Do I need to upgrade my Alternator for new subs+amp?

[Trey Hardy]

I’ve got a 2007 Chevy tahoe Ls package and I’m not sure how many amps my stock alternator has but I’m pretty sure its 145amp.
I currently have a single 10” skar audio subwoofer running on a 800w Rms skar amp but im wondering what steps I would need to take to upgrade to 2 12” Subs with a 2000w amp running 1k to each sub

I dont know alot just looking for some good information on what i should do as far as possibly needing a new alternator etc

I got 1/0 guage big 3 and running to the amp with the stock 145amp and I can’t turn the gain more then a 1/3rd of the way up without voltage dropping on my 2500watt I either need a bigger alt or just do a battery upgrade. I was looking around 550$ for the alternator or 600+\- for a lithium battery upgrade