Planar speaker driver
A planar magnetic driver includes covering plates that are maintained under tension to form a buckled or curved surface, thereby providing for a larger magnetic gap, and allowing for a larger excursion of the diaphragm and extended lower frequency response. Another aspect of the driver includes a corrugated region along the periphery of the diaphragm, which provides increased internal dampening.
1. A planar magnetic driver comprising:
top and bottom plates having respective interior facing surfaces;
top and bottom magnets located on the interior facing surfaces of the top and bottom plates, the top and bottom magnets positioned such that a repellant magnetic force is induced between the top and the bottom magnets, the repellant magnetic force biasing the top and bottom plates away from each other and maintaining each of the plates in an arcuate shape; and
a diaphragm positioned between the top and bottom plates having electrical conductors, the diaphragm configured to vibrate responsive to an electrical signal applied to the electrical conductors interacting with a magnetic field induced by the top and bottom magnets.
2. The planar magnetic driver of claim 1 , wherein the top and bottom plates each have respective side edges, and the side edges are clamped to each other.
3. The planar magnetic driver of claim 2 , wherein there is a magnetic gap between the top magnets and the bottom magnets, and wherein the magnetic gap between the top and bottom magnets proximal a medial axis of the top and bottom plates is greater than the magnetic gap between the top magnets and the bottom magnets disposed proximal the side edges.
4. The planar magnetic driver of claim 3 , wherein the magnetic gap between the top and bottom magnets proximal the medial axis of the top and bottom plates is approximately 1.5 to 2 times greater than the magnetic gap between the top magnets and the bottom magnets disposed proximal the side edges.
5. The planar magnetic driver of claim 3 , wherein the top and bottom plates are dimensioned such that excursion of the diaphragm within the gap is substantially maximized during vibration of the diaphragm.
6. The planar magnetic driver of claim 1 , wherein the top and bottom plates are dimensioned such that the repellant magnetic force induced by the top and bottom magnets creates mechanical tension across surfaces of the top and bottom plates.
7. The planar magnetic driver of claim 6 , wherein the top and bottom plates are dimensioned such that resonance of the top and bottom plates is dampened by the mechanical tension across the surfaces of the top and bottom plates.