I am building a new house and wiring my great room for 7.1 audio. I want to wire up 2 wall plates for subs. Of course these have RCA interfaces on them. Can I just use my 14 gauge in-wall rated speaker wire through the walls, or do I need RCA or something shielded through the walls?

Thanks!

You need interconnects which are either twisted and/or shielded. The sort that generally come with RCAs. Speaker wire is inappropriate. For more info, there are 2 other current threads on the same issue.