I have an 07 LS Cobalt coupe. Sometime last summer I started intermittently losing my turn signal sounds, which meant that front left speaker was cutting out. However turning up the volume louder would always "kick it back on," and then it'd be fine for awhile. Eventually it stopped cutting out, but it seemed to settle in a muffled/weak treble state and remained that way. To me that sounds like an obvious blown speaker. I recently brought my car in for inspection and asked them to check it out. They claim to have replaced the speaker, but I don't trust that they actually did any diagnosis and it still sounds the same to me. What else could be causing this? I can't imagine it being a wiring problem (especially since it was fine for a long time), but maybe it's a problem with what the head unit's putting out? Or should I maybe be suspicious that they didn't actually replace the speaker? Any thoughts would help, thanks.

 

pioneer system or base system? If its the pioneer then they might have replaced the speaker but the tweeter is whats actually blown. Otherwise they probably didn't replace the speaker