The low extension is incredible(you can ask tigerbass). I actually played a 22hz(pretty sure it was neway) 0db tone and watched the front passenger seat back rock front and rear

I absolutely love the tuning, but the original purpose was to get the enclosure's output the be as flat as possible. 23.7hz @ 2.26ft^3 was a "flat" response curve with -3db @ 22hz.
Red line is the flat response and black line is my enclosure.
The outcome is incredibly musical.//content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif