Incognito,

I would seriously re-think using the rears instead of the sides for surround music listening. When we listen in large venues, our sense of space comes from lateral (sideways moving) sound. That's one of the main reasons why concert halls are rectangular shaped. Even halls that are fan shaped (e.g., Tanglewood) have flat panels on the side walls that are swung out to be perpendicular to the audience in order to have better lateral reflections.

Try this experiment with your 950. Play some 2-channel music through the PLIIM CR mode so that you get surround content from all four surround speakers. Use the Channel Trim function to lower all the surround channels to the -15dB setting. Now, raise the volume of the two rear channels only; first to the +3dB setting, then to +6dB, even try +9dB. You'll notice the front soundstage getting louder. Now drop those channels back down to -15dB and then raise the volume of only the two side channels in similar steps as earlier. You'll notice the front soundstage actually gets wider, with imaging that extends outside your front left & right speakers.

If I had to use only two of the four surround speakers, it would have to be the ones at my side; they contribute much more when listening to music. Try it for yourself.

Best,
Sanjay