Abstract: In an apparatus (1) having a housing (2) and having an electroacoustic transducer (14) accommodated in the inner housing space (9) and having at least one passage (28, 29) which traverses a housing wall (6, 7) and which, together with the inner housing space (9) and the rear volume (25) of the transducer (14), which rear volume (25) is open to the inner housing space (9), forms an absorption-circuit resonator which causes a dip (31) in the sound pressure versus frequency response(27), a compensator (32) for the compensation of the dip (31) in the sound pressure versus frequency response (27) is provided and includes the housing (2) being provided with a plurality of ducts (33, 34, 35, 36; 41) traversing the housing (2), each duct forming an acoustic friction.

Abstract: A radiotelephone is provided which comprises a housing 1 having an earpiece port 4, a loudspeaker 6 and a resonator. The resonator comprises and earpiece path form the loudspeaker to the earpiece port4. Further, the resonator also comprises an internal cavity 7, which may be ring, and a path 8 from the loudspeaker 6 to the internal cavity 7, to provide a specified resonance performance.

Abstract: A mechanical device is tuned using a tunable damping rod. The tunable damping rod can have its tension increased between its respective engines, to in order to increase the resonant frequency of the mechanical device. Different aspects may also be included; the mechanical device may include a constrained layer damping material, which constraints certain mechanical vibrations. The tuning may tuned the mechanical device to reach that vibration.

Abstract: Acoustic diffuser comprising a containing element able to contain at least a loudspeaker, wherein the containing element is formed by a monocoque made with granules of solid mineral held together by a cohesion material.

Abstract: An apparatus for a microphone and speaker is provided which provides a sealed chamber behind the speaker to prevent sound waves behind the speaker from cancelling sound waves in front of the speaker. In addition, the apparatus is configured to mechanically isolate the speaker from the apparatus housing in order to improve performance of the system. A pliant material such as a damping material with a relatively linear compression characteristic, such as a thermal plastic elastomer, may be used to isolate the speaker from the apparatus housing as well as providing a relatively air tight chamber behind the speaker.

Abstract: The present invention concerns the reduction of vibrations of a loudspeaker enclosure caused by the mechanical vibrations of the dynamic loudspeaker element by virtue of attaching one or more additional masses to the loudspeaker driver unit using elastic and lossy means. The masses with their elastic attachments dimensioned according to the present invention resonate at frequencies excited by the vibrations of the loudspeaker element at frequencies where the reduction of the amount of vibration is desired. The magnitude of vibration coupled to the enclosure of a loudspeaker modified according to the present invention is significantly smaller than that of a conventional loudspeaker. Furthermore, it is technically and economically advantageous to implement the reduction of mechanical vibrations according to the present invention.

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: An electro-acoustic transducer, such as a speaker device or an earphone device. Includes an electro-acoustic transducing unit, such as a speaker unit, for converting input electrical signals into sound, a casing in which the electro-acoustic transducing unit is arranged and which delimits a back cavity towards the rear side of the electro-acoustic transducing unit, and at least two openings having a sound duct communicating with the back cavity. The sound radiated from the back surface of the electro-acoustic transducing unit is attenuated by being transmitted into the inside of the sound duct to prevent the radiated sound from being re-admitted into the electro-acoustic transducer.

Abstract: A module adapted for use in a noise reduction headset earcup has an enclosure having walls separating an interior of the enclosure from an exterior of the enclosure outside the earcup. There is a driver with a diaphragm. A port connects the interior and exterior. An acoustically resistive opening connects the interior and exterior in parallel with the port.

Abstract: Disclosed is an improved loudspeaker comprising a pre-stressed cabinet and a loudspeaker unit fixed to the inside of the cabinet. The cabinet comprises a hollow conical assembly including two conical bodies of high-rigidity metal, one press-fitted into the other by applying an increased compressive force. The hollow conical assembly has front and rear plates closing its front and rear openings. These front and rear plates are pulled toward each other by tightening screw rods.

Abstract: A speaker apparatus comprises a speaker unit, a cabinet for forming an internal space on the rear side of the speaker unit with a plurality of wall surfaces including a baffle plate for use in mounting the speaker unit, a acoustic tube which is formed along at least one wall surface out of the plurality of wall surfaces and has not only a substantially uniform hollow section but also an opening at one end, and an acoustical material for separating the internal space from the internal space of the acoustic tube by closing the opening of the acoustic tube. The speaker apparatus is characterized in that the acoustic tube has a tube length about 1/(2n) (n=positive integer) time as large as a wavelength corresponding to the lowest resonance mode of the standing wave produced along the one wall surface out of the standing waves produced in the internal space and that the opening is disposed close to the node of the standing wave.

