WO1983001884A1 - Loudspeaker assembly - Google Patents

Loudspeaker assembly Download PDF

Info

Publication number
WO1983001884A1
WO1983001884A1 PCT/GB1982/000296 GB8200296W WO8301884A1 WO 1983001884 A1 WO1983001884 A1 WO 1983001884A1 GB 8200296 W GB8200296 W GB 8200296W WO 8301884 A1 WO8301884 A1 WO 8301884A1
Authority
WO
WIPO (PCT)
Prior art keywords
pole piece
assembly
cone
magnet
loudspeaker
Prior art date
Application number
PCT/GB1982/000296
Other languages
French (fr)
Inventor
Products Limited Linn
Original Assignee
Tiefenbrun, Ivor, Sigmund
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Tiefenbrun, Ivor, Sigmund filed Critical Tiefenbrun, Ivor, Sigmund
Priority to AU90535/82A priority Critical patent/AU9053582A/en
Publication of WO1983001884A1 publication Critical patent/WO1983001884A1/en

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/06—Loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/02—Details

Definitions

  • the present invention relates to a loudspeaker assembly in particular, but not exclusively, for use in high fidelity sound reproduction.
  • the cone is mounted such that the cone apex points in the opposite direction from desired sound waves.
  • This chassis has to be strongly built and is a costly item.
  • This bell-shaped chassis known just as the chassis, will nevertheless possess inherent weaknesses for loudspeaker performance due to its bell shape and the fact that the heavy magnet assembly is mounted on the rear of this chassis whilst the whole unit is mounted to the cabinet from the front outer flange.
  • the chassis resonates and produces distortion. This results in increased materials and assembly time, which, in turn, increase the cost and weight of the loudspeaker.
  • a tunnel effect is produced, which also introduces distortion.
  • the object of the present invention is to obviate or mitigate these disadvantages.
  • a loudspeaker assembly having a cone portion, said cone portion being mounted with its apex extending in the direction of intended sound travel, said cone portion being mounted by suspension means, such that said cone portion is caused to vibrate in response to electrical signals passed through a coil which is placed within a magnetic field.
  • said loudspeaker assembly includes a magnet and a first pole piece, said first pole piece having a generally elongate portion, said magnet and said first pole piece being arranged such that the elongate portion extends along the cone axis.
  • a second pole piece is connected to the magnet assembly, the second pole piece producing a magnetic circuit with a gap between the elongate first pole piece portion and the second pole piece, and the magnet assembly and the cone portion being mounted in substantially the same axis.
  • the second pole piece is generally cone-shaped to reduce the length of the speaker coil former.
  • said cone portion is supported by first and second cone suspension means, said first suspension means extending axially from the end of the elongate portion of the first pole piece, and said suspension means mounting the cone portion to the surround means.
  • said second pole piece is mountable onto the loudspeaker surround and cabinet. Alternatively the loudspeaker is attached to the cabinet by an extension of rear or first pole piece.
  • a coil is located within said cone, said coil being arranged around said extending member.
  • said first pole piece includes a disc portion, said disc portion having at least one aperture therein to permit the passage of air there- through in response to movement of the cone portion.
  • the apex of the loudspeaker cone is truncated, said apex being covered by a membrane, which may or may not permit the passage of air.
  • the second pole piece and the magnet are secured to each other and to the surround by a ceramic anaerobic adhesive compound or by other suitable fastening means such as glues, screws, bolts etc.
  • a loudspeaker assembly comprises a cabinet 2 and a speaker portion 3.
  • the speaker portion 3 comprises a cone 4 which is mounted by a rubber surround 5 onto a pole piece 6.
  • the pole piece 6 contains apertures 6a by which it may be secured to the cabinet or baffle 2.
  • the baffle 2 has a circular aperture 2a in which is located a long-shaped magnet 7 of square cross section.
  • a second pole piece 8 is secured to the magnet 7, the second pole piece 8 being disc-shaped and having an elongate portion 8a extending from the centre of the disc along the cone axis towards the apex 4a.
  • the pole piece 8 has a plurality of apertures 8b therein to allow the passage of air from inside the cone to the exterior during movement.
  • the cone 4 is mounted by two suspensions 9 and 10.
  • Suspension 9 extends from portion 8a. which engages a stiffened porous felt pad 11 located at the apex 4a. of the cone.
  • Suspension 10 is the standard type of spyder.
  • An anaerobic ceramic adhesive compound is used to secure the suspension 10, the pole piece 6, and the magnet 7 together.
  • the ceramic adhesive may also be used to secure the pole piece 6 to the magnet 7 and the magnet 7 to the pole piece 8.
  • the loudspeaker coil 13 and electrical terminals 14 are located within the cone 4 and are mounted over the portion 8a and the suspension 10. In use, in response to electrical driving signals, the coil and cone 4 is caused to vibrate and sound energy is emitted principally in the direction A with accoustic dispersion which is generally dome-shaped and which has no tunnel distortion.
  • the second pole piece 8 is mounted on the baffle 2.
  • the first pole piece 6 is ring-shaped and has a rectangular cross-section.
  • the suspension 10 is mounted on a ring-bracket 10a mounted on the pole piece 6. Otherwise the construction is the same as the first embodiment and like numerals denote like parts.
  • the suspensions 9 and 10 may be arranged in a different manner although remaining consistent with the desired performance of the cone when driven, and the pole pieces 6 or 8 may be secured to the surround by any other suitable fastening means such as adhesive, screws or rivets.
  • Advantages of the preferred embodiment of the invention include; distortion is reduced by eliminating the tunnel effect, the structural arrangement of a cone is retained, with improved dispersion characteristics and few of the disadvantages of a dome, the mechanism is coupled to the cabinet and surround directly close to or at its centre of gravity providing improved sound balance and audio characteristics such as linearity, and the braced heavy bell-shaped chassis is not required which makes such loudspeakers more economic.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)

