I wrote PiAlign and I defined the term Qe used within it. I mis-spoke because Qe is actually a ratio of port length to area, not cabinet volume. But the point is that it is an indicator of port restriction to airflow.PiAlign was designed to iterate and find solutions to the forumulas that express Pi Alignment for a loudspeaker cabinet. To perform T/S analysis of a Pi aligned cabinet or others, I suggest using something like Carlson's BoxPlot. That will show you the response curve of a speaker using whatever alignment parameters you enter into the program.