Just cut out a small port(about the same size as the one on the back of the speaker) from either side of the column to allow the M22 to "breath" a little better into the room and cover that port with the same grille material and all should be good.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70