US3155774A - Loudspeaker arrangement - Google Patents

Loudspeaker arrangement Download PDF

Info

Publication number
US3155774A
US3155774A US129175A US12917561A US3155774A US 3155774 A US3155774 A US 3155774A US 129175 A US129175 A US 129175A US 12917561 A US12917561 A US 12917561A US 3155774 A US3155774 A US 3155774A
Authority
US
United States
Prior art keywords
loudspeaker
loudspeakers
cone
arrangement
air
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
US129175A
Inventor
Howell Derek
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.)
Pye Electronic Products Ltd
Original Assignee
Pye Ltd
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 Pye Ltd filed Critical Pye Ltd
Application granted granted Critical
Publication of US3155774A publication Critical patent/US3155774A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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
    • 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
    • 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 
    • 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 
    • H04R1/26—Spatial arrangements of separate transducers responsive 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
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/12—Circuits for transducers, loudspeakers or microphones for distributing signals to two or more loudspeakers
    • H04R3/14—Cross-over networks

Definitions

  • the present invention relates to a loudspeaker arrangement and has for an object to provide a loudspeaker arrangement which gives an improved response over the audio frequency range.
  • a loudspeaker arrangement comprises a plurality of loudspeakers mounted one behind the other, means being provided for enclosing a volume of air between successive loudspeakers to provide air coupling between the loudspeakers.
  • the speech coils of the loudspeakers are electrically connected to the source of audio frequency with which they are to be energized so that the cones of the loudspeakers work in phase.
  • the arrangement may consist of only two loudspeakers or alternatively more than two loudspeakers may be employed.
  • the loudspeakers are preferably mounted one behind the other with their cones facing in the same direction.
  • the invention provides a loudspeaker arrangement comprising two loudspeakers arranged one behind the other with their cones facing in the same direction and means for enclosing the space between the rear of the cone of the foremost loudspeaker and the front of the cone of the rearmost loudspeaker, whereby the volume of air between the loudspeakers is trapped in this space to provide air coupling between the loudspeakers.
  • the enclosing means may also serve to maintain the two loudspeakers separated by the desired distance.
  • FIGURE 1 is a diagrammatic section through one loudspeaker arrangement according to the invention.
  • FIGURE 2 is a circuit diagram showing the electrical connection of the loudspeakers.
  • FIGURE 1 there is shown a portion of a Wall of a cabinet or battle 1 having an aperture 2 behind which is mounted a loudspeaker 3, for example a 10 by 6" elliptical unit which operates over the full audio frequency range.
  • the cone 3b of loudspeaker 3 is attached by its periphery 3a to the cabinet 1 and is also located in a hole cut in ablock of wood 4 arranged behind the aperture 2, and surrounding the loudspeaker 3.
  • the block 4 supports the periphery 5a of the cone 5b of a second loudspeaker 5, for example a 12 unit which only operates below 200 cycles per second.
  • both of the loudspeakers are sealed at their connection to the cabinet 1 and block 4 respectively, and therefore the volume of air between them is trapped between the cones of the two loudspeakers and provides additional coupling between them.
  • the block 4 also acts as a spacer to maintain the desired distance between the two loudspeakers.
  • the loudspeakers must of course be spaced by a minimum distance which ensures that they are not in mechanical contact and the maximum spacing between them is determined by the distance where the volume of air trapped between the loudspeakers becomes an inefiicient coupling due to the elasticity of the air. This maximum distance will vary with the size of the loudspeakers and may also vary with their power.
  • an absorbent material 7 may be placed between the cones of the loudspeakers, this absorbent material being such that it will not substantially absorb frequencies below the upper frequency to be reproduced by the loudspeaker 5, e.g. below 200 cycles per second.
  • the absorbent material may be attached to the cone of the rear loudspeaker 5, but must not touch the cone of the front loudspeaker 3.
  • the absorbent material has the effect of preventing the reflection of frequencies of above 200 cycles per second produced by the front full range loudspeaker 3 by the cone of the rear bass loudspeaker 5. Such reflections, if present, would either add to or subtract from the output of the unit and would cause what ,is known as colouration.
  • Suitable absorbent materials are cotton, wool, kapok or a foamed plastic.
  • FIGURE 2 The electrical connection of the loudspeakers is shown in FIGURE 2.
  • This series combination of loudspeaker 5 and choke 6 is connected in parallel with the speech coil 30 of the full range loudspeaker 3, and the whole arrangement is in turn connected to the output terminals of an amplifier or other driving device.
  • the movement of the cone of the loudspeaker 3 is assisted by the cushion of air over all of its rear surface as well as being driven by its speech coil, whereby a reduction of cone break-up and/or flexing of the cone of the loudspeaker 3 is achieved.
  • a loudspeaker arrangement comprising a first loudspeaker having a speech coil and a cone arranged to operate over the full range of audio signals to be reproduced, a second loudspeaker of larger size than the first loudspeaker, a speech coil and a cone included in said second loudspeaker, a choke connected in series with the speech coil of the second loudspeaker, means conmeeting the series combination of said speech coil and said choke in parallel with the speech coil of said first loudspeaker, so that the higher audio frequencies are filtered out by said choke and said second loudspeaker only reproduces the lower audio frequencies, means for supporting said first and second loudspeakers with their cones facing in the same direction and with the second loudspeaker behind the first loudspeaker, and means for enclosing the space between the rear of the cone of the first loudspeaker and the front of the cone of the second loudspeaker to trap the volume of air between the cones of the loudspeakers to provide air coupling between the loudspeakers.

