Ported loudspeaker system and method with reduced air turbulence, bipolar radiation pattern and novel appearance

• US 7,162,049 B2
• Filed: 01/07/2003
• Issued: 01/09/2007
• Est. Priority Date: 01/07/2003
• Status: Expired due to Term

• Current Assignee: Polk Audio Incorporated (DEI Holdings Incorporated)
• Original Assignee: Britannia Investment Corporation
• Inventors: Polk, Matthew S Jr.
• Primary Examiner(s): Tran; Sinh
• Assistant Examiner(s): Briney, III; Walter F
• Application Number:
  US10/337,347
• Publication Number:
  US 20040131219A1
• Time in Patent Office: 1,463 Days
• Field of Search: 381/335, 381/186, 381/337, 381/338, 381/342, 381/345, 381/351, 381/163, 381/357, 381/180, 381/349, 381/350, 381/389, 381/71.4, 381/71.7, 381/146, 181/163, 181/147, 181/156, 181/145, 181/160, 181/199, 181/144, 181/155
• US Class Current: 381/345
• CPC Class Codes: H04R 1/2819 for loudspeaker transducers
• CPC Class Codes: H04R 1/2826 for loudspeaker transducers

Abstract

A loudspeaker system includes a cabinet with an interior air volume, a transducer, a first port extending from an opening in the front wall of the cabinet to the interior of the cabinet, and a second port extending from and opening in the rear wall of the cabinet to the interior of the cabinet. The first and second ports are aligned along a common longitudinal axis and the interior ends of the ports are separated from each other by a predetermined distance. First and second flanges having a diameter larger than the first and second ports are disposed at the interior ends of the first and second ports, respectively.

Claims

1. A loudspeaker system comprising:

an enclosure including a first exterior wall, a second exterior wall disposed opposite the first exterior wall, and an interior, wherein the first and second exterior walls separate the interior of said enclosure from an exterior of the loudspeaker system;

a transducer at least partially disposed within the interior of said enclosure;

a first port extending from an opening in the first exterior wall to an end of said first port in the interior of said enclosure; and

a second port extending from an opening in the second exterior wall to an end of said second port in the interior of said enclosure,

wherein said transducer is at least partially disposed in an interior air space that is the same interior air space occupied by the interior ends of said first and second ports, and

wherein the respective ends of said first port and said second port are separated by a predetermined distance within the interior of said enclosure, such that acoustic energy from the interior air space exits said enclosure through said first and second ports approximately simultaneously and air in said first and second ports and between the interior ends of said first and second ports operates substantially as a single acoustic mass.

2. The loudspeaker system of claim 1, further comprising:

a first flange disposed at the end of said first port in the interior of said enclosure; and

a second flange disposed at the end of said second port in the interior of said enclosure.

3. The loudspeaker system of claim 2, wherein said first port and said second port have a first diameter and said first flange and said second flange have a second diameter larger than said first diameter.

4. The loudspeaker system of claim 2, wherein the predetermined distance separating the respective ends and flanges of said ports is less than approximately a diameter of said first and second ports.

5. The loudspeaker system of claim 2, wherein said first flange extends around the end of said first port in the interior of said enclosure and generally away from a central axis of said first port, and said second flange extends around the end of said second port in the interior of said enclosure and generally away from a central axis of said second port, such that a cross-sectional area between said first and second flanges is larger than a cross-sectional area of either of the first or second ports.

6. The loudspeaker system of claim 1, wherein said first port and said second port are aligned on a common axis.

7. The loudspeaker system of claim 1, wherein said first port and said second port are arranged such that there is an unobstructed view from the exterior of the loudspeaker system, through the opening in said first exterior wall through the interior of the enclosure to the opening in said second exterior wall.

8. The loudspeaker system of claim 1, further comprising a flow guide disposed in the interior of said enclosure, said flow guide being located between the ends of said first port and said second port.

9. The loudspeaker system of claim 1, wherein said first port and said second port have substantially the same length.

10. The loudspeaker system of claim 1, wherein said first port and said second port are substantially circular in cross-section.

11. The loudspeaker system of claim 1, wherein said first and second ports have a diameter, and the predetermined separation distance between said first and second ports is approximately ½

of the diameter of said first and second ports.

