Abstract: A compact subwoofer with exceptionally low distortion at 30 Hz and below is provided by a unique combination of system Q and an unconventional synthesized bandpass filter. The speaker has a system Q of 1.2 which is unusually high for a high quality, low distortion system. Nonetheless, a high Q with low distortion is made possible by the novel filter which has an oversized inductor and capacitor to provide a low-pass corner frequency nearly equal to the system resonant frequency. The result is a surprisingly broad, flat response at extremely low frequencies.