US2690231A - Acoustic device - Google Patents
Acoustic device Download PDFInfo
- Publication number
- US2690231A US2690231A US148656A US14865650A US2690231A US 2690231 A US2690231 A US 2690231A US 148656 A US148656 A US 148656A US 14865650 A US14865650 A US 14865650A US 2690231 A US2690231 A US 2690231A
- Authority
- US
- United States
- Prior art keywords
- horn
- vertical
- rate
- expansion
- chamber
- 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
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Classifications
-
- G—PHYSICS
- G10—MUSICAL INSTRUMENTS; ACOUSTICS
- G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
- G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
- G10K11/18—Methods or devices for transmitting, conducting or directing sound
- G10K11/26—Sound-focusing or directing, e.g. scanning
- G10K11/28—Sound-focusing or directing, e.g. scanning using reflection, e.g. parabolic reflectors
-
- 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
- H04R1/32—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only
- H04R1/34—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means
- H04R1/345—Arrangements for obtaining desired frequency or directional characteristics for obtaining desired directional characteristic only by using a single transducer with sound reflecting, diffracting, directing or guiding means for loudspeakers
Definitions
- This invention has tondo ,Withhorn-tYDe loudspeakers adapted. tov producewide-angle distribution of sound.
- the horn-type loudspeaker of the. present in vention produces more uniform dispersion of sound over the area in the horizontal plane represented by a semi-circle in front of the speaker with greater signal amplitude than has previously been attained.
- a relatively uniform signal can be maintained over a large are on either side of the center axis of the horn and of substantially greater amplitude than any previously attained in directional loudspeakers. This is accomplished by arranging the horn walls so that in the initial stage the acoustic signal is expanded in a vertical direction .at the desired rate and, during the final stage, the signal is expanded in the horizontal direction at the same rate. During the final stage, the lateral or top and bottom walls restrict the expansion of the wave in the vertical plane, thus building up pressure which increases the signal energy radiated in the horizontal plane.
- Figure 1 is a perspective view of the horn
- Figure 2 is a vertical section taken along line 2-2 of Figure 1;
- Figure 3 is a horizontal section taken along line 3-3 of Figure 1.
- the horn IE1 is connected to a conventional driver (not shown) through any convenient coupling, such as the neck i I with internally tapped threads.
- the internal diameter of the horn throat l5 should be the same as the diameter of the driver sound throat.
- the cross-sectional area"of-the horn 10 from the throat I5 to themouthll increases at a predetermined rate, which may beat'anyof the expansion rates used in horn construction.
- a slight outward flare An inward flare should be avoided when the horn is to be cast.
- Theang-l'e of divergence betweenthe lateral walls I2 is chosen so that the cross-sectional area of the horn will increase at the selected expansion rate.
- the first chamber is extended preferably to a point where the distance between the lateral walls is approximately one-third of the wave length of the desired cut-off frequency.
- the lateral walls 12b extend from the first chamber substantially horizontally or are slightly flared from the horizontal depending on circumstances to be described.
- the vertical walls [db in the second chamber are flared sharply as shown, the degree of flaring being chosen so that the crosssectional area in the second chamber will continue to expand at the selected rate.
- this second chamber should extend from the first chamber approximately one-third of the wave length of the desired cut-off frequency. If the preferred dimensions given above for the two chambers in relation to the cut-off frequency are utilized, the axial lengths of the two chambers are, as shown in the drawings, approximately equal.
- the lateral walls 12b may be slightly flared so as to have the flare of the vertical flanges reach a tangential point at the point where it is desirable to have the mouth of the second expansion chamber located while still maintaining the desired rate of expansion.
- the cross-sectional area of the horn increases progressively at the selected rate throughout its entire length from the throat to the mouth of the horn.
- there appears to be a break or discontinuity there is no break or discontinuity in the rate of area increase throughout the horn length.
- discontinuity arises solely from the outward physical appearance of the horn and does not in fact exist a matter of air column expansion.
- the air column loading upon the diaphragm is uniform at all frequencies above the selected cuton frequency, and within this range standing waves or reflections within the horn caused by abrupt changes in horn loading are substantialiy avoided.
