Car Stereos: Monsoon car stereo troubles, alpine speakers, alpine stereo

Question
I have just purchased a used 2001 Grand Am GT 4dr Sedan with a 3.4 liter engine and the stereo sounds the shitty.   I have the following speakers 2 rear (9x6), 2door (6x4), 2 small 1.5 installed near each side mirror.  The speakers at low volume sound ok, but when I turn up the volume about half way they sound crack/destort and seems like they are blown. I decide to start with purchasing a pair of alpine speakers for the rear and went I went to install them it was worse then before.  I tried both the old set and new speakers in a different car and they sounded ok and not blown.  Please HELP!

Answer
Rod,  That sounds like just what I would have done.  Apparently the problem is in the stereo.  Sometimes, when stereos get used some parts just get worn out or dirty.  I would guess that your stereo amplifier (inside the unit) has got some serious dust on it, or has a burned up capacitor.  Either way, it is a malfunction inside the stereo, and you can have it repaired or replaced.  The cost will be about the same either way you go.  One suggestion that I tell most people is that your factory stereo is a high-end stereo.  It will sound better (repaired) than most aftermarket stereos.  If you like the features on the factory stereo, you should probably keep it.  However, if you like Alpine, an Alpine stereo will sound better than the stock stereo.  I would definitely replace the factory speakers for sound quality alone.  Hope this helps, Scott