I just bought an 07 civic Si, the rear speakers all seem to be having issues. The sub wont work at all, the other two speakers are stock and so is the head unit. But whenever i turn the volume more than halfway up only the rear speakers get distorted especially if i turn the bass past -6.... Or if I turn the subwoofer on at all. I even tried a new speaker which is still having the same issue. So any input would be greatly appreciated.