when im playing my music in my car loud, like around 80% of the total volume, my speakers start to make this poping noise. i dont know what is causeing this. i checked the speakers and they are not blown or anything. my sterio says 45 X 4 on it and the speakers say they can handle 80watts. so the speakers should be more then strong enough to handle the 45 X 4. any ideas on whats making this "popping" noise?