With Resonant Chamber Patents (Class 181/160)
  • Patent number: 6160897
    Abstract: An apparatus (1) is constructed for operation in an on-ear mode and an off-ear mode and includes a housing wall (6) having passages (15) to allow useful sound waves to pass through, and additional passages (16) to allow the passage of sound waves which are in phase opposition to the useful sound waves and includes, behind the housing wall (6), an electroacoustic transducer (7) having a diaphragm (12), the transducer (7) being accommodated in an acoustically substantially impervious holder compartment (17). Sound-pressure frequency response influencing structures (18, 19) are arranged both in the sound path between the frontside (13) of the diaphragm (12) and the passages (15), and in the sound path between the rearside (14) of the diaphragm (12) and the additional passages (16).
    Type: Grant
    Filed: May 11, 1999
    Date of Patent: December 12, 2000
    Assignee: U.S. Philips Corporation
    Inventor: Erich Klein
  • Patent number: 6062339
    Abstract: A vented or bass reflex speaker. The speaker is secured to an inner sleeve which inner sleeve is received within an outer sleeve with the sleeves defining an annulus therebetween. Acoustical flow channels are formed in the annulus. The back of the inner sleeve is spaced apart from the back of the outer sleeve to form a vented volume. The air in the channels is caused, by the loudspeaker driver, to resonate with the volume of air contained within the open-ended inner sleeve forming a Helmholtz element.
    Type: Grant
    Filed: November 27, 1995
    Date of Patent: May 16, 2000
    Inventor: Dana B. Hathaway
  • Patent number: 6031919
    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.
    Type: Grant
    Filed: April 2, 1997
    Date of Patent: February 29, 2000
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Osamu Funahashi, Norimitsu Kurihara
  • Patent number: 5929393
    Abstract: An audio speaker cabinet or enclosure having a sounding board and air space for enhancing the quality of sound produced by the speaker cabinet. The speaker enclosure is characterized in a preferred embodiment by a rectangular cabinet having a sounding board mounted in the cabinet enclosure interior between the front and rear panels of the enclosure, closely spaced with respect to the rear panel. A resilient membrane such as a sheet of vinyl is mounted on the front surface of the sounding board over an opening in the sounding board behind the speaker. A bass slot is included in the front panel below the speaker for air circulation into and from the enclosure interior and facilitating the attentuated sound produced by the vinyl sheet on the sounding board.
    Type: Grant
    Filed: July 12, 1996
    Date of Patent: July 27, 1999
    Inventor: Charles W. Jeter, Jr.
  • Patent number: 5809154
    Abstract: A vent loudspeaker system is provided which has at least one active driver and a port opening in a speaker cabinet. Disks or baffle plates are mounted a predetermined distance to and concentric to the port opening, resulting in a vented system achieving an equivalent performance as would result from a flared, ducted port, but with several performance advantages and simpler construction.
    Type: Grant
    Filed: May 26, 1995
    Date of Patent: September 15, 1998
    Assignee: Britannia Investment Corporation
    Inventor: Matthew S. Polk
  • Patent number: 5740259
    Abstract: An electroacoustical transducing system for exchanging pressure wave energy with a medium that propagates pressure waves includes an electroacoustical transducer having a vibratile surface. At least one low-loss pressure waveguide has one end adjacent to the vibratile surface and the other end adjacent to the medium. At least one acoustic immittance element is imposed in the length of the waveguide dimensioned and positioned to alter the transfer characteristic of the waveguide between the vibratile surface and the medium at the other end.
    Type: Grant
    Filed: April 28, 1995
    Date of Patent: April 14, 1998
    Assignee: Bose Corporation
    Inventor: Charles Dunn
  • Patent number: 5710395
    Abstract: A Helmholtz resonator loudspeaker having a capsule shape that may be truncated at one or both ends. When the housing is truncated, dampening material may be added at the truncated portion. Legs or a stand aid in the physical stability and to further assist the acoustics. The resonator tube is located on the interior of the housing chamber with one end opening into the interior concentric with an axis running along the length of the capsule and the other end exiting the housing below the speaker.
    Type: Grant
    Filed: March 28, 1995
    Date of Patent: January 20, 1998
    Inventor: Paul Wilke
  • Patent number: 5602367
    Abstract: A bass reflex loud speaker system for use in high power applications which includes an enclosure with at least two, and preferably three, cone drivers mounted in front of separate and acoustically isolated bass reflex chambers. Each bass reflex chamber is tuned to a separate octave such that the bass reflex modules formed by each bass reflex chamber and its associate cone driver produces a complex acoustical signal comprised of different frequency components in the low frequency range at high sound pressure levels, but with minimum driver cone excursion and distortion.
