My receiver doesnt have a sub out, so Im running speaker level inputs to the sub. My receiver only has 4 connections for speakers, 2 front, 2 rear. I have the front two speakers hooked up, then the sub in the back connectors. I plan on adding two rear surrounds, but my sub doesnt have high level outs, just high level in. How can i do this? Can i just plug the speakers, and the sub into the connectors on my receiver? Will that mess up the impedence or anything? Thanks in advance.