Description

Nov. 3, 1964 D. HOWELL 3,155,774
LOUDSPEAKER ARRANGEMENT Filed Aug. 3, 1961 Inventor Attorneys United States Patent 3,155,774 LOUDSPEAKER AGEMENT Derek Howeil, Cambridge, Engiand, assignor to Pye Limited, Cambridge, England, a British company Filed Aug. 3, 1961, Ser. No. 129,175 Claims priority, application Great Britain, Aug. 19, 1960, 28,817/ 60 1 Claim. (Cl. 179-1) The present invention relates to a loudspeaker arrangement and has for an object to provide a loudspeaker arrangement which gives an improved response over the audio frequency range.
According to the present invention a loudspeaker arrangement comprises a plurality of loudspeakers mounted one behind the other, means being provided for enclosing a volume of air between successive loudspeakers to provide air coupling between the loudspeakers. The speech coils of the loudspeakers are electrically connected to the source of audio frequency with which they are to be energized so that the cones of the loudspeakers work in phase. The arrangement may consist of only two loudspeakers or alternatively more than two loudspeakers may be employed. The loudspeakers are preferably mounted one behind the other with their cones facing in the same direction.
From another aspect the invention provides a loudspeaker arrangement comprising two loudspeakers arranged one behind the other with their cones facing in the same direction and means for enclosing the space between the rear of the cone of the foremost loudspeaker and the front of the cone of the rearmost loudspeaker, whereby the volume of air between the loudspeakers is trapped in this space to provide air coupling between the loudspeakers. The enclosing means may also serve to maintain the two loudspeakers separated by the desired distance.
An embodiment of the invention will now be further described with reference to the accompanying drawings, in which:
FIGURE 1 is a diagrammatic section through one loudspeaker arrangement according to the invention, and
FIGURE 2 is a circuit diagram showing the electrical connection of the loudspeakers.
Referring to FIGURE 1, there is shown a portion of a Wall of a cabinet or battle 1 having an aperture 2 behind which is mounted a loudspeaker 3, for example a 10 by 6" elliptical unit which operates over the full audio frequency range. The cone 3b of loudspeaker 3 is attached by its periphery 3a to the cabinet 1 and is also located in a hole cut in ablock of wood 4 arranged behind the aperture 2, and surrounding the loudspeaker 3. The block 4 supports the periphery 5a of the cone 5b of a second loudspeaker 5, for example a 12 unit which only operates below 200 cycles per second. The periphery of both of the loudspeakers are sealed at their connection to the cabinet 1 and block 4 respectively, and therefore the volume of air between them is trapped between the cones of the two loudspeakers and provides additional coupling between them. The block 4 also acts as a spacer to maintain the desired distance between the two loudspeakers. The loudspeakers must of course be spaced by a minimum distance which ensures that they are not in mechanical contact and the maximum spacing between them is determined by the distance where the volume of air trapped between the loudspeakers becomes an inefiicient coupling due to the elasticity of the air. This maximum distance will vary with the size of the loudspeakers and may also vary with their power.
3,155,774 Patented Nov. 3, 1964 Advantageously an absorbent material 7 may be placed between the cones of the loudspeakers, this absorbent material being such that it will not substantially absorb frequencies below the upper frequency to be reproduced by the loudspeaker 5, e.g. below 200 cycles per second. The absorbent material may be attached to the cone of the rear loudspeaker 5, but must not touch the cone of the front loudspeaker 3. The absorbent material has the effect of preventing the reflection of frequencies of above 200 cycles per second produced by the front full range loudspeaker 3 by the cone of the rear bass loudspeaker 5. Such reflections, if present, would either add to or subtract from the output of the unit and would cause what ,is known as colouration. Suitable absorbent materials are cotton, wool, kapok or a foamed plastic.
