Patent US3927261A successfully refreshed from Google Patents.
US3927261A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multiple driver dynamic loud speaker
Assignee: Individual
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Filing: 1974-05-14
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Granted: 1975-12-16
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Expires: 1994-05-14
Abstract
Abstract The present invention is directed to an improvement in dynamic loud speakers and is characterized by the sonic frequencies of the midrange and treble bands being generated by wide dispersion dynamic transducers which are mounted on or acoustically associated with specially designed baffle members, which baffle members are surrounded by free space in an acoustically transparent frame. A crossover network of the gradual attenuation type divides the frequencies to be reproduced by the various transducers, the size of the baffles being selected so as to cooperate with the attenuation effects of the crossover network in a synergistic manner, markedly to increase the attenuation effects of the crossover member. The baffles are sufficiently small to avoid diffraction effects and yet sufficiently large to increase the air coupling and, hence, the efficiency of the transducers associated therewith toward the lower limits of frequency range desired to be reproduced by that transducer.
Inventors
- 👤 Jon G Dahlquist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:33
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/26
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
188 words
A multi-driver dynamic loud speaker assembly comprising a frame including an acoustically transparent front face, an enclosure within said frame, a base radiator transducer mounted within said enclosure, at least two additional direct radiator dynamic transducers positioned within said frame, each said dynamic transducer having acoustically associated therewith a baffle member supported within said frame externally of said enclosure, said baffle members being substantially completely surrounded by free space, the effective dimension of each said baffle member measured in a direction normal to the radiating axis of its acoustically associated transducer being not greater than about one half of the wave length of a sound wave at the frequency of the lower nominal crossover frequency of the signal fed to the transducer acoustically associated with said baffle, the area within said frame rearwardly of said at least two transducers being substantially free of sound reflective surfaces facing the front of said loud speaker assembly, and a frequency divider network means for dividing the electrical signals fed to said loud speaker assembly into at least three discrete frequency bands, and applying an appropriate said band to each said transducer.
Claim 2
Dependent Claim
188 words
A multi-driver dynamic loud speaker assembly comprising a frame including an acoustically transparent front face, an enclosure within said frame, a base radiator transducer mounted within said enclosure, at least two additional direct radiator dynamic transducers positioned within said frame, each said dynamic transducer having acoustically associated therewith a baffle member supported within said frame externally of said enclosure, said baffle members being substantially completely surrounded by free space, the effective dimension of each said baffle member measured in a direction normal to the radiating axis of its acoustically associated transducer being not greater than about one half of the wave length of a sound wave at the frequency of the lower nominal crossover frequency of the signal fed to the transducer acoustically associated with said baffle, the area within said frame rearwardly of said at least two transducers being substantially free of sound reflective surfaces facing the front of said loud speaker assembly, and a frequency divider network means for dividing the electrical signals fed to said loud speaker assembly into at least three discrete frequency bands, and applying an appropriate said band to each said transducer.
Claim 3
Dependent Claim
29 words
A loud speaker assembly in accordance with claim 1 wherein said frequency divider network is of the gradual attenuation type, the attenuation rate being about 6 db per octave.
Claim 4
Dependent Claim
57 words
A loud speaker assembly in accordance with claim 2 wherein the effective dimension of said baffles is in the range of from about one half to one quarter of the wave length of a sound wave at the frequency of the lower nominal crossover frequency of the signal fed to the transducer associated with the respective baffle.
Claim 5
Dependent Claim
49 words
A loudspeaker in accordance with claim 2 wherein the frequencies reproduced by said direct radiator dynamic transducers below said lower nominal crossover frequency are attenuated at the rate of about 6 or more db per octave as a result of the combined effects of said baffles and crossover network.
Claim 6
Dependent Claim
56 words
A loudspeaker assembly in accordance with claim 1 wherein the effective dimension of said baffles is in the range of from about one half to one quarter of the wave length of a sound wave at the frequency of the lower nominal crossover frequency of the signal fed to the transducer associated with the respective baffle.
Claim 7
Dependent Claim
176 words
A multi-driver dynamic loud speaker system comprising frequency divider network means for dividing electrical signals fed to said system into at least three discrete frequency bands, a frame including an acoustically transparent front face, an enclosure within said frame, a bass radiator transducer mounted within said enclosure, at least two additional direct radiator dynamic transducers positioned within said frame, each of said at least two transducers having acoustically associated therewith a baffle member, said baffle members being essentially planar and surrounding the radiating diaphragms of said transducers, the plane of said baffles being aligned substantially perpendicular to the radiating axis of the transducer with which it is acoustically associated, the longest effective dimension of each said baffle member, measured in said plane, being not less than about one quarter and not more than about one half the wave length of a sound wave at the frequency of the lower nominal crossover frequency fed to that respective transducer, said baffles being supported within said frame externally of said enclosure and being substantially completely surrounded by free space.
Claim 8
Dependent Claim
176 words
A multi-driver dynamic loud speaker system comprising frequency divider network means for dividing electrical signals fed to said system into at least three discrete frequency bands, a frame including an acoustically transparent front face, an enclosure within said frame, a bass radiator transducer mounted within said enclosure, at least two additional direct radiator dynamic transducers positioned within said frame, each of said at least two transducers having acoustically associated therewith a baffle member, said baffle members being essentially planar and surrounding the radiating diaphragms of said transducers, the plane of said baffles being aligned substantially perpendicular to the radiating axis of the transducer with which it is acoustically associated, the longest effective dimension of each said baffle member, measured in said plane, being not less than about one quarter and not more than about one half the wave length of a sound wave at the frequency of the lower nominal crossover frequency fed to that respective transducer, said baffles being supported within said frame externally of said enclosure and being substantially completely surrounded by free space.
Claim 9
Dependent Claim
30 words
A loud speaker assembly in accordance with claim 6 wherein said frequency divided network means is of the gradual attenuation type, the attenuation rate being about 6 db per octave.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |