Patent ID: 11956612
Assignee: PURIFI APS
Field: Audio-visual technology (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A motor for an electrodynamic loudspeaker, comprising:
a magnetic circuit assembly arranged about a motor axis, comprising: an outer magnet, a magnetically permeable top plate, a magnetically permeable bottom plate,
a center pole piece and an air gap for receipt of a voice coil; wherein the air gap is formed by an inner axially extending wall of the magnetically permeable top plate facing an axially extending peripheral wall section of the center pole piece to define a width, a bottom, a top and height of the air gap;
an outwardly projecting magnetically permeable member arranged above the top of the air gap;
said center pole piece comprising a magnetic member extending axially from at least the bottom of the air gap to a magnetically permeable bottom member or to the magnetically permeable bottom plate;
wherein said magnetic member exhibits a relative alternating current (AC) magnetic permeability smaller than 10, or smaller than 5 or smaller than 2,
wherein a height of the magnetic member of the center pole piece is at least 0.5 times a height of the outer magnet or more than 0.7 times or 0.9 times the height of the outer magnet.