Originally Posted by adrummingdude
I owned a Supercube II for about 2 years and always found it a bit "slow." I know I'm opening up a big can of worms on this board by describing any piece of gear as such, but the single 8" with two 8" radiator design was just sloppy IMO. Don't get me wrong, I actually kind of miss that sub for movies because it could move a ridiculous amount of air for it's size, and like all Definitive products was built like a tank.
I would try removing the sub from your music system first and see how you like the mains alone. Give it a few days of listening to let your ears reaclimate themselves to hearing your rig without the sub. If after that time you truly do miss running a sub, I personally would look for a small sealed 8 or 10, as I've always liked them the best of mains integration. The Martin Logan Dynamo 700 is a great sub, as is the Velodyne optimum 8 and 10. Any of those will IMO sound more accurate than your current sub. Having been down the Supercube II road myself, I suspect your music woes have to do more with it than your mains.
A word of caution: While this is a great board and people are truly friendly and helpful, the main way subs are looked at around here (AVS in general) leans heavily towards big units which have huge outputs at room shaking extensions, which are great for action films, but often come at the expense of upper frequency accuracy and seamless mains integration. Small, sealed units with strong amps and light drivers are IMO best for that.
I had a supercube ii for a while as well and had pretty much the same thoughts as you. Pretty nice compact sub for movies, but for music it was severely lacking.
A few thoughts for Tgrshrk99:
1. I may be in the minority on this, but I'm not a fan of pure stereo. In my experience, better sound for stereo music can always be had by properly matching and setting up a good sub
2. None of definitive's built-in subs are going to give you the performance of good sub no matter what the marketing material says (or doesn't say, they don't make +/-3db numbers readily available for a reason). I have a pair of Mythos ST-L's, they are very nice but would improve immensely if I could afford a sub, but I just bought a pair of ST-L's so now I have no money
3. I've learned that my personal preference for subs is for sealed subs. This is anecdotal as I've not done a scientific double blind, but just listening, buying, and returning several subs over the years, I seem to stick with sealed ones. Perhaps it's due to the smoother roll-off in the lower frequencies that seem to improve music playback. Passive radiator subs behave like ported subs, perhaps you would prefer sealed for music.
4. I would also look for a better sub instead of changing out your mains. Depending on budget (you should be able to get a few hundred if you sell your SCII) I would consider a sealed sub from one of the ID companies, possibly the Rythmik F12 or SVS SB-2000