    Type: Grant
    Filed: December 19, 1994
    Date of Patent: February 11, 1997
    Assignee: Meyer Sound Laboratories Incorporated
    Inventor: John D. Meyer
  • Patent number: 5550921
    Abstract: A dual-speaker unit providing improved stereo base response and directionality for portable computer applications is disclosed. The small speakers direct low end frequencies into a mixing chamber which directs these frequencies out through a central exit port, thereby providing clearer base response without sacrificing psychoacoustic directionality.The speakers are mounted on the mixing chamber and also rotatable relative to it, for adjustable stereo imaging and compact portability.
    Type: Grant
    Filed: May 15, 1995
    Date of Patent: August 27, 1996
    Assignee: Sparkomatic
    Inventor: Tommyca Freadman
  • Patent number: 5517573
    Abstract: A vented loudspeaker system is provided which has at least one active driver and a port opening in a speaker cabinet, Disks or baffle plates are mounted a predetermined distance to and concentric to the port opening, resulting in a vented system achieving an equivalent performance as would result from a flared, ducted port, but with several performance advantages and simpler construction. Flow guides are provided, attached to the disks or baffle plates, extending back into the port to block areas of stagnant air and enhance laminar air flow.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: May 14, 1996
    Assignee: Polk Investment Corporation
    Inventors: Matthew S. Polk, Colin B. Campbell
  • Patent number: 5513270
    Abstract: This invention relates generally to vented loudspeakers for the reproduction of musical sounds, but particularly to the design and location of ports or vents that tune the enclosure. The loudspeaker system has an enclosure, having a front baffle and a pair of loudspeaker drivers mounted in the baffle. The enclosure has a hexagonal cross-section. A pair of vents are each located at a juncture of the vertical side edges of the front baffle and its adjoining panels. The vents lead into the enclosure via a conduit, which ends in an inlet. The inlet is positioned within the enclosure to face the rear of the loudspeaker driver. By this arrangement high to mid frequency sound waves radiated within the boundaries of the enclosure and entering the inlet are substantially attenuated in the conduit and low frequency sound waves radiated within the boundaries of the enclosure are reinforced with sound waves directly radiated from the front of the loudspeaker driver.
    Type: Grant
    Filed: February 7, 1994
    Date of Patent: April 30, 1996
    Inventor: Leopold A. Lewis
  • Patent number: 5479520
    Abstract: An enclosure (35) of a loudspeaker (37) is provided with a plurality of tubes (43) of different length via which the sound is emitted in order to achieve frequency spreading of resonance peaks in the SPL (sound pressure level) curve. The side walls (46, 47) of the tubes (43) have openings (63) via which the tubes are coupled to common Helmholtz resonators (59, 61) in order to suppress undesirable resonances in the tubes (43). By spreading the resonance peaks it is possible to use Helmholtz resonators of smaller dimensions than in the case that the sound would emanate via a single tube. This results in a loudspeaker system (33) with more compact and cheaper Helmholtz resonators (59, 61).
    Type: Grant
    Filed: September 17, 1993
    Date of Patent: December 26, 1995
    Assignee: U.S. Philips Corporation
    Inventors: Joris A. M. Nieuwendijk, Johannes W. T. Bax, Martinus P. M. Van Den Thillart
  • Patent number: 5475764
    Abstract: A single-vented bandpass woofer loudspeaker system design and method for enabling operation in smaller enclosure volumes with only moderate loss of efficiency. The bandpass system has an enclosure with a partition dividing it into a first sealed chamber and a second chamber having a passive radiating port communicating with air outside the enclosure. A driver is mounted in the partition. Novel, empirically determined tuning ratios which depend upon system variables are defined. By adjusting the system variables to keep the tuning ratios within empirically determined values, a good relationship between flat response, bandwidth and efficiency is achieved. Unexpectedly, using a higher than normal moving mass of the driver leads to an acceptable system with a very small enclosure volume.
    Type: Grant
    Filed: August 23, 1994
    Date of Patent: December 12, 1995
    Assignee: Polk Investment Corporation
    Inventor: Matthew S. Polk
  • Patent number: 5394478
    Abstract: A system for low frequency sound production in vehicular passenger compartments, comprising an electrodynamic driver, having a first acoustic mass and a first acoustic compliance; and a Helmhotz resonator, affixed to one side of said electrodynamic driver means and having a second acoustic mass and a second acoustic compliance, the second acoustic mass being affixed to a baffle facing the passenger compartment. The first and second acoustic mass have substantially similar magnitudes, and the Helmholtz resonator and the electrodynamic driver being substantially tuned to the highest and lowest frequencies of a desired passband, respectively, so as to provide a substantially flat pressure vas. frequency characteristic when the passenger compartment has dimensions generally smaller than one eighth wavelength of the lowest frequency.
    Type: Grant
    Filed: November 18, 1992
    Date of Patent: February 28, 1995
    Assignee: Advanced Composite Audio, Inc.
    Inventors: Dana B. Hathaway, Lawrence B. Nile
  • Patent number: 5303209
    Abstract: In an electroacoustic transducer (1) having a diaphragm (5), behind which a partition wall (24) is situated, which partition wall extends transversely of the transducer axis (9) and is traversed by partition openings (29, 30, 31, 32) having a small cross-sectional area of at the most 0.2 mm.sup.2, and having a mask wall (38) arranged adjacent the partition wall and provided with mask-wall openings (39, 40, 41, 42) of large cross-sectional area, in the other wall (38) being coincident with at least one opening (29, 30, 31, 32) of small cross-sectional area, each opening (29, 30, 31, 32) of small cross-sectional area is situated between two spacer elements (49, 50, 51, 52, 53, 54, 55, 56) arranged between the two walls (24, 38), and each time two spacer elements (49, 50, 51, 52, 53, 54, 55, 56) together with the two walls (34, 38) bound a duct-like gap (57, 58, 59, 60) between the two walls (24, 38) in order to form an acoustic resistance.
    Type: Grant
    Filed: June 16, 1993
    Date of Patent: April 12, 1994
    Assignee: U.S. Philips Corporation
    Inventor: Ewald Frasl
  • Patent number: 5261006
    Abstract: A loudspeaker system includes a housing (1) having therein at least one loudspeaker (3) which divides the volume of the housing into two parts (V.sub.1, V.sub.2). The first volume (V.sub.1) is coupled, via an aperture in the housing (1), to an acoustic tube (5) which includes a damping element (6). The first volume part (V.sub.1) has a smaller volume than the second volume part (V.sub.2). The damping element is in the form of a Helmholtz resonator.
    Type: Grant
    Filed: November 1, 1990
    Date of Patent: November 9, 1993
    Assignee: U.S. Philips Corporation
    Inventors: Joris A. M. Nieuwendijk, Johannes W. T. Bax, Frans A. Westra
  • Patent number: 5189706
    Abstract: An acoustic apparatus comprises an inner cabinet, a vibrator mounted thereon and an outer cabinet. The inner cabinet and the outer cabinet constitute an acoustic cabinet having a closed cavity. The outer cabinet covers the inner cabinet with a predetermined gap formed between the inner peripheral surface of the outer cabinet and the outer peripheral surface of the inner cabinet and has an opening causing the gap to communicate with the external region of the acoustic cabinet and to function as a resonance port. The resonance port and the closed cavity constitute a resonator. The vibrator is provided so as to face the closed cavity. The resonator radiates a resonant sound from the open end of the gap, i.e., the resonance port, upon being driven by the vibrator.
    Type: Grant
    Filed: January 22, 1990
    Date of Patent: February 23, 1993
    Assignee: Yamaha Corporation
    Inventor: Tatsuo Saeki
  • Patent number: 5184332
    Abstract: A multiport underwater sound transducer including a hollow resilient housing enclosing a volume with at least two ported resonant chambers and a transduction driver disposed within the volume with opposite sides of the driver driving the two chambers. The two ports are set to resonate at slightly different frequencies and the tranducer proudces an additive output at frequencies between the two slightly different frequencies due to phase reversals of oppositely phased sound waves.
    Type: Grant
    Filed: December 6, 1990
    Date of Patent: February 2, 1993
    Assignee: Image Acoustics, Inc.
    Inventor: John L. Butler
  • Patent number: 5173575
    Abstract: A compact acoustic apparatus in which a vibrator is arranged in a Helmholtz resonator having a resonance port, and is driven to radiate a resonant acoustic wave so as to perform lower bass sound reproduction, is characterized in that a cabinet is reduced in size by externally projecting the resonance port from the cabinet, and/or a boundary condition change buffer means is arranged at an opening portion of the resonance port to prevent noise caused by an air flow flowing through the resonance port.
