| 摘要 |
PROBLEM TO BE SOLVED: To provide a speaker in which a dynamic speaker and a piezoelectric speaker are driven with one amplifier, excellent in frequency characteristics.SOLUTION: A speaker 1 includes: a dynamic speaker 2; a piezoelectric speaker 3; and one current amplifier 4 for driving both of the dynamic speaker 2 and the piezoelectric speaker 3. When a rated impedance of the dynamic speaker 2 is denoted as Zd and impedance of a piezoelectric element 31 is denoted as Zp(ω), a value of a frequency ω, which satisfies Zd=Zp(ω), is made to be 20 to 50 kHz, thus high pass frequency characteristics becomes excellent.SELECTED DRAWING: Figure 2 |
