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US4756382A Expired / Lapsed US ⏱️ 0.0 years remaining

Loudspeaker having enhanced response at bass frequencies

Assignee: Individual
•
Filing: 1987-03-02
•
Granted: 1988-07-12
•
Expires: 2007-03-02
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Abstract

Abstract A loudspeaker is disclosed having an enhanced response at bass frequencies. The loudspeaker includes a tubular enclosure having a pair of outwardly directed, opposing loudspeaker drivers mounted over each end. A port is provided through the enclosure midway between the drivers and is coupled to the exterior of the loudspeaker by a perpendicularly projecting duct. The length and cross-sectional area of the duct, as well as the enclosure, are selected to describe an acoustic cavity having a predetermined mechanical resonance. The opposing nature of the drivers, spaced apart by the continuous curved walls of the enclosure, reduces spurious resonances within the enclosure. In addition, the resultant T-shaped configuration of the loudspeaker maintains the loudspeaker substantially stationary in a moving vehicle without the need for auxiliary fastening devices. In other arrangements, a longitudinally extending duct having a crescent-shaped cross section is employed instead of the perpendicularly projecting duct and the cross section of the enclosure may, for example, be elliptic rather than circular.

Inventors

  • 👤 Joseph L. Hudson, III

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 21:33
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/28; H04R1/2807; H04R1/2815; H04R1/2819; H04R1/227; H04R1/2869; H04R1/2884; H04R1/2888; H04R5/00; H04R5/02

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 125 words
A loudspeaker comprising: an enclosure having first and second open ends and a port, located between said first and second open ends; a duct, having four sides and a substantially rectangular cross section, projecting outward from said enclosure and extending from said port in a direction substantially perpendicular to the longitudinal axis of the enclosure, said duct having at least two sides that are substantially tangentially aligned with said enclosure, said duct and said port being for acoustically coupling the interior and exterior of said enclosure; first driver means, secured to said first open end of said enclosure, for converting electric energy into acoustic energy; and second driver means, secured to said second open end of said enclosure, for converting electric energy into acoustic energy.
Claim 2
Dependent Claim 125 words
A loudspeaker comprising: an enclosure having first and second open ends and a port, located between said first and second open ends; a duct, having four sides and a substantially rectangular cross section, projecting outward from said enclosure and extending from said port in a direction substantially perpendicular to the longitudinal axis of the enclosure, said duct having at least two sides that are substantially tangentially aligned with said enclosure, said duct and said port being for acoustically coupling the interior and exterior of said enclosure; first driver means, secured to said first open end of said enclosure, for converting electric energy into acoustic energy; and second driver means, secured to said second open end of said enclosure, for converting electric energy into acoustic energy.
Claim 3
Dependent Claim 14 words
The loudspeaker of claim 1, wherein said enclosure has a substantially circular cross section.
Claim 4
Dependent Claim 29 words
The loudspeaker of claim 2, wherein said duct has a width, normal to the longitudinal axis of said enclosure, that is substantially equal to a diameter of said enclosure.

References Cited (Backward Citations)

US2002390A Cited
US3512606A Cited
US4146744A Cited
US4284166A Cited
US4472605A Cited
US4567959A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-07-12 1992-01-11 1992-07-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-07-12 1996-01-11 1996-07-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-07-12 2000-01-11 2000-07-12 $7700.00 Window Closed / Lapsed

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