    Type: Grant
    Filed: March 21, 1989
    Date of Patent: December 22, 1992
    Assignee: Yamaha Corporation
    Inventor: Kazunari Furukawa
  • Patent number: 5111509
    Abstract: In the construction of an electric acoustic converter such as a speaker for musical instruments, a tone generating unit arranged near one open end of a resonant tube is accompanied with a partition which has a central through hole and extends across the longitudinal hole of the resonant tube. For complicated modes of resonance and rich acoustic vibration, two or more resonant tubes of different types may be used in combination with one or more tone generating units. Presence of such a partition clearly defines the length of the resonant air columns to be produced in the resonant tube and such clear-cut resonant air columns bring about high resonance sharpness.
    Type: Grant
    Filed: December 21, 1988
    Date of Patent: May 5, 1992
    Assignee: Yamaha Corporation
    Inventors: Akihiko Takeuchi, Shigeo Suzuki
  • Patent number: 5109422
    Abstract: An acoustic apparatus comprises a Helmholtz resonator which has a cavity and an open duct port for causing the cavity to communicate with an external region thereof and a vibrator which is arranged in the resonator to drive the resonator. In a first aspect, the open duct port comprises an air permeable member having a proper acoustic resistance and a viscoelastic member having no air permeability so that noise caused by an open duct resonant, wind noise, turbulence or the like is prevented. In a second aspect, a viscoelastic member is disposed at the mounting portion between the open duct port and a cabinet defining the cavity so that transmission to the cabinet of derivative vibration causing at the open duct port is prevented.
    Type: Grant
    Filed: September 27, 1989
    Date of Patent: April 28, 1992
    Assignee: Yamaha Corporation
    Inventor: Kazunari Furukawa
  • Patent number: 5092424
    Abstract: A loudspeaker system has at least a first electroacoustical transducer having a vibratable diaphragm for converting an input electrical signal into a corresponding acoustic output signal. An enclosure is divided into at least first, second and third subchambers by at least first and second dividing walls. The first dividing wall supports and coacts with the first electrical transducer to bound the first and second subchambers. At least a first passive radiator intercouples the first and third subchambers. At least a second passive radiator intercouples at least one of the second and third subchambers with the region outside the enclosure. Each passive radiator is characterized by acoustic mass. Each subchamber is characterized by acoustic compliance. The acoustic mass and acoustic compliances coact to establish at least three spaced frequencies in the passband of the loudspeaker system at which the deflection characteristic of the vibratable diaphragm as a function of frequency has a minimum.
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: March 3, 1992
    Assignee: Bose Corporation
    Inventors: William P. Schreiber, Brian J. Gawronski
  • Patent number: 5073946
    Abstract: A speaker which is thin but which is capable of providing high-fidelity reproduction and ensuring a suitable level of sound pressure even when it is brought close to a wall. A closed chamber is formed behind one part of a disphragm mounted in an enclosure, and an open chamber is formed behind another part of the diaphragm. At least one voice coil driver unit is connected to the diaphragm. The phase difference between sounds radiated from the front and rear surfaces of the diaphragm is increased as large as possible by using an acoustic duct for the sound radiated through the open chamber, thereby minimizing cancellation of sounds and improving the sound pressure level.
    Type: Grant
    Filed: November 28, 1989
    Date of Patent: December 17, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Katsuaki Satoh, Kazue Sato, Kousaku Murata, Tsuneo Tanaka, Shuji Saiki, Satoshi Takayama, Hiroyuki Takewa, Mitsuhiko Serikawa, Seiichi Ishikawa, Sawako Usuki, Yoichi Kimura, Shuichi Obata
  • Patent number: 5025885
    Abstract: A loudspeaker system has an enclosure with a baffle dividing the interior into first and second subchambers. The smaller subchamber is directly coupled to the region outside the enclosure by a port tube. The larger subchamber is coupled to the region outside the enclosure via the smaller subchamber by a port tube. The dividing baffle carries a woofer.
    Type: Grant
    Filed: July 14, 1989
    Date of Patent: June 25, 1991
    Assignee: Bose Corporation
    Inventor: Thomas A. Froeschle
  • Patent number: 5025474
    Abstract: A speaker system has an acoustic diaphragm and an image projection screen provided on a surface of the diaphragm integrally therewith so as to enable the user to enjoy both realistic image on the screen and powerful sound reproduced through the diaphragm. The rear surface of the diaphragm is closed at a peripheral portion thereof while the central portion of the rear surface of the diaphragm is opened to the exterior, so that the speaker system can provide a high level of reproduced sound pressure in low-pitched region, while the thickness of the speaker is reduced remarkably. The diaphgram can be driven by a plurality of driving units so that the speaker system can operate only with an ordinary stereophonic amplifier.
