Harsh Vocals.. A few Q's.

how do i know if it's coming from my diaphragm or not? i think i've got it but if it is then i've got a lot of work to do.

i know that i've got a lower than average lung capacity, if i growl from my throat i can only last 4-5 seconds before losing breath, but if i'm doing it from what i think is my diaphragm then i can't even get enough breath to even start the growl! surely this can't be right.
 
I try to do vocals like this, too, and what I noticed is: it's easier when you do it really loud
for example: if you wanna "sing" along to a CD, don't try to adjust your volume to the one of the CD-player, but sing really loud and adjust the CD-volume to YOUR volume (I have much less problems with thoat-hurting and such things doing it that way)
I hope you understand what I mean.....
 
I was the bassist for my band and we were looking for a vocalist. We were just messing around, and being the random crazy guy I am, I just screamed the loudest I could. My friends were baffled of my voice, and they asked me to be the vocalist. I can honestly say I am way better at singing than playing the bass by far.
 
I think that mics are VERY importand - after you get the techniques the guys mentioned above - you should find the mic that is suitable for your voice - I had many problems with that until I found that Shure SM58 fits best for my voice (it's dark growls a la early Moonspell) and of course the verb effects are very importand!!
 
Okay there goes another question...

I can sing "deep", like Ville from Sentenced and (Goth Forgive me) Valo from HIM, and with a little effort catch some moonspell-esque moments.

No major trouble on that end.

However there is where the shit starts, Im in a trash metal band, I discovered I can sound like Mille (kreator circa Violent Revolution, endorama) or Martin (Skyclad) with relative ease, however, I can always feel the stress on my throat, any tips for these more Trashy vocals? specially the higher screams?
 
some of you seem to have advice about equipment. i just recently started screaming too. i just discovered i could do it while i was at an in flames concert, surprised the hell out of me! i practice in the car now.
im a female, and interestingly enough, wages of sin is my favorite scream-along album.
people who know what they are talking about, please say more about gear for screamers!