WO1989011201A1 - Haut-parleur - Google Patents

Haut-parleur Download PDF

Info

Publication number
WO1989011201A1
WO1989011201A1 PCT/GB1989/000476 GB8900476W WO8911201A1 WO 1989011201 A1 WO1989011201 A1 WO 1989011201A1 GB 8900476 W GB8900476 W GB 8900476W WO 8911201 A1 WO8911201 A1 WO 8911201A1
Authority
WO
WIPO (PCT)
Prior art keywords
drive unit
high frequency
low frequency
diaphragm
voice coil
Prior art date
Application number
PCT/GB1989/000476
Other languages
English (en)
Inventor
Lawrence Reginald Fincham
Original Assignee
Kef Electronics Limited
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
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=10636585&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=WO1989011201(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Application filed by Kef Electronics Limited filed Critical Kef Electronics Limited
Priority to KR1019900700039A priority Critical patent/KR0171567B1/ko
Publication of WO1989011201A1 publication Critical patent/WO1989011201A1/fr
Priority to GB9023490A priority patent/GB2236929B/en
Priority to NO19904830A priority patent/NO317793B1/no
Priority to SG114393A priority patent/SG114393G/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
    • H04R9/02—Details
    • 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 
    • H04R1/24—Structural combinations of separate transducers or of two parts of the same transducer and responsive respectively to two or more frequency ranges
    • 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
    • H04R9/025—Magnetic circuit

