Pre-amplifier board for an ultra-deep subwoofer. It will deliver a powerful bass punch and be complemented by a JBL subwoofer. Dual power supply that ranges from 24 to 35 volts. This is the circuit you've been looking for if you simply want to play low audio frequencies (bass). It is a circuit for a low pass filter. Above these frequencies, the frequencies are classified as "MID" or "High." The LOW pass filter circuit