I have a 90 amp alt and will be driving a 12 btl with a dtr1 2200d soundstream amp that as a 200 amp fuse and a audiobahn a6601t that as 80 amp fuse i have a 3 farad cap and im going to buy a back up battery but i dont know wich one yet i will also buy an isolator but im wainting to see if i have to change my alternator...everything is going to be wired with 0 gauge and i changed my car battery ground and my motor ground for 0 gauge and added a extra wire from my alt to my batt. wainting for ya reply to get this thing loaded

do the big 3, along with a back batt(kinetik 1400/1800,batcap 2000, powermaster series,etc)

never change the wire, but add on to it. Yes all 1/0 is best, or even bigger.

invest in a voltage meter to keep an eye and see what you drop to.

if you dip below 12s then you definitely need an alt.

Ridn hit it pretty well on the head, but change out your stock battery, and drop the cap. The reason I say drop the cap, is beacuse its like a band aid on something that needs stitches.

If you need further help please ask.