US2947821A - Ceramic binaural phonograph pickup - Google Patents

Ceramic binaural phonograph pickup Download PDF

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US2947821A
US2947821A US730006A US73000658A US2947821A US 2947821 A US2947821 A US 2947821A US 730006 A US730006 A US 730006A US 73000658 A US73000658 A US 73000658A US 2947821 A US2947821 A US 2947821A
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electrodes
electrode
bar
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Jerome D Heibel
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Erie Resistor Corp
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Erie Resistor Corp
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    • HELECTRICITY
    • H04ELECTRIC COMMUNICATION TECHNIQUE
    • H04RLOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R17/00Piezo-electric transducers; Electrostrictive transducers
    • H04R17/04Gramophone pick-ups using a stylus; Recorders using a stylus
    • H04R17/08Gramophone pick-ups using a stylus; Recorders using a stylus signals being recorded or played back by vibration of a stylus in two orthogonal directions simultaneously
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S84/00Music
    • Y10S84/24Piezoelectrical transducers

Description

1 J. D. HEIBEL 2,947,821
CERAMI C BINAURAL PHONOGRAPH PICKUP Filed April 21, 1958 I i3 Z5 Z4 M FIG. 3
INVENTOR.
FIG-5 MQHM United States Patent O CERAMIC BINAURAL PHONOGRAPH PICKUP Jerome D. Heihel, Erie, Pa., assignor to Eric Resistor Corporation, Erie, Pa., a corporation of Pennsylvania Filed Apr. 21,1958, Ser. No. 730,006 9 Claims. (Cl. 179-10041) This invention is a piezoelectric element having separate outputs in response to stress in directions at right angles to each other. One use of such elements is in phonograph pickup cartridges for playing single groove binaural records. In such records, a needle tracking the record groove is moved simultaneously in two directions at right angles to each other, the needle excursion in each direction corresponding to the output of one of the two binaural channels. When the element is used in a binaural phonograph pickup, the output for each channel appears between a single electrode and ground.
In the drawings, Fig. 1 is a diagrammatic side elevation of a binaural pickup; Fig. 2 is a section on line 2-2 of Fig. 1; Fig. 3 is a diagram of the record groove; Fig. 4 is a circuit diagram; and Fig. 5 is a circuit diagram for another pickup.
The phonograph pickup is intended for single groove binaural records Where the inputs from two binaural microphones are cut in the groove at right angles to each other. For example, the output of the left microphone might cause the record cutter to have a lateral excursion in the groove while the output from the right microphone might cause the record cutter to have a hill and dale excursion. In another system, both microphones cause the record-cutter to have excursions along planes inclined 45 degrees to the record surface and 90 degrees to each other. This latter system is diagrammatically illustrated in Fig. 3 where the record surface is designated as 23, the record groove as 24, and the record cutter as 25. One of the binaural channels causes excursion of the cutter in the direction of arrow 26 while the other of the binaural channels causes excursion of the cutter in the direction of the arrow 27. In playing the record, the needle follows the record groove and duplicates the excursion of the record cutter.
The pickup has a piezoelectric element 1 of one of the polarizable ceramics such as barium titanate having one end fixed in a stationary support by a rubber bushing 2 and having the other end fixed in a socket 3 in a chuck 4 for a needle point 5. The element may be secured in the socket 3 bycementing and the needle 5 may likewise be secured in the chuck by cementing, thereby producing a rigid assembly.
The piezoelectric element consists of a bar of ceramic having four longitudinally extending electrodes symmetrically spaced about its longitudinal axis. The shape of the bar should be such that its stiffness is the same in all directions radial to its longitudinal axis. Among such shapes are bars of square or circular cross section or of the cross shape illustrated where the bar has four longitudinally extending radial flanges or ribs 6 spaced 90 degrees from each other. Longitudinally extending electrodes 7, 8, 9 and 10 are coated on the ceramic between adjacent flanges resulting in diametrically opposed pairs of electrodes with each pair centered on an axis 90 degrees from the other. For example, the electrodes 7 and 9 are opposite each other and are centered on an axis 11 2,947,821 Patented Aug. 2, 1960 to the electrode 8 while the arrows 14, 15 and 16 extend from the electrode 9 through electrodes 10 and 7 to the electrode 8. The polarization could be described as directly between adjacent electrodes 8 and 9 and in series from electrode 9 successively through electrodes 10 and 7 to electrode 8. The degree of polarization is the same between any two adjacent electrodes in order that the piezoelectric properties may match. This polarization may be obtained by first connecting electrodes 10 and 8 together, and 9 and 7 together, and then applying polarizing voltage between 7 and 8 to polarize all four legs 6 equally, with direction of polarization pointing from 7 to 8 (16), 9 to 8 (13), 9 to 10 (14), and 7 to 10 (opposite to 15). It is now necessary to reverse the polarization from 7 to 10. This may be accomplished by connecting electrodes 7 and 8 and 9 and 10, then applying polarizing voltage between 7 and 10 in such a direction as to reverse the polarization previously established across 7 and 10. This applies voltage across 8 and 9 in the same direction as previously, and if first polarization is made complete, no further change in polarization of leg corresponding to arrow 13 will take place, and all polarizations will be equal.
