I can understand the points made so far on multiple subs, but wouldn’t a single ULS15 work superbly in many situations? For example, in my dedicated home theater (about 2400 cubic feet), 90% of the listening and viewing is with me alone in the sweet spot. When others join me, they often praise the sound quality regardless of where they sit. Thus I don’t have a strong need for multiple subs to balance the frequency response throughout the room. As to power, wouldn’t one ULS15 have sufficient “oomff” and clarity? And even if I wanted to exaggerate the low end and get that “crushing base” Keef95 mentions, why not just turn up the level of a single ULS15 (which I assume would have power to spare) rather than putting more subs into the room?