That is interesting you preferred the XS30 to the SB13 Ultra. It seems like the XS30 would probably be better in terms of output and price, but the SB13 Ultra better in terms of size, fit and finish and DSP adjustments to make it work better in your room. So is music the priority for you or home theater?
I would love of Josh Ricci would review a big sealed sub like the Powersound XS30 or even the Rythmik F25. They seem to almost have the output capabilities of a good ported sub, like the SVS PB12+ or Rythmik FV15HP, but in a sealed design. Also, it would be interesting to see how they stack up to the SB13, since they do seem to have the price and output advantage, if you are okay with the larger size.