I recently bought a different car (a 1999 Sunfire GT) and I thought all the speakers worked at first, but then after awhile the front driver's side speaker quit working and the rear driver's side speaker wouldn't work. Then after awhile the rear driver's side speaker would work now and then. So when I got my empeg and amp installed I thought they would all work, but they don't. is there anyway to test the speaker to see if it works?