A properly installed Velodyne SMS-1 sub controller @ $450 with a 12" sealed sub from Rythmik (per my system) or SVS (pretty extensive word of mouth plus great test results, but no personal experience) @ $749 for either will almost certainly provide significantly smoother bass and will probably provide deeper, more powerful bass as well. Your total investment here is $1200. You may decide (as I diid) to use a different high pass unit (mine is a $300 NHT x-2) in place of the SMS-1's high pass, but this can be added later.
Good Luck
Marty
Good Luck
Marty