Normally the volume/gain knob is set just about half way and it does just fine when I'm sitting in the sweet spot. I put the M&K in because it helped fill in some dead zones as you walk around the room. It also gives a few db boost to the lower end. That and I had it so I might as well use it.

And really guys, the house isn't that big. Just an open floor plan with vaulted ceilings.