Definitions

  • This invention relates to loudspeakers and in particular to compound loudspeaker drive units in which separate diaphragms are provided for reproduction of the low and high audio frequencies.
  • separate loudspeaker drive units are provided for reproduction of bands of audio frequencies, for example a woofer unit for reproduction of sounds in a low frequency band and a tweeter unit for reproduction of sounds in a high frequency band.
  • the voice coils of the loudspeaker drive units are connected to the output of a power amplifier, or other source, through a suitable cross-over filter network which ensures that only electrical signals representing sounds in the appropriate bands are applied to the individual loudspeaker voice coils.
  • the characteristic of the cross-over filter is arranged so that in a mid frequency cross-over band intermediate the low and high frequency bands the outputs of the two loudspeaker drive units tail off; the output of the low frequency loudspeaker drive unit reduces with increase of frequency while the output of the high frequency loudspeaker drive unit reduces with decrease in frequency.
  • the low and high frequency loudspeaker drive units At a so-called crossover frequency the low and high frequency loudspeaker drive units have outputs which are equal but reduced in comparison with their outputs within their respective frequency bands.
  • the electrical energisations of the respective voice coils are adjusted so that the sound outputs of the loudspeaker drive units are relatively matched and together provide a substantially uniform output over the total frequency range of the combination of the two loudspeaker drive units.
  • the sound radiated from each of the drive units may be said to emanate from the apparent sound source or acoustic centre of that unit; the position of the acoustic centre is a function of the design of the particular unit and may be determined by acoustic measurement.
  • the loudspeaker drive units are usually mounted on a common baffle such that they lie in a common plane and are offset in a vertical direction in the plane of the baffle. For a listener positioned approximately in line with the axes of the loudspeaker drive units and approximately equidistant from the acoustic centres of both drive units, a desired balance of output from the two drive units can be obtained.
  • the distances between the listener and the acoustic centres of the two loudspeaker drive units will be different and hence sounds in the mid frequency band produced by both loudspeakers will be received by the listener from the two drive units with a difference in time.
  • This time difference between sounds received from the two drive units results in a change in phase relationship of the sounds received at the listening position from the two drive units.
  • the sounds from the two drive units no longer add together as intended in the cross-over band. Consequently the resultant received sound levels will vary with frequency and the overall sound output of the loudspeaker combination will appear to the listener to be non-uniform.
  • the resulting raggedness in sound output colours the sound and, with stereo sound systems, there is a loss of clarity in the apparent location of instruments in the sound stage. This is particularly apparent in respect of sound frequencies in the upper mid-range, for example in the region of 3kHz, at which the offset of the drive units relative to one another is comparable to the wavelength of the sound. At a frequency of 3kHz the wavelength is approximately 4 inches or 100 cm.
  • the compound co-axial loudspeaker drive unit consists of a generally conical low frequency diaphragm driven by a voice coil interacting with a magnetic structure having a central pole extending through the voice coil.
  • a high frequency diaphragm is positioned to the rear of the structure and sound output from this diaphragm is directed to the front of the loudspeaker drive unit by means of a horn structure extending co-axially through the centre pole of the magnetic structure which interacts with the low frequency diaphragm.
  • both the low frequency and high frequency sounds are directed in a generally forward direction from the compound loudspeaker drive unit.
  • this co-axial form of loudspeaker construction there is no vertical or horizontal offset of the apparent sound sources for low and high frequencies.
  • the low frequency diaphragm is positioned at the front of the loudspeaker unit whereas the high frequency diaphragm is positioned at the rear of the loudspeaker unit and this results in relative displacement of the apparent sound sources in the direction of the axis of the drive unit and an undesirable time difference in the arrival, at the listener, of sounds from the high and low frequency diaphragms.
  • a compound loudspeaker drive unit comprises a first transducer operable to generate sounds in a low frequency range and a second transducer operable to generate sounds in a high frequency range, said low and high frequency ranges overlapping in a cross-over region; said first transducer having a conical diaphragm flaring outwardly and forwardly from a neck; said second transducer being located in or adjacent to the neck of the conical diaphragm of the first transducer in such a position that effective acoustic centres of the first and second transducers are coincident and that in the cross-over region the flaring of the conical diaphragm imposes a directivity upon the radiation of sound from the second transducer whereby the directivities of the first and second transducers are matched over frequencies in the cross-over region where both transducers make significant contributions to the sound output of the drive unit.
  • a compound loudspeaker drive unit comprises a low frequency moving coil drive unit and a high frequency moving coil drive unit; said high frequency drive unit including magnetic means interacting with the moving coil thereof, said magnetic means including a permanent magnet formed of neodymium iron boron or of material having magnetic properties substantially similar or superior thereto.
  • the compound loudspeaker drive unit includes a low frequency drive unit comprising a substantially frusto-conical low frequency diaphragm flaring outwardly in a forward direction from a neck thereof, a low frequency voice coil connected to said neck of the diaphragm; and first magnetic means providing a magnetic flux interacting with the low frequency voice coil whereby electrical energisation of the voice coil is effective to impart movement to the diaphragm to produce sounds in a low frequency range; and a high frequency loudspeaker drive unit positioned adjacent to said neck of the low frequency diaphragm and comprising a high frequency diaphragm carrying a high frequency voice coil; and second magnetic means including a permanent magnet formed of neodymium iron boron, or of a material having magnetic properties substantially similar or superior thereto, providing a magnetic flux interacting with the high frequency voice coil whereby electrical energisation of the high frequency voice coil is effective to impart movement to the high frequency diaphragm to produce sounds in a high frequency range
  • the high frequency drive unit is disposed relative to the low frequency drive unit such that the apparent sound sources of the two units are substantially coincident.
  • annular baffle member may be provided effective to provide a continuation of the surface of the low frequency diaphragm toward the high frequency diaphragm.
  • a loudspeaker comprising co-axially disposed low and high frequency drive units
  • the high frequency drive unit is manufactured separately from said low frequency drive unit and is secured to a pole piece of magnetic means of the low frequency drive unit.
  • the pole piece of the low frequency drive unit has a central bore extending therethrough and the high frequency drive unit has a rod, preferably of non-magnetic material, projecting therefrom and engaging within said bore to locate the high frequency drive unit relative to the low frequency drive unit.
  • a compound loudspeaker drive unit with low frequency and high frequency transducers having co-axial low and high frequency voice coils comprises a chassis 10 in the form of a conical basket having a front annular rim 11 connected to a rear annular member 12 by means of a number of ribs 13.
  • the rear annular member 12 has an annular flange 14 and an annular seat 15.