In the assembly, the piezoelectric element is oriented so that the needle 5 is directly in line with one of the longitudinal flanges 6. The assembly is then located in the bushing support 2 so that the needle is perpendicular to the record surface. With this orientation, the movement of the needle due to the recording of the left channel of the binaural system will be in the direction of arrow 17 while the movement of the needle due to the recording of the right channel of the binaural system will be in the direction of arrow 18. Since the arrows 17 and 18 are at right angles to each other, the needle can follow independently the recording in each channel.
Any opposite pair of electrodes, for example the electrodes 8 and 10, are grounded. The output of the right channel then appears between electrode 9 and ground and is due to the polarization in the directions indicated by the arrows 13 and 14. The polarization indicated by the arrows 15 and 16 produces no output for the right channel because the voltages generated by the needle excursions from the right channel recording are equal and opposite. The left channel output appears between electrode 7 and ground and is due to the polarization indicated by the arrows 15 and 16. No output for the left channel is obtained from the polarization due to the arrows 13 and 14 because the voltages generated by the needle excursions from the left channel are equal and opposite.
To reconstitute the sound, the output from the right channel is fed through amplifier 19 to speaker 20 while the output from the left channel is fed through amplifier 21 to speaker 22. The speakers 20 and 22 are so located that the sound reproduces the input from the binaural microphones used in recording the record.
For perfect reproduction, it is necessary that the ceramic bar be accurately made, accurately oriented, and accurately polarized. Accuracy in manufacture insures the equality of the deflection characteristics about axes 11 and 12 so that equal forces from the needle produce equal deflections about these axes. Accuracy of polarization insures equality of output due to the polarization indicated by the arrows 13-16 inclusive so that the output for the right channel due to the polarization indicated by arrows 13 and .14 will (for equal needle excursions) be the same as that obtained in the left channel due to the polarization indicated by arrows 15 and 16. Furthermore, the equality in polarization results in com plete cancellation of output in the right channel due to the polarization indicated by arrows 15 and 16 and likewise results in complete cancellation of the output in the left channel due to the polarization indicated by arrows 13 and 14. Inaccuracy in orienting the needle with reference to the record surface results in a component of movement in one of the channels appearing as an out: put in the other channel. Inaccuracy in all of these factors results in interchannel cross talk which should be kept to a reasonable minimum. Some of the errors in manufacturing may tend to cancel each other. It is also possibleby changing the orientation of the needle 5 to introduce a compensating error which may be helpful in minimizing the interchannel cross talk due to other causes.
The pickup handles the binaural channels independently both'as to electrical and as to mechanical forces. The outputs for the channels appear in separate electrodes on opposite sides of the element and are partially shielded from each other by the grounding of the intermediate pair of electrodes.
. Fig. 5 is a circuit diagram showing another pickup having the binaural channel outputs each appearing between a single electrode and ground. The pickup element is a bar of polarizable material such as barium titanate ceramic having four longitudinally extending electrodes 28, 29, 30 and 31 spaced 90 degrees from each other. In a preferred form the electrodes are arranged between adjacent ribs or flanges 32, 33, 34 and 35 with electrode 28 between flanges 32, 33, electrode 29 between 'fianges 33, 34, electrode 30 between flanges 34, 35 and electrode 31 between flanges 35, 32. The bar is polarized by a field between electrodes 28, 30 and electrodes 29, 31 producing the polarization indicated by arrows 36, 37, 38 and 39.
The piezoelectric element is assembled, for example as shown in Fig. l, oriented so that the needle 5 is centered directly below one of the electrodes, for example the electrode 30, and the adjacent flanges or ribs 34, 35 are inclined at an angle of 45 degrees with respect to the record surface. the needle 5 by the recording of the left channel exerts a force in the direction of arrow 17 and causes bending of the piezoelectric element about axis 40 which extends along the center line of flanges or ribs 33, 35. Because the axis 40 is at the neutral axis of the piezoelectric element, no output is produced by the polarization in the direction of arrows 37 and 38 except that due to irregularities in the ceramic or in the application of the clectrodes or the degree of polarization. In this connection it should be noted that the polarization indicated by arrows 37 and 38 are opposite to each other so that such output as might exist due to the irregularities would tend to cancel. A force in the direction of arrow 17 produces a tension stress in rib 34 and a compression stress in rib 32. This produces a voltage between electrode 29 and ground electrode 30 and produces a voltage of the same sign and magnitude from electrode 28 to electrode 31. Electrode 31 accordingly by reason of the voltage generated due to the polarization of arrow 