Loudspeaker system

• US 4,468,530 A
• Filed: 01/25/1982
• Issued: 08/28/1984
• Est. Priority Date: 01/25/1982
• Status: Expired due to Fees

• Current Assignee: Scopus Tecnologia Ltda. (Banco Bradesco SA)
• Original Assignee: Scopus Tecnologia Ltda. (Banco Bradesco SA)
• Inventors: Torgeson, W. Lee
• Primary Examiner(s): Rubinson, G. Z.
• Assistant Examiner(s): Schroeder, L. C.
• Application Number:
  US06/342,469
• Time in Patent Office: 946 Days
• Field of Search: 179/115.5 PV, 179/115 R, 179/111 R, 179/115.5 PS, 179/115.5 VC, 179/115.5 ES, 179/117, 181/163, 181/164
• US Class Current: 381/402
• CPC Class Codes: H04R 1/24 Structural combinations of separate transducers or of two parts of the same transducer and responsive respectively to two or more frequency ranges
• CPC Class Codes: H04R 9/047 in which the windings of the moving coil lay in the same plane

Abstract

One aspect of the invention is an integrated induction speaker which produces coherent high frequency and low frequency output. In this embodiment, the high frequency unit is centered between the two split halves of the low frequency unit. Another aspect of the invention is a configuration for a midrange or bass speaker having a very uniform magnetic field and excellent linearity.

Claims

1. A loudspeaker which comprises:

(a) first and second flat steel perforated sheets,

(b) a first row of longitudinally extending magnets of alternating polarity, mounted on said first steel sheet with perforations between the magnets,

(c) a second row of longitudinally extending magnets of alternating polarity mounted on said second steel sheet with perforations between the magnets,

(d) means spacing said first and second sheets, to space said second row from said first row by an air gap,

(e) magnets of like polarities and dimensions in said respective row facing and being parallel to each othe across said gap,

(f) a diaphragm situated midway in said gap between said respective magnet rows,

(g) a plurality of conductors supported by said diaphragm and extending parallel to said longitudinally extending magnets,

(h) said magnets and conductors and diaphragm arranged to form a high frequency speaker element in the central region of said magnet rows and low frequency or mid-frequency regions on either side of said high frequency region.

2. The loudspeaker of claim 1, wherein the high and low frequency regions are isolated by separating means.

3. The loudspeaker of claim 2, wherein said separating means comprise strips of live rubber.

4. The loudspeaker of claim 1, further comprising means for uniformly tensioning said diaphragm.

5. The loudspeaker of claim 1, wherein said diaphragm is a Mylar polyester membrane tensioned to approximately the yield point.

6. The loudspeaker of claim 1, wherein

(a) in the high frequency section the conductors are arranged in sets comprising a plurality of longitudinally extending passages which are spaced approximately 0.125 inches apart,

(b) in the low frequency section the conductors are arranged in sets comprising a plurality of longitudinally extending passes substantially centered between a pair of adjacent magnets on the same side, and

(c) the distance between the midpoint of the conductor passes of each set is between approximately 0.65 and 0.75 inches.

7. A loudspeaker which comprises:

(a) first and second flat steel perforated sheets,

(b) a first row of longitudinally extending magnets of alternating polarity, mounted on said first steel sheet with perforations between the magnets,

(c) a second row of longitudinally extending magnets of alternating polarity mounted on said second steel sheet with perforations between the magnets,

(d) means spacing said first and second sheets, to space said second row from said first row,

(e) magnets of like polarities and dimensions in said respective rows facing and being parallel to each other across said gap,

(f) a diaphragm situated midway in said gap between said respective magnet rows,

(g) conductor means supported by said diaphragm and extending parallel to said longitudinally extending magnets,

(h) said conductor means being centered in the spaces between adjacent magnets on the same side of said diaphragm,

(i) the ratio of the distance (A) between the center of one magnet and the center of an adjacent magnet on the same side to the width (B) of the magnet to the thickness (C) of the magnet to (D) the combined thickness of a pair of opposed magnets plus the distance across the air gap being approximately 3;

1.5;

1;

3.4.

8. The loudspeaker according to claim 7, wherein the magnets are uniformly magnetized magnetic rubber.

9. The loudspeaker according to claim 7 or 8, wherein the distance across said gap between facing magnets is at least 0.2 inches.

10. The loudspeaker according to claim 7, wherein

(a) distance (A) is approximately 0.75 inches,

(b) distance (B) is approximately 0.375 inches,

(c) distance (C) is approximately 0.25 inches,

(d) distance (D) is approximately 0.85 inches,

(e) N, the number of conductor passes per space between adjacent magnets is 3 or 4, and

(f) the distance (E) is between the center of the first and last conductor passes in any single space between adjacent magnets is approximately 0.05 inches for N=3 and approximately 0.08 inches for N=4.

11. The loudspeaker according to claim 7 or 9, wherein the ratio of distance (C) to the distance (E) between the centers of the first and last conductor passes in any single space between adjacent magnets is approximately 1:

0.32.

12. The loudspeaker according to claim 7 or 10, wherein the magnets are uniformly magnetized material having an incremental permeability of about 1.0.

18. The loudspeaker of claims 7 or 8 or 9 or 11 or 13 or 14 or 15 or 17, further comprising

(a) a high frequency speaker section centrally located between the split halves of the bass or midrange sections,

(b) said high frequency section being comprised of a common diaphragm with said bass or midrange sections.

19. The loudspeaker of claim 11 further comprising

(a) a high frequency speaker section centrally located between the split halves of the bass or midrange sections,

(b) said high frequency section being comprised of a common diaphragm with said bass or midrange sections.

20. The loudspeaker according to claim 12, 14 or 16, wherein the magnets are uniformly magnetized magnetic material with an incremental permeability of about 1.0.

13. A loudspeaker unit, which comprises

(a) first and second flat steel perforated sheets,

(b) a first row of lognitudinally extending magnets of alternating polarity mounted on said first steel sheet with perforations between the magnets,

(c) a second row of longitudinally extending magnets of alternating polarity mounted on said second steel sheet with perforations between the magnets,

(d) means spacing said first and second sheets, to space said second row from said first row,

(e) magnets of like polarities and dimensions in said respective rows facing and being parallel to each other across an air gap,

(f) a diaphragm situated centrally in said gap between said respective magnetic rows,

(g) conductor means supported by said diaphragm,

(h) the passes of said conductor being centered in the spaces between adjacent magnets on the same side,

(i) the ratio of the distance (A) from the center of one magnet to the center of an adjacent magnet on the same side to the width (B) of the magnet to the thickness (C) of the magnet to the combined thickness (D) of two facing magnets plus the distance across the air gap being approximately 2.6:

1.5;

1;

3.

14. The loudspeaker according to claim 13, wherein the magnets are uniformly magnetized magnetic rubber.

15. The loudspeaker according to claim 13, wherein the ratio of distance (C) to a distance (B) between the centers of the fist and last conductor passes in any single space between adjacent magnets is approximately 1:

0.16 for N=3 or approximately 1;

0.32 for N=4.

16. The loudspeaker according to claim 14 or 15, wherein the distance across said gap between facing magnets is 0.2 inches or greater.

17. The loudspeaker according to claim 15, wherein the

(a) distance A is approximately 0.65 inches,

(b) distance B is approximately 0.375 inches,

(c) distance C is approximately 0.25 inches,

(d) distance D is approximately 0.75 inches,

(e) distance E is approximately 0.04 inches for N=3 or approximately 0.08 inches for N-4.