system help

[jinner44]

hey guys im new to the forum. i just got my 2000 ford explorer limited.
im going to put 2 12 jbl's (600 watt rms total) and jbl gto7001 amp in it. im worried this is going to put too much of a strain on the battery. do u guys think it will be too much?

if so, should i just get a capacitor or should i go for a dual battery set up?

what would the dual battery set up look like?

obviously i should run them in parallel because thats how u optimize power, but where would i put the 2nd battery and how would i run the wiring?


(the only reason im strongly considering the dual battery set up is cuz im eventually going to change the speakers as well)


thanks

 

[kkreit01]

Caps do nothing. Battery should be fine. You'd probably want to upgrade the alt before thinking of a 2nd battery. Do the "Big 3" first.

 

[jinner44]

thanks

 

[jinner44]

do u think i need to upgrade the alternator with only the subs/amp?

 

[kkreit01]

No -- I'd try it first. If your lights start dimming quite a bit, then you can think about upgrading. Make sure to use proper gauge wire, and proper ground spot for the amp. "Install" is key.

 

[PandorasCustoms]

Sounds about right, just be careful.

600 watts RMS at 12 volts is 50 Amps. I think most factory ford alternators are around 120 amps peak.

I am running the 95amp alternator with 650watts RMS and a cheapo battery, and I don't see dimming except on some HEAVY hitting songs. You should be fine, just might want to watch it if you are sitting at a stop light for a long time. Your car won't kill itself, but the extended wear on the alternator may not be so good if you run it at full crank all the time.

You got to think, unless you have your radio turned all the way up, you won't be using all 600 watts all the time. You know?

Get it installed, and try it out. Don't worry about a capacitor, it isn't worth it unless you have the alternator to keep up with it. It is really only used for SQ purposes and keeping the amplifier from dropping below recommended voltages. If you have a really hard time, upgraded battery would be the first thing to look into (And one of the cheapest).

 

[617ricky]

I was curious about how many amps a certain wattage would require.. I'm kinda pissed that I only got the 8g wiring kit for my amp when I could have gotten the 4g for just an extra $5-10.. I'm running a 240w amp now, but if I did wanna upgrade I really can't go much higher than that with the 8g.

 

[PandorasCustoms]

Ricky:
Figuring out the amps is easy...
It is just Amperage = Watts/Volts

But, the tricky part is in car audio, the voltage varies depending on your RPM due to the spindle rotation on the alternator. So, I always measure what the amperage would be at the lowest voltage the alternator can put out. If the alternator is putting out the recommended 14.4v, then you would be looking at only 42 amps for 600 watts RMS.

And, then the 12volt.com Recommended wire size chart works for maximum amount a wire size can handle.

So, with that 8agu, you could really run 600 watts, but over distance you would get some lost power. If you have a second battery close to your amplifiers, you would be fine though.

 

[PandorasCustoms]

Oh, rockford fosgate has a pretty cool calcualtor too.
It calculates what you are looking for and displays the power loss you see over time.

Rockford Amplifier Wire Calculator