how do i know if i need 2 batteries

 I tries looking for something similar to this but i was not able to find it. I would appreciate the help thank you. I wanted to know how i can figure out if i need two car batteries for the sound quality of my bass to be better aswell as my highs. Currently i have two 12 inch audiobahns (1100 rms) 4 6.5 pioneers (120 rms i think) 2 6x9 boston acoustic and six tweeters. My highs are powered by a 600.4 pioneer amp and my bass with a audiobahn 2200hct (1600watts) i currently have a hifonics 2 farad cap. I wanted to know if i should add a second battery.

Also my question would be what is better yellow top optima batteries or SVR batteries>?

Yes, a second battery would help you. Your alternator will thank you!!!

As far as battery brands go, I've had optima and svr, and personally I prefer svr batteries. Look for a 75-12 series or a 100-12 series to add in place of your cap. The 100-12 series battery can be had for about $229 at an svr dealer.

That's not entirely true. Sure a HO alternator is better than adding batteries, but thats' not what he asked. A spare battery is not for just running your system with your car off.  Almost every true spl competitor (high wattage classes) runs at least one extra battery whether they have an HO alternator or not. And we never, ever, run our systems with the vehicle off unless it is hooked to a high amp charger. I have 4 SVR batteries in my yukon right now, powering a 6000 watt rms system without a HO alternator and don't even experience any significant light dimming at high volumes. I have run my systems this way for many years, and have yet had to replace an alternator because of it.....I've also left my headlights on overnight in a drunken stupor and when I got up the next morning my truck would still start. Let's see a replacement alternator do that!

From Car Audio Magazine:

"Batteries are rated by the amount of cold-cranking amperes they produce. A small import car is likely to have a battery rated at 500 CCA. A large battery would have a CCA rating of 1,000. How big a battery should you install? Most experts say get one as the available space will allow. If your vehicle's charging system is significantly short on amperes, then adding a bigger battery will only create additional problems. Adding a second battery is an option, but is not recommended for a variety of reasons.

"I think multiple batteries are a bad idea for vehicles that are daily drivers," says Jeff Triplett, director of technical services for Memphis Car Audio. "A second battery has to be charged by the alternator just like the primary battery, so you're just creating more work for the alternator. If the motor is off and the system is running off battery power, the multiple batteries are OK. However, daily drivers simply have little to gain from multiple batteries."

Another strike against having multiple batteries is the safety issue. Batteries can be dangerous if improperly installed, so great care should be taken if you are thinking of putting in a battery in a non-stock location. Consult a qualified installer if you feel you must have a second or third extra battery."

What is the factory alt rating on the yukon??