摘要:
In a rolling process, the level of rolling performed by a rolling mill for one operation is set to 1 nullm to 20 nullm. A magnesium substrate is rolled by rollers while being heated by a thermostatic chamber. As a result, there is manufactured a high-quality magnesium sheet which is less susceptible to influence of oxidation, which realizes a high internal loss, prevention of a drop in sensitivity, and low distortion, and which has a thickness of 30 nullm to 100 nullm. Further, as a result of the magnesium sheet being formed into a semi-dome shape or a dome shape, the sheet can be inexpensively manufactured as a speaker for high-tone playback. In particular, in the case of a magnesium diaphragm into which a dome section and an edge section are integrally formed, high-quality sound can be played back in a high frequency range without involvement of a drop in sensitivity.
摘要:
A speaker's surround to be attached to an edge of a diaphragm in a speaker system is provided, which is capable of keeping its predetermined shape while repeating elastic deformation for accommodating large amplitude vibration of the diaphragm. Further, the surround is highly durable to withstand the repeated large amplitude vibration, and which can achieve high sound pressure levels. The surround for a speaker system includes a surround piece made of a rubber mold and a base member embedded in the surround piece. The base member is obtained by soaking a cloth material made of cotton or aramid fiber with a thermosetting resin such as phenol resin, and press-formed with heat into a predetermined shape. The surround thus has enhanced its shape maintaining capability.