Eh hem!...Subwoofers... What do ya know?

It really is easy, go big or go home! Just get a Wilson Audio Thor's Hammer and call it good. Kidding. Lot's and lot's of good info here. In the end though, one way or another, a compromise must be met. Budget constraints, testing capability, room realities etc. Not all can have the perfect acoustic room. Like Eric mentioned, get what you can, dial it in to what sounds good to your ears and call it good. OR, go all in, have the room tested, do all the treatment, demo locations/subs and take that route. I recently eliminated my sub for my two channel setup. My room constraints wound up creating more problems than I could/want to try to "fix" so I binned it. Being a drummer I like the low end, but at the end of the day, once my ears changed a bit and the low boomy bass I "thought" I liked, was actually a very real negative. Anyway... I compromised and now I'm happy. (for now) haha!