My basslink worked great, son blew fuse, replaced, now sounds lik

If the speaker has been overdriven, it may have damaged the cone surround or damaged the speaker coil, causing it to 'rub' inside the magnet. To check for rubbing, you need to move the speaker cone backwards and forwards by hand and listen where the speaker coil/cone goes into the magnet. It should be silent if ok. If you can heara rubbing or grating noise, then the speaker is damaged. If the output driver on the amp is damaged it can give a distorted sound, which could easily happen if it tries to provide too much current.