a quick couple of thoughts --

Boston subs are nice sounding subs that can handle some power, but they are SQ oriented.

ED makes their A series which can handle in the kilowatt range -- but they are also generally SQ subs and will be tight.

and be sure you check out the Focal V2 (Polyglass) series and make sure you're not over powering them, as they handle less power than the Utopias. the K series (PolyKevlars) handle a bit more power... equal to the Utopias actually.

Kicker solobarics have also been known to be quite loud and very boomy solid subs... i'm not sure it's the best pairing w/ what you're looking at though...

 

What if I don't need a low bass subwoofer, just a good sounding woofer enough to fill the S2K but not way too much? Which subwoofer would you guys recommand?

So many brands out there.. just donno how to make a decision. and dont want to make a wrong one and regret. Make me wanna just go with JL since it's got a more regonized name around.