After searching for the past week for a good dual sub combo for under $3000 I thought I was set on 2 Velodyne Optimum-12's. The only problem was that the only site that sold them for under $1500 was audiophileliquidators.net which I have found MANY horrible reviews about. I am in the military and have access to shop on aafes.com and just found that they sell brand new Velodyne DD-10's for $1199 and DD-12's for $1399!! I consider this a great deal since DD-12's usually retail for $2500. The only question I have is wether to get the DD-10's or the DD-12's. With nearly identical specs, except for the driver size and a 1hz lower in low end frequency response, is it worth an extra $400 for 2 DD-12's? I realize that 2 12inch drivers will push more air then 2 10inch drivers, but what are the real world effects to the sound quality/SPL? Thanks for your guys input. Also, I have concrete floors, does anyone recommend gramma pads, or something similar?