Magnetic device for loudspeaker system e.g. for underground stations, prevents adhesion of foreign bodies on loudspeaker or loudspeaker membrane

摘要

Magnetic device has at least one sound-permeable device with a definite or non-definite spacing or position relative to a flat panel loudspeaker, and preferably in front of the membrane of the loudspeaker or a panel of the loudspeaker. The magnetic device can be partly or completely joined to the flat membrane or to the loudspeaker. The flat loudspeaker membrane, the loudspeaker, or the loudspeaker cover completely or partly covers the length of the loudspeaker membrane, or of the loudspeaker only, or only of the cover. The magnetism of the magnetic device prevents adhesion of foreign bodies on the flat membrane of the loudspeaker, or on the loudspeaker itself, or on the cover of the loudspeaker.