US2917127A - Acoustic enclosure for loudspeakers - Google Patents

Acoustic enclosure for loudspeakers Download PDF

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Publication number
US2917127A
US2917127A US564809A US56480956A US2917127A US 2917127 A US2917127 A US 2917127A US 564809 A US564809 A US 564809A US 56480956 A US56480956 A US 56480956A US 2917127 A US2917127 A US 2917127A
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compartment
loudspeaker
enclosure
aperture
resonance
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US564809A
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Elliott Llewellyn John
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Pye Electronic Products Ltd
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Pye Ltd
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R1/00—Details of transducers, loudspeakers or microphones
    • H04R1/20—Arrangements for obtaining desired frequency or directional characteristics
    • H04R1/22—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired frequency characteristic only 
    • H04R1/28—Transducer mountings or enclosures modified by provision of mechanical or acoustic impedances, e.g. resonator, damping means
    • H04R1/2807—Enclosures comprising vibrating or resonating arrangements
    • H04R1/2815—Enclosures comprising vibrating or resonating arrangements of the bass reflex type
    • H04R1/2819—Enclosures comprising vibrating or resonating arrangements of the bass reflex type for loudspeaker transducers

Definitions

  • Y ⁇ A disadvantage of such a system is that although the main resonance of the speaker is effectively damped and the bass response extended, two subsidiary resonances are formed.
  • themass and air loading of the moving parts of the loudspeaker unit resonate with the acoustic capacitance of the air enclosed by the cabinet and in the other the mechanical stiffness of the unit resonates with the acoustic inductance of the port aperture of the resonator.
  • the frequency response of the system is non-linear in the region of these unwanted resonances.
  • one or more internal Helmholtz resonators arel introduced into a reex enclosure adapted to contain a loudspeaker unit and are tuned to the resonance frequency of the loudspeaker unit with the acoustic capacitance of the air enclosed by the enclosure or to frequencies in va band including that resonance.
  • a further subsidiary reflex system or systems are arranged to be coupled acoustically to the main port aperture or apertures of the main rellex system constituted by the enclosure and are tuned to the resonance of the loudspeaker unit with the acoustic inductance of the main port aperture or apertures or to frequencies in a band including that resonance.
  • the enclosure is constructed so as to be mechanically .rigid and lined with suitable sound absorbing material. If necessary membranes of a sound absorbing material such as felt are mounted across one or all of the internal chambers to absorb standing waves formed by reflections between the walls or partitions in the enclosure.
  • the frequency response of the system is considerably smoother and is extended further towards the lowest acoustic frequencies than that of a conventional recx system occupying the same volume and fitted with a similar loudspeaker uni-t.
  • Figure l is a front elevation of a loudspeaker enclosure according to the invention with the decorative fret removed, and
  • Figure 2 is a section taken on the line II-II in Figure 1.
  • the enclosure comprises an outer casing 1 of generally rectangular form and preferably made of wood, for example plywood and constructed so that it is mechanically rigid.
  • the side of the casing 1 which is intended to form the front, is closed by a loudspeaker board 2, n front on which is arranged a decora,-
  • tive fret 3 which may be a sheet of expanded metal, and is retained in position by means of a detachable framework or beading 4.
  • the interior of the cabinet is divided horizontally by means of a sloping shelf 5, which extends between the two opposite side walls of the casing 1. By making the shelf 5 sloping, the possibility of producing standing waves within the cabinet is reduced.
  • the space above the shelf 5 is divided vertically by a partition 6 extending between the upper surface of the shelf and the top of the casing 1 in order to form two compartments, namely a rear compartment A and a front compartment B.
  • the bottom of the front compartment B is formed by a horizontal shelf 7, which defines, with the shelf 5, 'a third compartment C below the compartment B.
  • the shelf 7 is provided with a plurality of apertures 7a y which provide communication between the compartment B and the compartment C.
  • the speaker board 2 is also and which is mounted with its cone over the aperture 2a in the speaker board 2 and, the rear of the loudspeaker extending through an aperture 6a in the partition 6.
  • the enclosure A and part of the enclosure B are lined with a sound-absorbing material 10, for example a layer of cotton waste covered with thick felt.
  • the main port apertures 7a resonate with the volumes of the compartments A and B at free air resonance of the loudspeaker unit as in a conventional reflex system.
