Essentially somewhere around 200 and 300Hz, something funny happens; the response becomes dominated by the room below those frequencies but remains dominated by the loudspeakers polar response above it. This is called the Schroeder Frequency. There are several factors that cause this. 1 is that most loudspeakers are essentially omni at low frequencies and another is that these wavelength are similar in size to the boundaries of the room and the distance to the boundaries from the loudspeaker. There is no clear cut division d/t the difference in all these factors in each of our rooms.
Tonally what we hear above this region seems to be most dominated by the listening window of the polar response, and below this region it is the ungated measured response of the louspeakers in the room at the listening position.
More to come later,