alt question

If your worried about the amps being underrated I would estimate what you think the rms is and go off of that. Or you could add up the fuses on the amps and use that as your amp age rating for the system, then factor in how many amps the cars electrical system pulls.

one choise is to get a 600amp emergancy vehicle alt. it will have a seperate voltage regulator. and cost about 700.00 bucks or more, but you will have your bases covered.Big Dave

if you have one of the first or second generation 2100HCCAs you are looking at some pretty serious power consumption...in 1 ohm mono you could potentially be pulling upwards to 200A with that amp on its own... however, if your 2100 is the same generation as your 225HCCAs then it probably wont really be near as bad...what generation is your 2100? is it fused? the original 2100s were absolute power pigs...almost as bad as you could get in a A/B amp...not quite as bad as a pure class A amp, but still horribly inefficient...now, if your 225s are of the same generation as the 2100, they are about 1/4 the power and therefore 1/4 of the power consumption...so, in theory, you are looking at about 400A for the stereo alone if its going to be working hard, and then your trailblazer can also consume about 110-120A of power when everythnig is running hard...so just on that theory, you are looking at over 500A of power consumption in your vehicle... what are you going to be driving with these amps? it sounds like a pretty heavy duty setup...I would love to see some pics if or when you get done, because I love that old gear...not many people have an appreciation or even knowledge of what those amps are or what they are capable of doing...some nice stuff there...

thanks for all the info everyone...FYI all my amps are the second generation...very power hungery but well worth it ...im thinking about running (2) JL Audio W-7  13.5 on the 2100hcca and the other 225s will be for mids and highs...going to be putting horns under the dash and seperates in the rear...not sure what kind of mids and highs yet... but i'll keep everyone informed ...lol gotta get my rims and tires first