  • the aperture 6a forms anannular air gap between the rear of the loudspeaker and the side walls of the partition 6 which resonates with the volume of compartment A as a Helmholtz resonator and reduces the amplitude of the resonance of the speaker unit with the volumes A and B.
  • this internal Helmholtz resonator is tuned to the resonance frequency of the loudspeaker unit with the acoustic capacitance of the air enclosed by the cabinet or to frequencies in a band including that resonance.
  • the apertures 8 resonate with the volume of air in the compartment C as a subsidiary reilex system and reduces the amplitude of resonance of the speaker unit with the main port apertures 7a.
  • this subsidiary reex system is coupled acoustically to the port apertures 7a of the main reflex system and is tuned to the resonance of the loudspeaker unit with the acoustic inductance of the main port apertures 7a or to frequencies in a band including that resonance.
  • the size and spacing of the holes 8 is important to give the desired resonance frequency.
  • the space beneath the shelf 5 forms a compartment D which may be emlployed to house an amplifier to be used in conjunction with the loudspeaker.
  • One end of this space may be divided by means of a wall 11, to form a subsidiary compartment E which may house an electrical cross-over unit.
  • Ventilation holes 12 are formed in the front, rear and bottom of the amplifier compartment D, and preferably the rear of the compartment is provided with a removable door 13, in order to give access to the interior Aof the cornpartment.
  • the loudspeaker enclosure may be mounted on castors 14 so that it can be readily moved from place to place.
  • the cabinet may be constructed without the bottom compartments intended to house the amplifier and cross-over unit.
  • An acoustic enclosure comprising a substantially 3 rectangular casing having a front wall, a rear wall, two side walls, a top and a bottom which slopes from one side to the other across the enclosure, an internal substantially vertical partition extending from side to side across the casing and dividing the internal space into a front compartment and a rear compartment which together form a bass-reex system, a loudspeaker unitarranged in said front compartment, an aperture ,in .said front wall for the egress of sound from the loudspeaker unit, an aperture in said partition through which the rear of the loudspeaker projects, and a space between the rear of said loudspeaker and the side wall of said aperture forming an air gap around the rear portion of the loudspeaker unit which is arranged to resonate with the volume of air in the rear compartment as a Helmholtz resonator and thereby reduce the amplitude of the resonance kof the loudspeaker unit with the volume of air enclosed in the casing.
  • An acoustic enclosure comprising a substantially rectangular casing having a front wall, a rear wall, two side walls, a top and a bottom which slopes from one side yto the other across the enclosure, an internal substantially vertical partition extending from side to side across the casing and dividing the internal space into a front compartment and a rear compartment which together form a bass-reilex system, a loudspeaker unit arranged in said front compartment, an aperture in said front wall for the egress of sound from the loudspeaker unit, an aperture in said partition through which the rear of the loudspeaker projects, and a space between the rear of said loudspeaker and the side wall of said aperture forming an air gap around the rear portion of the loudspeaker unit which is arranged to resonate with the volume of air in the rear compartment as a Helmholtz resonator and thereby reduce the amplitude of the resonance of the loudspeaker unit with the volume of air enclosed in the casing, and a membrane of sound absorbing material mounted across at least one of the
  • An acoustic enclosure comprising a substantially lrectangular casing having a front wall, a rear wall, two side walls, a top and a bottom, an internal substantially vertical partition extending from side to side across the casing and dividing the internal space into a front compartment and a rear compartment which together form a bass-retiex system, a loudspeaker unit arranged in said front compartment, an aperture in said front wall for the egress of sound from the loudspeaker unit, an aperture in said partition through which the rear of the loudspeaker projects, and a space between the rear of said loudspeaker and the side wall of said aperture forming an air gap around the rear portion of the loudspeaker unit which is arranged to resonate with the volume of air in the rear compartment as a Helmholtz resonator and thereby reduce the amplitude of the resonance of the loudspeaker unit with the volume of air enclosed in the casing, a horizontal partition arranged belowsaid loudspeaker unit and forming the bottom of said front compartment, a lower

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  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Details Of Audible-Bandwidth Transducers (AREA)
  • Obtaining Desirable Characteristics In Audible-Bandwidth Transducers (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Description

