| 摘要 |
PURPOSE:To simplify the constitution and to obtain a high sound pressure by constituting in such a way that a woofer disphragm, cylindrical acoustic filtering fixed to the inner peripheral edge of this woofer diaphragm and tweeter having a cylindrical frame for approaching and facing the inner peripheral surface of the acoustic filtering on the outer peripheral part are provided. CONSTITUTION:Numeric numbers 6, 7, 8 and 10 show an outer edge for supportig the outer peripheral edge of a woofer disphragm 5, cylindrical acoustic filterring 7 fixed to the inner peripheral edge of fhe woofer disphragm 5, tweeter having a cylindrical frama 9 for approaching and facing the inner peripheral surface of the acoustic filterring 7 and circular space in a simple shape obtained by modifying an inner edge frame 4, respectively. With this constitution, the length of the acoustic filtering 7 and an inverval between the acoustic filterring 7 and the cylindrical frame 9 of the tweeter 8 are decided by an expression I, which decides every volue so that a resonance frequency fr of the acoustic filter can be below a minimum resonance frequency or the woofer. Thus, when an inner edge is abolished and the inner edge frame is altered to the spacer 10, a high sound pressure can be obtained with simple constitution. |
