US3464514A - Loudspeaker - Google Patents
Loudspeaker Download PDFInfo
- Publication number
- US3464514A US3464514A US670045A US3464514DA US3464514A US 3464514 A US3464514 A US 3464514A US 670045 A US670045 A US 670045A US 3464514D A US3464514D A US 3464514DA US 3464514 A US3464514 A US 3464514A
- Authority
- US
- United States
- Prior art keywords
- diaphragm
- loudspeaker
- sound
- periphery
- ribs
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
Images
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/04—Plane diaphragms
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/04—Plane diaphragms
- H04R7/06—Plane diaphragms comprising a plurality of sections or layers
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
- H04R7/00—Diaphragms for electromechanical transducers; Cones
- H04R7/02—Diaphragms for electromechanical transducers; Cones characterised by the construction
- H04R7/12—Non-planar diaphragms or cones
Definitions
- a loudspeaker which comprises a diaphragm of a substantially flat plate made of foamed resin having substantial surface area, which diaphragm is clamped to its periphery on a frame, so that the periphery is prevented from forward and backward reciprocating movement, and adapted to be driven by a driving means substantially at the center.
- Said diaphragm has an asymmetric lshape in elevatio-n and a conical shape in section around the driven area, said conical shape having a curved generatrix gradually increasing its inclination toward the center of said driven area.
- Radial ribs are formed on said diaphragm ⁇ around 4said ldriven area and have curved form.
- the present invention relates to a loudspeaker and, particularly, -a loudspeaker which can produce a wide range of sounds from low frequency to high frequency by a singe diaphragm with high eiciency and with Ia multiresonance characteristic, which is particularly suitable for musical instruments.
- An electric or electronic musical instrument employs a loudspeaker as sound producing means.
- a special loudspeaker has been designed for the musical instrument, and, consequently, the loudspeaker of general type designed for usual sound instruments such as radio receiver, gramophone or the like has been employed in the musical instrument which has similar function to that of the usual sound instrument.
- a conventional cone-type loudspeaker generally used in sound instruments is so designed that its diaphragm makes a piston motion or overall reciprocating motion to obtain wide and at frequency characteristic to produce sound ou-tput with high fidelity. If a single loudspeaker cannot cover the frequency range to be reproduced, a set of loudspeakers may be employed to cover the respective ranges of frequency.
- a flat-plate type loudspeaker using la relatively large and substantially flat plate of foamed resin, which has been recently developed, is designed fundamentally on the same technical consideration so as to obtain characteristic similar .to that of the cone-type loudspeaker.
- the above-mentioned loudspeakers lare suitfable for sound reproducing means of the usual sound instruments but not suitable for sound producing means of the musical instruments.
- the sound of the musical instruments is required .to have complexity and variety from fthe viewpoint of beautifulness ⁇ and richness of sound, but an electronic musical instrument ⁇ contains only a limited number of sound sources (tone generators) from the economical point of view, so that it can produce only simple and unsatisfactory sounds peculiar .to electric or electronic ⁇ musical instruments if it faithfully transduces United States Patent O icc the electric signals produced by the sound sources into audible sounds.
- a sound producing means of a musical instrument which is considered to produce beautiful sounds, such as a sound board of piano or a sound box of violin, has a multi-resonance characteristic and is an efficient sound radiator, so that it is not a simple transducer for transducing the vibration of the strings faithfully into sounds but a sound generating means which is excited by :the vibration of the strings to make vibration with its own characteristic to create and radiate sounds.
- the present invention is based on 4the concept of creating sounds by the loudspeaker under the excitation of electrical signals .according to the sound generating principle of the general musical linstruments and utilizing the Imulti-resonance characteristic of the diaphragm, rather than faithfully transducing the electric signals into sounds.
- a loudspeaker comprising a diaphragm made of a substantially at plate made of foamed resin having substantial surface area, which diaphragm is clamped at its periphery on a frame, so that the periphery is prevented from forward and backward reciprocating movement, and adapted to be driven by a driving means substantially at the center, said diaphragm having an asymmetric shape in elevation and a conical shape in section around the driven area, said conical shape having a curved gen eratrix gradually increasing its inclination toward the center of said driven area, and radial ribs being formed on said diaphragm around said driven area and having curve form.
- the loudspeaker of the present invention produces flexural vibration of the diaphragm with a multi-resonance characteristic. Also, due to the asymmetric form in elevation of the diaphragm and the provision of the curved ribs radially arranged around the center, the resonances are so controlled that they appear with moderate level at many frequencies of the frequency characteristic curve of the diaphragm, without giving rise to concentration of resonances at certain particular frequencies with extreme level, by the degeneration of modes.
