Loudspeaker motor and suspension system

Patent metadata

Field	Value
Publication number	US-9854365-B2
Application number	US-201615130044-A
Country	US
Kind code	B2
Filing date	Apr 15, 2016
Priority date	Apr 15, 2016
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

A loudspeaker includes a voice coil in a balanced state. In the loudspeaker, at least a first suspension element acts on a first side of the voice coil, and at least a second suspension element acts on a second side of the voice coil. The loudspeaker includes a symmetric magnet assembly. The voice coil aligns with the symmetric magnet assembly. The symmetric alignment contributes to the loudspeaker yielding substantially symmetric motor force (BL), suspension stiffness (K), and inductance (Le).

First claim

What is claimed is:

1. A loudspeaker comprising:
a magnet assembly aligned along a longitudinal axis;
a frame encircled around the magnet assembly, wherein the magnet assembly and the frame form a voice coil gap therebetween;
a voice coil disposed in the voice coil gap and mounted for translation along the longitudinal axis, wherein the voice coil includes a first side longitudinally spaced from a second side;
a voice coil former attached to the voice coil;
a diaphragm attached to the voice coil former and adjacent to the first side of the voice coil;
a first suspension element attached to the diaphragm and the frame for supporting the first side of the voice coil during translation; and
a second suspension element attached to the voice coil former, adjacent to the second side of the voice coil, and attached to the frame for supporting the second side of the voice coil during translation;
wherein the voice coil is symmetrically aligned with the magnet assembly such that the magnet assembly includes an overall length along the longitudinal axis and the voice coil includes an overall length along the longitudinal axis, wherein a halfway point of the overall length of the magnet assembly coincides with a halfway point of the overall length of the voice coil when the voice coil is at rest.

2. The loudspeaker of claim 1 , wherein the first suspension element and the second suspension element place the voice coil in a balanced state such that the voice coil from the first side to the second side maintains a constant transverse spacing with the frame.

3. The loudspeaker of claim 2 , wherein the first suspension element and the second suspension element placing the voice coil in the balanced state further includes maintaining a constant transverse spacing with the magnet assembly.

4. The loudspeaker of claim 1 , further comprising a third suspension element attached to the voice coil former, adjacent to the first side of the voice coil, and attached to the frame for supporting the first side of the voice coil.

5. The loudspeaker of claim 4 , wherein the first suspension element, the second suspension element, and the third suspension element place the voice coil in a balanced state such that the voice coil from the first side to the second side maintains a constant transverse spacing with the frame.

6. The loudspeaker of claim 5 , wherein the first suspension element, the second suspension element, and the third suspension element placing the voice coil in the balanced state further includes maintaining a constant transverse spacing with the magnet assembly.

7. The loudspeaker of claim 1 , wherein the symmetrical alignment between the voice coil and the magnet assembly yields at least one of:
a substantially symmetric motor force,
a substantially symmetric suspension stiffness,
a substantially symmetric inductance.

8. The loudspeaker of claim 1 , wherein the frame includes an outer wall that encircles the magnet assembly, wherein the outer wall and the magnet assembly form the voice coil gap, wherein the outer wall includes an overall length along the longitudinal axis, wherein a halfway point of the overall length of the outer wall coincides with the halfway point of the overall length of the voice coil when the voice coil is at rest.

9. A loudspeaker comprising:
a magnet assembly aligned along a longitudinal axis;
a frame encircled around the magnet assembly, wherein the frame includes an outer wall, wherein the magnet assembly and the outer wall form a voice coil gap;
a voice coil disposed in the voice coil gap, wherein the voice coil includes a first side longitudinally spaced from a second side, and wherein the voice coil is aligned with the magnet assembly to yield at least two of:
a substantially symmetric motor force,
a substantially symmetric suspension stiffness,
a substantially symmetric inductance; and

a first suspension element attached to the frame and adapted to apply a first stiffness to the first side of the voice coil, and a second suspension element attached to the frame and adapted to apply a second stiffness to the second side of the voice coil.

10. The loudspeaker of claim 9 , wherein the first stiffness applied by the first suspension element to the first side of the voice coil is equal to the second stiffness applied by the second suspension element to the second side of the voice coil.

11. The loudspeaker of claim 9 , further comprising a third suspension element attached to the frame and adapted to apply a third stiffness to the first side of the voice coil.

12. The loudspeaker of claim 11 , wherein the first stiffness applied by the first suspension element plus the third stiffness applied by the third suspension element to the first side of the voice coil is equal to the second stiffness applied by the second suspension element to the second side of the voice coil.

13. The loudspeaker of claim 11 , wherein the first suspension element, the second suspension element, and the third suspension element place the voice coil in a balanced state such that the voice coil from the first side to the second side maintains a constant transverse spacing with the outer wall and the voice coil from the first side to the second side maintains a constant transverse spacing with the magnet assembly.

14. The loudspeaker of claim 9 , wherein the frame includes a first basket that angularly extends from the outer wall to a distal first portion, and the frame includes a second basket that angularly extends from the outer wall to a distal second portion.

15. The loudspeaker of claim 14 , wherein the first suspension element is attached to the frame at the distal first portion, and the second suspension element is attached to the frame at the distal second portion.

16. The loudspeaker of claim 15 , wherein the first suspension element is further attached to a diaphragm, and the diaphragm is attached to the voice coil.

17. The loudspeaker of claim 15 , wherein the second suspension element is attached to the voice coil.

18. The loudspeaker of claim 14 , further comprising a back plate that is attached to the magnet assembly and the distal second portion of the second basket.

19. The loudspeaker of claim 18 , wherein the back plate is made out of a non-ferrous material, and the frame is made out of a ferrous material.

20. The loudspeaker of claim 9 , wherein the voice coil is symmetrically aligned with the magnet assembly.

21. The loudspeaker of claim 9 , wherein the first suspension element and the second suspension element place the voice coil in a balanced state such that the voice coil from the first side to the second side maintains a constant transverse spacing with the outer wall and the voice coil from the first side to the second side maintains a constant transverse spacing with the magnet assembly.

22. A loudspeaker comprising:
a magnet assembly aligned along a longitudinal axis;
a frame encircled around the magnet assembly, wherein the magnet assembly and the frame form a voice coil gap;
a voice coil disposed in the voice coil gap, wherein the voice coil includes a first side longitudinally spaced from a second side;
a first suspension region including a first suspension element attached to the frame and the first side of the voice coil; and
a second suspension region including a second suspension element attached to the frame and the second side of the voice coil;
wherein the voice coil is symmetrically aligned with the magnet assembly such that th

Assignees

• Harman Int Ind

Inventors

• Sterling Brian

Classifications

• H04R9/025

  Magnetic circuit · CPC title

• H04R9/04

  Construction, mounting, or centering of coil · CPC title

• H04R2209/041

  Voice coil arrangements comprising more than one voice coil unit on the same bobbin · CPC title

• H04R9/045

  Mounting (H04R9/043 takes precedence) · CPC title

• H04R2400/07

  Suspension between moving magnetic core and housing · CPC title