Mission 752 and 771's Placement

[Nobber]

Hello

Just purchased a set of Mission 752 Freedoms(to use as rears) to match my fronts and I m unsure about the placement, so I now have 4 Miision 752's (Floor standers)and a set of Mission 771(Bookshelf)

my dilema is this, I can't get any of the speakers behind the seating position, so I've moved the surrounds slighlt forward and placed the surround backss along side the seating position.

Should I use the 752's or the 771's for the surround back or the other way round

is the sound similar coming out of the amps for the surround and the surround back or is there less emphasis from one of these
channels

thanks

Nobber

Sony VPL-11HT
Sony VA555ES & Sony STRDB930 for 7.1
Sony CX850 DVD



thanks


front speaker placement in my room (14*12) no problem surround and surround back