If you are using the bult-in room correction, plug your main speaker's ports and run it again. :)
In general though, I have not heard Yamaha HT receivers in a very long time, but I do know that the quality of the sound processing, especially the DAC's of HT processors is really very wide. The gap among products is really disappointingly wide, when you'd think it should be really close. So, generally speaking, I would encourage you to try out an Anthem if you can find one, only because they sound good and relatively inexpensive. For sure, not Onlyo or Emotiva.