Abstract: In the invented speaker system, a passive radiator 401 is mounted on a top board 403a of baffle 403 in a direction opposite to a speaker unit 402. The speaker unit 402 is mounted on the opening of a cylinder 403b protruding from top board 403a at a place inner from the end. The remaining part of the opening is closed with a sub-baffle 406, to form a front closed cavity 404 and a back closed cavity 405. In this way, both the passive radiator 401 and the speaker unit 402 are fixed to the top board 403a whose rigidity being the highest; which reduces the unwanted vibration.

Abstract: A mass excited acoustic device (1100) includes a soundboard (1102), a pedestal (1104) and a transducer (300). The soundboard (1102) has a predetermined resonance frequency and couples motional energy to a device user. The pedestal (1104) includes a platform (1106) formed for mounting a transducer (300), and a foot (1108). The platform (1106) and foot have an axis extending centrally therethrough. The foot (1108) is contiguous to the platform (1106) and to the soundboard (1102), and is substantially smaller in size than the platform (1106) and separates the platform (1106) from the soundboard (1102). The transducer (300) is coupled to the platform (1106) about the axis and converts an electrical input signal into motional energy generated in a direction parallel to the axis. The motional energy is delivered to the soundboard (1102) through the foot (1108) without substantially modifying the resonance frequency of the soundboard (1102).

Abstract: An assembly housing for accepting an electroacoustical transducer having a rear face with terminal pins proceeding therefrom, contact surfaces thereon, and at least one sound admission opening, is formed by an acceptor plate which is disposed adjacent the rear face of the electroacoustical transducer, and a covering cap which is fitted over the radial edge of the acceptor plate. The acceptor plate has respective openings therein proceeding completely through the acceptor plate which respectively receive the terminal pins, and has blind holes therein which respectively receive springs in registration with the electrical contact surfaces of the electroacoustical transducer. The acceptor plate has a radially-proceeding sound admission channel therein, with one end in registration with the sound admission opening in the rear face of the transducer, and an opposite end in registration with a sound admission opening in the covering cap.

Abstract: An apparatus to pick up and amplify sounds created by vibrations of a flexible member having a base which supports a sound pick up that transmits a signal to an amplifier. The apparatus is attached to the flexible member by an attachment assembly mounted on the base at an approximate center of gravity of the apparatus. The attachment assembly has two points of attachment such that when the flexible member is under tension a rotational force around the attachment assembly brings the sound pick up close to or in contact with the flexible member. The apparatus may also have the sound pick up mounted to a speaker that is mounted to the base. The apparatus may also have the sound pick up mounted to the base and transmit a signal to a separate amplifier.

Abstract: A low frequency vibrator has a stator member with a cylindrical, central chamber, a cylindrical, tubular liner of low friction, non-ferromagnetic material positioned in the chamber to form a bearing and a cylindrical, ferromagnetic, reciprocating piston slidably mounted in the liner. The stator has a pair of coils and a permanent magnet is positioned centrally in the reciprocating piston. A ferromagnetic flux conductor surrounds the coils and extends between opposite ends of the chamber. This structure creates a magnetic spring, having a spring constant K. The ratio of K to the mass M of the reciprocating member is made substantially equal to the square of a radian frequency in the operating frequency range of the vibrator.

Abstract: A small, compact subwoofer cabinet; openings in two cabinet walls; first and second cages mounted on respective ones of the walls in alignment with the openings; a voice coil driven driver including an annular magnet weighing approximately 225 oz. affixed to the first cage; a stationary pole piece extending through the magnet and defining a magnetic gap therebetween; a voice coil mounted on a cylindrical voice coil former positioned within the gap; a cone affixed to one end of the former; a first flexible surround secured to the outer end of the cone and to the first cage; a flexible spider secured to the former and to the first cage; a mass driven driver including a mass aggregating about 2 lbs.; a second flexible surround secured to the mass and to the second cage; a flexible spider attached to the second cage and to the mass; both surrounds having a thickness of about 0.1", an edgeroll having a diameter of about 1.5", and capable of standing off internal pressures up to about 3 lbs./in.sup.

Abstract: An audio frequency converter apparatus which includes an input amplifier, first threshold sensor, connected to an output of the input amplifier, for cutting off a voltage supplied by the input amplifier at a threshold, after rectification, and second threshold sensor, connected to the output of the input amplifier, for adding at a threshold the voltage supplied by the input amplifier after rectification. The second threshold sensor has a time constant which is at least equal to that of the first threshold sensor. A voltage controlled oscillator is connected to the output of the first threshold sensor to provide an oscillating output having a frequency that decreases with an increase in the output of the first threshold sensor.

Abstract: A transducer in communication with fluid in a pad held in close contact against a sound or movement source monitors acoustic signals transferred into the fluid. The signal pattern is monitored aurally and/or compared to predetermined reference patterns, and optional control and stimulation means can be activated in response to the comparison results. The sensed acoustic signal can be transmitted to a remote receiver or processed locally. Typically, the acoustic signal is representative of the heartbeat or breathing of a living organism. The monitoring system may be applied to diverse situations including SIDS, apnea, home baby monitoring, medical transport devices, blood pressure cuffs, seats, combat casualty care and hand-held devices.

