| 摘要 |
PURPOSE:To improve a band and the peak of a frequency characteristic and to miniaturize and lighten a relaying material by providing a circular slit and a cut-in at a flat plate diaphragm and driving the section circular diameter position of the secondary resonance frequency of the flat plate diaphragm. CONSTITUTION:At the circumferential part of a frame 3 linked to a magnetic circuit composed of a plate 6 with a center pole, a ring-shaped magnet 5 an a top plate 4, the circumferential part of an edge 14 is bonded and linked together with a gasket 15. At the outer circumference of a flat plate diaphragm 7 to stick skin materials 8 and 10 in the upper and lower directions of a core material 9, the inner circumference of the edge 14 is bonded and linked. To the position of a section circular diameter A of the secondary resonance frequency of the diaphragm 7 through a delaying material 11, a voice coil 13 is linked, the intermediate part of the voice coil 13 is supported by a damper 12, and the lower part is inserted into the magnetic gap of the magnetic circuit. At the core material 9 of the flat plate diaphragm 7, at least one circular slit 1 and 2 or cut-in is provided.
|