    Type: Grant
    Filed: September 27, 1988
    Date of Patent: June 18, 1991
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Tsuneo Tanaka, Kazue Sato, Hiroyuki Takewa, Akira Kurozuka, Tadashi Tamura, Katsuji Hattori, Satoshi Takayama, Kosaku Murata, Katsuaki Satoh, Mituhiko Serikawa, Youichi Kimura, Shuichi Obata
  • Patent number: 5012890
    Abstract: In an acoustic apparatus in which a vibrator is arranged in a Helmholtz's resonator having an open duct port, and the vibrator is driven to radiate a resonant acoustic wave, a duct resonance absorbing means is provided to the open duct port constituting the Helmholtz's resonator so as to remove an unnecessary resonant sound other than a Helmholz's resonant sound caused when the Helmholtz's resonator is driven, thereby removing noise in a radiated acoustic wave and improving distortion characteristics.
    Type: Grant
    Filed: March 15, 1989
    Date of Patent: May 7, 1991
    Assignee: Yamaha Corporation
    Inventors: Katsuo Nagi, Kazunari Furukawa
  • Patent number: 5010977
    Abstract: An acoustic apparatus comprises a plurality of resonators having different resonance frequencies, each of which is constituted by a closed cavity and acoustic mass for causing the cavity to acoustically communicate with an external region. A housing enclosing the plurality cavities is integrally formed. Resonance acoustic radiation portions of the resonators are arranged adjacent to each other on one side of the housing, whereby sound sources which correspond to the acoustic mass can be concentrated.
    Type: Grant
    Filed: July 13, 1989
    Date of Patent: April 30, 1991
    Assignee: Yamaha Corporation
    Inventors: Kazunari Furukawa, Daisuke Suzuki
  • Patent number: 5009280
    Abstract: An acoustic apparatus for improved bass sound reproduction comprising a resonator, a vibrator, and a vibrator drive means, the resnoator having a passive diaphragm serving as a resonance radiation unit for radiating an acoustic wave by resonance, the vibrator having an active diaphragm provided for the resonator, and the vibrator drive means having a drive control means for controlling a drive condition so as to cancel atmospheric counteraction of said resonator at the time of driving of the resonator, whereby the vibrator may be invalidated as viewed from the resonator, and the vibrator and the resonator can be independently designed.
    Type: Grant
    Filed: March 24, 1989
    Date of Patent: April 23, 1991
    Assignee: Yamaha Corporation
    Inventor: Kenji Yokoyama
  • Patent number: 5009281
    Abstract: An acoustic apparatus for improved bass sound reproduction comprises a resonator, a vibrator, and a vibrator drive means. The resonator has a resonance radiation unit for radiating an acoustic wave by resonance, the vibrator has a diaphragm disposed in the resonator, the vibrator drive means has a motional feedback (MFB) means for detecting the movement of the diaphragm and negatively feeding back a motional signal corresponding to the movement of the diaphragm to the input side of the circuit, and the counteraction of the resonator on the diagram is canceled upon driving of the resonator whereby the vibrator may be invalidated as viewed from the resonator, and the vibrator and the resonator can be independently designed.
    Type: Grant
    Filed: March 1, 1989
    Date of Patent: April 23, 1991
    Assignee: Yamaha Corporation
    Inventor: Kenji Yokoyama
  • Patent number: 5004066
    Abstract: In an acoustic apparatus in which a vibrator which drives a Helmholtz resonator having an open port by one surface thereof and directly radiates an acoustic wave from the other surface thereof is arranged in the Helmholtz resonator, the open port is arranged coaxially with the vibrator, and the vibrator is driven to cancel an air counteraction from the resonator when the resonator is driven. According to this construction, the acoustic apparatus can be rendered compact and the clear sound localization can be realized.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: April 2, 1991
    Assignee: Yamaha Corporation
    Inventor: Kazunari Furukawa
  • Patent number: 4997057
    Abstract: An acoustic reproduction range expanding apparatus includes a closed or bass-reflex speaker system which has a low-frequency drive speaker and can reproduce a sound to a predetermined lowest frequeny. A port portion adapter consists of a mounting portion attached to an openng formed in a closed cabinet or a bass-reflex port of a bass-reflex cabinet, and a port portion. The port portion constitutes a Helmholtz's resonator together with the cabinet when the port portion is attached to the cabinet, and has a port shape so that a resonance frequency becomes lower than the lowest frequency. A drive portion adapter consists of an amplifier for driving the low-frequency drive speaker, and eliminates or invalidates an internal impedance inherent to the low-frequency drive speaker. The amplifier generates a negative impedance component in an output impedance.
