Subwoofer repair

Sometimes you can repair them. Check the tinsel leads going to the terminal strip. If thats OK, carefully remove the dust cover with an exacto knife. The knife blade should be gently inserted parallel with the cone. Do this on a hot day or in a hot room (helps to soften up the glue). Check the connections there where the tinsel leads are soldered to the voice coil. You'll have to scrape some of the glue away to check continuity. If resoldering fixes it, reglue the dust cover to the cone.
While you have the dust cover open, check for a burnt varnish smell. If yes, then the coil is fried. Good luck