Need help from a metal/hardcore/post-hardcore screamer

If anyone of you have any experience or knowledge of the following, can you please send me a message. I have some questions that i really want to be answered. I've been performing normal and extremely low register exterme vocalization for years, but i want to try out some Underoath, which uses a high register. In advance, my question would be what should i be using for that style (Let's stick with Underoath as an example):
Falsetto or
Forced/shouted high head voice
I am confused on which one they use, because i tend to replicate their sound using my falsetto as my anchor. It sounds abit right, but it lacks something, that's why i figured that maybe it was a high head voice all along, especially for sing to scream transitions. I also can help to think that maybe they are really using their shouted high head voice because on their singing parts, i'm 70% sure that they are using their head voice, the 30% is my doubt that maybe i am already doing it correctly already with falsetto.
Thanks!
 
(For those who can't relate, i'm so sorry for putting such an awkward topic here. I just can't find any forum that i can ask this. I know this is a really weird and unappealing vocal style to many anyway, but i hope you guys can forgive me for this post. I really need help. Thank you and i hope someone has some knowledge about this.)

@skullsession
Thanks very much! Although i already discovered my question myself.

I confused the high note that comes out as a seperate tone instead of an overtone. Now i can do it A-OK with the exact sound i want. Thanks anyway!