  • a first magnetic structure 16 for the low frequency loudspeaker drive unit Secured to the flange 14 is a first magnetic structure 16 for the low frequency loudspeaker drive unit.
  • the magnetic structure 16 comprises a magnet ring 17, which may for example be formed of barium ferrite, a front annular plate 18 which forms an outer pole and a member 19 which forms a backplate and inner pole 20.
  • the plate 18, magnet ring 17 and member 19 are held together to provide a magnetic path interrupted by a non-magnetic air gap between the outer pole 18 and the inner pole 20.
  • the poles are circular and form therebetween an annular air gap.
  • the low frequency transducer or loudspeaker drive unit comprises a diaphragm 21 of generally frusto-conical form supported along the front outer edge thereof by a flexible surround 22 secured to the front rim 11 of the chassis 10.
  • a tubular coil former 23 is secured to the rear edge of the diaphragm 21 and is arranged to extend co-axially of the air gap in the magnetic structure 16.
  • the coil former carries a voice coil 24 positioned on the former such that the coil extends through the air gap.
  • the coil is of sufficient axial length as to ensure that for normal excursions of the voice coil, the poles always lie within the length of the voice coil.
  • the backplate and inner pole member 19 has a bore 26 extending co-axially thereof for the purpose of mounting a high frequency drive unit
  • the high frequency transducer or drive unit 27 comprises a second magnetic structure consisting of a pot 28, a disc shaped magnet 29 and a disc shaped inner pole 30.
  • the pot 28 has a cylindrical outer surface so dimensioned as to fit within the interior of the coil former 23 without making physical contact therewith.
  • the pot is formed with a circular recess 31 to receive the magnet 29 and an annular lip 32 to form an outer pole.
  • One circular pole face of the magnet 29 is held in engagement with the bottom wall of the recess 31 and the disc shaped inner pole 30 is held in engagement with the other circular pole face of the magnet such that the circular outer periphery of the inner pole 30 lies co-axially with and within the lip 32 forming the outer pole.
  • a non-magnetic air gap extends between the inner and outer poles.
  • a spacer ring 33 is secured to the front face of the pot 28.
  • the magnet 29 is formed of neodymium iron boron which allows a very substantially enhanced magnetic field strength as compared with other available magnetic materials to be attained in the air gap between the poles.
  • the overall size of the high frequency magnetic structure for a required flux in the air gap, can be smaller than hitherto thereby allowing the high frequency drive unit to be positioned within the coil former of the low frequency drive unit immediately adjacent to the apex of the low frequency diaphragm 21.
  • the magnet 29 may be formed of other materials having magnetic properties substantially similar or superior to that of neodymium iron boron.
  • a high frequency domed diaphragm 34 has an annular support 35 of annular corrugated form and this support is secured at its outer periphery to the spacer ring 33. Secured to the domed diaphragm 34 is a cylindrical coil former carrying a high frequency voice coil 36 such that the voice coil extends through the air gap between the poles 30, 32 of the magnetic structure.
  • a rod 37 is secured centrally to the rear face of the pot 28 and extends through the bore 26 of the low frequency magnetic structure.
  • the high frequency drive unit tends to be held in engagement with the pole 20 of the magnetic structure 16 by magnetic attraction therebetween but is secured to the structure 16 by a threaded end portion 38 of the rod 37 extending through an aperture in a plate 39 positioned at the rear of the backplate 19 and a nut 40 threaded onto the end portion 38.
  • connections to the low frequency voice coil 24 are provided by means of flexible leadout conductors 41 extending from the voice coil 24 to external connectors 42.
  • Connections to the high frequency voice coil 36 are provided by flexible conductors 43 which extend along a recess in the outer wall of the pot 30, between the pot 30 and the inner pole 20 and thence through the bore 26 to external connectors (not shown).
  • the rod 37 In order to allow the conductors to extend through the bore 26, the rod 37 has a diameter smaller than that of the bore 26 so as to leave an annular space through which the conductors 43 extend.
  • Means, not shown, are provided between the pole piece 20 and the pot 28 to ensure that the rod lies co-axially with the bore 26.
  • This means may be a disc secured to the pole piece 20 and having a central aperture of a diameter to receive the rod 37 in a sliding fit.
  • the disc may be grooved to provide a passageway for the conductors 43 between the pole piece 20 and the pot 28.
  • the rod 37 may be of circular, hexagonal or other section and the disc would be provided with a central aperture of matching shape.
  • a rod 37 of diameter smaller than that of the bore 26 if the rod is of hexagonal section its diameter may be of a size such that the rod is a sliding fit in the bore 26 to locate the high frequency drive unit co-axially of the pole piece 20 of the low frequency drive unit. Spaces between the faces of the hexagonal section rod and the wall of the bore 26 provide passageways for the conductors 43.
  • a moulding may be used. The moulding would be located by means of a boss on the moulding entering the bore 26. The moulding may be so formed as to provide a mounting for other components such as the electronic components of a cross-over filter and terminals for electrical drive signals for the compound loudspeaker drive unit.
  • the end 38 of the rod 37 being externally threaded, the end of the rod may be bored and threaded internally to receive a screw.
  • the construction described hereinbefore is particularly convenient in manufacture of the compound loudspeaker drive unit in that the high frequency drive unit is centralised relative to the low frequency drive unit prior to the high frequency drive unit reaching its final rest position on the pole piece 20. As a result the high frequency unit is prevented from engaging the low frequency voice coil during assembly of the compound loudspeaker drive unit. Furthermore this construction facilitates dis-assembly of the high frequency drive unit from the low frequency drive unit if and when any servicing of the units is necessitated without any need to demagnetise either of the magnetic assemblies.
  • annular baffle 44 having a frusto-conical front surface is secured to the front of the high frequency drive unit to provide a continuation of the surface of the low frequency diaphragm 21 towards the domed high frequency diaphragm.
  • the apparent sound source or acoustic centre of the high frequency drive unit is substantially co-incident with the apparent sound source or acoustic centre of the low frequency drive unit.
  • the radiation pattern or directivity of the low frequency drive unit is determined inter alia by the form of the low frequency diaphragm.
  • both drive units have substantially similar patterns of radiation or directivity.
  • the relative sound contributions from the two drive units as perceived by a listener are substantially unaffected by the listener being positioned at off axis positions.
  • the low frequency conical diaphragm is shown in the drawing as being of conical form having an angle of flare which increases from the neck of the diaphragm toward the outer periphery of the diaphragm.
  • the diaphragm may be of conical form having a uniform angle of flare.
  • the low frequency conical diaphragm may be of circular, elliptical or other section as desired.
  • the high frequency diaphragm is shown in the drawing as being of domed form. Such a diaphragm is suitable because its acoustic centre may readily be located in close coincidence with that of the low frequency diaphragm, and because, in the frequency range where both drive units contribute significant sound output, its small size relative to wavelength gives it, by itself, essentially non-directional sound radiation, allowing the effective directivity to be determined by the low frequency diaphragm. It will be appreciated that the high frequency diaphragm may alternatively be of any other form that provides these characteristics.

