I have the crappy Mach system in my '96 GT and I think my rear speakers are blown. Whenever thehead unitis on I hear the sound of when someone blows into a microphone. Even if the CD is paused or the volume is all of the way down. When I turn it off, the noise goes away. It's really annoying. It's only the rear speakers. I'm going to get two new ones. What size are they? Which brand do you guys recommend? Thanks...

 

If you get the noise when the the headunit is paused or the volume is all the way down; to me it sounds like you could have a few problems. A grounding issues, headunit issue, or the amplifier channel for the rears is calling it quits. Do you get the noise more when you rev the engine? Or all the time?

 

It's all of the time.