I'm thinking about buying the Sony DA5ES (Dolby Digital-EX / DTS-EX) receiver. However, looking at Crutchfield's photo of the back panel, I see that it only has one set of bananna plugs for the back surround. I went onto Dolby's website and saw that it's ideal to have 2 back surround speakers for the matrixed center for DD-EX. Does this prohibit me from having 2 speakers or can I put both speaker connectors (2 blacks/2 reds) into the 1 plug set. Thanks.