| 摘要 |
PURPOSE:To attain high efficiency of speakers almost without narrowering the reproducing frequency band of the speakers, by arranging the dome shaped 2nd diaphragm at the center of the ring shaped 1st diaphragm of sandwich construction. CONSTITUTION:Both sides of a ring shaped frame member 1 are bonded with a surface plate 2 to form the 1st diaphragm 3 of sandwich construction. The dome shaped 2nd diaphragm 4 is placed at the center of the diaphragm 3 to form the diaphragm of the speaker. The frame member 1 of the diaphragm 3 is expanded into a ring shape so that a plate body 5 is folded in zigzag, one side 5A is taken as an inner circumference and the other side 5B is taken as an outer circumference. For the 2nd diaphragm 4, a material such as FRP, paper, and plastic film is used, allowing to improve the efficiency of the speaker almost without narrowering the reproducing frequency band of the speaker. |