    Type: Grant
    Filed: March 15, 1989
    Date of Patent: March 5, 1991
    Assignee: Yamaha Corporation
    Inventor: Kazunari Furukawa
  • Patent number: 4989187
    Abstract: An acoustic apparatus comprises a resonator, a vibrator, and a vibrator drive circuit for an improved bass sound reproduction. The resonantor has a resonance radiation unit for radiating an acoustic wave by resonance, and the vibrator has a diaphragm constituting a part of the resonator and disposed in the resonator. The vibrator drive circuit for driving the vibrator has a negative impedance component in an output impedance, and a reaction from the resonator to the diagram is canceled upon driving of the resonator. Accordingly, the presence of the vibrator is invalidated as viewed from the resonator, and the vibrator and the resonator can be independently designed. As a result, the resonator can be realized in a compact size, and the resonance acoustic wave can be radiated powerfully.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: January 29, 1991
    Assignee: Yamaha Corporation
    Inventor: Kenji Yokoyama
  • Patent number: 4987564
    Abstract: An acoustic apparatus comprising a resonator having a resonance radiation unit for radiating an acoustic wave by resonance, a vibrator arranged in the resonator, and a vibrator drive means for driving the vibrator. The vibrator has a diaphragm having a direct radiator portion for directly radiating an acoustic wave, and a resonator driver portion for driving the resonator. The vibrator drive means has a drive control means for controlling the drive condition so as to equivalently reduce or invalidate the internal impedance inherent to the vibrator.
    Type: Grant
    Filed: April 26, 1990
    Date of Patent: January 22, 1991
    Assignee: Yamaha Corporation
    Inventor: Kenji Yokoyama
  • Patent number: 4953655
    Abstract: Disclosed is a compact, wide-range acoustic apparatus which can perform lower bass sound reproduction and is free from noise or distortion components. Spatially separated first and second chambers are formed. The first and second chambers communicate with each other through a port, so that the first chamber and a resonance port constitute a Helmholtz resonator. An open port is formed in or a passive vibrating body is arranged on the outer wall surface of the second chamber, so that the second chamber and the opening or the passive vibrating body constitute an essential low-pass type acoustic filter. A vibrator is attached to the outer wall surface of the first chamber, so that the Helmholtz resonator is driven at the inner surface side of the vibrating body of the vibrator, and an acoustic radiation is directly performed from its outer surface side. The vibrator is driven to cancel an air counteraction from the resonator when the Helmholtz resonator is driven.
    Type: Grant
    Filed: March 30, 1989
    Date of Patent: September 4, 1990
    Assignee: Yamaha Corporation
    Inventor: Kazunari Furukawa
  • Patent number: 4918738
    Abstract: An acoustical system for generating loud sound levels over a wider bandwidth includes a generally cylindrically-shaped cavity formed of a wall member and having front and back ends. A baffle member is disposed to close the front end of the cavity, and a rear wall panel is disposed to close the back end of the cavity. A crystal/diaphragm driver assembly is formed of a bimorph piezoelectric crystal of a generally circular configuration and a generally conical-shaped diaphragm whose apex is fixedly attached to the center of the crystal. The driver assembly serves to convert electrical signals applied thereto into acoustical signals. The crystal is freely suspended at a first predetermined distance from the rear wall panel to form a rear Helmholtz loading chamber therebetween. The baffle member is spaced at a second predetermined distance from the crystal so as to form a front, outer enclosing chamber therebetween.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: April 17, 1990
    Assignee: Federal Signal Corporation
    Inventor: Joseph F. Bader
  • Patent number: 4903794
    Abstract: A stethoscope for auscultating sounds from a subject, the stethoscope including a housing, a curvilinear convex diaphragm supported on the housing for interfacing with the site being auscultated and for receiving sounds therefrom, an enclosed acoustic chamber supporting on the housing and communicating with the curvilinear convex diaphragm for enhancing the fidelity of the received sounds, and means for transmitting the enhanced received sounds to the user, which can be a dual lumen wave guide to binaurals or a single lumen wave guide to one aural tube. With such an arrangement, the user is capable of taking vital signs through clothing, bandages, blankets are other obstructions, even in the presence of high ambient noise, and can auscultate low frequency sounds associated with heart sounds and bowel sounds with significantly improved clarity and volume.
