I'm 14' away from the M80s on the diagonal. The M80s are 10' apart and well away from the side walls. Spread yours further apart and you may never be able to put them closer together again. IMO, that opening to the living room isn't really as important as good soundstage...LOL!

Try putting the QS10s a foot ahead of your head if you can.

My side QS8s are 13' away from my MLP and 22' away from each other. Serenity_Now may be correct that I should try direct instead of reflecting speakers.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated