TL072 Car Subwoofer Filter Circuit

Here is the circuit diagram of an easy subwoofer filter that can be operated from a 12V DC supply. Such a circuit is incredibly helpful in automobile subwoofer applications. The circuit is nothing however a low pass filter whose pass frequency can be adjusted between 60 to 160 Hz.The circuit is designed based on the TL072 dual BIFET opamp IC. Out of the two opamps inside the chip, IC1A is wired