- the terms horizontal and vertical are used for the purposes of convenience to represent two planes .at right angles to each other.
- the point to be emphasized is .i the axis shown as 3-3 in Figure l, and referred to in the specification as the horizontal plane, constitutes the plane on which the widest dispersion of sound will take place regardless of the direction that this horn axis is placed with respect to the horizon.
- a loudspeaker horn for producing wide-angle distribution formed by vertical and lateral walls, in which for a portion of the horn the vertical walls are substantially parallel to each other and the lateral walls are inclined away from each other at an angle such that the cross-sectional area of said portion progressively increases at a selected rate, and for the remaining portion of the horn the lateral walls are substantially parallel to each other and the vertical walls flare outwardly at a rate such that the cross-sectional area of said remaining portion progressively increases at a selected rate, the axes of the two portions being straight and in alignment and the length of the axis of the second portion being approximately equal to the distance between the lateral walls at the exit from the first portion.
- a loudspeaker horn for producing wide-angle distribution according to claim 1 wherein the rates of increase of the cross-sectional areas of the first and remaining portions respectively of the horn are substantially the same.
Description
Sept. 28, 1954 S. E. LEVY ET AL 2,690,231
ACOUSTIC DEVICE Filed March 9, 1950 INVENTORS SIDNEY E. LEVY SAUL J. WHlTE -ABRAHAM B. COHEN BY THEIR ATTORNEYS Patented Sept. 28, 1954 ACOUSTIC DEVICE Sidney;Levy,- White Plains,= Saul :J; White, New Rochelle, and Abraham B. Cohen; Bronx; ,N; Y.',,
assignors to University Loudspeakers, 111%.,
White ,Plains, N; Y.', a corporation-ofNew-rYorka ApplicationMarch 9, 1950, Serial No'.'148,656
3' Claims. 1
This invention has tondo ,Withhorn-tYDe loudspeakers adapted. tov producewide-angle distribution of sound.
The horn-type loudspeaker of the. present in vention produces more uniform dispersion of sound over the area in the horizontal plane represented by a semi-circle in front of the speaker with greater signal amplitude than has previously been attained.
Conventional round horn-type loudspeakers produce a signal of maximum amplitude directly in front of the speaker but the amplitude cfthe signal decreases rapidly as the listener moves away from thecenterzaxis of-the speaker. As a result,- attempts have been made to design horns capable of producing, sound with'greater uniformity over a wide angle in the horizontal plane, but theseprior horns radiated-sound over:unnecessarily wide angles in the vertical plane: as well, and an excessive energy loss occurredso that dispersion of radiation: in, the horizontal plane was accomplished at the loss of considerable signal energy.
In the -horn-type loudspeaker of the present invention, sound radiation in-.the vertical plane is held to the minimum necessary and the signal energy thus conserved is utilized to expand the radiation in the horizontal plane. As a resuit, a relatively uniform signal can be maintained over a large are on either side of the center axis of the horn and of substantially greater amplitude than any previously attained in directional loudspeakers. This is accomplished by arranging the horn walls so that in the initial stage the acoustic signal is expanded in a vertical direction .at the desired rate and, during the final stage, the signal is expanded in the horizontal direction at the same rate. During the final stage, the lateral or top and bottom walls restrict the expansion of the wave in the vertical plane, thus building up pressure which increases the signal energy radiated in the horizontal plane.
In the accompanying drawings, Figure 1 is a perspective view of the horn;
Figure 2 is a vertical section taken along line 2-2 of Figure 1; and
Figure 3 is a horizontal section taken along line 3-3 of Figure 1.
The horn IE1 is connected to a conventional driver (not shown) through any convenient coupling, such as the neck i I with internally tapped threads. For best results, the internal diameter of the horn throat l5 should be the same as the diameter of the driver sound throat.
