| 摘要 |
PURPOSE:To realize a target sound pressure characteristic by detecting the vibration acceleration of air in the cabinet of a speaker device, and matching it with the acceleration having the same frequency characteristic as the frequency characteristic of the target sound pressure. CONSTITUTION:A speaker device 1 is constant voltage-driven by an amplifier 4, and a detector 5 detects the vibration speed of the voice coil of a speaker unit 2. A signal processor 6 prepares the vibration acceleration of the air in a cabinet 3 from the output of the detector 5, and an amplifier 7 amplifies it. On the other hand, a filter 9 whose interrupting frequency and interrupting characteristic are variable is set so as to have the same frequency characteristic as the frequency characteristic of the target sound pressure, and the filter 9 processes an input signal 8, and prepares an acceleration signal being a reference. Next, an arithmetic unit 10 calculates a difference between the reference value of the acceleration and the actual value. A filter 11 limits the band of the difference signal. Then, an arithmetic unit 12 calculates the sum of the input signal 8 with the output signal of the filter 11, and inputs it to the amplifier 4. |
