I am planning on an upgrade to my 09 hhr LS deck and speakers. I plan on running one amp to power the door speakers (approximately 200 to 300 watts) and another amp to power a 200 watt sub. Will I need a more powerful alternator or will I have to something different? I really don't want competition level, just GREAT sound that can be loud when I feel the mood.

Ha'way the Lads!!
Texasmagpie

 

The alternator will be fine... it is controlled by the computer from what i understand

 

I think it will be fine. I have a 4x100w for the doors with 500w for subs, no dimming and has run engine off for up to an hour.

 

Check out my amp install on my 08. No issues with battery (the original) no dimming. Running 70 watts rms per front speaker, and 1200 rms for sub box.BTW this is about the easiest amp install I've ever done. The package tray over the spare is a perfect place, close to battery, no heat issues. I put Focal brand in the doors, and a Rockford-Fosgate 10 in sub in a ported Memphis box. It rocks. The amps ,sub, and Eclipse HU came from a previous truck, but the Door speakers are new. Just use good wiring and make sure you have a good ground.(to the battery negative in my ride)

 

you'll be fine with a stock alt but i would personally get a xs power d1200