I Just Picked Up The Onky Xr705 And Have Cambrig Sndwrks Spkrs: Mc 200's For Mains,mc300 Cntr,s200's Surndand Basecube S10 For The Sub. I Need Help With Rear Surnds To Achieve 7.1. Have Talked To A Few People And Some Are Saying That Another Set Of Main Style Speakers Will Be Enough And Others Are Saying Use Surnd Style.