Question about stock HK stereo

I bought my 1998 E36 328i about 3 months ago, and it has the premium sound package(also known as the Harmon Kardon system). Well recently, my front speakers have been giving me a screetchy noise when vocals or high treble play. I usually play any tech music, so of couse I want clarity in my music, but now this is happening and I have to know what to do....1. get rid of the speakers and get new ones(aka they are blown)...OR 2. replace the capacitors as I have heard for the regular nokia system...OR 3. do i have to just tighten a few bolts...OR 4. get a damn new head unit?

I hope I'm not the only unfortunate sucker to have this happen, so if I'm not and anyone knows what to do, please help a fellow BMW owner out

Thanks for your time fellows- Joel :guns