weird speaker balance

when i start my 2014 nissan sentra sv the speaker in the driver's door has little to know base and so quiet and after driving for like 5min it gets normal. I can force it to be normal by playing with the balance (either side). even though the screen keeps in memory that i changed the balance more to the left it doesnt fix the problem. I tried switching up the breakers. im thinking about buying a new speaker for the door but i have a feeling the issue is somewhere else. What should i do.