The cross-sectional area"of-the horn 10 from the throat I5 to themouthll increases at a predetermined rate, which may beat'anyof the expansion rates used in horn construction. The
1 exponential rate of 'expansionais thatmost commonly-employed, aformula for which is as follows:
Then
to simplify casting operations, may be provided with .a slight outward flare: An inward flare should be avoided when the horn is to be cast. Theang-l'e of divergence betweenthe lateral walls I2 is chosen so that the cross-sectional area of the horn will increase at the selected expansion rate. The first chamber is extended preferably to a point where the distance between the lateral walls is approximately one-third of the wave length of the desired cut-off frequency.
In the second chamber, the lateral walls 12b extend from the first chamber substantially horizontally or are slightly flared from the horizontal depending on circumstances to be described. On the other hand, the vertical walls [db in the second chamber are flared sharply as shown, the degree of flaring being chosen so that the crosssectional area in the second chamber will continue to expand at the selected rate. For best results, this second chamber should extend from the first chamber approximately one-third of the wave length of the desired cut-off frequency. If the preferred dimensions given above for the two chambers in relation to the cut-off frequency are utilized, the axial lengths of the two chambers are, as shown in the drawings, approximately equal.
Depending on the rate of expansion chosen and the cut-off frequency selected, it may not be possible to maintain this rate of expansion in the second chamber to its mouth merely by the flaring of the vertical walls, i. e. the curve of the vertical walls may become tangential to a crosssectional plane of the horn before the desired distance to the mouth has been reached. In that event, the lateral walls 12b may be slightly flared so as to have the flare of the vertical flanges reach a tangential point at the point where it is desirable to have the mouth of the second expansion chamber located while still maintaining the desired rate of expansion.
It will be observed that in the second chamber Where the lateral walls 121) are disposed horizontally or at most have only a slight flare, vertical expansion of the sound Waves is largely prevented and this restriction on vertical expansion builds up pressure which serves to add energy to .and aid the dispersion of the sound waves in a horizontal direction which, due to the flaring of the vertical walls Mb, is relatively unopposed.
As before observed, the cross-sectional area of the horn increases progressively at the selected rate throughout its entire length from the throat to the mouth of the horn. Although at the junction 15 of the two chambers there appears to be a break or discontinuity, there is no break or discontinuity in the rate of area increase throughout the horn length. The impression of discontinuity arises solely from the outward physical appearance of the horn and does not in fact exist a matter of air column expansion. As a result, the air column loading upon the diaphragm is uniform at all frequencies above the selected cuton frequency, and within this range standing waves or reflections within the horn caused by abrupt changes in horn loading are substantialiy avoided.
In the above description, the terms horizontal and vertical are used for the purposes of convenience to represent two planes .at right angles to each other. The point to be emphasized is .i the axis shown as 3-3 in Figure l, and referred to in the specification as the horizontal plane, constitutes the plane on which the widest dispersion of sound will take place regardless of the direction that this horn axis is placed with respect to the horizon.
1'. claim:
1. A loudspeaker horn for producing wide-angle distribution formed by vertical and lateral walls, in which for a portion of the horn the vertical walls are substantially parallel to each other and the lateral walls are inclined away from each other at an angle such that the cross-sectional area of said portion progressively increases at a selected rate, and for the remaining portion of the horn the lateral walls are substantially parallel to each other and the vertical walls flare outwardly at a rate such that the cross-sectional area of said remaining portion progressively increases at a selected rate, the axes of the two portions being straight and in alignment and the length of the axis of the second portion being approximately equal to the distance between the lateral walls at the exit from the first portion.
2. A loudspeaker horn for producing wide-angle distribution according to claim 1 wherein the rates of increase of the cross-sectional areas of the first and remaining portions respectively of the horn are substantially the same.
3. A loudspeaker horn for producing wide-angle distribution as claimed in claim 2, in which the distance between the lateral walls at the end of said first portion is approximately one-third of the desired cut-off frequency and in which said remainder of the horn extends from the end of said first portion a distance approximately onethird of the wave length of the desired cut-off frequency.
