Baby Advent's tweeter is not working right

One of the tweeters is not working nearly as good as it should, one speaker is muffled (though there is some output on the tweeter) and one is pretty bright so there's a night and day difference between them. I've narrowed it down to the tweeter itself so is there any way to fix it without buying a working one?

 

If you have a multi-meter check if the voice coil is still good.