I have a Rockford Fosgate T2 12" and I built a box by Rockford specs and it doesn't hit nearly as hard or clean as i thought it should, I want to go with a bigger box but i don't know if that will fix it and I don't even know how big I should go or the ports. The amp i am using is a Rockford Fosgate T5002 and it is turned up 3/4 way. It's in a 2002 Chevrolet Tahoe so i got plenty of room.Let me know if you can help,thanks.
Here is the link to the box I built.
http://www.rockfordfosgate.com/products/product_details.asp?item_id=91849&locale=en_US