| 摘要 |
PURPOSE:To vibrate a diaphragm without distortion by arrainging a tube group gathered to equalize the sum of cut area with a closed tube and an open tube having almost equal acoustic length at the rear side of the diaphragm so as to cancel the sound wave at the rear side. CONSTITUTION:Both kinds of the open tube 1 and the closed tube 2 having almost equal acoustic length, the closed tube 1 and the open tube 2 are arranged checkerwise, and the sum of the cut area is made almost eual with both tubes. The sound waves directed in the rear side among the sound waves produced by the vibration of the diaphragm are reflected at the rear end of the tubes 1, 2 and returend to the rear side of the diaphragm 3, since the phase is opposite in the closed tubes 1 and the open tubes 2 (a difference of 180 deg.), the reflected waves are cancelled with each other and no effect is given to the diaphragm 3. Thus, the diaphragm 3 is vibrated without any distortion. |
