Hey guys, I'm designing a new box for my Shiva. It'll be ported with a 4" flared port and a 250 watt amp. Theres a boost of 4db at 25hz on my amp that I think is giving me problems. The sub right now is in a 3 cu ft enclosure tuned to 22hz. The sub bottoms out at frequencies around 30-40. Can someone help me with a solution to get rid of that bottoming out and still have the output? I was thinking a smaller box, different tuning? Getting another amp isnt an option, I'm stuck with this one due to money. I'd appreciate any input, thanks. Also, how do I calculate the length of a port thats flared? I know how to do it with regular ports but not flared, how long the the center peice be kinda thing, do I add, subtract anything?? ... thanks.