The 1000-4 will work just fine for the passive 1100s. The 1500 will drive them louder with improved noise performance.
BTW, I've been running my actives in pure 2.0 for music the last 3 weeks. There's no question sealed subbage makes a difference but I find with most material, a sub isn't needed. On some material, I even prefer them in 2.0. I find actually that I enjoy the dual 125s with them for music over any of the sealed subs.
I've come to understand that these actives are perfect for those who don't want to fuss with subs, room correction and placement. The more I listen to them, the more I realize what a gift they are to sound reproduction.