36 tends to Z3. direction of arrow 18 does not produce any output due to the polarization in the direction of arrows 36, 39 except that due to irregularity-in the ceramic or the electrodes or the polarization. The force in the direction of arrow 18 produces a tension stress in the rib and a compression stress in the rib 33. The tension stress in the rib 35 causes a voltage to be generated due to the polarization in the direction of arrow 38 between electrode 31 and ground electrode 30. V This voltage is fed to the right channel amplifier l9 and right channel speaker 2h; The stress in the direction of arrow 18 produces a voltage between electrodes 28 and 29 of the same magnitude and sign as the voltage between electrodes 31 and 30. That is, electrode 29 assumes the same polarity as ground'electrode 3t) and electrode 28 assumes the same polarity as electrode 31. This means that by reason of the voltage generated by a force in the direction of arrow 18, no voltage is fed to the left channel amplifier 21. i
The Fig. 5 pickup has very low interchannel cross talk because a voltage produced by the recording in one channel which normally would be electrostatically coupled to the other channel is opposed by an equal and opposite voltage generated by the same stress in the other channel. The result is that when the needle is following a recording for only one of the channels, an output is generated in the output electrode for that channel while the output electrode for the other channel in which there is no recording remains at ground potential. The Fig. 5 pickup has the advantage of having its output forboth channels between a single electrode and ground. This is the conventional single ended output in common use in the phonograph industry. The pickup accordingly can be readily substituted in existing phonographs.
When so mounted, excursion of p When either the top or bottom electrodes 28, 30 in Fig. 5 is grounded, the voltages appearing on the output electrodes 29, 31 due to a vertical force on the needle 5 are in phase with each other. When either the left or right electrodes 29, 31 in Fig. 5 is grounded, the voltages appearing on the output electrode 28, 30 due to a vertical force on the needle 5 such as caused by turntable rumble are out of phase with each other and may be trapped in a filter connected across the channel output electrodes. When any one of the four electrodes is grounded, the adjacent electrodes may be used as output electrodes respectively for the left and right channels. For example, if the electrode 35 is grounded, the left and right channel outputs will then appear respectively on electrodes 29 and 31. Similar analyses may be made for the grounding of any other electrode. Rumble may also be reduced when either the top or bottom electrode (28 or 30) is grounded by connecting a low pass filter from ground tothe one not grounded. The foregoing assume the same potential as ground electrode 30. This 7 means that the force due to the recording of the left channel as indicated by arrow 17 produces an output at electrode 29 which is fed through the amplifier 21 and speaker 22 as in Fig. 4. The voltage appearing on electrode 29 does not appear on the right channel elecr trode 31 and accordingly does not produce any output in the right channel speaker 20. The recording due to the right channel produces a force on the needle 5 in the direction of arrow 18 and causes bending of the piezoelectric element about the axis 41 which extendsalong the center line of flanges or ribs 32, 34 or along the neutral axis of the piezoelectric element. The force in the disclosure for reduction of rumble is being claimed in application Serial No. 737,574, filed May 26, 1958.
What is claimed as new is:
l. A'piezoelectric element having separate outputs respectively in response to bending in about one and the other of two axes substantially at right angles to each other, comprising a bar of polarizable ceramic having two pairs of longitudinally extending electrodes, with the electrodes of each pair on opposite sides of the bar and with the respective pairs arranged on a different one of one of said axes, said bar being polarized from one electrode of oneof the pairs in divergent directions to an adjacent electrode of the other pair, one'of the directions of polarization extending directly from said one electrode to said adjacent electrode, the other direction of polariza-' tion extending serially from said one electrode through the remaining electrodes to said adjacent electrode, one of the pairs of electrodes grounded, and the outputfor bending about one and the other ofsaid axes appearing respectively between ground and-one and the other of the remaining two electrodes.
2; A phonograph pickupforbinaural records having two channels cut in a single record groove in two directions at right angles to each other comprising a bar supported at one end and having a needle coupled to the other end for bending the bar about axes substantially at right angles to said two directions, said bar being of polarizable ceramic having two pairs of longitudinally extending electrodes, with the electrode of each pair on opposite sides of a different one of one of said axes, said bar being polarized from one electrode of one of the pairs in divergent directions to an adjacent electrode of the other pair, one of the directions of polarization extending directly from said one electrode to said adjacent electrode, the other direction of polarization extending serially from said one electrode through the remaining electrodes to said adjacent electrode, one of the pairs of electrodes grounded, and the output for bending about one and the other of said axes appearing respectively between ground and one and the other of the remaining two electrodes.
