| 摘要 |
PURPOSE:To increase the performance by making flat the audio pressure frequency response up to high band and making less the distortion, through the formation of vibration plate with ceramic material. CONSTITUTION:When the vibration plate 1 is formed with the ceramic material taking aluminum oxide as the major component, the audio pressure frequency response is made flat up to high band and since sufficient rigidness is obtained, distortion can remarkably be reduced. That is, when the vibration plate is made of conical cone, the frequency to start the split oscillation is in proportional to the speed of sound. While, in case of ceramic material, the speed of sound in it is about 3.5 times that in normal paper to extend the band of the audio pressure frequency response. Further, the rigidity for bending is about 100 times that of paper to reduce the distortion. Further, it is more effective when through-holes 1mm or less in diameter are provided in many number or when through-holes are filled with foam material to make light the vibration plate in weight. |
