subwoofer filter low pass frequency

Circuits Audio Preamplifier
Bass preamp circuit subwoofer preamplifier board
BY
Toni
Subwoofer preamplifier with bass preamp circuit filter, ideal for activating active subwoofer speaker, still requires a power amplifier. It has ...
Hi Toni, how to change the schematics to be single ended voltage so I can implemented to 0-12volt? Thanks