Are my speakers blown or can they be fixed?

I have two old RTR Series IV Model E speakers and about a month ago they started crackling real loud and before I could turn the mixer off the crackling stopped and I could get no sound. Ever since I have not been able to get sound out of them. Any ideas? They are very big speakers and I don't want to get rid of them because the sound quality was so good. Is it even possible to blow every single speaker? I mean theres 6 tweeters 2 speakers and a 12" and 10" sub woofer on EACH speaker. Any help would be highly appreciated for I do not know much about rewiring speakers so I haven't even opened them up yet.