The above is exactly what he is saying.
From the thread:
"The one thing about room response at LF that I feel gets missed in these discussions is how the response varies arround the room at LF. At near DC there is NO variation of the response arround the room, it is everywhere the same. As the frequency goes up it gets greater and greater. But a sub operating from 25-50 Hz will se virtually NO spatial variation in either its response at the seating location or its sensitivity to location. Usuing more than one will thus only increase the output, but do little to nothing to smooth the response as there basically is nothing to smooth."
