| 摘要 |
PURPOSE:To improve the rigidity of a diaphragm and to increase the resonance frequency by adhering at least a reinforcing thin plate along the long side of a core material and vertically to a surface material. CONSTITUTION:A core material 1 uses 40-time foamed styrene cut in about 5mm. thickness, 250mm. length and 50mm. width respectively, and aluminum foils are applied as surface materials 2 and 2'. Then the materials 2 and 2' are laminated on the surface of the material 1 by means of a polyamide film adhesive material. Thus a base material is obtained. Then aluminum foils 3 and 3' are bonded to the side faces of the base material in its long side direction to obtain a diaphragm. With this diaphragm set on a rectangular flat plate, two node lines are produced in parallel to the short side of said diaphragm against the first resonance frequency. However the first resonance is eliminated by driving the node line part, and therefore the flat sound pressure frequency characteristics can be obtained up to the second resonance frequency. |
