[Putting a plywood board under your subwoofer?]

I have a piece of wood under my sub too, but instead of painting it, I put some varnish, and stained it, it looks real nice.

[Crackles]

Well lets see, my rear right and my front left (the one with the controls) are crackling, and when I switch the cables the back one sound good , so the it must be a connection problem on the back of the sub. Please help!!!