EP0127247A2 - Wandler mit abstimmbarem Frequenzgang - Google Patents

Wandler mit abstimmbarem Frequenzgang Download PDF

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Publication number
EP0127247A2
EP0127247A2 EP84300273A EP84300273A EP0127247A2 EP 0127247 A2 EP0127247 A2 EP 0127247A2 EP 84300273 A EP84300273 A EP 84300273A EP 84300273 A EP84300273 A EP 84300273A EP 0127247 A2 EP0127247 A2 EP 0127247A2
Authority
EP
European Patent Office
Prior art keywords
plate
opening
transducer
diaphragm
frame
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.)
Withdrawn
Application number
EP84300273A
Other languages
English (en)
French (fr)
Other versions
EP0127247A3 (de
Inventor
William Neal House
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Harman International Industries Inc
Original Assignee
Harman International Industries Inc
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 Harman International Industries Inc filed Critical Harman International Industries Inc
Publication of EP0127247A2 publication Critical patent/EP0127247A2/de
Publication of EP0127247A3 publication Critical patent/EP0127247A3/de
Withdrawn legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R11/00—Transducers of moving-armature or moving-core type
    • 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 

Definitions

  • This invention relates to transducers, and more specifically to a tunable response transducer such as a tunable response variable reluctance speaker.
  • Microphones having variable directional characteristics are known. There are, for example, the devices disclosed in U.S. Patents 3,527,902 and 3,536,862. There are also the disclosures of U .S. Patents 3,502,811: 4,327,257; and 4,363,937.
  • a transducer comprises a frame for providing first and second openings, a diaphragm for covering the first opening, a motor, means for coupling the motor to the diaphragm such that actuation of the motor excites the diaphragm, the diaphragm defining a chamber within the frame and behind the diaphragm, means defining a passageway between the chamber and the second opening, and an adjustable valve for selectively controlling air flow through the second opening to permit tuning of the diaphragm's frequency response to motor actuation.
  • the transducer comprises a variable reluctance speaker.
  • the motor comprises a magnet, means for mounting the magnet in the frame, a transducer coil, means for reacting to the fields provided by the magnet and the transducer coil to produce diaphragm movement, and means for coupling the reacting means to the diaphragm.
  • the reacting means comprises a reluctor plate, for example, a disk of ferrous material
  • the means for coupling the reacting means to the diaphragm comprises means for mounting the reluctor plate from the diaphragm.
  • the means for selectively controlling the flow of air from the second opening comprises a plate covering the second opening, means for movably mounting the plate relative to the second opening, and means providing a port in the plate. Alignment of the port with the second opening optimizes venting of the chamber and movement of the plate into a position in which the port is less aligned with the second opening reduces the venting of the chamber.
  • the means for selectively controlling the flow of air from the second opening comprises a plate covering the second opening, means for movably mounting the plate relative to the second opening, and means providing a port in the plate.
  • a porous compressible material is captured between the frame and the plate.
  • the means for movably mounting the plate relative to the second opening includes means for selectively compressing the compressible material between the second opening and the port in the plate to control selectively the air flow between the second opening and the port in the plate.
  • the means for selectively controlling the flow of air from the second opening comprises a first plate covering the second opening, means for stationarily mounting the first plate over the opening, means providing a port in the first plate, a second plate, means for movably mounting the second plate relative to the first, and means providing a port in the second plate. Alignment of the port in the first plate with the port in the second plate optimizes the venting of the chamber. Movement of the second plate into a position in which the ports in the first and second plates are less aligned reduces the venting of the chamber.
  • the means for selectively controlling the flow of air from the second opening comprises a first plate covering the second opening, means providing a port in the first plate, a second plate, means for movably mounting the second plate relative to the first, and means for providing a port in the second plate.
  • a porous compressible material is captured between the first and second plates.
  • the means for movably mounting the second plate relative to the first includes means for selectively compressing the compressible material between the first and second plates to control selectively the air flow between the port in the first plate and the port in the second plate.
  • a method for tuning the frequency response of a transducer comprises the steps of providing a transducer frame having first and second openings, with the first opening covered by a diaphragm to define a cavity behind the diaphragm and within the frame, providing a passageway between the cavity and the second opening, providing an adjustable valve for varying selectively the air flow through the second opening, driving the motor element of the transducer, testing the response of the transducer, and adjusting the valve to provide the desired frequency response.
  • the method comprises the step of testing the response of the transducer after adjusting the valve.
  • a tuned transducer is obtained by providing a transducer frame having first and second openings, with the first opening covered by a diaphragm to define a cavity within the frame and behind the diaphragm, providing a passageway between the cavity and the second opening, providing an adjustable valve for selectively varying the air flow through the second opening, driving the motor element of the transducer, testing the response of the transducer, and adjusting the valve to provide the desired transducer response.
  • the transducer response is again tested after adjustment of the valve.
  • a tunable response transducer 20 includes a frame, or basket, 22, illustratively molded from a resin.
  • the basket 22 is generally right circular cylindrical in configuration, and provides a front opening 24 and a rear opening 26.
  • Basket 22 is provided with radially outwardly extending ears 28 disposed generally diametrically from each other. Each of ears 28 is provided with an eyelet 30 for mechanical mounting purposes, as well as to provide electrical terminations to the components inside the basket 22.
