Radio Problem on Grand Am

Hey Everyone, I seem to be having some problems with my stock radio in my 91 Grand Am. I had the brakes serviced, and when I got the car back, I turned on the radio, and I am having a breaking up noise in my front right speaker. Also, all my bass is gone. It has about as much bass as an alarm clock radio. Even if I try to move my bass slider up, there's no difference. Whats wrong?! Thanks, Gary