You need more than width.. For SQ you should tune low. Go for around 25Hz. Its gonna be a nice big box though. If you just want SQ though, you should build a sealed box. Common chamber ~ 7cuft box... Depends how much space you actually have though, and want to use. Those things can do well in a small, or large, sealed box. So do some measuring tomorrow on the space you would use, and get back to use.