| 摘要 |
PURPOSE:To suppress divisional vibration of a diaphragm without lowering efficiency considerably to prevent generation of self-vibration sound peculiar to materials of the diaphragm, by filling a soft foamed material consisting of open cells in the internal space of the conical diaphragm. CONSTITUTION:Soft foamed material 10 consisting of open cells is filled in the space by conical diaphragm 5. As a result, peak dip is reduced to obtain a smooth frequency characteristic. In respect to efficiency, large difference is not generated, for example, 2kHz or more. Directivity resulted by the 30 deg. characteristic is rather improved slightly. Further, harmonic distortion is reduced slightly. |