Abstract

The assembly has a moving cone (4) which is mounted with its apex towards the desired direction of sound propagation. The cone (4) is driven by a moving coil (13) in the field of a central magnet (7) acting via pole pieces (6) and (8).

Description

LOUDSPEAKER ASSEMBLY
The present invention relates to a loudspeaker assembly in particular, but not exclusively, for use in high fidelity sound reproduction. In conventional loudspeakers, the cone is mounted such that the cone apex points in the opposite direction from desired sound waves. This normally requires that the magnet assembly is mounted on a bell-shaped chassis. This chassis has to be strongly built and is a costly item. This bell-shaped chassis, known just as the chassis, will nevertheless possess inherent weaknesses for loudspeaker performance due to its bell shape and the fact that the heavy magnet assembly is mounted on the rear of this chassis whilst the whole unit is mounted to the cabinet from the front outer flange. The chassis resonates and produces distortion. This results in increased materials and assembly time, which, in turn, increase the cost and weight of the loudspeaker. In addition, with such cones, a tunnel effect is produced, which also introduces distortion.
The object of the present invention is to obviate or mitigate these disadvantages.
According to the present invention, a loudspeaker assembly is provided having a cone portion, said cone portion being mounted with its apex extending in the direction of intended sound travel, said cone portion being mounted by suspension means, such that said cone portion is caused to vibrate in response to electrical signals passed through a coil which is placed within a magnetic field.
Preferably, said loudspeaker assembly includes a magnet and a first pole piece, said first pole piece having a generally elongate portion, said magnet and said first pole piece being arranged such that the elongate portion extends along the cone axis.
Preferably also a second pole piece is connected to the magnet assembly, the second pole piece producing a magnetic circuit with a gap between the elongate first pole piece portion and the second pole piece, and the magnet assembly and the cone portion being mounted in substantially the same axis.
Preferably also, the second pole piece is generally cone-shaped to reduce the length of the speaker coil former.
Preferably also, said cone portion is supported by first and second cone suspension means, said first suspension means extending axially from the end of the elongate portion of the first pole piece, and said suspension means mounting the cone portion to the surround means. Preferably also, said second pole piece is mountable onto the loudspeaker surround and cabinet. Alternatively the loudspeaker is attached to the cabinet by an extension of rear or first pole piece.
Preferably also, a coil is located within said cone, said coil being arranged around said extending member.
Preferably also, said first pole piece includes a disc portion, said disc portion having at least one aperture therein to permit the passage of air there- through in response to movement of the cone portion.
Preferably also, the apex of the loudspeaker cone is truncated, said apex being covered by a membrane, which may or may not permit the passage of air.
Preferably also, the second pole piece and the magnet are secured to each other and to the surround by a ceramic anaerobic adhesive compound or by other suitable fastening means such as glues, screws, bolts etc.
Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings which are a cross-sectional view of a loudspeaker assembly in accordance with the present invention. Referring now to the Fig. 1, a loudspeaker assembly comprises a cabinet 2 and a speaker portion 3. The speaker portion 3 comprises a cone 4 which is mounted by a rubber surround 5 onto a pole piece 6. The pole piece 6 contains apertures 6a by which it may be secured to the cabinet or baffle 2. The baffle 2 has a circular aperture 2a in which is located a long-shaped magnet 7 of square cross section. A second pole piece 8 is secured to the magnet 7, the second pole piece 8 being disc-shaped and having an elongate portion 8a extending from the centre of the disc along the cone axis towards the apex 4a. The pole piece 8 has a plurality of apertures 8b therein to allow the passage of air from inside the cone to the exterior during movement. The cone 4 is mounted by two suspensions 9 and 10.
Suspension 9 extends from portion 8a. which engages a stiffened porous felt pad 11 located at the apex 4a. of the cone. Suspension 10 is the standard type of spyder. An anaerobic ceramic adhesive compound is used to secure the suspension 10, the pole piece 6, and the magnet 7 together. The ceramic adhesive may also be used to secure the pole piece 6 to the magnet 7 and the magnet 7 to the pole piece 8. The loudspeaker coil 13 and electrical terminals 14 are located within the cone 4 and are mounted over the portion 8a and the suspension 10. In use, in response to electrical driving signals, the coil and cone 4 is caused to vibrate and sound energy is emitted principally in the direction A with accoustic dispersion which is generally dome-shaped and which has no tunnel distortion.
In the embodiment shown in Fig. 2, the second pole piece 8 is mounted on the baffle 2. The first pole piece 6 is ring-shaped and has a rectangular cross-section. The suspension 10 is mounted on a ring-bracket 10a mounted on the pole piece 6. Otherwise the construction is the same as the first embodiment and like numerals denote like parts.
Without departing from the scope of the invention various modifications may be made to the apparatus as hereinbefore described; the magnet 7 and the pole piece
8 may be other than disc shaped; the suspensions 9 and 10 may be arranged in a different manner although remaining consistent with the desired performance of the cone when driven, and the pole pieces 6 or 8 may be secured to the surround by any other suitable fastening means such as adhesive, screws or rivets.
Advantages of the preferred embodiment of the invention include; distortion is reduced by eliminating the tunnel effect, the structural arrangement of a cone is retained, with improved dispersion characteristics and few of the disadvantages of a dome, the mechanism is coupled to the cabinet and surround directly close to or at its centre of gravity providing improved sound balance and audio characteristics such as linearity, and the braced heavy bell-shaped chassis is not required which makes such loudspeakers more economic.

