connection between the speaker and an outside source. A hanger is pivotally engaged with the speaker enclosure such that the speaker enclosure is positionable over a range of downwardly directed angles relative to the hanger. The invention includes a breather hole that provides ventilation between the grille and the interior space of the enclosure. This ventilation allows the speaker to vibrate for maximum sound quality, while also excluding dust from the speaker enclosure.

Abstract: A vibration actuator for effecting paging is provided in which a vibrating section of an electroacoustic transducer is driven using low frequencies to collide it against a fixed section, and the vibration generated from the collision is transferred as external vibration. The vibrating section of a coil and the fixed section are bonded via an elastic member provided therebetween. The vibration generated at the time of collision can be effectively increased by flexibly supporting a magnetic circuit composed of a magnet, a yoke, etc. and by driving the magnetic circuit with alternating current which has a polarity. To permit easier assembly and to prevent damage or deterioration in characteristics, it is preferable to provide an annular molded member, which has hook-like projections, around the magnetic circuit and to support the magnetic circuit by a rubber member attached to the hook-like projections.

Abstract: This invention outlines several applications of piezoelectric vibrators to produce quality flat panel speakers in passenger cabin applications. A system consisting of an audio amplifier and transformer is used to drive the piezo speaker. The electronics are packaged so that they fit in small modules that can be attached to a cabin structure to produce a speaker. The invention includes a variety of flat panel speaker designs, including one in which the existing structure is converted into a speaker, and thin membrane and or panels that are fitted with piezoelectric elements. A system consisting of cabin quieting and flat panel speakers is also discussed where the mid and high frequency audio is produced by panel speakers and the low frequency audio is produced from dynamic loudspeakers. The cabin systems discussed in this patent are applicable to automobiles, aircraft, trucks and buses.

Abstract: A sound monitoring system includes a resonator platform comprised of musician support plate, a base plate, and at least one transducer. The musician support plate acts as a surface upon which the user may stand or sit. In response to high-frequency filtered and amplified electrical signals from a sound source, the transducer of the resonator platform imparts vibrational energy to the musician support plate, which in turn acts as a diaphragm to impart low frequency sounds to the musician by touch without generating appreciable audible energy. The base and musician support plates may have various geometric shapes and sizes, and are composed of materials suitable for transmitting vibrational energy.

Abstract: An audio loudspeaker assembly for use with a recessed lighting fixture includes a housing, a male socket attached to and projecting from the housing and being adapted for insertion into a female socket within the recessed lighting fixture, a pair of electrical contacts mounted to the male socket for making an electrical connection with a pair of like electrical contacts mounted to the female socket, an audio loudspeaker module having electrical terminals and being disposed in the housing, and a pair of internal electrical conductor wires disposed in the housing and being connected to the pair of electrical contacts of the male socket and extending therefrom and being connected to the electrical terminals of the audio loudspeaker module.

Abstract: An noise attenuation system disposed on a movable side glass (14) of a motor vehicle for reducing the noise within the passenger compartment. In the preferred embodiment, a piezoceramic sensor (46) and piezoceramic actuators (42, 44) are disposed on a side glass (14) below the beltline (24) of a door (10) on a motor vehicle. The actuators (42, 44) are controllably vibrated in reverse phase to a signal generated by the sensor (46) to cancel or reduce vibrations of the side glass (14). The noise transmitted into the passenger compartment by the side glass (14) is thereby significantly reduced.

Abstract: A sound transducer or reproductive system has a radiating flexible diaphragm which is attached to a sound radiating board, for example, walls, doors, car body, etc., causing the sounding board to radiate sound. The electromagnetic circuit/driving member is resiliently attached to an armature so that the armature and its driving members react to create motion and also, produce good quality low frequency response or bass tones as well as mid-range and high frequency response. A resilient compressible and expandable means such as pads, springs or clips with an adjustable magnetizable bumper means is interposed between the driving means and the driven means and creates an air gaps which is critical for optimum performance.

Abstract: An electronic driver for use with linear and non-linear transducers includes a voltage controlled oscillator (1630) to generate an output signal (1603) in response to a frequency control signal (1625); a transducer driver (1604), coupled to the voltage controlled oscillator (1630) and to the transducer (600), includes an electromagnetic driver (604) to generate an electromagnetic field in response to the output signal (1603), and a power control circuit (2104, 2106) to suspend generation of the electromagnetic field for a portion of the output signal, the electromagnetic field generating movement of a magnetic motional mass (636) which is transformed into tactile energy; and a tactile energy monitor (1606) coupled to the electromagnetic driver (604) for monitoring a level of tactile energy generated by the movement of the magnetic motional mass (636), and in response thereto generates the frequency control signal (1625) to maximize the level of tactile energy generated.

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 driver training system for a user of a simulated vehicle. The system includes input devices for controlling the simulated vehicle, a video display having three dimensional graphics, a computer, modeling software for determining position information based on the input devices, atmospheric effects software to simulate time-of-day and weather conditions, and realistic operating feedback software for simulating on the input devices the feedback normally experienced with operating the vehicle. One aspect of the preferred embodiment is a system including a low frequency speaker mounted on an enclosure adjacent to the simulation user's seat through which road feel cues such as hitting an object are transmitted to the user in response to signals received from the computer. Another aspect of the invention is the a system for simulating the feel to the user of anti-lock brakes on a brake pedal in response to signals received the computer.

