| 摘要 |
PROBLEM TO BE SOLVED: To make a low sound frequency characteristic more flat regardless of provision of a long acoustic tube to obtain high narrow directivity. SOLUTION: In a line microphone where a long acoustic tube with high directivity is provided and a condenser unit 3A employing a polymer film for a diaphragm 35 is used for a microphone unit, a support projection 342 with nearly the same height as a circumferential edge of a support 34 and having a throughhole 351 penetrated in axial direction is formed in the middle of the support 34 of the diaphragm 35, the diaphragm 35 is fixed to the circumferential edge 341 of the support 34 and the support projection 342 with a prescribed tension and an opening 30 in communication with the throughhole 351 is provided to acoustically couple a front chamber 353 and a rear chamber 352 of the diaphragm 35.
|
