Patent US4475233A successfully refreshed from Google Patents.
US4475233A
Expired / Lapsed
US
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Resistively damped loudspeaker system
Assignee: Individual
•
Filing: 1981-10-08
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Granted: 1984-10-02
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Expires: 2001-10-08
Abstract
Abstract A loudspeaker system is provided wherein the coils, capacitors, and loudspeaker drive units and combinations thereof are resistively damped to provide electrical damping of the back EMF of these components and thereby reduce ringing in the loudspeaker crossover networks. The result is a measurable and clearly audible improvement in the accuracy of the sound produced by the loudspeaker system.
Inventors
- 👤 William H. Watkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:21
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/04
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
110 words
In a loudspeaker system comprising at least a high frequency loudspeaker driver unit and a low frequency loudspeaker driver unit, and input circuitry connected to said driver units and comprising crossover networks comprising capacitors and coils, the improvement comprising resistive damping means for electrically damping the back EMF of the system coils, capacitors, drive units and combinations thereof to reduce the ringing voltage in the loudspeaker crossover networks, said resistive damping means comprising a plurality of damping resistors individually in shunt with a like plurality of individual capacitors and coils, and a said damping resistor being connected in shunt with each of the individual capacitors and coils of the system.
Claim 2
Dependent Claim
110 words
In a loudspeaker system comprising at least a high frequency loudspeaker driver unit and a low frequency loudspeaker driver unit, and input circuitry connected to said driver units and comprising crossover networks comprising capacitors and coils, the improvement comprising resistive damping means for electrically damping the back EMF of the system coils, capacitors, drive units and combinations thereof to reduce the ringing voltage in the loudspeaker crossover networks, said resistive damping means comprising a plurality of damping resistors individually in shunt with a like plurality of individual capacitors and coils, and a said damping resistor being connected in shunt with each of the individual capacitors and coils of the system.
Claim 3
Dependent Claim
47 words
A loudspeaker system as claimed in claim 1 wherein the input circuit connected to at least one of said driver units comprises a parallel combination of a capacitor and a coil and said resistive damping means includes a damping resistor connected in parallel with said parallel combination.
Claim 4
Dependent Claim
56 words
A loudspeaker system as claimed in claim 1 or 2 wherein the input circuitry connected to the low frequency driver unit includes a low pass filter comprising a pair of series-connected coils and a shunt-connected capacitor and said resistive damping means includes a damping resistor connected across each of the series-connected coils and the shunt-connected capacitor.
Claim 5
Dependent Claim
57 words
A loudspeaker system as claimed in claims 1 or 3 wherein the input circuitry connected to the high frequency driver unit comprises a high pass filter comprising a pair of series-connected capacitors and a shunt-connected coil and said resistive damping means includes a damping resistor connected across each of the series connected coils and the shunt-connected capacitor.
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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) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |