i have 2 ported 8 inch boxes dual chamber the boxes are tuned for about 40hz which isnt bad, i have 2 of the boxes i have 4 8's but they were kinda cancelling eachother out in my camaro hatch so i built a box with 3 cu. ft. with aeroports where they are all pointing straight up at the glass...hit over 150 db. with 8 inch subwoofers, pretty impressive..i do it for a living lol, local pickup only alton, illinois(southwestern) ill take 60 for both boxes, used for one day!!!!!618-920-1376