References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,314,980 Pognowski Sept. 2, 1919 1,477,556 Grissinger Dec. 18, 1923 1,689,009 Byrns Oct. 23, 1928 1,747,830 Harrison Feb. 18, 1930 1,754,425 Hinckley Apr. 15, 1930 2,537,141 Klipsch Jan. 9, 1951 FOREIGN PATENTS Number Country Date 775,561 France Jan. 4, 1935
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US148656A US2690231A (en) | 1950-03-09 | 1950-03-09 | Acoustic device |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US148656A US2690231A (en) | 1950-03-09 | 1950-03-09 | Acoustic device |
Publications (1)
Publication Number | Publication Date |
---|---|
US2690231A true US2690231A (en) | 1954-09-28 |
Family
ID=22526742
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US148656A Expired - Lifetime US2690231A (en) | 1950-03-09 | 1950-03-09 | Acoustic device |
Country Status (1)
Country | Link |
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US (1) | US2690231A (en) |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3972385A (en) * | 1973-01-17 | 1976-08-03 | Onkyo Kabushiki Kaisha | Horn speaker |
US4040503A (en) * | 1973-01-17 | 1977-08-09 | Onkyo Kabushiki Kaisha | Horn speaker |
US4091891A (en) * | 1973-01-17 | 1978-05-30 | Onkyo Kabushiki Kaisha | Horn speaker |
FR2396485A1 (en) * | 1977-06-27 | 1979-01-26 | Altec Corp | LOUDSPEAKER PAVILION |
US4171734A (en) * | 1977-11-10 | 1979-10-23 | Beta Sound, Incorporated | Exponential horn speaker |
US4187926A (en) * | 1977-06-27 | 1980-02-12 | Altec Corporation | Loudspeaker horn |
FR2482402A1 (en) * | 1980-05-06 | 1981-11-13 | Lansing Sound | SPEAKER PAVILION |
US4324313A (en) * | 1978-08-01 | 1982-04-13 | Tomiyo Nakagawa | Exponential horn for use in horn-type loudspeakers |
US4344504A (en) * | 1981-03-27 | 1982-08-17 | Community Light & Sound, Inc. | Directional loudspeaker |
US4390078A (en) * | 1982-02-23 | 1983-06-28 | Community Light & Sound, Inc. | Loudspeaker horn |
US4469921A (en) * | 1981-03-17 | 1984-09-04 | Pioneer Electronic Corporation | Horn type loudspeaker |
FR2553249A1 (en) * | 1983-10-05 | 1985-04-12 | Jbl Inc | SPEAKER PAVILION COVERING A BOUNDARY AREA |
US6059069A (en) * | 1999-03-05 | 2000-05-09 | Peavey Electronics Corporation | Loudspeaker waveguide design |
WO2003061342A1 (en) * | 2002-01-14 | 2003-07-24 | Harman International Industries, Inc. | Constant coverage waveguide |
US20090057052A1 (en) * | 2007-08-30 | 2009-03-05 | Klipsch, Llc | Acoustic horn having internally raised geometric shapes |
USD772198S1 (en) * | 2015-06-12 | 2016-11-22 | Chiwan Art Inc. | Speaker |
USD828328S1 (en) * | 2016-10-21 | 2018-09-11 | Joseph Dieudonne Morin | Passive sound proliferation device |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1314980A (en) * | 1919-09-02 | Nowski | ||
US1477556A (en) * | 1921-07-12 | 1923-12-18 | Grissinger Elwood | Sound-projecting apparatus and method |
US1689009A (en) * | 1927-08-15 | 1928-10-23 | Stephen H Byrns | Horn for loud speakers |
US1747830A (en) * | 1923-10-21 | 1930-02-18 | Bell Telephone Labor Inc | Acoustic horn |
US1754425A (en) * | 1926-05-28 | 1930-04-15 | Columbia Phonograph Co Inc | Sound amplifier |
FR775561A (en) * | 1934-02-26 | 1935-01-04 | A multi-element phonograph soundbox device of various sizes and operating with a single diaphragm | |
