| 摘要 |
A moving coil loudspeaker having a cone (14) made of homopolymeric polypropylene which is stiffened by the incorporation of from 20% to 40% mineral filler such as talc or chalk, possibly also up to 5% carbon black filler, and preferably is additionally rigidified at the cone center by a stiffening ring (21) of nylon or like hard plastics material. A further feature of the invention resides in the provision of a metal former (22) carrying lapping paper (25) at the joint with the cone. |