- the loudspeaker according to the present invention increases the efficiency over the wide range from low frequency to highfrequency.
- FIG. 1 is a front elevation4 of the loudspeaker according to the present invention
- FIG. 2 is a rear elevation of the loudspeaker as shown in FIG. 1;
- FIG. 3 is a section of line III-I'II in FIG. 2;
- FIG. 4 is an enlarged sectional view of the mounting portion of the periphery of the diaphragm
- FIG. 5 is an enlarged sectional view of the driven area of the diaphragm.
- FIG. 6 is an enlarged sectional view on line VI-VI in FIG. 2.
- FIGS. 1-3 show an embodiment of the invention, in which 1 is a diaphragm, 2 is a frame, 3 is a driving means, 4 is a thin packing, 5 is a voice coil, 6 is a damper, 7 is a cap, 8 is an adapter, and 9 is a terminal.
- the diaphragm 1 is made of foamed resin, such as foamed polystyrene, ⁇ having light weight and high rigidity.
- the diaphragm may be made of other material, such as,polyvinyl chloride, polyethylene, polyamide, polyurethane, polycarbonate, polypropylene, polyacetal, acrylic resin and ABS resin (acrylonitrile/butadiene/styrene copolymer).
- the diaphragm 1 is clamped at the periphery thereof so that the periphery is prevented lfrom forward and backward reciprocating movement, by fixedly holding the periphery to the frame 2 by means of a tapping screw 22 through a gasket 21.
- the diaphragm 1 when driven by the driving means 3 mounted on the frame 2, makes a flexural movement rather than a piston motion or overall reciprocating motion, whereby the mechanical resonance characteristic is used to produce sounds.
- the diaphragm 1 does not serve as a simple transducer -for converting electric signals into sounds, but as a sound producing means which vibrates with its own vibration characteristics in the form of a plate clamped at the periphery thereof, under the excitation of electric signals and radiates the sounds created thereby.
- the thin packings 4 such as adhesive tapes of foamed elastic material, between the diaphragm 1 and the frame 2 and between the diaphragm 1 and the gasket 21, the bending stress at the periphery of the diaphragm is reduced and the durability of the diaphragm is increased.
- the diaphragm 1 and the frame 2 can be fixed together thereby, preventing the occurrence of noise due to abnormal trembling of the diaphragm or air passing through the narrow space around the periphery of the diaphragm.
- the sound particularly suitable for the musical instruments can be obtained by clamping the periphery of the diaphragm 1 and driving the central area 11 to produce flexural movement of the diaphragm, but there remains a problem of the undesirable occurrence of extreme peaks and dips in the output frequency characteristic curve of the loudspeaker.
- Vibration mode trisecting the diaphragm namely, third-order vibration mode occurs.
- higher-order vibration'mode occurs f due to the standing waves produced by the reflection from the confronting sides, thus producing eXtreme peaks and dips in the frequency characteristic curve.
- the present invention overcomes such problem by forming the diaphragm in an asymmetric shape, such as elliptical shape or oval shape partly convexed inward.
- the third-order vibration mode assumes a distorted shape so that the Vibration mode is not clearly established and particularly the mode portions at the opposite ends assume different shapes so that resonance and antiresonance at the frequencies thereof decrease remarkably.
- the geometric form of this diaphragm is defined by an irregular curve and does not have parallel confronting sides, so that standing waves do not appear.
- the present invention includes a further feature as hereinafter described.
- the dr-iven area 11 of the diaphragm 1 is constructed as shown in FIG. 5, in which the driving means 3 is mounted on the frame 2 through the adapter 8 and a winding 51 of the voice coil 5 is positioned in a gap between a center pole 32 in front of the magnet 31 and an outer pole 33 and a damper is connected between the outside surface of a bobbin 52 and the adapter 8.
- the front surface of the voice coil 5 is covered by a cap 7.
- the input terminals 9 (one of which is shown in FIG. 5) are connected to the winding 51 of the voice coil through lead wires 91 passing the central conical portion of the diaphragm and flexible wires 92.
- the driven area 11 including the voice coil 5 is arranged substantially at the center of gravity of the diaphragm.
- the radiation efcieucy of the low frequency sound is relatively high but the radiation efficiency of the medium and high frequency sound is relatively low in the conventional loudspeaker having the uniformly flat diaphragm.
- the present invention overcomes this problem by increasing the rigidity of the driven area of the diaphragm to increase the radiation efficiency of the medium and high frequency sound.
