| 摘要 |
PURPOSE:To realize smooth high-frequency-range cutoff characteristics by fitting a plane diaphragm backwardly away from a plane baffle, and then fitting an acoustic filter having a >=30% opening rate to the front surface of the plane diaphragm. CONSTITUTION:To attenuate the high-frequency characteristics of a woofer, a diaphragm 1 is fitted backwardly away from a baffle plate 7 by a fitting member 8, and an acoustic filter 9 having a >=30% opening rate is fitted in the same surface with the baffle plate. When the opening rate is >=30%, the effect of the acoustic filter 9 is shown by frequency characteristics C, D, E, and F which attenuate gently in a high frequency range. A speaker unit having the characteristics shown in Fig. 5 is fitted the diaphragm at a position a/1=2.7 and an acoustic filter having a 50% opening rate is fitted to its front surface, so that the characteristics attenuate gently without disorder in the high frequency range. |