Dec. 15, 1959l L.. J. ELLIOTT 2,917,127
ACOUSTIC ENCLOSURE FOR LOUDSPEAKERS Filed Feb. 1o, 195e 5" |56- e` -efc :gio o o o o /fl g ||io o ooo 4 51H0 o o o o VA 1 lUV T n *02 2d:- 6a j Q--f 1 5 I f I 3 r// I m E 2 7 E a 9. `5
nvenlor l A Harney United States Patent O 2,917,127 ACOUSTIC ENCLOSURE FOR LOUDSPEAKERS Llewellyn .lohn Elliott, Cambridge, England, assignor to Pye Limited, Cambridge, England, a British company Application February 10, 1956, Serial No. 564,809
Claims priority, application Great Britain February 17, 1955 3 Claims. (Cl. 181-'31) The useof an enclosure inthe form of a Helmholtz resonator tuned to the free air resonance of a loudspeaker unit is well known in the art. v Such enclosures are generally known as bass-reflex or phase inverter cabinets. n
Y `A disadvantage of such a system is that although the main resonance of the speaker is effectively damped and the bass response extended, two subsidiary resonances are formed. In one themass and air loading of the moving parts of the loudspeaker unit resonate with the acoustic capacitance of the air enclosed by the cabinet and in the other the mechanical stiffness of the unit resonates with the acoustic inductance of the port aperture of the resonator. As a result the frequency response of the system is non-linear in the region of these unwanted resonances.
It is an object of the present invention to reduce the amplitude of these unwanted resonances with a resulting smoother frequency response and consequent reduction in distortion of the reproduced sounds.
According to the invention, one or more internal Helmholtz resonators arel introduced into a reex enclosure adapted to contain a loudspeaker unit and are tuned to the resonance frequency of the loudspeaker unit with the acoustic capacitance of the air enclosed by the enclosure or to frequencies in va band including that resonance.
According to a feature of the invention, a further subsidiary reflex system or systems are arranged to be coupled acoustically to the main port aperture or apertures of the main rellex system constituted by the enclosure and are tuned to the resonance of the loudspeaker unit with the acoustic inductance of the main port aperture or apertures or to frequencies in a band including that resonance.
The enclosure is constructed so as to be mechanically .rigid and lined with suitable sound absorbing material. If necessary membranes of a sound absorbing material such as felt are mounted across one or all of the internal chambers to absorb standing waves formed by reflections between the walls or partitions in the enclosure.
The frequency response of the system is considerably smoother and is extended further towards the lowest acoustic frequencies than that of a conventional recx system occupying the same volume and fitted with a similar loudspeaker uni-t.
In order that the invention may be more fully understood reference will now be made to the accompanying drawing in which:
Figure l is a front elevation of a loudspeaker enclosure according to the invention with the decorative fret removed, and
Figure 2 is a section taken on the line II-II in Figure 1.
Referring to the drawing, the enclosure comprises an outer casing 1 of generally rectangular form and preferably made of wood, for example plywood and constructed so that it is mechanically rigid. The side of the casing 1 which is intended to form the front, is closed by a loudspeaker board 2, n front on which is arranged a decora,-
ice
tive fret 3 which may be a sheet of expanded metal, and is retained in position by means of a detachable framework or beading 4. The interior of the cabinet is divided horizontally by means of a sloping shelf 5, which extends between the two opposite side walls of the casing 1. By making the shelf 5 sloping, the possibility of producing standing waves within the cabinet is reduced. The space above the shelf 5 is divided vertically by a partition 6 extending between the upper surface of the shelf and the top of the casing 1 in order to form two compartments, namely a rear compartment A and a front compartment B. The bottom of the front compartment B is formed by a horizontal shelf 7, which defines, with the shelf 5, 'a third compartment C below the compartment B. The shelf 7 is provided with a plurality of apertures 7a y which provide communication between the compartment B and the compartment C. The speaker board 2 is also and which is mounted with its cone over the aperture 2a in the speaker board 2 and, the rear of the loudspeaker extending through an aperture 6a in the partition 6.
The enclosure A and part of the enclosure B are lined with a sound-absorbing material 10, for example a layer of cotton waste covered with thick felt.
In operation, the main port apertures 7a resonate with the volumes of the compartments A and B at free air resonance of the loudspeaker unit as in a conventional reflex system. According to the invention, the aperture 6a forms anannular air gap between the rear of the loudspeaker and the side walls of the partition 6 which resonates with the volume of compartment A as a Helmholtz resonator and reduces the amplitude of the resonance of the speaker unit with the volumes A and B. Thus this internal Helmholtz resonator is tuned to the resonance frequency of the loudspeaker unit with the acoustic capacitance of the air enclosed by the cabinet or to frequencies in a band including that resonance.
