Loudspeaker suspension
View Patent ↗An annular surround for a loudspeaker cone wherein a radial cross-section of the surround varies around the circumferential extent of the surround, so as to accommodate peripheral expansion or contraction of the surround by bending. Thus a trough shaped cross-section of the surround may vary sinusoidally with angle around the polar axis of the surround between a semicircular and semielliptical cross-section. The trough section may bland to an adjacent portion of the surround by a fillet which also varies sinusoidally in cross-section in phase with the variation of the trough.
1. A suspension for a loudspeaker diaphragm being an annular surround, wherein a radial cross-section of the surround varies around the circumferential extent of the suspension, wherein the radial cross-section of the suspension includes a trough-shaped portion, and wherein the depth of the trough varies around the circumferential extent of the suspension.
2. A suspension as claimed in claim 1 wherein the width of the trough is substantially consistent.
3. A suspension as claimed in claim 1 wherein the greatest depth of the trough is between 1.1 and 1.5 times, the least depth of the trough.
4. A suspension as claimed in claim 1 wherein the trough varies between a semicircular and semielliptical cross-section.
5. A suspension as claimed in claim 1 wherein the fillet or blending radius varies sinusoidally with angle around a polar axis of the suspension and wherein a maximum cross-section of the fillet or a maximum of the blending radius is in phase with a maximum depth of the trough.
6. A suspension for a loudspeaker diaphragm being an annular surround, wherein a radial cross-section of the surround varies around the circumferential extent of the suspension, wherein the radial cross-section of the suspension includes a trough-shaped portion, and wherein the trough merges with an adjacent part of the suspension by a fillet or blending radius which varies around the circumferential extent of the suspension.
7. A suspension as claimed in claim 6 wherein the adjacent part is a radially inner flange of the suspension.
8. A suspension as claimed in claim 6 wherein the variation of the fillet or blending radius is in step with the variation of the radial cross-section of the suspension.
9. A suspension as claimed in claim 8 wherein the variation of the fillet or blending radius is periodic and has a consistent phase relationship with the variation of the radial cross-section.
10. A suspension as claimed in claim 9 wherein the fillet or blending radius varies sinusoidally with angle around the polar axis of the suspension.
11. A suspension as claimed in claim 10 wherein the fillet or blending radius varies sinusoidally with angle around the polar axis of the suspension and wherein the maximum cross-section of the fillet or the maximum of the blending radius is in phase with the maximum depth of the trough.