Semi - Review
As an update for anyone in a similar situation the supercube 4000 is nice, but not for the size room I have. I bought one from a local best buy that was an open box item because the salesman was insisting it would work well for my needs, and if not they have a 15 day return policy (more on this at the end). Well I brought it home and was impressed with the fit and finish. I hooked it up to my system which is made up of Onkyo TX-NR616 receiver, Energy CF-50 towers, and def tech pro 1000 center. After adjusting the settings and with just the super cube 4000 attached I was under impressed with its performance in my room for the price. On half power it is very clean and sounds good, and would probably perform well in a one story standard size living room. My home happens to have a very open floor plan. My living room is two stories as well as my foyer which is directly attached. Also my kitchen and keeping room are attached through two different wide hall ways.
Now for my experience with BestBuy. I went to the store to return the sub and was treated nicely by the woman at the customer service counter. Right as she was finishing up my return she called over her radio for someone from the home theater department to come to the desk. She explained, without me asking, that the magnolia manager likes to know when items are returned. A man walked up to me with a another best buy employee who looked as if he was part of their loss prevention staff. The magnolia manager asked what the problem was, and I explained my situation. He began to talk to me as if I must be deaf, because in his words (we have one in the room back there, and it is very strong). I replied with well that may be the case in that room, but I am dealing with 5 or 6 times the volume and a lot of openings. He began to get aggressive with pushing for me to keep that sub and that it should be very strong. He also starting asking me all of the same questions over again. I cut him off in his tracks by stating I had already explained the situation and then asked him if there was a problem. He said there wasn't and handed me my receipt. I have to say I am pretty pissed off about the way he acted towards me. I was considering ordering a 8000 from them, but that encounter has changed my mind. I am going to most likely go with the PSA XV15 now.
Rant cliff notes - magnolia manager at bestbuy was very rude, and will not be getting my business in the future.
Thanks for all of the advice on other sub choices.