Furthermore, the apertures 8 resonate with the volume of air in the compartment C as a subsidiary reilex system and reduces the amplitude of resonance of the speaker unit with the main port apertures 7a. Thus this subsidiary reex system is coupled acoustically to the port apertures 7a of the main reflex system and is tuned to the resonance of the loudspeaker unit with the acoustic inductance of the main port apertures 7a or to frequencies in a band including that resonance. The size and spacing of the holes 8 is important to give the desired resonance frequency.
In this embodiment of the invention, the space beneath the shelf 5 forms a compartment D which may be emlployed to house an amplifier to be used in conjunction with the loudspeaker. One end of this space may be divided by means of a wall 11, to form a subsidiary compartment E which may house an electrical cross-over unit. Ventilation holes 12 are formed in the front, rear and bottom of the amplifier compartment D, and preferably the rear of the compartment is provided with a removable door 13, in order to give access to the interior Aof the cornpartment. The loudspeaker enclosure may be mounted on castors 14 so that it can be readily moved from place to place.
Whilst a particular embodiment has been described, it will be understood that various modifications may be made without departing from the scope of this invention. For example the cabinet may be constructed without the bottom compartments intended to house the amplifier and cross-over unit.
I claim:
1. An acoustic enclosure comprising a substantially 3 rectangular casing having a front wall, a rear wall, two side walls, a top and a bottom which slopes from one side to the other across the enclosure, an internal substantially vertical partition extending from side to side across the casing and dividing the internal space into a front compartment and a rear compartment which together form a bass-reex system, a loudspeaker unitarranged in said front compartment, an aperture ,in .said front wall for the egress of sound from the loudspeaker unit, an aperture in said partition through which the rear of the loudspeaker projects, and a space between the rear of said loudspeaker and the side wall of said aperture forming an air gap around the rear portion of the loudspeaker unit which is arranged to resonate with the volume of air in the rear compartment as a Helmholtz resonator and thereby reduce the amplitude of the resonance kof the loudspeaker unit with the volume of air enclosed in the casing.
2. An acoustic enclosure comprising a substantially rectangular casing having a front wall, a rear wall, two side walls, a top and a bottom which slopes from one side yto the other across the enclosure, an internal substantially vertical partition extending from side to side across the casing and dividing the internal space into a front compartment and a rear compartment which together form a bass-reilex system, a loudspeaker unit arranged in said front compartment, an aperture in said front wall for the egress of sound from the loudspeaker unit, an aperture in said partition through which the rear of the loudspeaker projects, and a space between the rear of said loudspeaker and the side wall of said aperture forming an air gap around the rear portion of the loudspeaker unit which is arranged to resonate with the volume of air in the rear compartment as a Helmholtz resonator and thereby reduce the amplitude of the resonance of the loudspeaker unit with the volume of air enclosed in the casing, and a membrane of sound absorbing material mounted across at least one of the compartments to absorb standing waves.
3. An acoustic enclosure comprising a substantially lrectangular casing having a front wall, a rear wall, two side walls, a top and a bottom, an internal substantially vertical partition extending from side to side across the casing and dividing the internal space into a front compartment and a rear compartment which together form a bass-retiex system, a loudspeaker unit arranged in said front compartment, an aperture in said front wall for the egress of sound from the loudspeaker unit, an aperture in said partition through which the rear of the loudspeaker projects, and a space between the rear of said loudspeaker and the side wall of said aperture forming an air gap around the rear portion of the loudspeaker unit which is arranged to resonate with the volume of air in the rear compartment as a Helmholtz resonator and thereby reduce the amplitude of the resonance of the loudspeaker unit with the volume of air enclosed in the casing, a horizontal partition arranged belowsaid loudspeaker unit and forming the bottom of said front compartment, a lower compartment beneath said horizontal partition, at least one aperture between said lower compartment and the outside of the cabinet, at least one aperture in the horipartment and the outside of the cabinet resonating with the volume of air in the lower compartment as a subsidiary reflex system and reducing the amplitude of resonance -of the speaker unit with the at least one aperture in the horizontal partition.
References Cited in the le of this patent UNITED STATES PATENTS 1,804,676 Dalton May 12, 1931 l1,837,755 Carlisle et al. Dec. 22, 1931 1,869,178 Thuras July 26, 1932 1,969,704 DAlton Aug. 7, 1934 2,020,166 Swinyard Nov. 5, 1935 2,179,840 Bucky Nov. 14, 1939 `2,642,948 Olson et al June 23, 1953 2,694,462 Robbins et al Nov. 16, 1954 2,766,839 Baruch et al Oct. 16, 1956 FOREIGN PATENTS 434,563 Great Britain Sept. 4, 1935 489,588 Great Britain July 29, 1938 496,487 Great Britain Nov. 28, 1938 663,734 Great Britain Dec. 27, 1951 696,671 Great Britain Sept. 9, 1953
US564809A 1955-02-17 1956-02-10 Acoustic enclosure for loudspeakers Expired - Lifetime US2917127A (en)

