The Cambridge Soundworks computer speakers attached to my Mac Pro just weren't cutting it. I'd known this for a few years but never got around to doing anything about it. Mainly, I couldn't find much off-the-shelf gear that would fit in the 10x10 room with the rest of my stuff. I finally settled on building
Zaph Audio Hi-Vi B3S bookshelf speakers and a
RJB Audio Cerberus 6.5" subwoofer. I picked up a NuForce uDAC2 and a Virtue Audio One to drive everything.
Zaph Audio Hi-Vi B3S:

Cerberus:

After setting everything up, I did some measurements with REW and got the subwoofer integrated fairly well. There is a fairly big peak around 50Hz that is only present when the sub is on but otherwise, I've got a fairly flat response down to 35Hz. Sadly, I forgot to save the plots.
A/Bing with the Cambridge stuff is night and day. Now I just need to pick out some paint and do all the finish work.