http://www.eminent-tech.com/RWbrochure.htm
"Subwoofer electronics usually contain a cutoff filter which sharply rolls off content to the subwoofer below 20Hz to protect the speaker. On the other hand, the rotary woofer has enough acoustic output to move a open door back and forth .5” between 1 and 5Hz! It has enough output to find resonance frequencies of walls and ceilings in a room. It requires no equalization to achieve flat response to below 1Hz. "
"Subwoofer electronics usually contain a cutoff filter which sharply rolls off content to the subwoofer below 20Hz to protect the speaker. On the other hand, the rotary woofer has enough acoustic output to move a open door back and forth .5” between 1 and 5Hz! It has enough output to find resonance frequencies of walls and ceilings in a room. It requires no equalization to achieve flat response to below 1Hz. "
