I have a woofer in a downfiring sub and I noticed it wasn't sounding that hot. I've had it for years. Last night I flipped it over and took it out expecting to find a rip in the surround or cone. Nada. It looked fine. Then I noticed the cone travel was off kilter. The cone has actually sagged in its resting position! Is there anything I can do about this? Can I face it upright and put a soft weight on the cone to bring it back?Thanks in advance for any advice. Drew