Subwoofer active low pass filter A simple circuit based on the LM358 opamp to be placed before an audio amplifier driving a subwoofer loudspeaker.
Subwoofer passive low pass filter A simple capacitors and resistors network to be placed before a generic audio amplifier in order to filter the high frequencies
Subwoofer third order passive low pass filter Project and schematic of a passive circuit made of capacitors and resistors to be placed before an audio amplifier to filter the high frequencies