Diffuser and speaker using the same

• US 7,466,837 B2
• Filed: 07/27/2004
• Issued: 12/16/2008
• Est. Priority Date: 08/12/2003
• Status: Active Grant

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Nakamura, Takeshi
• Primary Examiner(s): Young; Wayne R
• Assistant Examiner(s): PENDLETON, DIONNE
• Application Number:
  US10/567,830
• Publication Number:
  US 20070064958A1
• Time in Patent Office: 1,603 Days
• Field of Search: 381/335, 381/336, 381/152, 381/337, 381/338, 381/339, 381/340, 381/341, 381/342, 381/343, 381/347, 381/350, 381/352, 381/160, 181/191
• US Class Current: 381/337
• CPC Class Codes: H04R 1/345 for loudspeakers

Abstract

A spherical wave generating diffuser positioned in front of the sound emission side of a sound source. The diffuser comprises an inner horn and an outer horn positioned concentrically around the inner horn. The diffuser generates pseudo-spherical waves centered on the inner horn because the emission speed of the sound waves emitted from between the outer horn and the inner horn are slower than the emission speed of sound waves emitted from within the inner horn.

Claims

1. A diffuser for placement in front of a sound wave emission side of a cone-shaped sound source, the diffuser comprising:

a first flow plate positioned along a sound wave emission direction of the sound source, the first flow plate having a wall tapered inwardly in the sound wave emission direction, the wall of the first flow plate being positioned outside of an area defined by the cone-shaped sound source and dimensioned so as to allow sound waves emitted from the cone-shaped sound source to pass on both sides of the wall; and

a second flow plate positioned adjacent the first flow plate along the sound wave emission direction, the second flow plate having a wall tapered outwardly in the sound wave emission direction, and the first flow plate being located within an area defined by the wall of the second flow plate.

2. The diffuser as claimed in claim 1, wherein the first flow plate is a tapered cone shape.

3. The diffuser as claimed in claim 1, wherein the first flow plate includes at least two spaced apart plates, inclined towards each other.

4. The diffuser as claimed in claim 1, wherein the second flow plate includes at least two spaced apart plates, inclined away from each.

5. A speaker comprising:

a sound source having a sound wave emission side; and

a diffuser according to claim 1 located in front of the sound wave emission side of the sound source.

6. The speaker according to claim 5, further comprising a protective net disposed in front of the sound wave emission side of the sound source, the diffuser being fixed to the protective net.

7. The speaker according to claim 6, wherein the diffuser is fixed in front of the protective net, behind the protective net, or both in front of and behind the protective net.

8. A diffuser for placement in front of a sound wave emission side of a cone-shaped sound source, the diffuser comprising:

a first flow plate positioned along a sound wave emission direction of the sound source, the first flow plate having a first opening proximal to the sound source and a second opening distal from the sound source, the first opening being larger than the second opening, the first opening of the first flow plate being positioned outside of an area defined by the cone-shaped sound source, and the first flow plate being dimensioned so as to allow sound waves emitted from the cone-shaped sound source to pass on both sides of the first flow plate; and

a second flow plate positioned adjacent the first flow plate along the sound wave emission direction of the sound source, the second flow plate having a first opening proximal to the sound source and a second opening distal from the sound source, the first opening being larger than the second opening, the first opening of the second flow plate being positioned outside of an area defined by the cone-shaped sound source, and the second flow plate being dimensioned so as to allow sound waves emitted from the cone-shaped sound source to pass on both sides of the second flow plate.

9. The diffuser as claimed in claim 8, wherein the first flow plate is a tapered cone shape.

10. The diffuser as claimed in claim 8, wherein the first flow plate includes at least two spaced apart plates, inclined towards each other.

11. The diffuser as claimed in claim 8, wherein the second flow plate includes at least two spaced apart plates, inclined towards each other.

12. A speaker comprising:

a sound source having a sound wave emission side; and

a diffuser according to claim 8 located in front of the sound wave emission side of the sound source.

13. The speaker according to claim 12, further comprising a protective net disposed in front of the sound wave emission side of the sound source, the diffuser being fixed to the protective net.

14. The speaker according to claim 13, wherein the diffuser is fixed in front of the protective net, behind the protective net, or both in front of and behind the protective net.