Speaker upgrade

I recommend Wilson Alexandria X-2 or X-1 Grand Slam depending on your budget. It should get you where you want to go. Add a pair of Wilson XS subwoofers if you really want to fill out that bottom end.

You may want to listen to some vandersteen 5a or quatros depending on your buget very much the same sound as Thiels. I had the same bass issues now I have the 5a couldn't be happer. The trick is they have there own powered subs that are phase correct in the speakers. This produces tons of fast bass and also provides a natural by amping so if you run high end amps they just need to consentrate on the mids and highs. I have found subs never really work out well they just don't match the speakers 100% or the volume is not consistant. The Vandersteens also have a very advanced crossover that gets tuned to the room and your equipnment so you can alwas tweek the bass for more or less bass.

How do you spell D-U-N-L-A-V-Y ?!?

You want vocals? Jazz? Check out quality electrostatic speakers from Soundlab and Quad.

i've gotta say it. a mac pre and mcd 205 will nail realistic bass in any average size room with the thiels you have. you won't give up midrange to get it either. the musical fidelity plays....the mac controls