Hi Wayne, thanks for the link. Explains a lot.
Regarding the placement, I placed the sub up the wall incrementally to the sides of the seating, but kept getting a serious null moving from 40 to 60 hz. Until I placed the sub in the corner location behind, perhaps it sitting on the riser at that point, with the elevation was enough to flatten the frequency out a bit more.
Any suggestions on whether it would be more advantageous to keep settings on receiver as flat, and pick up a BFD 1124 or use an overall room correction device (ezset/eq) that exists in the Harman? Or maybe both together.
On a side note, being relatively new to the field, I really appreciate any time experienced members, like yourself, take to help out guys like me, who would be quite lost without a bit of helping hand in the right direction. Thanks for the patience!