Abstract: A speaker system suppresses standing waves generated in the system and reproduces clear and dynamic bass sound. The system includes a cabinet formed of acoustic isolation walls, and at least one partition wall situated inside the cabinet to form a space by surrounding the space. The partition wall suppresses the standing waves generated inside the cabinet and is formed of a material having high internal loss. The space has a total capacity more than one tenth of a capacity of the cabinet, wherein a closed end of the partition wall is located between one-half and four-fifths of a distance from one end to the other end, and an opening area of the same partition wall is located at a side opposite to the closed end in a longitudinal direction of the cabinet. The opening area is located between four-fifths and five fifths of a distance from one end to the other end.

Abstract: The present invention is related to a cabinet for consumer electronic devices equipped with loudspeakers. Examples for such devices are audio equipment like CD players, tape recorders, radios, and television receivers. In particular, the invention is related to devices where the loudspeakers form an integral part of it.

Abstract: The present invention provides a speaker device in which assembly is easy, and which has high sensitivity and low distortion. The speaker device comprises a frame member, a piezoelectric element to which a sound signal is applied, a diaphragm attached to the piezoelectric element, a coil for boosting the sound signal, and a damper attached to the piezoelectric element in the opposite side face to the diaphragm to elastically support the piezoelectric element. The coil is wound with respect to the frame member, and the damper is attached on the frame member.

Abstract: A bandpass loudspeaker enclosure system including at least one electro-acoustic transducer with a vibratable diaphragm having a first acoustical coupling surface and a second acoustical coupling surface, and at least one differential area passive radiator with three separate acoustical coupling surface areas. The first acoustical coupling surface of the vibratable diaphragm is substantially air coupled through a first enclosure volume to a first of the three separate acoustical coupling surface areas of the at least one differential area passive radiator. A second of the three separate acoustical coupling surface areas of the at least one differential area passive radiator is substantially air coupled through a second chamber to the external environment through a restricted acoustic opening or passive acoustic radiator of predetermined characteristics.

Abstract: An acoustic waveguide loudspeaker system has an electroacoustical transducer having a vibratile surface. An acoustic waveguide has a first end open and a second end adjacent to the vibratile surface and an effective length corresponding substantially to a quarter wavelength at the lowest frequency of pressure wave energy to be transmitted between the first and second ends. Damping material in the waveguide near the vibratile surface is positioned so as to negligibly attenuate bass frequency energy while of sufficient volume to damp peaks at higher frequencies above the range of the bass frequency energy.

Abstract: A loudspeaker system comprises an enclosure which accommodates a loudspeaker device and a bass-reflex port (105). The port has two open ends (105b, 105c) and a central area (c) provided with perforations (109), as well as a foam material (111) provided in and/or on the perforations.

Abstract: A damped structural panel includes a panel having bending modes including demanding bending modes. The demanding bending modes have subsonic bending waves along at least one axis, and require damping treatment based on sound radiation properties of the panel. A viscoelastic material is applied within a limited area adjacent to the panel edges based on the demanding bending modes. The viscoelastic material damps sound radiation caused by bending waves during use of the structural panel, such as use as a body panel on an aircraft.

Abstract: An apparatus for protecting equipment in an outdoor communication structure from adverse weather conditions, vibration, and vandalism includes a housing that possesses hidden lip door edges and is assembled such that no screws, nuts, hinges, etc. are left exposed. Also, any speakers and/or microphones are largely isolated from potential vibration by surrounding them with vibration dampeners such as foam or other padding or insulation. Heat, dust intake, vibration, and electricity usage are reduced by providing convection venting wherein the internal cavity of the housing narrows at a top region of the housing. Vents in the top region of the housing allow air from the narrowed internal cavity to escape as it heats and expands. As hot air is displaced from the narrowed internal cavity, cooler ambient air is drawn into the internal cavity through bottom vents in a bottom region of the housing.

