Browsing the reviews on Sonic electronix on this one particular sub, this guy said that he was able to build a quality sub box based on the parameters he put in. First time I've ever used this program.
Here's his review and y'all might be able to help:
"picked one of these up because I am limited to only 350 watts RMS and this sub impressed the heck outta me! I entered the TS parameters in an enclosure modeling app (speaker box lite) and built a box similar to the specs the app suggested for maximum flat output and this inexpensive sub hits lows I didn't expect. I played a test sweep from 10hz to 100hz and it handled the whole sweep like a champ! it's not even broken in yet either! my enclosure is 1.62 cuft tuned to 25hz. my f3 is 22hz and my f10 is 18hz. since I am going for SQ, I am only around 115-120db, but that is loud enough for me. definitely recommend this sub, or any NVX for that matter - my buddy has a vcw104 and it is equally impressive (can handle more power tho) - and with their prices you can't go wrong!"