Abstract: An audio frequency converter apparatus which includes an input amplifier, first threshold sensor, connected to an output of the input amplifier, for cutting off a voltage supplied by the input amplifier at a threshold, after rectification, and second threshold sensor, connected to the output of the input amplifier, for adding at a threshold the voltage supplied by the input amplifier after rectification. The second threshold sensor has a time constant which is at least equal to that of the first threshold sensor. A voltage controlled oscillator is connected to the output of the first threshold sensor to provide an oscillating output having a frequency that decreases with an increase in she output of the first threshold sensor.

Abstract: A graphics display controller is used to manage audio data within a computer-based multimedia system. A portion of the video display memory associated with the graphics display controller is allocated to one or more audio data buffers to hold digitized data for audio recording and/or playback. Preferably, the size and location of the audio buffer(s) relative to the video data is dynamically configureable within the memory. The timing of the audio data transfer into or out of the video display memory is preferably controlled by the video horizontal sync (HSYNC) signal, so that audio data transfers occur substantially during the pauses in video-memory access that correspond to the retrace time at the end of each video display line. A single, unified host CPU interface and related circuitry is preferably used for control or data-transfer functions related both to video graphics and to audio.

Abstract: An taut armature, resonant impulse transducer (100) includes an armature (12), including an upper (14) and a lower (16) non-linear resonant suspension member, each including at least two juxtaposed planar compound beams (202, 204 and 206, 208) connected symmetrically about a contiguous planar central region (210), and further connected to two contiguous planar perimeter regions (212, 214), an electromagnetic driver (24, 26), coupled to the upper and lower non-linear resonant suspension members (14, 16) about the two contiguous planar perimeter regions (212, 214), the electromagnetic driver (24, 26) effecting an alternating electromagnetic field in response to an input signal, and a magnetic motional mass (18) suspended between the upper and lower non-linear resonant suspension members(14, 16) about the contiguous planar central region (210), and coupled to the alternating electromagnetic field for generating an alternating movement of the magnetic motional mass (18) in response thereto, the alternating moveme

Abstract: A high-volume source for very low frequency applications in which conventional speakers are inadequate is disclosed. A presently preferred embodiment comprises a reservoir 32 with a pressure relief 33; a controller 34; a supply blower 36; an exhaust blower 38; a positive plenum 40; a negative plenum 42; an orifice plate with valving 44; a horn 46; and pressure transducers 48, 50, 52, 54, feeding detected pressure levels to the controller 34. An electrical command signal s(t) is also input to the controller. The command signal is a voltage analogous to the acoustic pressure or volume velocity to be output by the source.

Abstract: A phase-insensitive ultrasonic transducer has a zinc oxide single crystal as a piezoelectric semiconducting acoustoelectric element, providing high sensitivity and operable over a range of wavelengths of the ultrasonic waves. The electrical conductivity of said zinc oxide single crystal may be selected in the range 10.sup.-8 to 10.sup.-2 .OMEGA..sup.-1.cm.sup.-1. The single crystal can have an attenuation rate for ultrasonic waves of 10 MHz of at least 0.8 cm.sup.-1.

Abstract: A hand-held sound digitizer system for recording sound in a personal computer, including an enclosure capable of being held in one hand, a microphone built into the enclosure for providing an analog sound signal output, and circuitry within the enclosure for digitizing the analog signal output. Further provision is made for reading the digitized signal to a parallel printer port of the computer for storage of the digitized sound in the computer.

Abstract: The telephone handset is provided with at least one piezoelectric transducer (6, 7). The transducer is received in a housing part (2) which includes fixing means for the transducer and its electrical connection means. The housing part is assembled with at least one other complementary part (1) in order to form the handset shell, and it closes the shell locally. An adaptor sleeve makes it possible to replace the piezoelectric transducer by an electromagnetic transducer.

Abstract: A loudspeaker component is bonded to a diaphragm formed of an olefinic resin, by applying an adhesion primer to bonding positions of the component and/or the diaphragm, applying an adhesive to the bonding positions after the primer has cured, and superposing the component and diaphragm. An air curing unsaturated polyester resin is used as the adhesion primer.

Abstract: A boundary-layer microphone may obtain a frequency independent, hemispherical directional characteristic with a high tonal quality. The geometrical configuration of the mounting plate and the installed location of the membrane within the surface of the mounting plate are chosen so that a flat frequency response is obtained at the installed location of the membrane, i.e., the superposition of the incident primary sound field on the secondary sound field created by diffraction will not cause any deviation from a flat frequency response and a smooth, hemispherical polar pattern. The mounting plate may be triangular. The membrane may be installed in the vicinity of the center of gravity of a scalene triangle.