Abstract: This invention presents a passive vibroacoustic device that serves the dual function of attenuating the vibration of a flexible structure, and providing acoustic dissipation to the volume or cavity enclosed by the structure. This reduces the transmission of sound from external sources into the enclosure, and reduces vibration of the structure. By design of the shunting resistor and the mass and suspension properties, the device can be optimized to achieve high levels of both structural vibration attenuation and acoustic attenuation. Incorporating a feedback loop or adaptation mechanism will permit the device to maintain optimum attenuation in the case of time varying systems.

Abstract: A mechanical mounting system and extensional damping technique for loudspeaker crossover networks. This system decouples the crossover network from the loudspeaker enclosure (cabinet), isolating it from any vibrational energy in the cabinet walls. In addition, an extensional damping material is applied to the crossover network to damp any vibrational energy which may be coupled from the surrounding air into the network. The mounting system can be used for mounting any sensitive electronic components within an enclosure to provide isolation from the walls of the enclosure and from surrounding or environmentally induced vibrational energy.

Abstract: A dome speaker comprises a dome section including a vibrating diaphragm having a dome shape, an annular edge damper section provided surrounding the dome section, an annular coil holder provided between the dome section and the annular edge damper section for holding a voice coil. In particular, the dome section further includes a cap having substantially the same shape as the vibrating diaphragm, said cap being bonded on the said vibrating diaphragm.

Abstract: The present invention provides a microphone in which a first acoustic capacity for mainly determining resonance frequency and a second acoustic capacity for mainly determining resonance sharpness are defined in a resonance portion, said first acoustic capacity and said second acoustic capacity being arranged in parallel in a direction of crossing relative to a moving direction of a sound wave, said second acoustic capacity capable of being communicated with only said first acoustic capacity to control resonance frequency.

Abstract: A unidirectional microphone element can be embedded within an object and be made flush to the object's surface yet retain its directional discrimination characteristic. Acoustic waveguides transmit acoustic input signals from acoustic ports to the front and rear input ports of the microphone element while also providing intelligibility-enhancing frequency response shaping. The housing wherein the microphone element is mounted acoustically isolates the front and rear input ports of the microphone element.

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 speaker system excellent in reproduction in bass range, which comprises a reinforcing post 3a to abut against the back side of a speaker unit 5 installed in a front cabinet 2. The reinforcing post 3a is formed integrally in a back cabinet 3, and is fixed with a cover 4. In this constitution, unwanted vibrations generated in the back cabinet 3, cover 4, and speaker unit 5 due to rear release wave b can be suppressed.

Abstract: A piezoelectric speaker has a substantially reduced size and reproduces sound in the low sound range. The piezoelectric speaker includes a cylindrical main body. First and second sounding members are secured to apertures of both sides of the main body in an air tight arrangement via ringed dampers made of rubber. An external opening is created at the middle of a side surface of the main body. The opening is created so as to have an area which is less than area of a vibrating portion of the sounding members. Sound absorbing members are provided within the main body, on the outside of the first sounding member and on the outside of the second sounding member. Caps having a plurality of holes are secured to the apertures of the both sides of the main body so as to cover the sound absorbers. The main body is supported on concave portions of leg members.

Abstract: The present invention provides a small electroacoustic transducer which is improved in sound characteristic by enlarging and adjusting a volume of a resonance space. A second resonant chamber as an auxiliary space is formed relative to a first resonant chamber formed in front of a resonance plate, wherein the first and second resonant chambers are connected with each other to enlarge the volume of the resonant volume.

Abstract: The invention provides an electroacoustic transducer wherein the resonant chamber is given a space and volume necessary for resonance and the vibration system is given an efficient air damping effect and thereby undesired vibrations are suppressed with the resonant effect maintained. The electroacoustic transducer according to the invention is provided with a resonant chamber for resonating with the vibration of a diaphragm and a sound ejecting hole for communicating the resonant chamber with the outside air formed on a position off to the central axis of the diaphragm. Furthermore, an air damping means for compensating the lowering of the air damping effect due to the dislocation of the sound ejecting hole from the central axis of the diaphragm is provided on the inner wall of the resonant chamber so as to surround the central axis of the diaphragm.

Abstract: A loudspeaker system having a multiple driver array arranged in a push-pull configuration is loaded into an acoustic transmission line ported to the outside of the loudspeaker enclosure. The transmission line is preferably tapered and is filled with acoustic damping material. The combination of the push-pull driver configuration loaded into an acoustic transmission line produces a high performance, spatially enhanced sound reproduction.