Patent US3780824A successfully refreshed from Google Patents.
US3780824A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acoustic loading system
Assignee: Individual
•
Filing: 1972-08-14
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Granted: 1973-12-25
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Expires: 1992-08-14
Abstract
Abstract A loudspeaker system comprising an enclosure having at least one active radiator and at least one passive radiator mounted in respective openings in the enclosure. The passive radiator has a diaphragm supported by a highly compliant suspension. A mass is coaxially distributed and attached to the passive diaphragm. The mass is chosen so that the movement of the passive radiator will be substantially in phase with the movement of the active radiator within the frequency range of between approximately 20 Hz - 100 Hz. This mass is sufficient to reduce the natural resonance frequency of the loudspeaker system to a frequency substantially lower than its natural resonance frequency without the added mass attached to the passive diaphragm.
Inventors
- 👤 G Prince
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:54
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/283; H04R1/2834
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
122 words
A loudspeaker system comprising an enclosure having at least one active radiator and at least one passive radiator mounted in respective openings in said enclosure, said passive radiator having a diaphragm supported by a highly compliant suspension and a mass coaxially distributed and attached to said passive diaphragm, said mass being chosen so that the movement of the passive radiator will be substantially in phase with the movement of the active radiator within the frequency range of between approximately 20 Hz- 100 Hz, said mass being sufficient to reduce the natural resonance frequency of said loudspeaker system to a frequency substantially lower than its natural resonance frequency without said added mass attached to said passive diaphragm, said reduction being approximately one octave.
Claim 2
Dependent Claim
122 words
A loudspeaker system comprising an enclosure having at least one active radiator and at least one passive radiator mounted in respective openings in said enclosure, said passive radiator having a diaphragm supported by a highly compliant suspension and a mass coaxially distributed and attached to said passive diaphragm, said mass being chosen so that the movement of the passive radiator will be substantially in phase with the movement of the active radiator within the frequency range of between approximately 20 Hz- 100 Hz, said mass being sufficient to reduce the natural resonance frequency of said loudspeaker system to a frequency substantially lower than its natural resonance frequency without said added mass attached to said passive diaphragm, said reduction being approximately one octave.
Claim 3
Dependent Claim
37 words
A passive radiator diaphragm as claimed in claim 1 whereby the phase of said passive radiator diaphragm is retarded approximately 180*, relative to the phase of the back pressure of said active radiator, by said additional mass.
Claim 4
Dependent Claim
25 words
A passive radiator diaphragm as claimed in claim 1 wherein said additional mass is a weighted element secured substantially at the center of said diaphragm.
Claim 5
Dependent Claim
17 words
A passive radiator diaphragm as claimed in claim 1 wherein said loudspeaker enclosure is an air-tight enclosure.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |