This is a low pass filter subwoofer using IC 324 and some other components.
This car subwoofer circuit set Suitable for use with a great car audio system. Since this circuit is designed to operate with a 12 volt DC power.
This is mini subwoofer circuit stereo system for home using low noise LF347, it can select frequency output filter is 60Hz,50Hz and boost up preamplifier. [...]