"What would a movie be without low-frequency effects? Even non-macho films like Sense and Sensibility have their share of carriage-wheel rumblings and horse-hoof thuds. Without a serious subwoofer that extends down to a solid 30Hz, and preferably even lower, a home-theater system can hardly be called "high-end."

Fortunately for aficionados of the subterranean, there exist companies like Earthquake Sound, which since 1986 has dedicated itself to the art of reproducing low frequencies. The SuperNova MKIV-15 represents Earthquake's latest thinking on what should go into a flagship subwoofer. After carefully checking my house's foundations for potential cracks and my walls for loose spots, I was fully prepared to find out if the MKIV was the best subwoofer in the known galaxy."
Steven Stone, Stereophile Guide To Home Theater