power capacitor or optima yellow top

hi guys i am having a problem i dont know what to use i have a jbl 1200.1 amplifier a 2.4 farad digital capacitor and 2 yellow top batterys.right now i was going to use 1 yellow top and the stock battery i have a 120amp alternator which set up would be better.

How many times do I need to say caps are worthless in one week? What's the big problem you think a capacitor will fix?New Project: 2003 Pathfinder

dude you need to do a search, caps are worthless, upgrade your alternator first if you are having amperage problems.

What exactly is the problem? As mentioned, upgrading the alternator along with the 'big 3' will help tremendously.

the problem is that without the optima in the trunk if i hit a really deep bass note the voltage would drop to 10 volts if i check the voltage with a dmm only in the trunk. in the front of the car at the battery the voltage would be 13 volts and when that deep bass note comes around again it drops to 12 .what could be wrong i had the amp checked it isnt that i am running 4 guage power and ground the amp has 3 40 amp fuses on it i dont know what to do .