Definitions for "Pole Piece"
(1) A piece of ferromagnetic material used to control the distribution of magnetic lines of force; that is, it concentrates the lines of force in a particular place or evenly distributes the lines of force over a wide area. (2) The shaped magnetic material upon which the stator windings of motors and generators are mounted or wound.
The piece of metal in a speaker that concentrates and focuses energy from the speaker magnet to create a magnetic circuit. Because heat can build up during this process, many pole pieces are vented for cooler, more efficient operation.
The cylindrical core of a loudspeaker motor, one end of which forms the inside of the magnetic gap within which the voice coil moves.