This morning after a bit of frustration trying to eq level out some peaks I decided to try moving the sub from the rear corner position. The sub came alive with the new position. It is still about 4 feet from a front corner but really shakes the concrete floor slab, and blends much better with my mains. I continue to be amazed at how huge the impact of room position becomes as a more powerful sub is used. The bass is now strong, effortless and no longer fights with the mains for sound recognition. I found the new position allows me to run the sub with less severe EQ to achieve a flat response.