You can buy a speaker refoam kit from Ebay for about 20 bucks and do it yourself. There is even a guy on Ebay who will refoam the woofers for you if you ship them to him. They are easy to remove.
Get on Ebay and do a search on "advent woofers" and check it out.
Get on Ebay and do a search on "advent woofers" and check it out.