ctpg,
In the grey "NOTE:" box at the bottom of page 28 in the manual, the last line says "If you have no side surround speakers, the back surround channels are automatically deactivated." So you should not even be able to get sound out of your speakers if you chose SURROUND BACK, but haven't chosen SURROUND. I just got my 970 today for a second setup and remembered seeing that when I was perusing the manual. Good luck and enjoy your Outlaw gear.
Jeff
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HT: Outlaw 975/7125 | Sony 55" SXRD | Roku Ultra | Sony BDP-S790 | Mirage OMD-15 (fronts) and Prestige 4 + Center Channel | Outlaw LFM-2
LR: ARC Reference 1 | Emotiva XPR-2 | Music Hall MMF2.2 | Oppo BDP-83SE | Polk XRt12 XM Receiver | Emotiva XDA-1 DAC | Sony HAP-S1 (digital audio player) | Sansui TU-217 Tuner | Magnepan 3.6R w/Mye-Stands | SVS SB-16 sub | BA VR-M90s | Audio Quest 72db speaker cable
Office: Drobo 5N running as PLEX media server
Closet: too many pieces to put all into place, I need more rooms