| 摘要 |
PROBLEM TO BE SOLVED: To solve a problem in a conventional MFB speaker system, that the capability of its amplifier cannot efficiently be used because the sound pressure level is decreased in a frequency band higher than a minimum resonance frequency f0 when the reproduction frequency band is extended toward a low audio frequency. SOLUTION: In the MFB speaker system provided with an enclosed cabinet 5, a speaker unit 4, a vibration displacement detection means 6 and a vibration velocity detection means 7 to detect a vibration displacement and a vibration velocity of the diaphragm of the speaker unit 4, an adder 2 that superimposes an external input signal on a feedback signal, and a power amplifier 3 that amplifies the total signal outputted from the adder 2, the vibration displacement signal and the vibration velocity signal are positively fed back to the adder 2.
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