The system in my JK, consists of 5 separate amplifiers and is close to 3000 Watts "RMS" total. I'm driving dual 12" Infinity Kappa Perfect subs, each having their own amplifier. When it was 1st installed and turned up, I would get head light dimming on Bass hits.

I shopped around for an alternator upgrade and what you will find is that the JK already has a pretty high output alternator. You can get a higher output alternator, but it's going to be expensive and will only give you about 20-30amps more than the stocker, which I found was not worth the price of admission.

Here's what I did, and in the order of what I would consider to be most important.

1. Big 3 electrical system wiring upgrade (Google it, if you haven't heard of it).
2. Installed a Sears Die-Hard Platinum Marine Battery (probably doesn't need to be marine, but I went with the Marine because it had extra posts. Definitely, needs to be a higher CCA AGM battery).
3. Installed a 1 Farad Cap (I know what the general rule of thumb is) Caps are a waste of money in most instances.

You don't need a dual battery setup. The Kicker gear setup you're looking at is only 325 Watts RMS into 2 Ohms or 750 Watts RMS into 1 ohm. That will not require a dual battery setup.

Another thing to keep in mind. Most of the "general rules of thumb" you'll find out there for car audio systems.... for example your 1 Farad/1000 Watts general rule of thumb, and there are many more examples, no longer apply and end up being overkill. The reason being is due to the different amplifier technologies used today. For example, the Kicker amp you posted is listed as a 750 Watt amplifier. It's also a "Class-D" amplifier. All these general rules of thumb were established using Class A/B amplifier systems, yet the "Watts" rating between the 2 different amp classes are measured the same, "Across the outputs of the amplifiers."

So anyways, what I'm referring to is that Class A/B amps where only 40-50% efficient. So what's that mean? It means if you bought a 500 Watt amplifier, that amplifier had to draw 1000 Watts of power from your electrical system, into the input of that amplifier to be able to give you 500 Watts of power to your speakers. That's why the heat sync cases were bigger, because that 500 Watts of lost power got dissipated into heat. Class-D amplifiers are 80-90% efficient. So if you buy a 500 Watt Class-D amp, you are now drawing 555 Watts from your electrical system to be able put that same 500 Watts to your speakers.

You will find there are a lot of people out there that will insist you need 0 AWG wire run all over the place with 5 banks of 3 Farad caps, with high output alternators, and dual battery setups. Their suggestions are all based off of general rules of thumbs that were established when using Class A/B technology amplifiers and none of them seem to know the differences between a Class A/B amp and a Class D amp. The only thing they know is "Watts", which is the same on the output of these amps, but nowhere close to the same on their input and it's the total watts the system is drawing that matters when you start to upgrade your electrical system.

 

A solenoid battery isolator / smart charger is typically more reliable than diode.
It must have higher Amp. than your alternator.

I chose this one - Red Arc Smart Isolator - SBI212 200 Amp, and two Optima yellow tops.

 

However, he'll only need that if he's into wasting money on unnecessary items.

 

I agree that the OP would better give it a try with one good deep discharge battery, but he asked about dual too... and we all know how much unnecessary items we got... and that 'unnecessary' is subjective...

 

Thank you both for the help! Unfortunately the kit I picked (all kits in general) will not fit in my car, I am contacting Sonic E. now and asking if I can substitute the box for two single (slightly) smaller boxes. Do either of you have a suggestion (more importantly a link) to a Big 3 kit? I heard good things about Kicker's but it's discontinued.

 

Every website I go to keeps telling me 34, is it different between two and four door? how did you find it out?

 

Trial and error. The first one I tried didn't work due to the post locations.

 

I'll take your word. Amazon be glitchy ATM. It tells me that D34 is compatible and when I click on Yellow top D34 it tells me it isn't... Weird but okay?

 

I didn't even know they made a "kit" you could buy. I just purchased wire and made my own.

There's a lot of Youtube videos out there which describes the Big 3 upgrade.

Here's one, where this guy does a pretty decent job of a walk through.
http://www.youtube.com/watch?v=iX9Rcq5DnKw Keep in mind, all of these big 3 upgrades videos usually recommend 0 AWG wire. Personally, I feel that is overkill based on the same principle I mentioned earlier and I also find 0 AWG is hard to work with. I used 4 AWG, which was added in parallel to the existing JK wiring. With 4 AWG, if you find it isn't thick enough, then you can just run an additional 4AWG wire, where (2) 4AWG wires in parallel with each other equates to the current carrying capability of a 1AWG wire.

 

It only gives direct replacement battery suggestions. D34/78 is the right one.