Title:
LOUDSPEAKER
Document Type and Number:
Japanese Patent JPS5591297
Kind Code:
A
Abstract:
In conventional commercial loudspeakers having a permanent magnet of the flat ferrite type, the magnet is provided with a central hole and is arranged in the magnet system as an outer cylindrical part about a central rod of soft iron, the voice coil being received in the annular air gap between the rod and the wail of the hole in the flat magnet. The invention provides for an inverted arrangement, in which a flat magnet disc member 4 (with or without, a central hole, and a pole piece 18) is used as the central rod member while the outer cylindrical part 6 is made of soft iron, e.g. integrally with the rear pole plate 2 of the magnetic system. The use of a conventional ferrite magnet conditions a low price and a voice coil 12 of large diameter, whereby the loudspeaker may be driven at high electrical effect due to an effective cooling of the voice coil. The outer annular soft iron member acts as a magnetic shield which makes the loudspeaker substantially free of any exterior magnetic field.
Inventors:
EYUBINDO SUKANNINGU
Application Number:
JP13472179A
Publication Date:
July 10, 1980
Filing Date:
October 18, 1979
Export Citation:
Assignee:
SKAANING EJVIND
International Classes:
H04R9/02; (IPC1-7): H04R9/02; H04R9/06