If you remove the woofer driver you can normally see the x-over small circuit inside. ...Did you do that? And if you do, look for any type of damage in the form of brownish caps or resistors (burnt).
If I was you, indeed I would get new speakers (better).
* Where do you live; perhaps a member here can send you a pair that he isn't using anymore and which would be the world for you! Are you in the USA, Canada, Europe, Russia, China, Iraq?
Also, check your local Salvation Army stores, or thrift stores. ...Speakers you can find for peanuts.
...Same thing for a receiver.