| 摘要 |
PURPOSE:To obtain sound with good articulation, by remarkably attenuating >=5kHz high frequency components and eliminating unnecessary noise components, through only sticking a high band attenuation filter having a specific value or below of permeability on the sound radiation surface of a speaker. CONSTITUTION:A piezoelectric element 1 of unimorph type in which lead titanate or zirconate of 27phiX0.1mm. and brass plate of 40phiX0.1mm. are pasted, is supported to a frame 2, and a high frequency attenuating filter 3 made of a nonwoven cloth having 1-3cc/cm<2>/sec of permeability is pasted to the sound output side of a speaker with a little distance from the element 1. In this case, excessive frequencies of 5kHz or over can remarkably be attenuated and a piezoelectric type speaker having excellent articulation can be obtained. |