Abstract: A microphone apparatus consists of a microphone body which incorporates a built-in microphone chip; a microphone cover formed of a net material and secured to the front end of the microphone body to enclose and protect the microphone chip inside; and a resilient ring whose outer circumference is shaped into a polygon. The resilient ring may be fitted directly over the net microphone cover; or it may be installed in a coupling ring that connects separated base and end portions of the microphone cover together. The polygonal outer surface of the resilient ring on the microphone cover prevents the microphone apparatus from rolling and fall when placed on a table because one of the flat sides of the polygon which is in contact with the table surface stabilizes the apparatus. Thanks to its resiliency, the polygonal resilient ring can be removed from the microphone cover so that any change that might occur when the ring blocks the sound wave can be prevented.

Abstract: An intra-concha type electroacoustic trasducer has an auxiliary supporter projecting in opposite direction to entrance part of external auditory meatus of the user's ear from a side of the transducer opposite to its sound-radiating side disposed to face the auditory meatus entrance. Reliable mountability of the transducer with respect to auricle of the user's ear is thereby ensured, while an unpleasantness or pain given to the user upon mounting to the auricle can be at least reduced to a remarkable extent.

Abstract: A loudspeaker assembly includes a vibrating element which generates pressure waves in a first predetermined frequency range which propagate in a first forward direction and a second backward direction. A driver drives the vibrating element. A first diffuser uniformly diffuses the forward waves. A tuner selects back waves in a second predetermined frequency range within said first predetermined frequency range. The tuner includes a second diffuser for diffusing the back waves within said second frequency range such that the selected back waves and the front waves are in phase.

Abstract: An adjustable headset headband including a resilient band of a shape and size to fit over the head of a wearer. The band has a first end and a second end and a positioning member fixedly attached adjacent the first end. The headband also includes a housing having a first end and a second end. The positioning member is movably mounted within the housing such that the second end of the housing is oriented nearest the second end of the band. The housing includes a plurality of depressions linearly arranged within the housing from the first end of the housing to the second end of the housing, each depression of the plurality of depressions having a shallower depth than the preceeding depression. The positioning member releasably engages one of the plurality of depressions so as to maintain the positioning member at a predetermined portion within 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 electret condenser microphone includes a cup-shaped metallic case having an apertured end wall, a tubular metal ring received in the metallic case, a vibratory diaphragm having on its one surface a deposited metal film and bonded to an end face of the tubular metal ring in confronting relation to the end wall with an air gap defined therebetween, and a condenser composed of a movable electrode and a fixed counter electrode, the fixed counter electrode comprising at least a part of the end wall of the metallic case while the movable electrode comprises the vibratory diaphragm. Partly because the end wall of the metallic case serves as the fixed electrode, and partly because the vibratory diaphragm is bonded to the end face of the metal ring, the number of the components of the microphone is relatively small.

Abstract: A wiring structure of a loudspeaker having a signal input path to a voice coil, the path being established by electrically interconnecting a conductor and an input terminal mounted on a frame, and the conductor being disposed, on a damper having corrugations of concentric circles, along the corrugations from the inner to outer periphery thereof, includes a projection mounted on the damper extending from the outer periphery of the damper to a substrate of the input terminal, the end of the conductor being extended on and along the projection, whereby the end portion of the conductor is connected to a lug on the substrate of the input terminal.

Abstract: A double annular ring gasket (202) interfaces a speaker (201) to a housing (200) in a portable radiotelephone, providing a conformal and acoustic seal between the speaker (201) and the housing (200), and compensating for dimensional tolerance between the housing (200) and the circuit board subassembly (204) on which the speaker (201) is mounted. The gasket (201) includes outer ring (205), inner ring (206) and intermediate ring (207) therebetween. The gasket (202) is inserted into a cavity (203) in the housing (200). Then, the speaker (201), as part of a printed circuit board subassembly (204), is pressed into place against the outer ring (205) of gasket (202) to form an axial seal and the inner ring (206) is deformed radially by the speaker (201) to form a conformal seal.

Abstract: Audio-frequency converter apparatus, in particular for treating subjects suffering from audio-phonatory disorders, the apparatus being suitable for generating, on the basis of an input audio frequency signal, a parametric signal for application via an electro-acoustic transducer to a person being treated.

Abstract: A loud-speaker is combined with a device for producing lighting speakers is covered by two discs provided with openings and, for example, being formed of a grating. The inner disc of the discs, which is facing the speaker cone is rotatable, whereas the outer disc is stationary. Rotation of the rotatable disc is driven either via a motor or via driver members fixed to the speaker cone of the loud-speaker which are actuated by transmission of the vibrations of the speaker cone to the rotating disc in order to provide rotating movement. Light sources for illuminating the surface of the inner or, respectively, outer disc, which is facing the light sources, are provided either within the speaker cone or outside of the loud-speaker. The lighting effects are then generated by the rotation of the inner disc.

Abstract: Audio frequency converter apparatus, in particular for treating subjects suffering from audio-phonatory disorders, the apparatus being suitable for generating, on the basis of an input audio frequency signal, a parametric signal for application via an electro-acoustic transducer to a person being treated.