Cheerier Baton

I want a sealed subwoofer enclosure for 2 sundown audio x-8 v.3 D2 subwoofers that can blow away some completion but not damage the subs. Can anyone tell me the dimensions I’ll need for a simple rectangular enclosure. The material will be .75 inch thick. i really enjoy sealed enclosures so it really help me out guys. I can’t find anything and I can’t think of anything. If I just slap something together it gone end up sounding like crap and probably damage these little monsters.