Oh, I see, sorry. I think what you would actually need to do is have the wavefront cancel the next incoming wavefront at the entrance to the dining room. But you can only do this for certain frequencies at any given time... if it works at all...That's the third method I tried. Summary of the three curves:
1. Control curve. No changes to the DSP.
2. Right sub phase shifted according to the formula.
3. Left sub delayed with respect to the right sub. The delay was obtained by placing the mic at the tip of the red arrow and measuring the arrival of both sub peaks. I then time aligned the left to the right sub with respect to the microphone position, which "should" give me a wavefront heading into the dining room.
I can't remember which curve is which, but that is academic now because all 3 are exactly alike.
Solution: Put some subs in the dining room! Easy!