hello i am looking to upgrade my system, i mainly use it just for movies of course and xbox360. i would like the best sound for the cheapest cost right now, im looking at most to spend 1,000. i have and onkyo ht510 6.1 home theater system in a box. i am looking at the polk audio rm6750. i listen to it today and sounded very good. is there anything else u would recommend that would be better? or is that polk audio good? my room size is 10x11. i am roughly at max 6ft away from all my speakers. i also am planning to hook up the new sub along with my existing, so if i split the feed will it reduce the power to both subs? if so can i fix that in anyway to utilize both of them? PLEASE HELP.