Maybe this would help you, i had a big ass box for 2 DD´s 1510 at one time, it had a 37 hz tuning , i took the subs out because i wanted to confirm this "myth" , so i installed a pair of MTX 7500´s wich had a FS around 44 hz iirc , they weren´t as loud as the DD´s on the lows but of course totally different subs, they might needed a different box, but anyways, they sounded awesome for a couple of months, didn´t have any problems with them about unloading,bottoming out,getting hot or anything like that, so in my opinion, no problems tuning a box around the FS of the sub...