I'm very late to the game here, but I will chime in for only one reason. I, as a fellow apartment dweller, will advise against the SuperCube. I bought the SuperCube I, the one the SC6000 replaced, and was very disappointed at the performance in comparison to other subs I have that cost much less, weigh less, and have approximately the same food print. I expected and wanted that subwoofer to perform and it just didn't do it. It was a beatiful sub (big reason why I wanted it) and very tiny looking (good for apartment right?). My $100 Athena AS-P400 sounds better and goes lower and is nearly as capable in output despite it's meager specifications. Based on the published specs alone you would expect the SuperCube to trounce the Athena in every possible way but does not in the slightest in the real world.
Also, I was told not to buy it by just about everyone here. I did not listen and I received my just rewards.