The Monitor Audios have arrived but I need some help in positioning the BFX rears. My room is 5m x 4m with my seating position approx. 1m in front of the back wall. I intend to wall mount the BFXs so do I mount on the back wall or on the side walls level with my seating position? Normally I would mount on the back wall but as they are bi-pole units I think I should mount on the side wall. What do you think?