Im trying to figure out how to rasp my voice, kinda like Marcus Mumford (Mumford & Sons) and also Andy Hull (Manchester Orchestra)

I do mostly acoustic stuff along the lines of Mumford and sons, and just want to be able to get raspy for powerful parts. I tried messing around with it and my throat is a little sore. I tried watching the diaphragm videos that teach about the 'angry sigh' but I'm having a hard time actually incorporating it into singing without it hurting my throat. No other threads or videos really go into detail with that from what Ive seen. Any help would be appreciated.

Busking the Local Subway Near You

YouTube Channel

Fender MIM Strat
Fender Acoustic
Epiphone Explorer

This will answer your questions. After reading this you will have all the information you need but understand that this takes a great deal of time and practice. Your brain has to figure out what the heck its trying to do. We are talking 3-8 months of solid practice just to be able to get the sound without hurting and being able to use it.