Identify diagram

Here is the circuit diagram of simple and easy subwoofer filter which will be operated from a 12V DC supply. Such a circuit is incredibly helpful in Car subwoofer applications. The circuit is nothing however a low pass filter whose pass frequency will be adjusted between 60 to 160 Hz.

The circuit is intended round the TL072 twin BIFET opamp IC. Out of the 2 opamps within the chip, IC1A is wired as a buffer. The left and right audio inputs when mixing is fed to the input of the IC1A using the DPDT switch S1. Switch S1 is that the section control switch which might be used to create the subwoofer in section with different speakers.



When S1 is in position {2, 180 degree phase shift are induced.POT R7 will be used for controlling the level. IC1B forms the low pass filter whose pass frequency will be controlled by adjusting the twin gang POT R13.