Claims

CLAIMS 1. A loudspeaker assembly having a cone portion, said cone portion being mounted with its apex extending in the direction of intended sound travel, said cone portion being mounted by suspension means, such that said cone portion is caused to vibrate in response to electrical signals passed through a coil which is placed within a magnetic field.
2. The assembly of claim 1, including a magnet and a first pole piece, said first pole piece having a generally elongate portion, said magnet and said first pole piece being arranged such that the elongate portion extends along the cone axis.
3. The assembly of claim 2, in which a second pole piece is connected to the magnet assembly, the second pole piece producing a magnetic circuit with a gap between the elongate first pole piece portion and the second pole piece, and the magnet assembly and the cone portion being mounted in substantially the same axis.
4. The assembly of claim 3, in which, the second pole piece is generally cone-shaped.
5. The assembly of any of claims 2 to 4, in which said cone portion is supported by first and second cone suspension means, said first suspension means extending axially from the end of the elongate portion of the first pole piece, and said suspension means mounting the cone portion to the surround means.
6. The assembly of claim 3, in which said second pole piece is mountable onto the loudspeaker surround and cabinet.
7. The assembly of any of claims 1 to 5, in which the loudspeaker is attached to a cabinet by a rearward extension of the first pole piece.
8. The assembly of any preceding claim, in which said first pole piece includes a disc portion, said disc portion having at least one aperture therein, to permit the passage of air therethrough in response to movement of the cone portion.
9. The assembly of any preceding claim, in which the apex of the loudspeaker cone is truncated, said apex being covered by a membrane.
10. The assembly of claim 9, in which the membrane is permeable to air.
11. The assembly of claim 9, in which the membrane is impermeable to air.
12. The assembly of claim 3, in which the second pole piece and the magnet are secured to eaάh other and to the surround by a ceramic anaerobic adhesive compound.
PCT/GB1982/000296 1981-11-17 1982-10-19 Loudspeaker assembly WO1983001884A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU90535/82A AU9053582A (en) 1981-11-17 1982-10-19 Loudspeaker assembly

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8134641 1981-11-17
GB8134641811117 1981-11-17

Publications (1)

