Mitch4t,
Sorry, I just realized that I did not completely answer your question... Also yes, you can put a sub behind you. Back at Marcof Electronics seems like 300 years ago, we had our own sub design. We buit an 8, 10, 12 & 15 inch model.. At some time or another we had tried each of these sitting right behind us, Maybe 2 feet, while the speakers were about 8 feet in front of us. Once spl was matched, they all worked well, undetectable.