Electroacoustic transducers

Claim 2

In an electroacoustical transducer having an annular permanent magnet with a center aperture, a pole piece positioned in the aperture, a voice coil surrounding the pole piece, a diaphragm operatively connected to the pole piece, a front flux plate with a center aperture aligned with the aperture of the magnet, a back flux plate attached to the pole piece, the improvement comprising: at least one of said flux plates having opposite parallel faces, one of which is completely flush with the annular magnet and said one flux plate having at least five sides substantially perpendicular to and between the faces, each side having an inner edge abutting the annular magnet, an outer edge substantially parallel to the inner edge, and two edges in common with adjacent sides; and the inner face edges of the one flux plate being contained within the area bounded by the outer diameter of the annular magnet.

Claim 3

An electroacoustical transducer as described in claim 1 wherein: the inner face edges of the one flux plate define an area of 70-91 percent of the surface area defined by the outer diameter of the annular magnet.

Claim 4

An electroacoustical transducer as described in claim 2 wherein: the one flux plate has a short diameter equal to 80-85 percent of the outer diameter of the annular magnet; the one flux plate has a longer diameter equal to 85-95 percent of the outer diameter of the annular magnet.

Claim 5

An electroacoustical transducer as described in claim 3 wherein: the inner face edges of the one flux plate form an irregular octagon with eight edges, four edges being of one length, four other edges being a shorter length alternately disposed between the four edges of longer length.

Claim 6

An electroacoustical transducer as described in claim 4 wherein: the one flux plate's side edges define an area of 75-80 percent of the surface area defined by the outer diameter of the annular magnet.

Claim 7

An electroacoustical transducer as described in claim 1 wherein both flux plates have at least five sides and have their inner edges contained within the area bounded by the outer diameter of the annular magnet.

Claim 8

An electroacoustical transducer as described in claim 6 wherein the inner face edges of the flux plates form an irregular octagon with eight edges, four edges being of one length, four other edges being a shorter length and disposed alternately between the four edges of longer length.

Claim 9

An electroacoustical transducer as described in claim 7 wherein the flux plate's side edges define an area of 70-91 percent of the surface area defined by the outer diameter of the annular magnet.

Claim 10

An electroacoustical transducer as described in claim 8 wherein the flux plate's side edges define an area of 75-80 percent of the surface area defined by the outer diameter of the annular magnet.

Claim 11

An electroacoustical transducer as described in claim 8 wherein the edges of the front flux plate are parallel and aligned with corresponding edges of the back flux plate.

Claim 12

An electroacoustical transducer as described in claim 1 wherein: each of the flux plates has opposite parallel faces, one face of each flux plate being completely flush with the annular magnet; each flux plate has eight rectangular sides substantially perpendicular to and between the faces of the respective flux plate; each side has an inner edge abutting the annular magnet, an outer edge parallel to the inner edge, and two edges in common with adjacent sides, each common edge being perpendicular to the plane defined by the flush face of the flux plate; the face edges of the flux plate form irregular octagons with eight edges, four edges being of one length, four other edges being a shorter length alternately disposed between four edges of the longer length; the inner face edges of the flux plate define an area of 75-80 percent of the surface area defined by the outer diameter of the annular magnet; the flux plate has a short diameter equal to 80-85 percent of the outer diameter of the annular magnet; and the flux plate has a longer diameter equal to 85-95 percent of outer diameter of the annular magnet.