After searching on here for Monsoon issues I cannot find the same issue I'm experiencing. My 2002 Trans Am WS6 (coupe) with stock Monsoon radio and amp have decided to play a game with fader and balance controls. The front door speakers (tweeters and mid) fade in and out every 2-3 seconds, EVEN when I have balance and fader set 100% to one of the rear speakers. Both front speakers also fade in and out independently of each other as well. Sometimes the rear speakers stay on even when balance is set 100% to front. It happens regardless of source (radio, CD, etc).

From what I read on here the headunit controls the front door speakers, so I'm leaning towards it being the culprit. I don't have another amp or headunit laying around to test with. Anyone else have any ideas or troubleshooting I could try?

 

No, the head unit doesn't control the front door speakers - at least not in the way you're thinking. The head unit sends four channels of speaker level output to the amp (left front, right front, left rear, right rear) just like any other four speaker OEM system. The amp them amplifies, splits and filters that signal to eight output channels for the speakers. In a Camaro, all of those eight channels go to front doors, sail panel subs, and hatch speakers. The 10-speaker setup in a Firebird is somewhat different - the sail panel subs are dual voice coil so they use up four channels and the door mids and hatch mids use up the other four leaving the door tweeters and hatch tweeters to be powered directly by the head unit.

So the head unit powers all of the speakers - either through the amp or directly (tweeters). The doors are not separate. That being said, if you are having problems with both the mids and the tweeters fading then you can rule out the amp since it doesn't handle the tweeters. In that case, it is almost certainly the head unit. If everything except the tweeters is fading then it would be the amp causing the problem.

 

Thanks for the help. Last night I tested the front speakers and they're ok so it isn't a wiring issue. I'll try troubleshooting the headunit some more.

 

Found the issue, there's a ribbon cable inside the headunit that was not seated correctly. After reseating the cable all is good!

 

Good catch!