- the driven area is formed in the conical shape having the curved generatrix increasing its inclination toward the center so that the rigidity increases gradually toward the center whereby the effective driven area is decreased and the driven mass is decreased as the frequency is increased.
- ribs 12 and 13 are formed on the rear surface of the diaphragm 1 as shown in FIG. 2. These ribs are arranged radially around the driven area 11 to improve the propagation of the vibration of the medium and high frequencies and suppress the extreme resonance owing to the flexural movement of the diaphragm.
- the radial ribs 12 and 13 the propagation of the vibration of the medium and high frequencies in the diaphragm from the driven area to the periphery is improved, while the radiation efficiency of the low frequency sound is not decreased since the rigidity of the diaphragm is decreased toward the periphery thereof.
- the ribs are curved, so that the rigidity of the diaphragm in the circumferential direction is increased and the asymmetricity of the diaphragm is further increased, thereby suppressing the occurrence of the excessive vibration mode.
- the ribs are formed integrally with the diaphragm 1, but the ribs may be formed of separate material such as aluminum sheet, paper or the like which are adhered on the material of the diaphragm.
- the wider and longer rib 12 is disposed at the point where the third-order vibration mode is largely affected by the rib.
- the curvatures of the respective ribs are different. By changing the construction, the curvature and/or the number of the rigs, the occurrence of the vibration mode is changed and the frequency characteristic can be controlled according to the design.
- the diaphragm 1 is a diaphragm 1:
- the loudspeaker according to the present invention produces sounds by the flexural movement of the diaphragm which movement is suitably suppressed to obtain the optimum peaks and dips in the frequency characteristic and good radiation efliciency throughout the whole range of low frequency to high frequency sounds.
- the present invention provides a loudspeaker which produces beautiful sound suitable for the musical instruments with high efficiency.
- a loudspeaker comprising a diaphragm of a substantially fiat plate made of resin having substantial surface area, which diaphragm is clamped at its periphery on a frame and adapted to be driven by a driving means substantially at the center, said diaphragm having an asymmetric shape in elevation and a conical shape in section around the ⁇ driven area, said conical shape having a curved generatrix gradually increasing its inclination toward the center of said driven area, and radial curved ribs having different respective curvatures formed on said diaphragm around said driven area.
- a loudspeaker according to claim 4 wherein said ribs are of aluminum adhered to said diaphragm.
- a loudspeaker according to claim 1 wherein a packing of elastic material is provided between said diaphragm and said frame.
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Signal Processing (AREA)
- Diaphragms For Electromechanical Transducers (AREA)
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP3178766 | 1966-04-06 | ||
JP2474566 | 1966-04-19 | ||
JP2474666 | 1966-04-19 | ||
JP4106566U JPS4427432Y1 (de) | 1966-05-03 | 1966-05-03 | |
JP6461866U JPS459353Y1 (de) | 1966-07-07 | 1966-07-07 | |
JP7254766 | 1966-11-02 |
Publications (1)
Publication Number | Publication Date |
---|---|
US3464514A true US3464514A (en) | 1969-09-02 |
Family
ID=27549208
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US670045A Expired - Lifetime US3464514A (en) | 1966-04-06 | 1967-09-25 | Loudspeaker |
Country Status (8)
Country | Link |
---|---|
US (1) | US3464514A (de) |
AT (1) | AT301644B (de) |
DE (1) | DE1299041B (de) |
FR (1) | FR1517610A (de) |
GB (1) | GB1186722A (de) |
NL (1) | NL144117B (de) |
NO (1) | NO119596B (de) |
SE (1) | SE342962B (de) |
