just so you know, a sub with C-3s will be pretty powerful, especially at nearfield.
the C-3s seem to have a *lot* of bass energy, more than the typical bookshelf in this budget range. they can really thump. if it were me, i would get the C-1s for that kind of setup. if you plan to use the system for a lot of gaming, the C-3 plus sub will obviously give a more visceral impact.
but for music, the C-3 seems to have more than enough bass for *most* music. i don't even use my sub for 2-channel listening with the C-3s, they seem to sound more balanced without one.
in fact, i'll go further and say that if the receiver doesn't have a "small" setting for the speakers with a separate crossover setting for the sub like an HT receiver, i think C-3 + sub would be overkill. i say that because i've tried it, and you really have to set the sub x-over low (like at ~45-50 !!) to avoid that weird kind of interference in the lower frequencies. set any higher, and the sub and the C-3 bass fight each other and it sounds horrible. w/out sub, or with sub crossed over properly and speaker low freqs sent to the sub, it's fine, obviously. i've never had a 2.1 receiver, so i'm just not sure which ones have that capability (or do all of them?) so i just thought i'd throw that out there, fwiw.
