| 摘要 |
PURPOSE:To enhance the magnetic and mechanical nonlinearity by installing the individual voice coil into the magnetic gap each formed at ssveral areas in the length direction of the center pole, thus ensuring a high-performance electricity-sound conversion with a reduced distortion mudulus. CONSTITUTION:Center pole 2 made of the columnar or cylindrical mangetic material is fixed in plural units at th upper part of the center of flange 1 made of the nonmagnetic material, and air escape holes 3-5 are drilled through at the periphery and the center area of pole 2. furthermore, ring-shaped permanent magnet 6 of a prescribed thickness is held between 1st and 2nd plates 7 and 8 made of the magnetic material, and then plate 8 is fixed to flange 1. At the same time, frame 11 is fied to plate 7, and diaphragm 13 is attached between frame 11 and voice coil bobbin 14. Then 1st and 2nd voice coils 18 and 19 are installed between pole 2 and plares 7/8 with a link to diaphragm 13, and coils 18 and 19 are supported by 1st and 2nd dampers 15 and 16 so that these coils may be shifted in the length direction. |