3. The piezoelectric element of claim 1 in which the bar has four longitudinal flanges so it is of cross shape in transverse section and the electrodes are between adjacent flanges.
4. The piezoelectric element of claim 1 in which the bar has equal stiffness in all radial directions.
5. A piezoelectric element having separate outputs respectively in response to bending about one and the other of two axes substantially at right angles to each other, said element comprising a bar-like body of polarizable ceramic having a pair of electrodes centered on one of the axes and spaced on opposite sides of the other of the axes, a second pair of electrodes centered on said other axis and spaced on opposite sides of the first axis, said body being polarized on one side of the first axis from one of the electrodes of the second pair in diverging directions respectively to one and the other of the electrodes of the first pair, and said body being polarized on the other side of the first axis from one electrode of the first pair to the other electrode of the second pair and thence to the other electrode of the first pair.
6. A piezoelectric element comprising a bar-like body of polarizable ceramic having four longitudinally extending electrodes symmetrically spaced about the longitudinal axis of the element in diametrically opposed pairs centered on axes substantially 90 degrees from each other, said bar being polarized by a field from one pair of electrodes to the other pair of electrodes, means applying forces to said element in two directions at right angles to each other to cause bending about axes at right angles to each other and at 45 degrees to the axes on which the respective pairs of electrodes are centered, means for grounding one electrode, means for connecting one of the electrodes adjacent the grounded electrode to an output for bending of the bar in one of said two directions, means for connecting the other of the electrodes adjacent the grounded electrode to another out put for bending of the bar in the other of said two directions, whereby cross talk between said outputs is reduced.
7. A phonograph pickup for binaural records having two channels cut in a single record groove in two directions at right angles to each other comprising a bar supported at one end and having a needle coupled to the other end for bending the bar about axes at right angles to said two directions, said bar having four symmetrically spaced longitudinally extending ribs with two pairs of diametrically opposed ribs respectively substantially centered on one and the other of said axes, four electrodes symmetrically spaced about the longitudinal axis of the bar with each electrode between adjacent ribs, said bar being of polarizable ceramic and polarized by a field from two diametrically opposed electrodes to the other two electrodes, means for grounding one electrode, means for connecting one of the electrodes adjacent the grounded electrode to an output for bending of the bar in one of said two directions, means for connecting the other of the electrodes adjacent the grounded electrode to another output for bending of the bar in the other of said two directions, whereby cross talk between said outputs is reduced.
8. A phonograph pickup for binaural records having two channels cut in a single record groove respectively in two directions at right angles to each other and at 45 degrees to the record surface comprising a bar supported at one end and having a needle coupled to the other end for bending the bar about two axes at right angles to said two directions, said bar having four longitudinally extending radial ribs spaced substantially degrees from each other with diametrically opposite pairs of ribs centered on one and the other of said two axes, four electrodes on the bar spaced 90 degrees from each other with two electrodes centered on an axis perpendicular to the record surface and the other two electrodes centered on an axis parallel to the record surface, said bar being of polarizable ceramic and polarized by a field from said first two electrodes to said other two electrodes, means for grounding one electrode, means for connecting one of the electrodes adjacent the grounded electrode to an output for bending of the bar in one of said two directions, means for connecting the other of the electrodes adjacent the grounded electrode to another output for bending of the bar in the other of said two directions, whereby cross talk between said outputs is reduced.
9. A phonograph pickup for binaural records having two channels cut in a single record groove respectively in two directions at right angles to each other and at 45 degrees to the record surface comprising a bar supported at one end and having a needle coupled to the other end for bending the bar about two axes at right angles to said two directions, four electrodes on the bar spaced substantially 90 degrees from each other with two electrodes centered on an axis perpendicular to the record surface and the other two electrodes centered on an axis parallel to the record surface, said bar being of polarizable ceramic and polarized by a field from said first two electrodes to said other two electrodes, means for grounding one electrode, means for connecting one of the electrodes adjacent the grounded electrode to an output for bending of the bar in one of said two directions, means for connecting the other of the electrodes adjacent the grounded electrode to another output for bending of the bar in the other of said two directions, whereby cross talk between said outputs is reduced.
References Cited in the file of this patent UNlTED STATES PATENTS 2,43 9,499
US730006A 1955-06-20 1958-04-21 Ceramic binaural phonograph pickup Expired - Lifetime US2947821A (en)

