Yeah, the small lower end boost you're getting on the green speaker is likely due to corner placement. As is the case with a sub, corner placement accoustically couples the speaker better to the room and excites all resonances to give a boost in gain.
I'm afraid my experience is limited to low frequency equalization and not to room treamant. Hopefully others can chime in and help out with that.
Overall though I would say you need to lower somewhat the peak between ~120-150Hz and try and lower the upper end which must be a bit bright? A slow declining 'house curve' I've shown usually sounds best.
brucek