The electrical connection of the loudspeakers is shown in FIGURE 2. A choke 6, which may have a value of between 15 and 20 mH in the present embodiment, is connected in series with the speech coil 50 of the bass loudspeaker 5 to filter out frequencies in excess of 200 c./s. This series combination of loudspeaker 5 and choke 6 is connected in parallel with the speech coil 30 of the full range loudspeaker 3, and the whole arrangement is in turn connected to the output terminals of an amplifier or other driving device.
In operation, the movement of the cone of the loudspeaker 3 is assisted by the cushion of air over all of its rear surface as well as being driven by its speech coil, whereby a reduction of cone break-up and/or flexing of the cone of the loudspeaker 3 is achieved.
The arrangement according to the present invention has the following advantages:
(1) A good bass response down to 30 c./s. can be achieved.
(2) A more linear impedance is presented to the amplifier than in multi-loudspeaker devices as at present constructed.
(3) A smoother response is obtained at the lower frequencies due to absence of cone break-up.
I claim:
A loudspeaker arrangement comprising a first loudspeaker having a speech coil and a cone arranged to operate over the full range of audio signals to be reproduced, a second loudspeaker of larger size than the first loudspeaker, a speech coil and a cone included in said second loudspeaker, a choke connected in series with the speech coil of the second loudspeaker, means conmeeting the series combination of said speech coil and said choke in parallel with the speech coil of said first loudspeaker, so that the higher audio frequencies are filtered out by said choke and said second loudspeaker only reproduces the lower audio frequencies, means for supporting said first and second loudspeakers with their cones facing in the same direction and with the second loudspeaker behind the first loudspeaker, and means for enclosing the space between the rear of the cone of the first loudspeaker and the front of the cone of the second loudspeaker to trap the volume of air between the cones of the loudspeakers to provide air coupling between the loudspeakers.
References Cited in the file of this patent UNITED STATES PATENTS 2,426,948 Preston Sept. 2, 1947 2,539,672 Olson et al Jan. 30, 1951 2,832,828 Levy Apr. 29, 1958 2,857,478 Harnis Oct. 21, 1958 2,993,091 Guss July 18, 1961
US129175A 1960-08-19 1961-08-03 Loudspeaker arrangement Expired - Lifetime US3155774A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2881760 1960-08-19

Publications (1)

Publication Number Publication Date
US3155774A true US3155774A (en) 1964-11-03

Family

ID=10281642

Family Applications (1)

Application Number Title Priority Date Filing Date
US129175A Expired - Lifetime US3155774A (en) 1960-08-19 1961-08-03 Loudspeaker arrangement

Country Status (1)

Country Link
US (1) US3155774A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3984635A (en) * 1975-03-11 1976-10-05 Electro Acoustical Labs, Inc. Low range loudspeaker system
US4176253A (en) * 1977-05-20 1979-11-27 Gabr Saad Z M Current loaded pneumatically driven loudspeaker arrangements
US5193119A (en) * 1985-09-02 1993-03-09 Franco Tontini Multiple loudspeaker
US5229555A (en) * 1990-03-30 1993-07-20 Matsushita Electric Industrial Co., Ltd. Speaker system and tv with the same
WO1995009516A1 (en) * 1993-09-29 1995-04-06 Eastern Acoustic Works, Inc. Speaker design with attenuated reflection
US5909014A (en) * 1991-08-29 1999-06-01 Mengel; Clare Louis Low frequency equaphase surround loudspeaker
US6115475A (en) * 1998-07-23 2000-09-05 Diaural, L.L.C. Capacitor-less crossover network for electro-acoustic loudspeakers
US6310959B1 (en) 1999-08-24 2001-10-30 Diaural, Llc Tuned order crossover network for electro-acoustic loudspeakers

