I am planing on buying an amplificator with a budget of 600$. I was thinking of the Yamaha rsv863. I already have two front CerwinVega speakers (model E310). I would also need a center, a sub and two rear. My living room is in an open area so for now 5.1 is ok. My budget is about 700$ for speakers and sub. I saw some Ikon speakers. What do you think about them. What brand of sub would be the best for me. I listen to pop rock music not clasical!