I've been mixing this Contemporary Christian CD and I find that the amount of true bass - say 40-50Hz and below - doesn't translate well to an environment like a car where this range is hyped. This hasn't been much of an issue before. My mixes of jazz, folk, Americana, etc. are pretty old school and don't put much energy in those frequencies. I mix with JBL 6328P's and except for this issue I've been pretty pleased. Mixes translate well to other systems. I have a lot of Arulex and 703 bass traps in the room, and while it is too dead to be considered a "good" room, it's pretty neutral. (I have to admit that I haven't measured the response in a while.) Anyway, I'm thinking of adding a sub woofer. The obvious choice is the JBL 6312SP. Any other recommendations? Any suggestions other than adding the sub?