You could factory restore it and then it will be good as new unless there's a hardware issue.
On a pc using Windows 7 here. I suddenly have thin, weak sounding audio from my laptop's speakers. Sounds like a terrible EQ setting.
I do know that it changed after I tried fixing a hanging/lagging issue. I'd disabled a bunch of stuff from the start up & that seemed to fix the lagging, but then...
So, how can I restore it back to that full, rich sound?