The post explains a simple low pass filter circuit which can be used in conjunction with subwoofer amplifiers for acquiring extreme cuts or bass in the frequency range 30 and 200Hz, which is adjustable.
How the Circuit Works
Several low pass filter circuits for subwoofer application are presented all over the net however this one is an upgraded example.
The circuit provided here utilizes the high efficiency opamp TL062 from ST Micro electronics. TL062 is a twin high input impedance J-FET opamp exhibiting minimal power consumption and large slew rate.
The opamp possesses outstanding digital attributes as well as being exceptionally compatible with this circuit.
Between the two opamps inside TLC062, one is connected in form of the mixer with pre amplifier stage. The left/right channels are linked to the inverting input of IC1a for mixing.
The gain of first stage may be tweaked utilizing POT R3.The output of the 1st stage is hooked up to the input of next stage via the filter circuit containing parts R5,R6,R7,R8,C4 and C5.
The second opamp (IC1b) functions as a buffer as well as the filtered output can be obtained at the pin 7 of the TLC062.