| 摘要 |
PURPOSE:To improve a directional pattern by installing an acoustic equalizer at a constant interval on the front part of a diaphragm, and adjusting sound pressure from the front and the rear. CONSTITUTION:A ring 54 and an equalizer plate 56 for constituting the acoustic equalizer are installed successively on the front of the inside of a metallic case 2, and one or more throgh-holes 58 are formed at a position spaced by a fixed distance from the center of the equalizer plate 56. A ring stucle with a diaphragm 8 is installed on the back of the equalizer plate 56, and a back pole 14 is installed through a spacer 12 on the back part of the diaphragm 8. A back plate 62 is installed through a conductive spacer 60 on the back part of the back pole 14, and a through-hole 66 is formed in the center part of the back plate 62. Accordingly. sound pressure P1 operating on the front of the diaphragm 8 and sound pressure P2 operating on the bak go to P1 P2, and a difference between the back sensitivity and the front sensitivity increases, therefore, to obtain a monodirectional pattern. |
