I currently own an RSW15 which sounds great with music. It does well for HT too, but I would like something that can reach a little lower. After running Audyssey on my Denon 4311 the response is less boomy which is good. But I believe a second sub would help even out the response throughout the room. Is it worth trying to integrate another sub such as an HSU VTF-15H, better to replace with two matching subs, or possibly use trhe RSW15 for music and another for HT?