With 29db gain from xpa-2 and 85 db Philharmonic's, you would be at 114db before distance db deduction. So you should be roughly at 108db at MLP when oppo is at 100 volume level.
Another potential problem could be that the xpa-2 doesn't produce enough current for the Phil's.
You will want to check your spl level at MLP to ensure you are actually at 108db. If not, either your amp or 105 could be malfunctioning.
Edited by Slinkee - 12/20/13 at 4:40pm