Who are some of elite sub woofers?

Duke, I understand the subs in a swarm design all reproduce a combined left plus right (monaural) signal, even on material containing stereo bass (rare, but not unheard of). Is that correct? Is there any out-of-phase (left minus right), very low frequency, info lost when doing so?

There is one sub in a different class from all others, and that's not said pejoratively. The Eminent Technology TRW-17 Rotary Woofer is designed to be used from 30Hz down, a subwoofer for all other subwoofers.