hi guys im looking to seriously upgrade my system now i have a couple of issues that i can get my head around fully
i currently have a 2900w 5 ch amp runnin 2x 12" sony subs with 2 x 6 speakers in each door and 6x9s on the parcel shelf i all ready have the large battery 750cca twin cell and a 140amp alternator and i get the worst dimming even engine idle shifts when im sitting at the lights
i want to put in 3 sound storm amps 2x STA120s and one STA412 SOUND STORM | everything else is just noise

now what i would like to know is what gage wire should i go to ????
capacitor will it help ???? like 3F or higher????
is there anything else i should look into ????
how hard is a dual battery system to put in ???? how much will it cost ????
will i need distribution blocks or are soldering the 4G wires good enough ????