US1631646A - Sound-reproducing apparatus - Google Patents

Sound-reproducing apparatus Download PDF

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Publication number
US1631646A
US1631646A US702452A US70245224A US1631646A US 1631646 A US1631646 A US 1631646A US 702452 A US702452 A US 702452A US 70245224 A US70245224 A US 70245224A US 1631646 A US1631646 A US 1631646A
Authority
US
United States
Prior art keywords
diaphragm
sound
air
sides
reproducing apparatus
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
Application number
US702452A
Other languages
English (en)
Inventor
Chester W Rice
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.)
General Electric Co
Original Assignee
General Electric Co
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 General Electric Co filed Critical General Electric Co
Priority to US702452A priority Critical patent/US1631646A/en
Priority to GB23690/24A priority patent/GB231420A/en
Priority to GB23691/24A priority patent/GB231421A/en
Priority to FR30476D priority patent/FR30476E/fr
Priority to FR595818D priority patent/FR595818A/fr
Application granted granted Critical
Publication of US1631646A publication Critical patent/US1631646A/en
Priority to GB28723/35A priority patent/GB464418A/en
Priority to BE417960D priority patent/BE417960A/xx
Priority to FR47708D priority patent/FR47708E/fr
Priority to BE421801D priority patent/BE421801A/xx
Anticipated expiration legal-status Critical
Priority to BE324881D priority patent/BE324881A/xx
Expired - Lifetime 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
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/06—Loudspeakers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • 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
    • 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
    • H04R9/04—Construction, mounting, or centering of coil

Definitions

  • My present invention relates to apparatus for producing sound from electric currents corresponding to original sounds, and more particularly to devices now commonly known as loud speakers.
  • One of the objects of my invention is to provide a device of the class mentioned whereby the reproduction of sounds may be made with greater accuracy and fidelity than with devices of this class previously-cmployed.
  • a further object of my invention is to provide an apparatus in which the usual horn may be dispensed with and the sound the device in a more satisfactory manner than with the usual form of horn.
  • FIG. 1 is a cross sectional view of a device constructed in accordance with my invention
  • Fig. 2 is an elevation of one end of the sound reproducing device
  • Figs. 3 to 10 inclusive are diagrammatic views of further modifications of my invention.
  • the device illustrated in Figs. 1 and 2 compris es a diaphragm 1 of conical formwhich is supported in an annular air gap'for'n'ied by the concentric pole pieces 2 and 3.
  • T hose may be the pole pieces of a permanent magnet or the magnetic field may be produced by means of an exciting coil 4 surrounding fported on pole piece the pole piece 2.
  • the diaphragm 1 is provided. with a flange 5 at its base evtendiruc at right angles to its axis whereby it is sup 3 by means of a clamping ring 6.
  • the apex of the diaphragm may also be supported. in that case the apex of the cone is flattened and the flattened portion secured at the center to the pole piece 3 by means of a bolt 7 extending through the pole piece 3.
  • the diaphragm '1 instead of being rigid as in most forms of loud speakers may be made extremely flexible. It may consist of a coil 8 to which the actuating currents are material 9 such as cloth or rubber.
  • the diaphragm 1 being entirely non-magnetic, there is no tendency for it tomove toward either pole piece in the absence of current in the coil 8. Therefore the elastic restoring force required to return it to its mean position between the pole pieces is very small and 'a fundamental resonance point of the diaphragm may beseeured at a frequency below any of the important voice frequencies.
  • the driving force is also applied uniformly'over substantially the entire working area of the diaphragm so that the tendency of the diaphragm is to vibrate as a whole without breaking up into higher modes of oscillation.
  • - Pole piece 3 is provided with a plurality of radial slots 10. to permit the escape of the sound produced.
  • Another feature which is essel'itial to the satisfactory operation of a loud speaker is the avoidance of resonant air chambers next to the diaphragm.
  • the space behind the diaphragm is completely enclosed there will: be a certain frequency at which the enclosed air will furnish an elastic restoring force to the diaphragm causing a strong resonance effort, and other frequencies at which the air will so resist the motion of the diaphragm as to greatly reduce its amplitude of vibration.
  • the space behind the diaphragm is enclosed except at the outer edge and hence the air cannot readily escape.
  • the tendency of this construction to introduce resonant air effects may be eliminated by providing radial slots 11 in the pole piece 2 for the purpose of adequately venting the air spacebehind the diaphragm.
  • This'efli'e'ct may be had'by surroundingthe diaphragm by a battle 13' of fairly massive or rigid material in such a manner as to efi'ec- 'tively prevent circulation. Under these con-.
  • both sides of the diaphragm give useful radiation so that there is in all four times as much sound energy radiated with a large bafile, as with no baflie and the back of the diaphragm enclosed. From the above we also see that a baflie may be used to advantage in increasing the sound radi-.
  • the baffle may be given a conical shape as indicated in Figs. 3 and 4: provided the angle is not much less than 90, without bringing in the detrimental resonant efl'ects characteristic of horns.
  • Another effective method is to make the battle in the form of a shallow'box with open back as indicated in Figs. 5 and 6.
  • Naturally many other arrangements will suggest themselves which. are equally effective and non-resonant, such, for example, as a pyramid shaped bafile, as shown in Figs. 7 and 8.
  • a diaphragm I term an inertia controlled diaphragm.
  • the volume of sound produced by such a diaphragm may be made to be substantially independent of the frequency provided the current supplied for actuating the diaphragm is independent of the frequency for equal sound power input at the various frequencies.
  • a current of the desired characteristic may be obtained from a pick-up device of the usual type which has an elastic controlled diaphragm that is one in which the fundamental frequency is above the important voice frequencies.
  • actuating means for said diaphragm and a bafiie surrounding said diaphragm for increasing the length of the path through the air between the two sides of the diaphragm to a distance at least approximately equal to one quarter wave length of the longest useful sound waves to be reproduced thereby.
  • said diaphragm being so arranged that air can circulate freely on both sides thereof, actuating meansfor said diaphragmand a baflie surrounding said diaphragm, said baf: fie having such configuration as to materially decrease the solid angle-into which energy will be radiated from either side of said diaphragm without at the same time introducing resonant effects -which would modify materially ,thejsound reproduction.
  • a diaphragm for sound reproduction comprising a sheet of rubber of conical form in which an actuating coil is embedded, said diaphragn'i having at. its base a flange formed by an-extensiou of the rub- I her sheet. said flange extending at a right angle to the axis of the diaphragm.
  • a diaphragm for sound reproduction comprising a sheet-of rubber of conical form in which an actuating coil is embedded, said 50 dia phragm having at its base a flange formed length of the longest usehaving its apex flattened and means for supporting said diaphragm from its base and its apex.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Audible-Bandwidth Dynamoelectric Transducers Other Than Pickups (AREA)
  • Toys (AREA)
US702452A 1924-03-27 1924-03-27 Sound-reproducing apparatus Expired - Lifetime US1631646A (en)

