All I can think of right now is do the sub crawl with your sub in the listening position. I have my system in the basement, concrete everywhere, so lack of bass was an issue for me as well. Now I'm running with EP500 AND another 10" sub up front. With both subs going and my main tower speakers to LARGE, and having done the sub crawl to determine the best bass sound in the room, I finaly have the amount of bass I want.

As for acoustic panels, they certainly will not increase your bass response, but they will help with echo / ringing etc.. if you have those issues.

Acoustic Zen Adagio, Veritas center, Axiom EP500, QS8s, Anthem AVM20, MC20,Adcom GFA7400