Cited By (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3979566A (en) * | 1973-12-12 | 1976-09-07 | Erazm Alfred Willy | Electromagnetic transducer |
US4003449A (en) * | 1974-11-28 | 1977-01-18 | Jose Juan Bertagni | Planar diaphragm |
FR2345048A1 (fr) * | 1976-03-19 | 1977-10-14 | Harwood Hugh | Membrane de transducteur electro-acoustique |
US4323737A (en) * | 1979-06-30 | 1982-04-06 | Pioneer Electronic Corporation | Driver unit for planar diaphragm type loudspeaker |
US4581496A (en) * | 1979-09-04 | 1986-04-08 | Emhart Industries, Inc. | Diaphragm for attenuating harmonic response in an electroacoustic transducer |
US4761817A (en) * | 1986-01-27 | 1988-08-02 | Harman International Industries, Incorporated | Diaphragm structure for a transducer |
US20040125980A1 (en) * | 2002-12-31 | 2004-07-01 | Turnmire Patrick M. | Electromagnetic transducer with asymmetric diaphragm |
EP1665883A1 (de) * | 2003-09-18 | 2006-06-07 | John M. Norton | Lautsprecherbox |
KR100842606B1 (ko) * | 2002-04-12 | 2008-07-01 | 엘지전자 주식회사 | 저 왜율 유선형 진동판을 갖는 스피커 |
US20090038878A1 (en) * | 2007-08-10 | 2009-02-12 | Victor Company Of Japan, Limited | Acoustic diaphragm and speaker |
US20150003646A1 (en) * | 2012-09-26 | 2015-01-01 | Kyocera Corporation | Acoustic generator, acoustic generation device, and electronic device |
WO2016014515A1 (en) * | 2014-07-23 | 2016-01-28 | Bose Corporation | Sound producing system |
IT201600082006A1 (it) * | 2016-08-03 | 2018-02-03 | Enrico Ciresa S R L | Accessorio diffusore di suoni |
WO2021021936A1 (en) * | 2019-07-29 | 2021-02-04 | Polk Audio, Llc | Loudspeaker cone with raised curved protrusions and method for controlling resonant modes |
Families Citing this family (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2182823A (en) * | 1985-11-07 | 1987-05-20 | Midlen Trading Corp | Diaphragm and driver for a loudspeaker |
US4928312A (en) * | 1988-10-17 | 1990-05-22 | Amel Hill | Acoustic transducer |
GB2360665B (en) * | 1998-06-22 | 2003-01-15 | Slab Technology Ltd | Loudspeakers |
GB2435008B (en) * | 2001-01-29 | 2007-11-21 | Tannoy Ltd | Loudspeaker diaphragm and method of manufacture thereof |
WO2009080055A1 (en) * | 2007-12-20 | 2009-07-02 | Scan-Speak A/S | Asymmetric reinforcement of a membrane |
GB2489700B (en) * | 2011-04-04 | 2013-09-18 | Canon Kk | Method and device for controlling the vibration modes of a vibrating support |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1990409A (en) * | 1932-02-19 | 1935-02-05 | Neville Athol Ernest | Acoustical diaphragm |
US2716462A (en) * | 1952-10-25 | 1955-08-30 | Joseph B Brennan | Reinforced acoustic diaphragms and method of making the same |
US2905260A (en) * | 1955-02-24 | 1959-09-22 | Muter Company | Loud speaker diaphragm |
US3180945A (en) * | 1961-09-22 | 1965-04-27 | Wm H Welsh Co Inc | Loudspeaker |
GB1003608A (en) * | 1962-01-15 | 1965-09-08 | Akg Akustische Kino Geraete | Improvements in or relating to diaphragms for loudspeakers |
US3247925A (en) * | 1962-03-08 | 1966-04-26 | Lord Corp | Loudspeaker |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE900228C (de) * | 1937-01-20 | 1953-12-21 | Dr Emil Podszus | Membran grosser Steifigkeit fuer Tonwiedergabe |
DE835757C (de) * | 1949-10-26 | 1952-04-03 | Klangfilm G M B H | Kalottenmembran fuer Trichterlautsprecher |
US2960177A (en) * | 1957-11-25 | 1960-11-15 | Hawley Products Co | Acoustical devices |
GB852006A (en) * | 1957-11-25 | 1960-10-19 | Hawley Products Co | Improvements in or relating to loudspeaker diaphragms |
NL283889A (de) * | 1961-10-04 |
-
1967
- 1967-02-17 DE DEN30028A patent/DE1299041B/de not_active Withdrawn
- 1967-02-23 NL NL676702816A patent/NL144117B/xx not_active IP Right Cessation
- 1967-03-09 GB GB01216/67A patent/GB1186722A/en not_active Expired
- 1967-03-16 AT AT257167A patent/AT301644B/de not_active IP Right Cessation
- 1967-04-05 FR FR101622A patent/FR1517610A/fr not_active Expired
- 1967-09-25 US US670045A patent/US3464514A/en not_active Expired - Lifetime
