if you are getting bass cancellation in the new arrangement, that would make it sound quieter, encouraging you to mix it too loud. putting up some auralex bass traps can fix that.

but note that having your speakers in the corner makes them essentially twice as loud as against the wall, so if you were used to that, you are probably cranking it harder now to get it to sound the same. once you get used to the new placement, your mixes should sort themselves.