I had finally nailed down that I was going to get the 6.1 reference home theatre package. But due to room constraints and WAF I am now looking at using only bookshelf speakers in the front. I am concerned that the 2.1's won't be large enough for the 20' X 20' room. Can the C3's be used vertically as the left and right? And if they can be used, will they be large enough to fill the room with sound?