90 Amp Alternator 1000w x1 amp

[jmathiasTN]

I drive a 2008 Kia Spectra with a 90 amp alternator. I have a Rockford Fosgate PRIME R1000-1D amp that does RMS 1000w x1 at 2 Ohms. I was wondering if this amp would give my alternator trouble. I spoke to some local guys, and the guys from the shops want to sell me an alternator, but the DIY guys at home say that it should be ok. Thanks in advance for any input.

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[ejschultz 10+ year member]

The amp has 3 30 amp fuses on it. The amp is capable of drawing 90 amps of current under extreme circumstances. More than likely, you will never get the amp to pull that much current, unless you have the gain cranked like a volume knob and the "Punch Bass" turned all the way up. The amp probably isn't a true 1 kWRMS either. Assuming 90% efficiency (which really doesn't exist - someone correct me if I'm wrong there), the amp will put out just under 1000 RMS (12 V * 90 A * .9 = 972 watts). Assuming RF measures their power at 14.4 volts rather than 12, you'll get about 1 kWRMS at 80 % efficiency (using the same equation-Ohm's Law). With your car running and nothing on, the car should sit between 13.8 and 14.4 volts. You may or may not ever see that 1 kW out of that amp. As far as your alternator running it, set it right and you'll be fine. You'll probably get a little dimming but as long as your voltage doesn't drop below 12 V, you're fine.

 

[jmathiasTN]

Thanks for the input. It leads me to another question now. The subs I want to get are the Rockford P3D2-12 Punch subs which take 600 watts RMS, and would get 2 subs. DVC 2 ohm so will pull the 1000x1 RMS 2 ohm load from the amp, 500 watts each sub. Would this be under powering the subs? Especially if the amp isnt going to be actually producing those watts all the time?

 

[wone 10+ year member]

man my car has a 90 amp alt and im running 2 4ch's and 4k+ watts with no dimming and no problems!

 

[jsluss17 10+ year member]

i have a 105 amp alternator and a dx1000.1 amp that does 1000 watts at 2 ohms and it gives me problems sometimes only when im stopped though whenever i'm driving it gives me no problems. lights dim pretty badly though

 

[MANTI5 10+ year member]

Do the big 3 and get the biggest AGM that will fit under your hood, go from there.

 

[ejschultz 10+ year member]

You'll be "underpowering" them by 100 watts. It's not bad for them as long as you don't clip the signal going to them by turning the amp up too high. You cannot harm a speaker by underpowering it. Heat, on the other hand, can hurt a speaker. Square waves, caused by clipping, cause voice coils to heat up. Even if the power is under what the sub supposedly handles, the coils will get warm, hot, start smoking, then seize, possibly.

 

[Bettr n' Revrse 5,000+ posts]

You wont have any problems... Just do a couple minor upgrades...