12. A loudspeaker system comprising:

a transducer;

an enclosure including a first exterior wall, a second exterior wall disposed opposite the first exterior wall, and an interior, wherein the first and second exterior walls separate the interior from an exterior of the loudspeaker system;

a first port extending from an opening in the first exterior wall to an end of said first port in the interior of said enclosure; and

a second port extending from an opening in the second exterior wall to an end of said second port in the interior of said enclosure,

wherein the respective ends of said first port and said second port are separated by a predetermined distance within the interior of said enclosure such that the total acoustic radiation pattern from the first port and the second port is approximately bipolar and air in said first and second ports and between said interior ends of said first and second ports operates substantially as a single acoustic mass.

13. The loudspeaker system of claim 12, further comprising:

a first flange disposed at the end of said first port in the interior of said enclosure; and

a second flange disposed at the end of said second port in the interior of said enclosure.

14. The loudspeaker system of claim 13, wherein said first port and said second port have a first diameter and said first flange and said second flange have a second diameter larger than said first diameter.

15. The loudspeaker system of claim 13, wherein the predetermined distance separating the respective ends and flanges of said ports is less than approximately a diameter of said first and second ports.

16. The loudspeaker system of claim 13, wherein said first flange extends around the end of said first port in the interior of said enclosure and generally away from a central axis of said first port, and said second flange extends around the end of said second port in the interior of said enclosure and generally away from a central axis of said second port, such that a cross-sectional area between said first and second flanges is larger than a cross-sectional area of either of the first or second ports.

17. The loudspeaker system of claim 12, wherein said first port and said second port are aligned on a common axis.

18. The loudspeaker system of claim 12, wherein said first port and said second port are arranged such that there is an unobstructed view from the exterior of the loudspeaker system, through the opening in said first exterior wall through the interior of the enclosure to the opening in said second exterior wall.

19. The loudspeaker system of claim 12, further comprising a flow guide disposed in the interior of said enclosure, said flow guide being located between the ends of said first port and said second port.

20. The loudspeaker system of claim 12, wherein said first port and said second port have substantially the same length.

21. The loudspeaker system of claim 12, wherein said first port and said second port are substantially circular in cross-section.

22. The loudspeaker system of claim 12, wherein said first and second ports have a diameter, and the predetermined separation distance between said first and second ports is approximately ½

of the diameter of said first and second ports.

23. A loudspeaker system comprising:

a transducer;

an enclosure including a first exterior wall, a second exterior wall disposed opposite the first exterior wall, and an interior, wherein the first and second exterior walls separate the interior of the enclosure from an exterior of the loudspeaker system;

a first port extending from an opening in the first exterior wall to an end of said first port, wherein the end of said first port includes a flange located in the interior of said enclosure; and

a second port extending from an opening in the second exterior wall to an end of said second port, wherein the end of said second port also includes a flange located in the interior of said enclosure and oriented to oppose the flange of the first port,

wherein the respective ends and flanges of said first and second ports are separated by a predetermined distance within the interior of said enclosure, such that air in said ports and between the respective ends and flanges of said first and second ports operates as a single acoustic mass.

24. The loudspeaker system of claim 23, wherein the predetermined distance separating the respective ends and flanges of said first and second ports is less than approximately a diameter of said first and second ports.

25. The loudspeaker system of claim 24, wherein said first port and said second port have a first diameter and said first flange and said second flange have a second diameter larger than said first diameter.

26. The loudspeaker system of claim 23, wherein said first port and said second port are aligned on a common axis.

27. The loudspeaker system of claim 23, wherein said first port and said second port are arranged such that there is an unobstructed view from the exterior of the loudspeaker system, through the opening in said first exterior wall through the interior of the enclosure to the opening in said second exterior wall.

28. The loudspeaker system of claim 23, further comprising a flow guide disposed in the interior of said enclosure, said flow guide being located between the ends of said first port and said second port.

29. The loudspeaker system of claim 23, wherein said first port and said second port have substantially the same length.

30. The loudspeaker system of claim 23, wherein said first port and said second port are substantially circular in cross-section.

31. The loudspeaker system of claim 23, wherein said first flange extends around the end of said first port in the interior of said enclosure and generally away from a central axis of said first port, and said second flange extends around the end of said second port in the interior of said enclosure and generally away from a central axis of said second port, such that a cross-sectional area between said first and second flanges is larger than a cross-sectional area of either of the first or second ports.