Serpentine Belt Squeek

I recently purchased a 98 Legacy Outback. The previous owner says it threw 2 serpentine belts in the past year. The current belt is squeeking but was fairly recently replaced. I'm wildly guessing that one of the pully hangers is bent but know no way to tell for sure. The alternator was replaced some time ago, which is the only work (other than belt replacement) that has been been done on the belt line. Any thoughts about what's wrong & what to do? Thanks