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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2997548A (en) * 1958-05-27 1961-08-22 Vries Machiel De Pick-up
US3176251A (en) * 1960-01-26 1965-03-30 Erie Resistor Corp Electromechanical tuned filter
US3576956A (en) * 1958-06-20 1971-05-04 Philips Corp Stereophonic phonograph transducer
FR2503515A1 (en) * 1981-04-01 1982-10-08 Klein Siegfried OMNIDIRECTIONAL SPEAKER FOR ACUTE SOUND SPECTRUM FREQUENCIES

Families Citing this family (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL110623C (en) * 1958-02-10
NL236717A (en) * 1958-03-03
NL113247C (en) * 1958-03-20
US3377439A (en) * 1958-04-03 1968-04-09 Erie Technological Prod Inc Binaural piezoelectric pickup
US3108161A (en) * 1958-08-06 1963-10-22 Rca Corp Stereophonic phonograph pickup
US3043921A (en) * 1958-10-13 1962-07-10 Clairex Corp Piezoelectric transducer for stereophonic phonograph pickup
US3214525A (en) * 1959-10-22 1965-10-26 Gulton Ind Inc Stereophonic piezoelectric bender-type transducer
US3073202A (en) * 1959-11-18 1963-01-15 Star Valley Electronics Inc Timbre control for string instruments
US3023627A (en) * 1960-04-25 1962-03-06 Bell Telephone Labor Inc Strain gauges and accelerometers
US3409377A (en) * 1964-11-17 1968-11-05 Vernon L. Rogallo Apparatus and methods for measuring energy of light beams and ion beams
US3437851A (en) * 1966-08-17 1969-04-08 North American Rockwell Piezoelectric transducer
US3578994A (en) * 1969-10-22 1971-05-18 Dynamics Corp Massa Div Piezoelectric clamped-free beam type transducer
US3754153A (en) * 1971-12-02 1973-08-21 Bulova Watch Co Inc Crystal mounting assembly
US4951370A (en) * 1979-11-05 1990-08-28 Texas Instruments Incorporated Method of making an intelligent multiprobe tip
US4888550A (en) * 1981-09-14 1989-12-19 Texas Instruments Incorporated Intelligent multiprobe tip
FR2519293B1 (en) * 1981-12-31 1984-04-06 Thomson Csf
US4904222A (en) * 1988-04-27 1990-02-27 Pennwalt Corporation Synchronized sound producing amusement device
US8455749B1 (en) * 2009-11-16 2013-06-04 David Rowland Gage Detachable electric pickup for musical instrument
CA2930206A1 (en) 2013-11-21 2015-05-28 Thunder Bay Regional Research Institute Methods of driving polarization inversion in ferroelectric materials and devices