Abstract

L'unité d'excitation de haut-parleur compound décrite comprend une unité à basse fréquence, pourvue d'un diaphragme conique évasé vers l'extérieur et vers l'avant (21), et une unité d'excitation à haute fréquence (27) placée à l'intérieur ou à proximité adjacente de l'étranglement du diaphragme conique à basse fréquence, de sorte que les centres acoustiques des deux unités sont sensiblement concïdents et, pour une gamme de fréquences de chevauchement pour lesquelles les deux unités d'excitation contribuent à une sortie acoustique significative, la directivité du rayonnement acoustique émis par l'unité de haute fréquence (27), lorsqu'elle est chargée acoustiquement par le diaphragme conique à basse fréquence (21), est sensiblement identique à celle de l'unité à basse fréquence. Une structure magnétique (28, 29, 30) pour l'unité à haute fréquence utilise un aimant (29), constitué d'un alliage de bore-fer-néodyme, qui permet à l'unité à haute fréquence (27) d'être disposée à l'intérieur d'une bobine excitatrice (23, 24) pour le diaphragme à basse fréquence, tout en assurant une valeur élevée requise de flux magnétique.
PCT/GB1989/000476 1988-05-09 1989-05-05 Haut-parleur WO1989011201A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
KR1019900700039A KR0171567B1 (ko) 1988-05-09 1989-05-05 라우드스피커 구동유니트
GB9023490A GB2236929B (en) 1988-05-09 1990-10-29 Loudspeaker
NO19904830A NO317793B1 (no) 1988-05-09 1990-11-06 Hoyttalerdrivenhet
SG114393A SG114393G (en) 1988-05-09 1993-10-18 Loudspeaker

