looked through this article and found this lol
Best Upgrades for Any Car Stereo System - Guides - Car Audio and Electronics
What to Avoid!
We’ve spent some time talking about what things you should do, but what about some of the things you should avoid? There are plenty of shortcuts and bad advice out there that ultimately end up making no improvement to your audio system, even some that can make it worse! Beyond that, why would you want to spend any money on something that will not add any benefit to your system with better performance, sound, or additional features that are useful? We’ve put together a few suggestions to keep you out of the deep end.
Don’t Bother Adding Batteries
If you are driving the vehicle regularly when you are enjoying the music, you aren’t going to do much good by adding batteries. Although it’s true extra batteries help when the car is parked so that the audio system can play longer, they only add extra workloads to the car’s alternator when the engine starts running. The more batteries you add, the more likely you will be to experience premature alternator failures because of it. Remember, in daily drivers you only need one, well-maintained battery to start the engine. Beyond that, if you drive the car, all of the electrical system is powered by the car’s alternator.
Capacitors Don’t Fix Weak Electrical Systems
Sometimes you may have been told that putting stiffening capacitors in an audio system will help with the fact that the amplifier power in the system is too much for the car’s capacity to electrically support. Somehow the stiffening capacitor has gone from a small storage of energy on really dynamic music for an amplifier to use as an occasional reserve to all these car audio urban myths about how it helps the bass sound better because the headlights no longer dim to the beat of the repetitious music once it's installed. If you could see the amplifier’s input voltage terminals that started with severe voltage drop problems because of inadequate power from the vehicle, you would still see similar voltage drops with all the same conditions after the capacitor was installed. Don’t make the mistake of thinking that because the headlights stop dimming, the amplifier has gotten the same electrical benefits. A headlight consumes much less energy than a large amplifier, so of course the headlight will show improvement when a capacitor is installed. Once it’s out of reserve energy, which depletes quickly, you have another electrical workload to charge it back up. Of course you could buy bigger and bigger capacitors to extend the time they have a charge, but then you really need to ask yourself if the money those cost could be spent elsewhere in the system to make a noticeable improvement. If the car has simply too much amplifier power to be able to be supported by the stock electrical system, the only way it’s going to be helped is by upgrading to a higher output alternator, at least if it’s a car that drives on the road.
