When running in 6.1 should I combine the left and right surround back outputs with a reverse splitter or do they have the same output? I currently use DTS ES and Dolby Digital EX via the optical input. I plan on using the 7.1 input with a Blu-ray with internal decoding in the near future. When running in Dolby True HD and DTS HD, are the surround back channels discrete? Thanks.