I can't say for certain but, after trying the remedy suggested above, you may want to try calibrating with a SPL meter. Many around here will mention that the auto calibration leaves something to be desired. I'm always amazed at how poorly I do it by ear and swear by my SPL meter.

If I understand correctly, it is also ideas to make a equilateral triangle with yourself and the front mains. So, perhaps try sitting ~ 9 ft from each of the mains with ~ 9 ft separation between them.

Good luck mate.