- 1967-11-02 NO NO170375A patent/NO119596B/no unknown
- 1967-11-02 SE SE15045/67A patent/SE342962B/xx unknown
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1990409A (en) * | 1932-02-19 | 1935-02-05 | Neville Athol Ernest | Acoustical diaphragm |
US2716462A (en) * | 1952-10-25 | 1955-08-30 | Joseph B Brennan | Reinforced acoustic diaphragms and method of making the same |
US2905260A (en) * | 1955-02-24 | 1959-09-22 | Muter Company | Loud speaker diaphragm |
US3180945A (en) * | 1961-09-22 | 1965-04-27 | Wm H Welsh Co Inc | Loudspeaker |
GB1003608A (en) * | 1962-01-15 | 1965-09-08 | Akg Akustische Kino Geraete | Improvements in or relating to diaphragms for loudspeakers |
US3247925A (en) * | 1962-03-08 | 1966-04-26 | Lord Corp | Loudspeaker |
Cited By (25)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3979566A (en) * | 1973-12-12 | 1976-09-07 | Erazm Alfred Willy | Electromagnetic transducer |
US4003449A (en) * | 1974-11-28 | 1977-01-18 | Jose Juan Bertagni | Planar diaphragm |
FR2345048A1 (fr) * | 1976-03-19 | 1977-10-14 | Harwood Hugh | Membrane de transducteur electro-acoustique |
US4190746A (en) * | 1976-03-19 | 1980-02-26 | Harwood Hugh D | Diaphragm material for moving coil loudspeaker, may be laminated or integral with surround |
US4323737A (en) * | 1979-06-30 | 1982-04-06 | Pioneer Electronic Corporation | Driver unit for planar diaphragm type loudspeaker |
US4581496A (en) * | 1979-09-04 | 1986-04-08 | Emhart Industries, Inc. | Diaphragm for attenuating harmonic response in an electroacoustic transducer |
US4761817A (en) * | 1986-01-27 | 1988-08-02 | Harman International Industries, Incorporated | Diaphragm structure for a transducer |
KR100842606B1 (ko) * | 2002-04-12 | 2008-07-01 | 엘지전자 주식회사 | 저 왜율 유선형 진동판을 갖는 스피커 |
US20040125980A1 (en) * | 2002-12-31 | 2004-07-01 | Turnmire Patrick M. | Electromagnetic transducer with asymmetric diaphragm |
US7177440B2 (en) * | 2002-12-31 | 2007-02-13 | Step Technologies Inc. | Electromagnetic transducer with asymmetric diaphragm |
EP1665883A1 (de) * | 2003-09-18 | 2006-06-07 | John M. Norton | Lautsprecherbox |
EP1665883A4 (de) * | 2003-09-18 | 2007-07-04 | John M Norton | Lautsprecherbox |
US20090038878A1 (en) * | 2007-08-10 | 2009-02-12 | Victor Company Of Japan, Limited | Acoustic diaphragm and speaker |
US7845461B2 (en) * | 2007-08-10 | 2010-12-07 | Victor Company Of Japan, Limited | Acoustic diaphragm and speaker |
US20150003646A1 (en) * | 2012-09-26 | 2015-01-01 | Kyocera Corporation | Acoustic generator, acoustic generation device, and electronic device |
US9369810B2 (en) * | 2012-09-26 | 2016-06-14 | Kyocera Corporation | Acoustic generator, acoustic generation device, and electronic device |
WO2016014515A1 (en) * | 2014-07-23 | 2016-01-28 | Bose Corporation | Sound producing system |
CN106537935A (zh) * | 2014-07-23 | 2017-03-22 | 伯斯有限公司 | 发声系统 |
US9628917B2 (en) | 2014-07-23 | 2017-04-18 | Bose Corporation | Sound producing system |
CN106537935B (zh) * | 2014-07-23 | 2019-06-07 | 伯斯有限公司 | 发声系统 |
IT201600082006A1 (it) * | 2016-08-03 | 2018-02-03 | Enrico Ciresa S R L | Accessorio diffusore di suoni |
WO2018025138A1 (en) * | 2016-08-03 | 2018-02-08 | Enrico Ciresa S.R.L. | Sound diffuser accessory |
US10777170B2 (en) | 2016-08-03 | 2020-09-15 | Enrico Ciresa S.R.L. | Sound diffuser accessory |
WO2021021936A1 (en) * | 2019-07-29 | 2021-02-04 | Polk Audio, Llc | Loudspeaker cone with raised curved protrusions and method for controlling resonant modes |
US11974111B2 (en) | 2019-07-29 | 2024-04-30 | Polk Audio, Llc | Loudspeaker cone with raised curved protrusions and method for controlling resonant modes |
Also Published As
Publication number | Publication date |
---|---|
SE342962B (de) | 1972-02-21 |
AT301644B (de) | 1972-09-11 |
NO119596B (de) | 1970-06-08 |
GB1186722A (en) | 1970-04-02 |
FR1517610A (fr) | 1968-03-15 |
NL144117B (nl) | 1974-11-15 |
DE1299041B (de) | 1969-07-10 |
NL6702816A (de) | 1967-10-09 |
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