Battery or Alternator Upgrade?

When I'm watching a video in my truck, everytime the bass hits, my screen dims and for lack of a better word, flinches a bit.  Would I be better off upgrading to a different battery (possibly Kinetik) or upgrading to a high output alternator?

both

I had the same issue with my ride. I put in a red top Optima, high output alt, and a power cap. Problem solved! Worth the money.

try upgrading the wiring first. do the big 3 with 0gauge wiring first, and see if that helps.

Do you recommend having the stock alternator built to produce more amps or to buy a new high output alternator? Also, since you both suggest a new battery and high output alt, which one do you recommend first as this will be a multi-purchase deal for me?