I have 2 10 if ssd's in a .90 ft3@ 36hz smallest box fi recommends I have had it in a couple larger boxes tuned lower and they didn't sound right. The smaller box sounds **** near perfect to me there getting 500 apiece from a sound stream ref1.1000 which is a large amp but if you can find one for the right price I highly recommend it. One more thing when u build your box brace the hell out of it these subs have serious impact if there is anything loose in your rig you will know right away.