Abstract: A screen device suited to use in a projection type display device for a high-definition television set. The screen device includes a screen on which television images are projected, and a screen frame to which this screen is attached at the central section thereof. Incorporated into this screen frame are speakers which are used as the front speakers of a sound reproduction system of the type which is commonly known as the 3-1 type 4-channel system.

Abstract: Transducer apparatus includes a two-part housing having a rear boss for securing the transducer to a wall. Within the housing are two magnetic elements for providing an output in response to electrical input signals, and the output is transmitted to the wall through the housing and rear boss. The magnetic elements are secured within the housing by the internal configuration of the housing.

Abstract: An automatic message system employs a transducer to provide sound reproduction through a sounding surface which is isolated from the environment, as in museum display cases and the like or in outdoor displays. The sounding surface can be any semicompliant surface, including glass, and the system can be switched by means of a remote sensor which may act through the sounding surface. The device may be removably mounted on the sounding surface by use of suction cups or other devices. The sound reproduction system eliminates conventional speaker diaphragms, which may be damaged by weather or abuse. A stiff inverted cone is used to transmit the sound vibrations from the voice coil of the transducer directly to the sounding surface for amplification.

Abstract: A sound transducer converts electrical signals into mechanical motion. A transducer comprises a transducer housing including a diaphragm section having an inner concave surface and an outer convex surface. A stem element projects outwardly from the diaphragm housing section and has a structural configuration effective to penetrate a panel or sounding board. A securing device is adapted to cooperate with the stem for connecting the diaphragm housing section to the sounding board. An electromagnetic driver assembly is resiliently mounted to the inner surface of the diaphragm housing section. The electromagnetic driver assembly includes an annular magnetic gap and a voice coil assembly located in the magnetic gap. The voice coil assembly includes a coil member having a cylindrical voice coil portion at one end thereof disposed in the magnetic gap and the other end thereof connected to the stem.

Abstract: The present invention constitutes a sound output unit for installation in a ceiling structure including an assembly for mounting a loudspeaker for use in conjunction with said output unit. The sound output unit comprises a polyhedral chamber or enclosure, a loudspeaker, an amplifier, and two sets of baffles. The polyhedral chamber is specially shaped in order to help reduce resonant vibrations. The loudspeaker is mounted in a large opening in the bottom plate of the enclosure so that it can radiate sound out from the enclosure into the area below the ceiling structure in which the unit has been installed. The amplifier is secured on the top of the loudspeaker inside the chamber and provides local power amplification. The baffles are mounted on the interior surfaces of the top and bottom plates of the enclosure and help reduce spurious sound reflections within the enclosure.

Abstract: A speaker system includes a thin plate type vibrating element mounted in, and brought into contact with, a balloon formed of a synthetic rubber or resin film. The balloon comprises a balloon member formed of a flexible film such as a vinyl chloride resin or synthetic rubber film and having therein a pocket, in which an inner film forming the pocket has an area somewhat larger than that surrounded with a laminating line on an outer film forming the pocket, whereby the inner film is brought in pressure contact or engagement with the outer film, when the balloon assembly is inflated.

Abstract: In a sound emitter including an emitting piston powered by a three phase asynchronous electric motor, the torque curve of the motor may be adjusted to suit any temperature, causing variations in the emitted resonance frequency by using a motor having its maximum torque at less than half the maximum speed. This may be done by using an alloy of silicon and aluminum in the rotor winding.

Abstract: A reverberating platform structure usable as an exercise floor or, depending upon the configuration thereof, for the support of people or objects thereon wherein the platform is supported by an anchor structure above a foundation such that there is an open space between the foundation and the undersurface of the platform. The anchor structure may be essentially flexible so as to provide a giving or flexible structure to the platform for a person to exercise, dance, or otherwise move thereon. An agitator assembly primarily in the form of a plurality of speakers are disposed within the space immediately adjacent to the space slightly from the undersurface of the supporting platform wherein activation of the speakers causes vibration to be communicated directly to the platform but wherein the platform is further structured not to generate specific sounds therefrom so as to be considered part of the speaker system itself.

Abstract: A speaker system having a magnet and voice coil are mounted within a dome-shaped enclosure in such a way as to be capable of transmitting sonic vibrations and audio waves through a liquid medium or solid structure, the dome-shaped enclosure cooperating with the magnet and voice coil in such a way as to greatly enhance the waves and sonic vibrations generated to the other medium or structure.

Abstract: An improved ceiling mountable acoustic transducer mountable in a ceiling tile without the cutting of a hole. A pair of elongated members which pierce the ceiling tile are attached to a housing which holds the acoustic transducer. The housing is held in contact with the surface of the ceiling tile by a pair of spring clips which engage the elongated members. The electrical connection of the transducer to an acoustical electrical signal source is made through the elongated members to the acoustic transducer by attachment of leads to the clips.

Abstract: A woofer system for an automotive audio system is provided with a protective cover extending over a section of a vehicle panel which both forms part of a vehicle body and serves as a speaker diaphragm producing acoustic vibrations at audio frequencies. The cover is in a spaced-apart relationship with said section so as not to interfere with oscillation of the section of the vehicle panel while it is oscillating at audio frequencies. The cover has a support extending toward the vehicle panel and surrounding the section. The support is formed with at least one opening for transmitting acoustic vibrations produced by oscillation of the section of the vehicle panel.

Abstract: A sound-wave receiving applicance comprises a resonance panel and a crystal type piezoelectric microphone responsive to oscillations generated by the soundwaves, said microphone being adapted for connection to an amplifier. The crystal of the microphone is subjected, between two pole members, to a mechanical initial pressure to increase the pressure sensitivity of the microphone relative to the resonance panel. The receiving applicance preferably has means for manual adjustment of the initial pressure which is absorbed by the resonance panel via one pole member. The resonance panel of the receiving appliance preferably is made of a material, such as a cellular plastic, having a higher porosity and a lower specific gravity than ordinary wood.

Abstract: An electro-vibration transducer for converting sound signals into body-sensible acoustic vibrations to permit the listener to sense sound directly through his or her body and having a wide effective bandwidth and good transient response characteristic. An auxiliary vibrator, namely, a weight, is attached to a magnetic circuit of the transducer via an elastic member. The auxiliary vibrator can be attached to an outer annular surface of the magnetic circuit, or to a lower planar surface thereof. Preferably, the elastic member is made of a visco-elastic material.

Abstract: A body-sensible acoustic device which can be readily mounted on and detached from a seat of an automobile. A drive unit driven by acousto-electrical signals is mounted on a vibration transmitting member. A pair of clamping members are provided which are coupled to the vibration transmitting member in such a manner as to be slidable with respect thereto and swingable in a plane including the vibration transmitting member. Each clamping member has an arm for a holding a side frame provided in the seat body.

Abstract: An audio-frequency electromechanical vibrator having a flat hollow case with a thin cover plate, a flat ring-shaped permanent magnet axially magnetized and a flat annular drive coil unit. The magnet and the coil unit are disposed in the case coaxial with one another and with an axial space therebetween. The magnet is fixedly mounted on the bottom of the case and the coil unit is elastically supported to the case by a spring plate so that the vibrator can generate strong vibrations without noise generation corresponding to a comparatively higher frequency component in an audio signal applied to the coil unit.