This subwoofer active filter circuit is a 24 dB octave filter with a Bessel character and cutoff frequency of 200 Hz. So, if you are interested in experimenting with audio circuits in subwoofer range, ...

Bought some new full range left+ rights which make me desire a bigger sub. (Klipsch r820's on the recent sale, so lame). Svs, monoprice and others sell 1500-2000+ watt rms subs for when it needs to be ...