Car Speakers

I recently installed two brand new pioneer speakers and a brand new alpine radio to my audi a4 2001 quattro. the sound is great at low volumes however when the volume is turned up moderately, a slight static can be heard from the speakers, correlating with the song playing. it is not a constant static, only during certain parts of a song. voices from am stations also often cause static. the thing that is weird is that the static happens only on certain songs. one song may come on and i can play it loud no problem and then another one will come on and my speakers will go crazy with static. the static sounds like white noise but loud. , any ideas? the speakers are in perfect condition- no tears- no dirt- and i have tried treble and bass way down- same result

All speakers are like that. the way to fix that problem is to get an amplifier to make the quality of the sound better and to reduce static at high volume.