I agree with Buck. The XSub is a nice intermediate step. Not the most musical sub, but pretty darn good. Great for HT. The H100 is another great sub in this price range, as well. However, the PB10, at least to me, is justifiable as a next step upgrade. I had 2 XSubs stacked. I got the full 6db output increase. It was very nice. A single PB10 still was cleaner, had more output and extention. In a small to medium size room < 2200^3, it's a monster sub.