2005 Saab 9-3 Door Speakers Not Working

[Saab9.3]

I've got a 2005 Saab 9-3 Linear with the 7 speaker sound system. My 3 speakers in the front dash work fine and the 2 in the rear are fine as well. When the car is warm I notice when I adjust the volume from a lower volume to higher the door speakers make a slight popping noise... but they never end up working... center speaker works so is the amp control the door and center speakers in such a way that it could be the amp1?

Does anyone have the same problem or know what the issue could be?

thanks

[Diggs]

Could be amp1. Check for water intrusion.