Priority Applications (10)

Application Number Priority Date Filing Date Title
US702452A US1631646A (en) 1924-03-27 1924-03-27 Sound-reproducing apparatus
GB23691/24A GB231421A (en) 1924-03-27 1924-10-07 Improvements in sound-reproducing apparatus
GB23690/24A GB231420A (en) 1924-03-27 1924-10-07 Improvements in sound-reproducing apparatus
FR595818D FR595818A (fr) 1924-03-27 1925-03-26 Perfectionnements aux appareils reproducteurs de sons
FR30476D FR30476E (fr) 1924-03-27 1925-03-26 Perfectionnements aux appareils reproducteurs de sons
GB28723/35A GB464418A (en) 1924-03-27 1935-10-17 Improvements in or relating to sound reproducing apparatus
BE417960D BE417960A (de) 1924-03-27 1936-10-17
FR47708D FR47708E (fr) 1924-03-27 1936-10-17 Perfectionnements aux appareils reproducteurs de sons
BE421801D BE421801A (de) 1924-03-27 1937-05-28
BE324881D BE324881A (de) 1924-03-27 1946-09-14

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US702452A US1631646A (en) 1924-03-27 1924-03-27 Sound-reproducing apparatus

Publications (1)

Publication Number Publication Date
US1631646A true US1631646A (en) 1927-06-07

Family

ID=24821277

Family Applications (1)

Application Number Title Priority Date Filing Date
US702452A Expired - Lifetime US1631646A (en) 1924-03-27 1924-03-27 Sound-reproducing apparatus

Country Status (4)

Country Link
US (1) US1631646A (de)
BE (3) BE417960A (de)
FR (3) FR30476E (de)
GB (3) GB231421A (de)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2445276A (en) * 1945-05-04 1948-07-13 Massa Frank Electrodynamic loudspeaker
US2854529A (en) * 1954-03-18 1958-09-30 Ferranti Ltd Gramophone pick-up heads
US6704425B1 (en) * 1999-11-19 2004-03-09 Virtual Bass Technologies, Llc System and method to enhance reproduction of sub-bass frequencies
US8989429B2 (en) 2010-01-15 2015-03-24 Phl Audio Electrodynamic transducer having a dome and a buoyant hanging part
US9042594B2 (en) 2010-01-15 2015-05-26 Phl Audio Electrodynamic transducer having a dome and an inner hanging part
US9084056B2 (en) 2010-01-15 2015-07-14 Phl Audio Coaxial speaker system having a compression chamber with a horn

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2445276A (en) * 1945-05-04 1948-07-13 Massa Frank Electrodynamic loudspeaker
US2854529A (en) * 1954-03-18 1958-09-30 Ferranti Ltd Gramophone pick-up heads
US6704425B1 (en) * 1999-11-19 2004-03-09 Virtual Bass Technologies, Llc System and method to enhance reproduction of sub-bass frequencies
US20040218774A1 (en) * 1999-11-19 2004-11-04 Virtual Bass Technologies, Inc. System and method to enhance reproduction of sub-bass frequencies
US8989429B2 (en) 2010-01-15 2015-03-24 Phl Audio Electrodynamic transducer having a dome and a buoyant hanging part
US9042594B2 (en) 2010-01-15 2015-05-26 Phl Audio Electrodynamic transducer having a dome and an inner hanging part
US9084056B2 (en) 2010-01-15 2015-07-14 Phl Audio Coaxial speaker system having a compression chamber with a horn
US9232301B2 (en) 2010-01-15 2016-01-05 Phl Audio Coaxial speaker system having a compression chamber

Also Published As

Publication number Publication date
FR30476E (fr) 1926-07-17
GB231421A (en) 1925-09-17
FR595818A (fr) 1925-10-09
GB231420A (en) 1925-08-20
BE421801A (de) 1937-06-30
GB464418A (en) 1937-04-19
BE417960A (de) 1936-11-30
FR47708E (fr) 1937-06-22
BE324881A (de) 1949-09-30

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