| 摘要 |
PURPOSE:To enhance the reproducing capacity till the low frequency band and enhance the acoustic improvement limit even in a small-sized acoustic box, by providing a flowing-out port at positive pressure with leed valve and a flowing-in port at negative pressure to a speaker acoustic box. CONSTITUTION:When an acoustic box inside is at positive pressure, the flows A and B of a sudden curve by the direction of leed valve 2' are guided. For this reason, because it is largely opposite to the nature of rectangular movement, the flowing-out resistance is considered to be large. At this time, since the flowing-out movement by a lead valve 3' of a port 3 flows like C and D that do not disturbe the rectangularity suddenly, that of port 3 has more flowing-out quantity than a port 2. On the contrary, when the acoustic box inside is of negative pressure and the outside is of positive pressure, the port 2 is small in flowing-in resistance, and the port 3 is large. in such a way, when the sound pressure of the acoustic box inside hanges to the positive pressure and the negative pressure, since the port is of forward movement being the flowing-in for port 2 and the flowing-out for port 3, the circulating movement is guided. Therefore, the air movement change rate of the sound wave is lowered. |
