On subwoofers.... perhaps a pair of smaller accurate Velodynes would do the trick... or maybe even better, a pair of small Bob Carver True Subs would give you ease of placement, high output capability, low frequency extension, without 2 big boxes sitting in your room. An aside, please consider upgrading your CAL DX-2 to something better. I own the CAL Icon MK II Power Boss, which blows the doors off the DX-2 in terms of bass solidity, depth of soundstage, and imaging. I've compared both head-to-head and there really is no contest. You can probably find a used Icon for $700 or so - it would be money well spent, considering the quality of your speakers (Pro-Ac is known for their excellent imaging potential). Just some words of advice, take them as you will..... Good Listening!!