| 摘要 |
PURPOSE:To increase the sound pressure characteristics at low frequencies and to increase the entire sound pressure, by providing a vacant chamber infront of a diaphragm plate and through-hole linked to external side at a part of this vacant chamber. CONSTITUTION:A diaphragm plate 32 is provided an opening of a console 31 and a coil spring 33 is provided between a bottom section and the diaphragm plate 32 in the console 31. A console 35 forming a vacant chamber 34 is provided in front of the diaphragm plate 32. Sound waves entering from a through-hole 36 is given to a microphone device 37 directly and the diaphragm plate 32 is oscillated. The sound waves produced with this plate 32 enters the device 37 as the echo component to drive the diaphragm plate 32. Thus, the sound pressure characteristics of low frequencies can be increased by providing the vacant chamber 34, allowing to increase the entire sound pressure. |
