Keta,
Thanks for your reply. I don't know why I haven't thought about borrowing someone else's subwoofer to try out the two sub scenario. Just like your situation, no matter where I place my current subwoofer, I still get very boomy sound. And when I calibrated my current sub, the dial is only about 1/2 way only so I know it is not pushing the sub to its max output yet. And hearing SACD or DVD-A, the bottom end sounds very "muddy" without very good definition to it. So now to test whether two subs are going to help in my situation, I just need to find somebody with a decent subwoofer for me to borrow. I am keep looking for any of my friends who might have SVS PB2+ for their setup so that I can listen for myself. Whatever I decide, I will try to post my experience with this matter soon.