Most subs have built in low-pass filters. If you can get a line level (lower than speaker) signal then you are all set.
4 responses Add your response
A pair of Harrison Labs FMOD RCA Inline Low Pass Crossover should work. https://images-na.ssl-images-amazon.com/images/I/61i5NiPOviL._AC_SY355_.jpg If you need to feed the subwoofer amplifier from your radio speaker output, add a LOC. https://m.media-amazon.com/images/I/71hR6X1q89L._AC_SL1500_.jpg Radio speaker output > LOC > Inline Low Pass Crossover > subwoofer amplifier |