Ok I just had my new stereo system installed. The speakers I am running are Alpine Type X. The amp is an Alpine V Series 100X4. Anyway when I turn up the music pretty loud everything sounds good, but on a few songs with heavier bass, the speakers make a farting sound. They are brand new so I am pretty worried they might be blown already? It only occurs when I am set really loud, like on the threshold of where you want to listen, if I stay just under that it sounds awesome. Could it just be the speakers are underpowered?