ACOUSTIC REPRODUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an acoustic reproducing device which is stable over a wide frequency, also secures a high S/N and can substantially improve acoustic characteristic of a speaker in an acoustic reproducing device which is used for various acoustic devices. SOLUTION: A negative feedback circuit is structured by connecting a filter 16 to an output of a microphone amplifier 15, processing a signal of an acoustic signal detection microphone 14 which is placed within a closed box 12, then performing addition processing of an output signal of the filter 16 and an output signal of a subtracter 10 by an adder 17 and then connecting the adder 17 to a negative input terminal. Thus, a feedback system which secures a high S/N as well as being stable is realized.