My Z has less than 4000 miles on it, but the driver side door speaker/panel is making a blatting sound. When I open the door the sound in more pronounced in the area where the reflector is on the door panel. Is this a common problem, should it be under waranty? I like my hearing so I dont blast my music to unheard of levels, which leads me to believe its not a blown out speaker, or is it? Thanks.