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GB4786/55A GB793193A (en) 1955-02-17 1955-02-17 An improved acoustic enclosure for loudspeakers

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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3047090A (en) * 1958-05-07 1962-07-31 Robert G Pruden Tuned acoustical device
US3938617A (en) * 1974-01-17 1976-02-17 Fort Enterprises, Limited Speaker enclosure
US4029170A (en) * 1974-09-06 1977-06-14 B & P Enterprises, Inc. Radial sound port speaker
US4131179A (en) * 1976-12-17 1978-12-26 Pope Darrel L High fidelity speaker system
AT385384B (en) * 1986-07-28 1988-03-25 Stastny & Schroegendorfer Ges SPEAKER COVER
US5920633A (en) * 1996-02-12 1999-07-06 Yang; Yi-Fu Thin-wall multi-concentric cylinder speaker enclosure with audio amplifier tunable to listening room
US20030161495A1 (en) * 2000-07-21 2003-08-28 Nevill Stuart Michael Acoustic structures
EP1498317A1 (en) * 2003-07-18 2005-01-19 Pioneer Corporation Door loudspeaker apparatus and door panel
US20070256888A1 (en) * 2004-05-12 2007-11-08 Tbi Audio Systems Llc Speaker System With Improved Frequency Response
US8439153B2 (en) * 2008-06-27 2013-05-14 Rgb Systems, Inc. Method and apparatus for a loudspeaker assembly
USD826902S1 (en) * 2016-12-27 2018-08-28 Monolith Cooperation, LLC Component and speaker assembly with integrated dolly

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB8503389D0 (en) * 1985-02-09 1985-03-13 B & W Loudspeakers Loudspeaker enclosures
GB2206262A (en) * 1987-08-07 1988-12-29 Samsung Electronics Co Ltd Loud speaker
JPH0759184A (en) * 1993-03-05 1995-03-03 Matsushita Electric Ind Co Ltd Case and acousting video equipment and its manufacture
US11128941B1 (en) 2018-11-20 2021-09-21 Edward G. Blemel Method for passive dissipation of deconstructive harmonics during audio amplification and reproduction

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1804676A (en) * 1925-03-05 1931-05-12 Columbia Phono Graph Company I Radio apparatus
US1837755A (en) * 1929-06-22 1931-12-22 Westinghouse Electric & Mfg Co Translating device
US1869178A (en) * 1930-08-15 1932-07-26 Bell Telephone Labor Inc Sound translating device
US1969704A (en) * 1932-06-03 1934-08-07 D Alton Andre Acoustic device
GB434563A (en) * 1934-08-13 1935-09-04 Philip Keston Turner Improvements in and relating to baffles and containers for loud speakers
US2020166A (en) * 1935-03-23 1935-11-05 Hazeltine Corp Sound reproducing apparatus
GB489588A (en) * 1936-09-02 1938-07-29 Standard Telephones Cables Ltd Improvements in or relating to sound-translating devices
GB496487A (en) * 1937-05-26 1938-11-28 Murphy Radio Ltd Improvements in cabinets for sound reproducing instruments
US2179840A (en) * 1938-05-03 1939-11-14 Frida Bucky Loudspeaker arrangement
GB663734A (en) * 1948-01-13 1951-12-27 Murphy Radio Ltd Improvements in and relating to loud speakers
US2642948A (en) * 1948-05-28 1953-06-23 Rca Corp Portable radio with a bass-reflex cabinet
GB696671A (en) * 1949-09-23 1953-09-09 British Broadcasting Corp Improvements in and relating to loudspeakers
US2694462A (en) * 1951-09-19 1954-11-16 Robbins Frank Acoustic system for loud-speakers
US2766839A (en) * 1953-03-16 1956-10-16 Research Corp Loudspeaker system