US2537141A (en) * | 1945-06-15 | 1951-01-09 | Paul W Klipsch | Loud-speaker horn |
-
1950
- 1950-03-09 US US148656A patent/US2690231A/en not_active Expired - Lifetime
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1314980A (en) * | 1919-09-02 | Nowski | ||
US1477556A (en) * | 1921-07-12 | 1923-12-18 | Grissinger Elwood | Sound-projecting apparatus and method |
US1747830A (en) * | 1923-10-21 | 1930-02-18 | Bell Telephone Labor Inc | Acoustic horn |
US1754425A (en) * | 1926-05-28 | 1930-04-15 | Columbia Phonograph Co Inc | Sound amplifier |
US1689009A (en) * | 1927-08-15 | 1928-10-23 | Stephen H Byrns | Horn for loud speakers |
FR775561A (en) * | 1934-02-26 | 1935-01-04 | A multi-element phonograph soundbox device of various sizes and operating with a single diaphragm | |
US2537141A (en) * | 1945-06-15 | 1951-01-09 | Paul W Klipsch | Loud-speaker horn |
Cited By (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4040503A (en) * | 1973-01-17 | 1977-08-09 | Onkyo Kabushiki Kaisha | Horn speaker |
US4091891A (en) * | 1973-01-17 | 1978-05-30 | Onkyo Kabushiki Kaisha | Horn speaker |
US3972385A (en) * | 1973-01-17 | 1976-08-03 | Onkyo Kabushiki Kaisha | Horn speaker |
FR2396485A1 (en) * | 1977-06-27 | 1979-01-26 | Altec Corp | LOUDSPEAKER PAVILION |
US4187926A (en) * | 1977-06-27 | 1980-02-12 | Altec Corporation | Loudspeaker horn |
US4171734A (en) * | 1977-11-10 | 1979-10-23 | Beta Sound, Incorporated | Exponential horn speaker |
US4324313A (en) * | 1978-08-01 | 1982-04-13 | Tomiyo Nakagawa | Exponential horn for use in horn-type loudspeakers |
FR2482402A1 (en) * | 1980-05-06 | 1981-11-13 | Lansing Sound | SPEAKER PAVILION |
US4308932A (en) * | 1980-05-06 | 1982-01-05 | James B. Lansing Sound, Inc. ("Jbl") | Loudspeaker horn |
US4469921A (en) * | 1981-03-17 | 1984-09-04 | Pioneer Electronic Corporation | Horn type loudspeaker |
US4344504A (en) * | 1981-03-27 | 1982-08-17 | Community Light & Sound, Inc. | Directional loudspeaker |
US4390078A (en) * | 1982-02-23 | 1983-06-28 | Community Light & Sound, Inc. | Loudspeaker horn |
FR2553249A1 (en) * | 1983-10-05 | 1985-04-12 | Jbl Inc | SPEAKER PAVILION COVERING A BOUNDARY AREA |
EP0140465A2 (en) * | 1983-10-05 | 1985-05-08 | Jbl Incorporated | Defined-coverage loudspeaker horn |
EP0140465A3 (en) * | 1983-10-05 | 1986-03-19 | Jbl Incorporated | Defined-coverage loudspeaker horn |
US6059069A (en) * | 1999-03-05 | 2000-05-09 | Peavey Electronics Corporation | Loudspeaker waveguide design |
WO2003061342A1 (en) * | 2002-01-14 | 2003-07-24 | Harman International Industries, Inc. | Constant coverage waveguide |
US7936892B2 (en) * | 2002-01-14 | 2011-05-03 | Harman International Industries, Incorporated | Constant coverage waveguide |
US8548184B2 (en) | 2002-01-14 | 2013-10-01 | Harman International Industries, Incorporated | Constant coverage waveguide |
US20090057052A1 (en) * | 2007-08-30 | 2009-03-05 | Klipsch, Llc | Acoustic horn having internally raised geometric shapes |
US7686129B2 (en) * | 2007-08-30 | 2010-03-30 | Klipsch Llc | Acoustic horn having internally raised geometric shapes |
USD772198S1 (en) * | 2015-06-12 | 2016-11-22 | Chiwan Art Inc. | Speaker |
USD828328S1 (en) * | 2016-10-21 | 2018-09-11 | Joseph Dieudonne Morin | Passive sound proliferation device |
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