Publication Number Publication Date
WO1983001884A1 true WO1983001884A1 (en) 1983-05-26

Family

ID=10525946

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1982/000296 WO1983001884A1 (en) 1981-11-17 1982-10-19 Loudspeaker assembly

Country Status (2)

Country Link
EP (1) EP0093736A1 (en)
WO (1) WO1983001884A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0356433A1 (en) * 1987-04-08 1990-03-07 Harman International Industries, Incorporated Shallow loudspeaker
US6219432B1 (en) 1996-07-09 2001-04-17 B&W Loudspeakers Limited Loudspeaker drive unit
EP2801708A1 (en) * 2013-05-08 2014-11-12 Eberspächer Exhaust Technology GmbH & Co. KG Sound Generator for an Anti-noise System for influencing exhaust Noises and/or intake Noises of a Motor Vehicle

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2512323A (en) * 1946-09-09 1950-06-20 Radio Frequency Lab Inc Reentrant diaphragm with central closure member
US2537723A (en) * 1946-11-22 1951-01-09 Truvox Engineering Company Ltd Electromagnetic transducer
DE1061826B (en) * 1952-11-06 1959-07-23 Telefunken Gmbh Tweeter with conical cone
FR1353622A (en) * 1963-01-17 1964-02-28 Audax Improvements to Direct Radiation Loudspeakers
US3310131A (en) * 1964-01-30 1967-03-21 Emi Ltd Reinforcing cap for moving coil loudspeakers
FR2256619A1 (en) * 1973-12-28 1975-07-25 Elektroakusztikai Gyar Electro-acoustical transducer - has magnetic circuit consisting of armature(s) and magnet(s)
US4029910A (en) * 1974-05-01 1977-06-14 Allison Acoustics, Inc. Wide dispersion loudspeaker with flexing diaphragm
GB2012520A (en) * 1978-01-12 1979-07-25 Peerless Gmbh Loudspeaker

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2512323A (en) * 1946-09-09 1950-06-20 Radio Frequency Lab Inc Reentrant diaphragm with central closure member
US2537723A (en) * 1946-11-22 1951-01-09 Truvox Engineering Company Ltd Electromagnetic transducer
DE1061826B (en) * 1952-11-06 1959-07-23 Telefunken Gmbh Tweeter with conical cone
FR1353622A (en) * 1963-01-17 1964-02-28 Audax Improvements to Direct Radiation Loudspeakers
US3310131A (en) * 1964-01-30 1967-03-21 Emi Ltd Reinforcing cap for moving coil loudspeakers
FR2256619A1 (en) * 1973-12-28 1975-07-25 Elektroakusztikai Gyar Electro-acoustical transducer - has magnetic circuit consisting of armature(s) and magnet(s)
US4029910A (en) * 1974-05-01 1977-06-14 Allison Acoustics, Inc. Wide dispersion loudspeaker with flexing diaphragm
GB2012520A (en) * 1978-01-12 1979-07-25 Peerless Gmbh Loudspeaker

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0356433A1 (en) * 1987-04-08 1990-03-07 Harman International Industries, Incorporated Shallow loudspeaker
EP0356433A4 (en) * 1987-04-08 1991-07-10 Harman International Industries, Incorporated Shallow loudspeaker
US6219432B1 (en) 1996-07-09 2001-04-17 B&W Loudspeakers Limited Loudspeaker drive unit
EP2801708A1 (en) * 2013-05-08 2014-11-12 Eberspächer Exhaust Technology GmbH & Co. KG Sound Generator for an Anti-noise System for influencing exhaust Noises and/or intake Noises of a Motor Vehicle
CN104141521A (en) * 2013-05-08 2014-11-12 埃贝施佩歇尔排气技术有限及两合公司 Sound generator for an anti-noise system for influencing exhaust noises and/or intake noises of a motor vehicle
DE102013104810A1 (en) * 2013-05-08 2014-11-13 Eberspächer Exhaust Technology GmbH & Co. KG VEHICLE GENERATOR FOR AN ANTI-VALL SYSTEM FOR INFLUENCING EXHAUST VACUUM AND / OR INTAKE NOISE OF A MOTOR VEHICLE
US9374632B2 (en) 2013-05-08 2016-06-21 Eberspächer Exhaust Technology GmbH & Co. KG Sound generator for an anti-noise system for influencing exhaust noises and/or intake noises of a motor vehicle

Also Published As

Publication number Publication date
EP0093736A1 (en) 1983-11-16

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Designated state(s): AT BE CH DE FR GB LU NL SE