| 摘要 |
A complex-type speaker has plural piezoelectric vibrating boards. This speaker has a circular piezoelectric vibrating board (5), a cone paper (6,8), a ring-shaped piezoelectric vibrating board (7), a supporter for the ring-shaped vibrating board (9), a flexible layer (10,12), and a frame (11). The resonance frequency of the piezoelectric vibrating board is in inverse proportion to the diameter of the vibrating board. In this construction, a circular vibrating board of small diam. offers the high frequency range, and the ring-shaped vibrating board offers the low frequency range. The two boards allow a frequency range to be obtained.
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