I'd like to go ahead and add an additional speaker to do 6.1 with the surround back speaker. I suppose typically a center channel speaker is used for this purpose, but my receiver only has an RCA-type out (like for the sub) for the "6th" channel. Anyone know of any decent (under $200) speakers out there with this type of connection? Or is there a way to reconfigure a cable like used for the sub to work with the spring clip type speakers? Thanks in advance.