    Type: Grant
    Filed: March 23, 1988
    Date of Patent: February 27, 1990
    Inventors: Don H. Klippert, Don E. Klippert
  • Patent number: 4875546
    Abstract: A loudspeaker having means for acoustically impeding excursion of the transducer diaphragm and means for acoustically attenuating the output of acoustic vibrations of frequencies above a preselected frequency. The loudspeaker includes first and second subchambers separated by a dividing wall in which the transducer is mounted. A first port acoustically couples the first subchamber with the second subchamber and a second port acoustically couples the second subchamber with the outside environment surrounding the loudspeaker.
    Type: Grant
    Filed: June 2, 1988
    Date of Patent: October 24, 1989
    Assignee: Teledyne Industries, Inc.
    Inventor: Palo Krnan
  • Patent number: 4872527
    Abstract: A speaker system especially designed to improve the characteristics of low sound bands. The speaker system desirably includes a partition dividing the interior of a cabinet into a speaker chamber and a resonance chamber, and two radiation ports. One radiation port is formed on the partition and the other one on the walls of the resonance chamber which do not face each other.
    Type: Grant
    Filed: May 27, 1988
    Date of Patent: October 10, 1989
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Bong H. Han
  • Patent number: 4867267
    Abstract: This invention is concerned with a hearing aid including a microphone, an adjustable amplifier, and an acoustic transducer positioned within a first, large acoustic chamber defined by an in-the-ear housing. The acoustic transducer is in communication with a sound outlet passage which leads into the user's ear canal. The acoustic transducer includes a sound generating diaphragm driven by an acoustic driver. The diaphragm and driver are mounted in the acoustic transducer, with the diaphragm dividing the transducer into second and third acoustic chambers. A vent passage is provided between the first and third acoustic chambers. An acoustic resistance is mounted in the vent passage to modify the operating characteristics of the hearing aid.
    Type: Grant
    Filed: January 3, 1989
    Date of Patent: September 19, 1989
    Assignee: Industrial Research Products, Inc.
    Inventor: Elmer V. Carlson
  • Patent number: 4858719
    Abstract: A pressure gradient pickup, particularly a capacitor microphone or a dynamic microphone, has a diaphragm arranged in a housing and at least one sound entry opening which conducts the sound to the rear side of the diaphragm. Acoustically acting phase-shifting sections are connected in the interior of the housing to the at least one sound entry opening. The at least one sound entry opening is located at least approximately in the same plane as the diaphragm and is preferably arranged concentrically relative to the diaphragm edge.
    Type: Grant
    Filed: January 13, 1987
    Date of Patent: August 22, 1989
    Assignee: AKG Akustische u. Kino-Gerate Gesellschaft m.b.H.
    Inventors: Werner Fidi, Heinz Renner
  • Patent number: 4823110
    Abstract: A tone generator of the type in which a housing defines a pair of communicating chambers one of which is closed except for an area of communication with the other chamber. A thin flat diaphragm of circular configuration is mounted in an operative position over the area of communication between the chambers in engagement with a flat annular surface defining the same. An annular diaphragm retaining member is mounted in an operative position in superposed relation to the diaphragm in fixedly secured relation within the housing. An improved mounting for the diaphragm is provided which includes a plurality of annularly spaced transversely extending diaphragm engaging lugs formed on the retaining member. The lugs extend in engagement with the diaphragm so that when the retaining member is in its operative position the engagement of the lugs with the diaphragm serves to retain the diaphragm in its operative position.
    Type: Grant
    Filed: April 22, 1988
    Date of Patent: April 18, 1989
    Assignee: Magna International Inc.
    Inventors: Donald Dorward, Waldemar A. Hupa
  • Patent number: 4817168
    Abstract: A directional microphone operating according to the electrostatic or electrodynamic transducer principle. The pickup effect of the microphone is determined by a single phase-shifting delay line section between the rear side of the active transducer diaphragm and at least one sound entry opening provided in the microphone housing at a distance behind the plane of the diaphragm. The microphone includes at least one acoustic element coupled to the delay line section. The delay line section is arranged with the acoustic element or elements so as to have a lower limit frequency in the range of 300 Hz.
    Type: Grant
    Filed: March 17, 1987
    Date of Patent: March 28, 1989
    Assignee: AKG Akustische u. Kino-Gerate Gesellschaft m.b.H.
    Inventor: Werner Fidi
  • Patent number: 4811816
    Abstract: A device having two sets of oppositely facing corresponding resonance cavities; i.e., an upper and a lower resonance cavity. Each of the resonance cavities include a piezo-electric type diaphragm consisting of a vibration diaphragm and a start-up plate. Electric signals cause the piezo-electric type diaphragm to vibrate back and forth and produce sound waves from the upper and lower resonance cavity.
