My worksheets take into account the actual speaker design, enclosure and driver, and reflections from the room.
The EDGE only accounts for the geometry of the baffle and the placement of the driver. If you extended the baffle in the EDGE to be really really large (infinite baffle) you would get a flat SPL response all the way down to the lowest frequencies independent of the driver fs and roll off, clearly this is not true for a real driver. The EDGE is a great tool for asessing the impact of moving a driver around on a baffle, but people are sometimes fooled into thinking this will be the total SPL response of their speaker.
Internal to my worksheets I can create a plot of only the baffle geometry and layout to compare against the EDGE, when I do this the results are very similar.
