| 摘要 |
PURPOSE:To obtain satisfactory sound radiating ability with an acoustic equipment by detecting a motional signal corresponding to the movement of a vibrating body forming partly a resonator to negatively feed said motional signal back to the input side and applying the motional feedback to a vibrator. CONSTITUTION:The driving state of a vibrator driving means 30 undergoes follow-up control in response to the movement of a motional feedback means 25 containing the means 30 so that the value corresponding to the drive input is always transmitted to the equivalent motional impedance side. Thus the internal impedance intrinsic to the vibrator 20 is apparently reduced or invalidated. Therefore, the vibrator 20 serves as an element which works in response to only the input of an electrical drive signal. As a result, the vibrator 20 performs ideal working with no production of transient responses at all. At the same time, the resonance system of the vibrator 20 is not substantially equal to a due resonance system and is equivalent to the wall surface of a resonator 10. As a result, the resonance Q value of the resonator 10 is extremely high and therefore the satisfactory sound radiating ability is secured for the resonator 10. |