    Type: Grant
    Filed: April 22, 1988
    Date of Patent: March 14, 1989
    Inventor: Tse-Hung Lin
  • Patent number: 4800982
    Abstract: A hearing aid including a microphone, an adjustable amplifier, and a transducer comprising an acoustic driver driving a diaphragm disposed within an acoustic chamber, all mounted in an in-the-ear housing having a sound outlet passage leading from the acoustic chamber into the user's ear canal, is provided with a cleaning passage that is accessible from the outside of the housing and that connects to the inner end of the sound outlet passage, through a portion of the acoustic chamber. Throughout internal cleaning is effected by pumping a solvent through the continuous conduit formed by the cleaning passage, the acoustic chamber, and the sound outlet passage, without disassembly of the hearing aid.
    Type: Grant
    Filed: October 14, 1987
    Date of Patent: January 31, 1989
    Assignee: Industrial Research Products, Inc.
    Inventor: Elmer V. Carlson
  • Patent number: 4790407
    Abstract: A vehicular speaker system in which a resonance of the vehicle's interior is compensated by a resonance of a chamber enclosing the rear of the speaker unit. The chamber includes rearwardly facing ports.
    Type: Grant
    Filed: August 27, 1986
    Date of Patent: December 13, 1988
    Assignee: Pioneer Electronic Corporation
    Inventors: Hideo Yamamoto, Kazunori Takagi
  • Patent number: 4742887
    Abstract: An earphone has a housing divided by a driver unit into front and back cavities with a sound generation opening at the front thereof, a duct extending from the back cavity of the housing and having a length substantially larger than its diameter, and a casing attached to the housing and communicating with the back cavity through a pipe having a length longer than its diameter, with the resonant frequency determined by the casing and pipe being made near to the resonant frequency determined by the equivalent mass of the vibration system, that is, the diaphragm and voice coil of the driver unit, and by the compliance of the back cavity, so that the lowest resonant frequency of the earphone can be lowered while the peak that would otherwise be formed in the frequency characteristic of the earphone by the resonance between the back cavity and mass of the vibration system can be supressed for improving the high frequency characteristic.
    Type: Grant
    Filed: February 12, 1987
    Date of Patent: May 10, 1988
    Assignee: Sony Corporation
    Inventor: Makoto Yamagishi
  • Patent number: 4739860
    Abstract: An ultrasonic rangefinder capable of detecting a distance between a vehicle and an object with high accuracy is shown. The measurements for microphones for transmitting and receiving ultrasonic waves are chosen so that detour waves are restricted.
    Type: Grant
    Filed: May 28, 1985
    Date of Patent: April 26, 1988
    Assignee: Nissan Motor Co., Ltd.
    Inventors: Hiroshi Kobayashi, Hiroaki Obayashi
  • Patent number: 4727583
    Abstract: An audio arrangement includes a thin speaker/transducer positioned within a portable housing wherein the speaker cavity is dimensioned to move the resonant frequency of the speaker/housing combination up to approximately the free-air cutoff frequency of the speaker/tranducer. The resulting response then falls off at about 6 db/octave below that point. An amplifier having gain increasing at 6 db/octave is placed in the signal input path for creating an essentially flat frequency response in the normally desired audio range.
    Type: Grant
    Filed: October 28, 1986
    Date of Patent: February 23, 1988
    Assignee: Motorola, Inc.
    Inventor: Paul J. Weber
  • Patent number: 4718098
    Abstract: An electro-mechanico-acoustic structure in which magnetic wave energy is converted directly into acoustic energy and partly stored and then converted into audiible acoustic energy in a gradual manner over a period of time.
    Type: Grant
    Filed: July 22, 1986
    Date of Patent: January 5, 1988
    Inventor: William J. Ashworth
  • Patent number: 4714133
    Abstract: The invention presents a method for improving overall efficiency and quality in sound reproduction systems by providing a system which establishes positive phase control over the many and varied resonant characteristics encountered in the reproduction and presentation of audio energy. The apparatus embodying the present method primarily consists of speaker structures within which drivers such as conventional cone drivers are acoustically coupled to both air and to the materials from which the enclosure of the speaker structure is formed by optimizing existing atmospheric pressure differentials and induced audio vibration readily available within these structures. The coupling is obtained through the use of acoustical resonator structure placed within a speaker enclosure and through particular distribution of mass in the enclosure and in the materials.
    Type: Grant
    Filed: June 14, 1985
    Date of Patent: December 22, 1987
    Inventor: John E. Skaggs, Jr.