Bad sound fron FG enclosure!

check your seams and seals, dynomat the inside of the box. Try this and see if the box still does it. Also check the sub to make sure it is not blown or something. What brand of sub is it if you don't mind me asking?

I have found that fiberglass meeting with mdf in corners and so on creat leaky pockets, MY solution, tigerhair ALL areas inside the enclosure where wood meet fiberglass all corners speaker rings and so on, be sure to press a plastic bag down on wet tiger hair for a smooth finsh that comes in handy later. Then resign over the tiger hair a few times or until your sure that the corners dont leak. While your in their look for loose bacing or an area of large glass or wood that could be making contact outside the enclosure. Now if your subs are revese mounted, ( magnets out) make sure the rings are not rubbing the enclosure, and lastly make sure you have a good seal around your subs, if the subs are mounted directly to the enclosures painted surface use a tin rubber ring that you can make your self. good luck hope this helps.