  • annular lip 32 is provided around the perimeter of rear opening 26. As best seen in Fig. 2, the annular lip includes a rearward radially inner step 34 and a forward radially outer step 36. Step 36 steps out to the dimension of the generally right circular cylindrical inner wall 38 of basket 22.
  • the rear opening 26 is covered by two generally circular flat plates 40, 42.
  • the diameter of plate 42 is such that it fits within the diameter of step 34 with sufficient clearance to be rotated when force is applied to rotate it. When no force is applied to plate 42, however, the frictional engagement between plate 42 and step 34 is sufficient to hold plate 42 in its adjusted position.
  • the diameter of plate 40 is sufficient that it is stationary within the inner wall 38.
  • Plate 40 serves as the pole plate for the transducer 20.
  • Plate 40 is provided with a plurality of ports 44, illustratively four.
  • Plate 42 is provided with a plurality of ports 46, also illustratively four in number.
  • the ports 44, 46 are spaced sufficiently close together that they all lie within the diameter of the center opening 48 provided in a right circular cylindrical magnet 50 positioned within the inner wall 38 against plate 40.
  • Magnet 50 may be mounted in the basket 22 by the use of an adhesive.
  • Plate 40 is provided with a pole piece 52 which extends generally coaxially within the center opening 48.
  • Pole piece 52 is generally right circular cylindrical in configuration.
  • a stationary coil 54 surrounds pole piece 52, and includes leads 56 which extend through the side wall 58 of basket 22 and terminate at respective eyelets 30.
  • the front opening 24 is closed by a phenolic, or the like, film diaphragm 60 which is glued or otherwise attached to the basket 22 edge surrounding the front opening 24.
  • the diaphragm may be formed with concentric compliances in it.
  • a reluctor plate 62 is glued or otherwise attached to the outside surface 64 of diaphragm 60.
  • the reluctor plate is typically constructed from a ferromagnetic stainless steel.
  • Rotation of plate 42 into a position in which the ports 44, 46 are less aligned reduces the venting of the cavity 66 and dampens the response of the transducer 20 in the vicinity of the principal resonant frequency of the moving system.
  • a layer 70 of woven material is inserted between plates 40, 42 to enhance the tuning effect of this adjustment.
  • a tunable response transducer 120 includes a frame, or basket, 122.
  • the basket 122 is generally right circular cylindrical in configuration, and is provided with a front opening 124 and a rear opening 126.
  • Basket 122 is provided with generally diametrically disposed, radially outwardly extending ears 128. Each of ears 128 is provided with an eyelet 130 for mechanical mounting purposes and electrical termination.
  • annular lip 132 is provided around the perimeter of rear opening 126. As best seen in Fig. 4, the annular lip includes a rearward radially inner step 134 and a forward radially outer step 136. Step 136 steps out to the dimension of the generally right circular cylindrical inner wall 138 of basket 122.
  • the rear opening 126 is covered by two generally circular flat plates 140, 142.
  • the diameter of plate 142 is such that it fits within the diameter of step 134 with sufficient clearance to be moved axially of inner wall 138 relative to plate 140.
  • the diameter of plate 140 is sufficient that it is maintained stationary within the inner wall 138.
  • a screw-threaded opening 141 is provided at the center of plate 140.
  • An unthreaded opening 143 is provided at the center of plate 142.
  • a layer 147 of a woven material is inserted between plates 140, 142.
  • a screw 145 is passed through opening 143 and cloth 147, and is threaded into opening 141.
  • Plate 140 serves as the pole plate for the transducer 120.
  • Plate 140 is provided with a plurality of ports 144, illustratively four.
  • Plate 142 is provided with a plurality of ports 146, also illustratively four.
  • the ports 144, 146 are spaced sufficiently close together that they all lie within the diameter of the center opening 148 provided in a right circular cylindrical magnet 150 positioned within the inner wall 138 against plate 140.
  • Magnet 150 may be mounted in the basket 122 by the use of an adhesive.
  • Plate 140 is provided with a pole piece 152 which extends generally coaxially within the center opening 148.
  • Pole piece 152 is generally right circular cylindrical in configuration.
  • a stationary coil 154 surrounds pole piece 152, and includes leads 156 which extend through the side wall 158 of basket 122 and terminate at respective eyelets 130.
  • the front opening 124 is closed by a phenolic, or the like, film diaphragm 160 which is glued or otherwise attached to the basket 122 edge surrounding the front opening 124.
  • a reluctor plate 162 typically constructed from a ferromagnetic stainless steel, is glued or otherwise attached to the outside surface 164 of diaphragm 160.
  • the venting of cavity 166 through ports 144, woven material 147, and ports 146 can be controlled by controlling this compression of the layer of woven material. This permits selective tuning of the dampening of the response of transducer 120 in the vicinity of its principal resonant frequency.
  • Other techniques which can be used to tune the stiffness of the transducer include, without limitation, the use of screw-adjustable valves, and combined rotary plate port-alignment and woven layer-compression techniques.
  • the configuration of the ports and the types of woven materials are also variable to achieve desired damping and tuning effects.
  • a device of the type illustrated in Figs. 1-4 can have a frequency response characteristic like that illustrated in dotted line. Testing of the frequency response of the device immediately after manufacture yields this frequency response characteristic. The device is then tuned, illustratively by rotation of the plate 42 with a spanner wrench (Figs. 1-2), or by loosening or tightening of the screw 145 to reduce or increase, respectively, the compression of the layer 147 of woven material (Figs. 3-4) until the frequency response characteristic is "flattened” somewhat in the operative range of the transducer, to achieve a characteristic such as that illustrated in solid line in Fig. 5. Typically, after tuning, the transducer is tested again to ensure that its frequency response is satisfactorily flattened.
EP84300273A 1983-05-23 1984-01-17 Wandler mit abstimmbarem Frequenzgang Withdrawn EP0127247A3 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US49706283A 1983-05-23 1983-05-23
US497062 1995-06-30