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR887596A (en) * 1941-04-29 1943-11-17 Fides Gmbh Quartz crystal for bending vibrations
US2439499A (en) * 1942-08-20 1948-04-13 Brush Dev Co Piezoelectric motor
US2476848A (en) * 1945-07-05 1949-07-19 Farnsworth Res Corp Variable resistance phonograph pickup and system
US2518348A (en) * 1946-08-16 1950-08-08 Bell Telephone Labor Inc Apparatus for the determination of viscosity of liquids
US2540412A (en) * 1947-12-26 1951-02-06 Zenith Radio Corp Piezoelectric transducer and method for producing same
US2900536A (en) * 1954-11-18 1959-08-18 Astatic Corp Design of electro-mechanical transducer elements

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE348417A (en) * 1927-01-28
US1855151A (en) * 1930-01-25 1932-04-19 Jones W Bartlett Electrical phonograph pick-up and apparatus
US2025388A (en) * 1934-09-05 1935-12-24 Bell Telephone Labor Inc Sound reproducing system
BE489589A (en) * 1948-06-12
US2841722A (en) * 1953-03-18 1958-07-01 Clevite Corp Bending-responsive electromechanical transducer device
US2880334A (en) * 1955-06-13 1959-03-31 Bell Telephone Labor Inc Ferroelectric torsional transducer

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR887596A (en) * 1941-04-29 1943-11-17 Fides Gmbh Quartz crystal for bending vibrations
US2439499A (en) * 1942-08-20 1948-04-13 Brush Dev Co Piezoelectric motor
US2476848A (en) * 1945-07-05 1949-07-19 Farnsworth Res Corp Variable resistance phonograph pickup and system
US2518348A (en) * 1946-08-16 1950-08-08 Bell Telephone Labor Inc Apparatus for the determination of viscosity of liquids
US2540412A (en) * 1947-12-26 1951-02-06 Zenith Radio Corp Piezoelectric transducer and method for producing same
US2900536A (en) * 1954-11-18 1959-08-18 Astatic Corp Design of electro-mechanical transducer elements

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2997548A (en) * 1958-05-27 1961-08-22 Vries Machiel De Pick-up
US3576956A (en) * 1958-06-20 1971-05-04 Philips Corp Stereophonic phonograph transducer
US3176251A (en) * 1960-01-26 1965-03-30 Erie Resistor Corp Electromechanical tuned filter
FR2503515A1 (en) * 1981-04-01 1982-10-08 Klein Siegfried OMNIDIRECTIONAL SPEAKER FOR ACUTE SOUND SPECTRUM FREQUENCIES
EP0063094A1 (en) * 1981-04-01 1982-10-20 Siegfried Dr. Klein Tweeter

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GB823241A (en) 1959-11-11
FR1229068A (en) 1960-09-02
US2944117A (en) 1960-07-05

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