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1804676A (en) * 1925-03-05 1931-05-12 Columbia Phono Graph Company I Radio apparatus
US1837755A (en) * 1929-06-22 1931-12-22 Westinghouse Electric & Mfg Co Translating device
US1869178A (en) * 1930-08-15 1932-07-26 Bell Telephone Labor Inc Sound translating device
US1969704A (en) * 1932-06-03 1934-08-07 D Alton Andre Acoustic device
GB434563A (en) * 1934-08-13 1935-09-04 Philip Keston Turner Improvements in and relating to baffles and containers for loud speakers
US2020166A (en) * 1935-03-23 1935-11-05 Hazeltine Corp Sound reproducing apparatus
GB489588A (en) * 1936-09-02 1938-07-29 Standard Telephones Cables Ltd Improvements in or relating to sound-translating devices
GB496487A (en) * 1937-05-26 1938-11-28 Murphy Radio Ltd Improvements in cabinets for sound reproducing instruments
US2179840A (en) * 1938-05-03 1939-11-14 Frida Bucky Loudspeaker arrangement
GB663734A (en) * 1948-01-13 1951-12-27 Murphy Radio Ltd Improvements in and relating to loud speakers
US2642948A (en) * 1948-05-28 1953-06-23 Rca Corp Portable radio with a bass-reflex cabinet
GB696671A (en) * 1949-09-23 1953-09-09 British Broadcasting Corp Improvements in and relating to loudspeakers
US2694462A (en) * 1951-09-19 1954-11-16 Robbins Frank Acoustic system for loud-speakers
US2766839A (en) * 1953-03-16 1956-10-16 Research Corp Loudspeaker system

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3047090A (en) * 1958-05-07 1962-07-31 Robert G Pruden Tuned acoustical device
US3938617A (en) * 1974-01-17 1976-02-17 Fort Enterprises, Limited Speaker enclosure
US4029170A (en) * 1974-09-06 1977-06-14 B & P Enterprises, Inc. Radial sound port speaker
US4131179A (en) * 1976-12-17 1978-12-26 Pope Darrel L High fidelity speaker system
AT385384B (en) * 1986-07-28 1988-03-25 Stastny & Schroegendorfer Ges SPEAKER COVER
US6634455B1 (en) 1996-02-12 2003-10-21 Yi-Fu Yang Thin-wall multi-concentric sleeve speaker
US5920633A (en) * 1996-02-12 1999-07-06 Yang; Yi-Fu Thin-wall multi-concentric cylinder speaker enclosure with audio amplifier tunable to listening room
US20030161495A1 (en) * 2000-07-21 2003-08-28 Nevill Stuart Michael Acoustic structures
US6896096B2 (en) 2000-07-21 2005-05-24 B&W Loudspeakers Limited Acoustic structures
EP1498317A1 (en) * 2003-07-18 2005-01-19 Pioneer Corporation Door loudspeaker apparatus and door panel
US20050013459A1 (en) * 2003-07-18 2005-01-20 Pioneer Corporation Door speaker apparatus and door panel
US20070256888A1 (en) * 2004-05-12 2007-11-08 Tbi Audio Systems Llc Speaker System With Improved Frequency Response
US8439153B2 (en) * 2008-06-27 2013-05-14 Rgb Systems, Inc. Method and apparatus for a loudspeaker assembly
USD826902S1 (en) * 2016-12-27 2018-08-28 Monolith Cooperation, LLC Component and speaker assembly with integrated dolly

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