Publications (2)

Publication Number Publication Date
EP0127247A2 true EP0127247A2 (de) 1984-12-05
EP0127247A3 EP0127247A3 (de) 1986-02-05

Family

ID=23975307

Family Applications (1)

Application Number Title Priority Date Filing Date
EP84300273A Withdrawn EP0127247A3 (de) 1983-05-23 1984-01-17 Wandler mit abstimmbarem Frequenzgang

Country Status (2)

Country Link
EP (1) EP0127247A3 (de)
JP (1) JPS59216397A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2261794A (en) * 1991-11-06 1993-05-26 Hsiao Yu Teng Variably ventable loudspeaker unit
EP3177037A3 (de) * 2015-12-04 2017-09-06 Sonion Nederland B.V. Balanced armature wandler mit bistabiler balanced armature

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1646628A (en) * 1927-10-25 James g
GB670868A (en) * 1950-05-11 1952-04-23 Machiel De Vries A filter for sound vibrations and a microphone and telephone provided therewith
DE1076182B (de) * 1957-02-21 1960-02-25 F & H Schumann G M B H Filteranordnung fuer elektro-akustische Wandler
DE1437376A1 (de) * 1963-10-04 1968-10-24 Akg Akustische Kino Geraete Reibungswiderstand fuer Mikrophone mit veraenderbarer Richtcharakteristik und/oder veraenderbarem Frequenzgang
FR2201603A1 (de) * 1972-09-29 1974-04-26 Ericsson Telefon Ab L M
DE2547925A1 (de) * 1974-11-13 1976-05-20 Komatsu Nakamura Kopfhoerer
US3999020A (en) * 1975-10-29 1976-12-21 Koss Corporation Transducer with variable frequency response
GB2014017A (en) * 1977-12-29 1979-08-15 Seiko Instr & Electronics Electro-magnetic acoustic transducer

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1646628A (en) * 1927-10-25 James g
GB670868A (en) * 1950-05-11 1952-04-23 Machiel De Vries A filter for sound vibrations and a microphone and telephone provided therewith
DE1076182B (de) * 1957-02-21 1960-02-25 F & H Schumann G M B H Filteranordnung fuer elektro-akustische Wandler
DE1437376A1 (de) * 1963-10-04 1968-10-24 Akg Akustische Kino Geraete Reibungswiderstand fuer Mikrophone mit veraenderbarer Richtcharakteristik und/oder veraenderbarem Frequenzgang
FR2201603A1 (de) * 1972-09-29 1974-04-26 Ericsson Telefon Ab L M
DE2547925A1 (de) * 1974-11-13 1976-05-20 Komatsu Nakamura Kopfhoerer
US3999020A (en) * 1975-10-29 1976-12-21 Koss Corporation Transducer with variable frequency response
GB2014017A (en) * 1977-12-29 1979-08-15 Seiko Instr & Electronics Electro-magnetic acoustic transducer

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2261794A (en) * 1991-11-06 1993-05-26 Hsiao Yu Teng Variably ventable loudspeaker unit
GB2261794B (en) * 1991-11-06 1995-06-07 Hsiao Yu Teng Loudspeaker
EP3177037A3 (de) * 2015-12-04 2017-09-06 Sonion Nederland B.V. Balanced armature wandler mit bistabiler balanced armature
US10582303B2 (en) 2015-12-04 2020-03-03 Sonion Nederland B.V. Balanced armature receiver with bi-stable balanced armature
US10986449B2 (en) 2015-12-04 2021-04-20 Sonion Nederland B.V. Balanced armature receiver with bi-stable balanced armature

Also Published As

Publication number Publication date
EP0127247A3 (de) 1986-02-05
JPS59216397A (ja) 1984-12-06

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Inventor name: HOUSE, WILLIAM NEAL