LOW SOUND FREQUENCY CORRECTION CIRCUIT FOR ACOUSTIC REPRODUCTION DEVICE

摘要

PURPOSE:To realize the low sound frequency correction circuit for the acoustic reproduction device in which a sense of deficiency of a low sound frequency is corrected in a sound volume and a natural sound is reproduced by solving a problem of occurrence of a undistinct sense of low and medium sound frequencies in a small sound volume with respect to the low sound frequency correction circuit used for various acoustic reproduction devices. CONSTITUTION:An interlocking variable resistor 8 in interlocking with a sound volume adjustment variable resistor 10 and a 5th resistor 7 determining a cut-off frequency and a Q of a 2nd-degree positive feedback high pass filter are connected in series between ground and a 1st resistor being a positive feedback resistor of the 2nd-degree positive feedback high pass filter employing an operational amplifier 9 to amplify only a low sound frequency signal deficient at a small sound volume especially and natural low sound frequency is corrected with respect to the sound volume.