Seen that this guy in his review has the speakers 30 inches from the rear wall & using all rear port plugs...

what is your setup with the m100's? I have mine 10 inches from the rear walls and 6 inches from side walls, slightly toed in, 10 feet apart and haven't experimented with the port plugs yet.

7.1.4 * MRX1120 * M100s * 180HP * 4x M3-on walls * 4x M3-IC * dual XV15se * Shakers