| 摘要 |
PURPOSE:To attain flat output sound pressure characteristic by making the vertex angle of each cross section of an inner diaphragm and an outer diaphragm different from each other so as to make the vibration frequency of normal mode of the inner vibrating part and the outer vibrating part nearly equal to each other. CONSTITUTION:A diaphragm 10 consists of the inner diaphragm 10a and the outer diaphragm 10b constituted by a part of a conical form and the vertex angle of cross section theta1, theta2 of the inner diaphragm 10 and the outer diaphragm 10b is in the relation of theta1>theta2. The inner ridge of the inner diaphragm 10a and the outer ridge of the outer diaphragm 10b are fixed respectively to a prescribed position of a magnetic circuit part 14 by fixed rings 12, 13. Through the constitution above, the vibration frequency of normal mode of the outer diaphragm 10b is increased and it is made equal to the vibration frequency of normal mode of the inner diaphragm 10a by selecting properly the value of the vertex angles theta1, theta2 of cross section. Thus, a speaker having a flat output sound pressure characteristic is obtained. |
