hooking 2013 up

hey guys i have a 2013 i'm planning on putting after market sub in it and wondering what exactly i would need to do after i put the sub and amp in i really dont want to mess it up it has the touch screen entune head unit i havent touched anything yet so any info would be great i've only messed with aftermarket head units on cars under 2000 lol... THANKS

 

You could do a high level to low level input. Splice into the speaker cables and put a low level adaptor (for lack of a better term) in and it will reproduce the bass frequecies your looking for. I did this once and it sounded decent.
Maybe the stock deck will have an output for a sub.

 

the truck came with a stock sub so i think it does hopefully... lol