probably what u'll need to do is to get a voltmeter/multimeter to check the voltage at your battery point and at your amp terminal what's the voltage drop when engine running, aircon on, HID on, and bass hitting. i don't know what's the acceptable voltage drop as i'm not an electrician, my view is, if it drops below 12volt at battery point, then u might have to do something. If it drops below 12volt at amplifier terminal, probably u need to upgrade your power cable to larger size to reduce voltage drop along the line.

either which your situation is, in my humble opinion, definitely battery upgrade 1st, and as zennn suggest, BIG 3 upgrade as well. if you have a high demanding system, try deep cycle battery, they can give out plenty of juice...

@zennn, not to be rude, but SQ might be quite demanding on the current as well....i'm currently running about 375A (rated) of system from 3 amps...however, like howie said, we're not listening to our system at full volume all the time...furthermore, the actual current flowing would definitely be lower then the total rated amperage(at least this is the case in my system). So there isn't a need to upgrade the alternator as such, as a deep cycle battery would probably be sufficient to do the job...

This post has been edited by hyy87: May 2 2011, 05:14 AM