I scanned the webpage, but didn't read every word. It seems like a variation of an idea that's become somewhat popular in Germany where you mount a mirror image of your front wall-mounted subs on the rear wall. Then you phase flop the rear wall, delay the output to it by the travel time of the front wall's wave and the rear wall 'sucks up' the low end produced by the front wall so you only [theoretically] hear it once. Seems like it should work to some extent at least. I remember one of the more credible audiophile reviewers--Anthony Cordesman--raving about the performance of a Bag End sub system; it impressed me so much, I based my own dual sub setup on their concept. Meaning that their removal device is probably also good (imo).