Abstract: The present invention is for a conference system that provides microphones that are ceiling mounted and retract into the ceiling when not in use. The system has microphones that mount on wands with the wand and microphone forming a unit which is stored above the ceiling when not in use. In a preferred embodiment, the wand is connected to an automobile power antenna which is energized to raise and lower the antenna. The system is preferably activated by a proximity sensor, located in the cradle of a phone that senses the presence of a phone hand piece and activates the system when the phone hand piece is removed from the cradle.

Abstract: A loudspeaker is designed for mounting on a wall and which uses the wall to help generate sound from electrical signals supplied by an amplifier. The magnetic assembly consists of three disk shaped layers, the outer layers being a magnet and a ferromagnetic pole plate, the layers being separated by a spacer made of resilient material. The magnet and spacer both have roughly identical holes which are coaxially aligned. A center pole, on which a voice coil is wound, extends from the pole plate through the hole in the spacer and partially into the hole in the magnet. A frame serves to hold the magnetic assembly and press the magnet against the wall during operation. Electrical signals fed to the voice coil cause the magnet to vibrate against the wall, exciting the wall to create sound energy.

Abstract: Apparatus and method for securing a speaker within a radio housing includes a bezel connected to the grill of the radio and a rim having vertical side walls disposed along the perimeter of the bezel. The rim defines a cavity in which to position the speaker adjacent to the bezel. "U-shaped" clips having engaging barbs slidably attach to the rim until the clips provide a downward securing force against the base of the speaker. The barbs engage the rim to prevent the clips from loosening, allowing the speaker to vibrate.

Abstract: A grille cloth for speaker assemblies is preformed into a desired shape and has sufficient rigidity to maintain this pre-formed shape while being supported in a non-tensional manner only at its periphery. The use of such a pre-formed fabric as a grille cloth eliminates a need for non-peripheral support while visually obscuring the components of the speaker assembly behind the grille cloth. The grille cloth is comprised of a polyester material which is substantially transparent to acoustic radiation in the audible frequency range while also being substantially opaque to visible light.

Abstract: A wall panel mounting speaker unit and bracket therefor, the bracket including a pair of beams for bridging a blind opening of the panel, the beams being connected by screws to a housing of the speaker unit for clamping the panel against a bezel flange of the speaker unit. A pair of foot members are tiltably attached to each beam, the foot members making level contact with the panel regardless of bending deflections of the beams due to clamping forces produced by the screws.

Abstract: A coneless, no-moving-parts dynamic speaker has its internal components firmly locked within a plastic housing structure to prevent their movement relative to the housing, and may be secured to a wall of a room. During operation of the speaker, mechanical sound energy that it creates is transmitted through the walls and ceiling of the room to provide an expanded sound generation pattern. The internal components of the speaker include a voice coil internally anchored to a wall of the housing, an annular magnet member sandwiched between and fixedly secured to first and second annular metal washer members, and a metal alignment shaft having one end closely received in the core portion of the voice coil, and an opposite, radially enlarged end press-fitted into one of the washers and forming with the side surface of the central magnet member opening a reverberation chamber which is closely adjacent the voice coil but does not physically receive the coil.

Abstract: An acoustic transducer is disclosed for incorporation into an engine exhaust system or other gas carrying duct. The transducer produces pressure variations within the duct in accordance with an applied electrical signal. The transducer is especially suitable for use as part of a noise cancellation system whereby inverse pressure variations produced by the transducer cancel noise propagating in the duct. The design of the transducer allows its use when the duct is one carrying high temperature gases such as an automobile exhaust pipe.

Abstract: An omnidirectional siren having a plurality of hollow modules supported in vertical alignment on a single, central pole. Active modules each enclose a plurality of audio transducers (i.e., compression drivers) and a horn mechanism which guides sound waves from the drivers to an outlet in the lower surface of the module. The drivers are positioned peripherally within each module so that they can be easily accessed for repair or replacement through slots in the peripheral surface of the module.

Abstract: A loud speaker vibration transmitting apparatus has a speaker housing which encloses a speaker cone which vibrates within the housing and a propagation member which has a first contact end in contact with the speaker cone. In one embodiment, the propagation member extends out of the housing so that the vibration of the speaker cone can be directly transmitted out of the housing while the vibration also can be propagated into the housing. In another embodiment, the housing is designed to maintain a vacuum inside of the housing so that the vibrations of the speaker cone are propagated to the surface of the housing through the propagation member without transmitting audible sounds from the housing.

Abstract: Electroacoustic novelties are disclosed having a piezoelectric polymer film which functions as a speaker or microphone. The novelties include flags, banners, posters or articles of headwear. The piezoelectric polymer film may be attached to a portion of the flexible substrate forming the novelty, or it may be used as an integral part of the novelty structure. An audio output or recording device is electrically coupled to the piezoelectric polymer film. Both the piezoelectric polymer film and the electrodes may be transparent so that the adjoining portion of the novelty is visible.

Abstract: An audio transducer for activating a sounding board and a loudspeaker combined in one structure operating together simultaneously and using only one activating diaphragm to drive a sounding board and to produce sound pressure in an air cavity inside the transducer structure and expelling the sound pressure developed in the air cavity.

Abstract: An elastic material such as rubber is employed as the material of a diaphragm and the diaphragm is constructed in such a state that tension is made to exist intrinsically therein, whereby the vibration of the diaphragm when the vibration is applied to it has a large amplitude at the center thereof, gets smaller when approaching the perimeter thereof and finally reaches zero at the edge portion. Accordingly, almost no phenomenon occurs in which air in front and air in the rear of the diaphragm interfere with each other, a speaker box is not required and a tone of good quality may be reproduced.