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB888810943A GB8810943D0 (en) 1988-05-09 1988-05-09 Loudspeaker
GB8810943.4 1988-05-09

Publications (1)

Publication Number Publication Date
WO1989011201A1 true WO1989011201A1 (fr) 1989-11-16

Family

ID=10636585

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1989/000476 WO1989011201A1 (fr) 1988-05-09 1989-05-05 Haut-parleur

Country Status (12)

Country Link
EP (1) EP0341926B2 (fr)
JP (1) JP2766862B2 (fr)
KR (1) KR0171567B1 (fr)
AT (1) ATE115352T1 (fr)
AU (1) AU3558189A (fr)
CA (1) CA1339519C (fr)
DE (1) DE68919746T3 (fr)
ES (1) ES2065988T3 (fr)
GB (2) GB8810943D0 (fr)
HK (1) HK71893A (fr)
NZ (1) NZ229054A (fr)
WO (1) WO1989011201A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0551845A1 (fr) * 1992-01-14 1993-07-21 C.I.A.R.E. S.p.A. Transducteurs électro-acoustiques composite
US5418336A (en) * 1990-10-17 1995-05-23 Canon Research Centre Europe Ltd. Sound output device
WO2002052892A1 (fr) * 2000-12-26 2002-07-04 Anders Sagren Convertisseur electroacoustique multibande concentrique coplanaire
WO2011007151A2 (fr) 2009-07-17 2011-01-20 Gp Acoustics (Uk) Limited Perfectionnements apportés à des suspensions périphériques pour excitateurs audio ou s'y rapportant

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH06501354A (ja) * 1990-10-09 1994-02-10 スタージェ・アコムパニー・ベスローテン・フェンノートシャップ 冷却装置を備えたダイナミックラウドスピーカ
DE4225156A1 (de) * 1992-07-30 1994-02-03 Nokia Deutschland Gmbh Magnetsystem für elektroakustische Wandler
DE4234069A1 (de) * 1992-10-09 1994-04-14 Nokia Deutschland Gmbh Konuslautsprecher in Leichtbauweise
DE29512102U1 (de) * 1995-07-27 1995-10-05 Nokia Deutschland Gmbh Magnetsystem
GB2359213B (en) * 1999-10-29 2004-05-19 Kef Audio High frequency transducer
GB2364847B (en) * 2000-07-11 2004-10-13 Kef Audio Compound loudspeaker having a magnet system
CA2352732A1 (fr) * 2000-07-11 2002-01-11 Philip Jeffrey Anthony Excitateur de haut-parleur combine a systeme d'aimants
GB2368484B (en) * 2000-10-25 2004-06-16 B & W Loudspeakers Distributed mode panel type loudspeakers
ITVI20030041A1 (it) * 2003-03-03 2004-09-04 Alessandro Riccobono Diffusore acustico a colonna.
AU2008352372B2 (en) * 2008-03-05 2013-12-19 Genelec Oy Nested compound loudspeaker drive unit
DE102008049560B3 (de) * 2008-09-30 2010-07-01 Kuhnke Automotive Gmbh & Co. Kg Elektrischer Schwingungserreger
EP2457382B1 (fr) * 2009-07-24 2013-09-11 TP Vision Holding B.V. Système de reproduction du son
GB2474853B (en) 2009-10-27 2014-01-01 Gp Acoustics Uk Ltd Loudspeakers
FR2955447B1 (fr) * 2010-01-15 2012-08-03 Phl Audio Transducteur electrodynamique comprenant un guide d'ondes acoustiques assurant une dissipation thermique
FR2955446B1 (fr) * 2010-01-15 2015-06-05 Phl Audio Transducteur electrodynamique a dome et suspension flottante
FR2955445B1 (fr) * 2010-01-15 2013-06-07 Phl Audio Transducteur electrodynamique a dome et suspension interne
FR2955444B1 (fr) * 2010-01-15 2012-08-03 Phl Audio Systeme de haut-parleur coaxial a chambre de compression
CN110830891B (zh) * 2018-08-07 2021-05-07 深圳市宝业恒实业股份有限公司 一种大功率自分频全频扬声器