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426948A (en) * 1945-01-02 1947-09-02 Rca Corp Coaxial dual-unit electrodynamic loud-speaker
US2539672A (en) * 1949-04-29 1951-01-30 Rca Corp Coaxial dual-unit electrodynamic loud-speaker
US2832828A (en) * 1955-09-26 1958-04-29 Arthur Blumenfeld Loudspeaker circuitry
US2857478A (en) * 1954-09-13 1958-10-21 Radio Speakers Canada Ltd Co-planar loud speaker
US2993091A (en) * 1957-04-02 1961-07-18 Guss Reuben Variable dynamic infinite damping loudspeaker enclosure device

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2426948A (en) * 1945-01-02 1947-09-02 Rca Corp Coaxial dual-unit electrodynamic loud-speaker
US2539672A (en) * 1949-04-29 1951-01-30 Rca Corp Coaxial dual-unit electrodynamic loud-speaker
US2857478A (en) * 1954-09-13 1958-10-21 Radio Speakers Canada Ltd Co-planar loud speaker
US2832828A (en) * 1955-09-26 1958-04-29 Arthur Blumenfeld Loudspeaker circuitry
US2993091A (en) * 1957-04-02 1961-07-18 Guss Reuben Variable dynamic infinite damping loudspeaker enclosure device

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3984635A (en) * 1975-03-11 1976-10-05 Electro Acoustical Labs, Inc. Low range loudspeaker system
US4176253A (en) * 1977-05-20 1979-11-27 Gabr Saad Z M Current loaded pneumatically driven loudspeaker arrangements
US5193119A (en) * 1985-09-02 1993-03-09 Franco Tontini Multiple loudspeaker
US5229555A (en) * 1990-03-30 1993-07-20 Matsushita Electric Industrial Co., Ltd. Speaker system and tv with the same
US5909014A (en) * 1991-08-29 1999-06-01 Mengel; Clare Louis Low frequency equaphase surround loudspeaker
WO1995009516A1 (en) * 1993-09-29 1995-04-06 Eastern Acoustic Works, Inc. Speaker design with attenuated reflection
US6115475A (en) * 1998-07-23 2000-09-05 Diaural, L.L.C. Capacitor-less crossover network for electro-acoustic loudspeakers
EP1097510A1 (en) * 1998-07-23 2001-05-09 Diaural, LLC Capacitor-less crossover network for electro-acoustic loudspeakers
EP1097510A4 (en) * 1998-07-23 2005-09-14 Diaural Llc Capacitor-less crossover network for electro-acoustic loudspeakers
US6310959B1 (en) 1999-08-24 2001-10-30 Diaural, Llc Tuned order crossover network for electro-acoustic loudspeakers

Similar Documents

Publication Publication Date Title
US4301332A (en) Woofer loudspeaker
US3688864A (en) Infinite dynamic damping loudspeaker systems
US4128738A (en) Compact transmission line loudspeaker system
US5471019A (en) Multiple chamber loudspeaker system
GB1316771A (en) Sound reproducing system
US3356179A (en) High fidelity speaker enclosure
US2143175A (en) Sound reproducing system
US2866513A (en) Apparatus for generating sound
JPS61167299A (en) Speaker unit
US3155774A (en) Loudspeaker arrangement
US3473625A (en) Sound reproduction system and loudspeaker assembly
US3909531A (en) Acoustic transducer system
US4924963A (en) Compact and efficient sub-woofer system and method for installation in structural partitions
US4135600A (en) Loudspeaker system
US3984635A (en) Low range loudspeaker system
US3768589A (en) Loudspeaker
US3858679A (en) Loudspeaker system which produces stereo-like sounds
GB1462919A (en) A loudspeaker cabinet
US2768702A (en) Sound reproducing systems
US3131783A (en) Loud-speaker enclosure
US2841648A (en) Sound producing device
US2927657A (en) Loud speaker system
US2688373A (en) Sound translating apparatus
US2643728A (en) High fidelity loud-speaker cabinet
US3089562A (en) Loudspeaker baffle assembly