ok but im sure you know not to put a 15" sub in a .5^3ft enclosure with 6^2 inches of port area with 3000w behind it. im saying you should at least have a reason for starting somewhere.
if you are just doing random shit, IMO, i think you are wasting your time and money. at least have a reason for trying something.
if the kid tried to do this because he thought it would work awesome, thats fine. but its obvious he just pieced things together and hoped it would work. IIRC he said it only played upto about 36hz or so. look at the time spend and money spent on this project and what it amounts too.