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GB665815A (en) * 1945-01-02 1952-01-30 Marconi Wireless Telegraph Co Improvements in sound reproducing devices
FR1001734A (fr) * 1946-08-13 1952-02-27 Subalpine Apparecchiature Elet Haut-parleur à large bande de fréquences et à double système vibrant
US4492826A (en) * 1982-08-10 1985-01-08 R&C Chiu International, Inc. Loudspeaker
GB2153628A (en) * 1984-01-27 1985-08-21 Tannoy Ltd Moving coil loudspeaker
US4552242A (en) * 1983-04-15 1985-11-12 Soshin Onkyo Works, Ltd. Coaxial type composite loudspeaker
EP0230639A2 (fr) * 1985-12-23 1987-08-05 Unique Mobility, Inc. Transducteur électromagnétique allégé de forte puissance

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JPS5353543A (en) * 1976-10-27 1978-05-16 Nippon Kokan Kk Welding process for tubes
DE2833202A1 (de) * 1978-07-27 1980-02-14 Schering Ag Neue indanyl- und tetralinylamide, verfahren zu ihrer herstellung und diese enthaltende pharmazeutische praeparate

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Publication number Priority date Publication date Assignee Title
GB665815A (en) * 1945-01-02 1952-01-30 Marconi Wireless Telegraph Co Improvements in sound reproducing devices
FR1001734A (fr) * 1946-08-13 1952-02-27 Subalpine Apparecchiature Elet Haut-parleur à large bande de fréquences et à double système vibrant
US4492826A (en) * 1982-08-10 1985-01-08 R&C Chiu International, Inc. Loudspeaker
US4552242A (en) * 1983-04-15 1985-11-12 Soshin Onkyo Works, Ltd. Coaxial type composite loudspeaker
GB2153628A (en) * 1984-01-27 1985-08-21 Tannoy Ltd Moving coil loudspeaker
EP0230639A2 (fr) * 1985-12-23 1987-08-05 Unique Mobility, Inc. Transducteur électromagnétique allégé de forte puissance

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5418336A (en) * 1990-10-17 1995-05-23 Canon Research Centre Europe Ltd. Sound output device
EP0551845A1 (fr) * 1992-01-14 1993-07-21 C.I.A.R.E. S.p.A. Transducteurs électro-acoustiques composite
WO2002052892A1 (fr) * 2000-12-26 2002-07-04 Anders Sagren Convertisseur electroacoustique multibande concentrique coplanaire
EP1703765A3 (fr) * 2000-12-26 2007-01-10 Anders Sagren Transducteur électro-acoustique avec diaphragme démontable et assemblage de bobine mobile
CN1311712C (zh) * 2000-12-26 2007-04-18 安德斯·萨格伦 同心共平面的多频带电－声转换器
AU2002216597B2 (en) * 2000-12-26 2007-05-10 Anders Sagren Concentric co-planar multiband electro-acoustic converter
KR100896738B1 (ko) 2000-12-26 2009-05-11 안데르스 사그렌 동심 동일 평면상의 다중 대역 전기 음향 변환기
WO2011007151A2 (fr) 2009-07-17 2011-01-20 Gp Acoustics (Uk) Limited Perfectionnements apportés à des suspensions périphériques pour excitateurs audio ou s'y rapportant
US9271082B2 (en) 2009-07-17 2016-02-23 Gp Acoustics (Uk) Limited Surrounds for audio drivers

Also Published As

Publication number Publication date
JPH03504310A (ja) 1991-09-19
EP0341926A1 (fr) 1989-11-15
GB2236929B (en) 1992-11-04
ES2065988T3 (es) 1995-03-01
GB2236929A (en) 1991-04-17
GB8810943D0 (en) 1988-06-15
NZ229054A (en) 1992-03-26
DE68919746T3 (de) 2001-06-13
DE68919746D1 (de) 1995-01-19
HK71893A (en) 1993-07-30
KR0171567B1 (ko) 1999-03-30
CA1339519C (fr) 1997-10-28
AU3558189A (en) 1989-11-29
GB9023490D0 (en) 1991-01-09
EP0341926B1 (fr) 1994-12-07
ATE115352T1 (de) 1994-12-15
KR900702744A (ko) 1990-12-08
DE68919746T2 (de) 1995-04-20
EP0341926B2 (fr) 2001-02-07
JP2766862B2 (ja) 1998-06-18

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