Sub at the weakest bass point in a room?

What Eric said.
While your sub is at the listening position map out all the locations where the bass sounds strongest. 
A cheap dolly from Harbor Freight could save your back. 

Get sliders (Harbor Freight) to get them it (them) placed. When your done with the major moving, remove two and leave two, for the final placement.
I can move 200 lb pretty easy, with just a heal bar (crow bar) and one slider, like a 5th wheel. Then use the heal bar to remove the last two when your done. I leave  two.

On rough concrete, I just use 1-2" dowels, a few inches wider than the bass bins..

A single sub can add a lot, with placement.. It can also cancel/comb at the cross over points.
  
With DSP/phase correction, either, on board or passive, via OXO, placement can be pretty precise. With an active mic being used
for real time correction, you can hear the distortion, being cleaned up and more than one note can be heard, in REAL time.. Kinda cool really..
Know your room, AY.. 

and then there are Columns... COLUMNS. . . . .C O L U M N S.....

Regards

LoL @ millercarbon.

You should have added or until you decide to just buy speakers that play lower or until you’ve sold yourself on the idea that bass isn’t that important...

What’s really funny is no one wants to admit what I said is true. Their solution is sliders so you can fail more times before you get tired. Oh and of course how not to buy EQ and GIK. At the very least they should recommend something that might actually provide really powerful and perfectly smooth bass like put the sub in the middle of the room and sit on it.

Miller is the most important advocate of the distributed bass array cult, and he's' exactly why I won't engage with any of them.