i've possibly posted a little too much recently about this, and it's worth me reiterating again that i'm by no means an authority, merely an opinion but one that's been gained through some relative amount of experience. i'm no more correct than the next person, but if it helps - i studied the subject fairly extensively with my vocal tutors at drama school and now with ed staunton of voxbox studios.
ultimately, i'm just a singer posting in a guitarist's forum.
one thing i will just ask is that, by all means, arrive at your own conclusion as to how best to 'scream', but do me a favour - please don't use the idea of employing any kind of external substance like whiskey or chemicals specifically in order to reach a point that you can sound extreme. you will, seriously, only cause long term damage. i've been performing extreme vocals now for over 12 years and been checked recently for nodules or damage - i'm clear.
i'd hate to suggest that your singer using low volume screaming is
wrong, but i hope you won't mind me saying my part. compare these two videos:
michael bolton 'singing' nessun dorma. the moment at 2:50, arguably the most famous of the aria, present bolton giving the note in the most amateur fashion ever seen. standing
that close to a mic, he's using the same (external. ie throat) mucles employed in doing an impression of bert from sesame street. in his case, a cop out.
placido domingo singing nessun dorma. the moment at 2:50, and the notes following, are a singer using comfortable force through a relatively low larynx position, generating a note that contains not only the pitch desired, but many of the surrounding notes. it's full, it's powerful, it's also perfectly safe.
to bring it home a bit, imagine playing the riff to enter sandman using a piece toilet roll as a plectrum and using only your last 2 fingers. it's still the same notes, but nowhere near the same sound.
low volume metal vocals have their place, such as occasional use of the inhalation point for lower work (the "bree" or pig squeal) or for higher moments of wipe-out vox via the whistle note (dani filth / mariah carey). if used continually, the actualy
extremity of the vocal is lost, for instance like listening to most modern screamcore bands - one note, one feeling, one result.
may i suggest that, instead of just shouting loudly and seeing what comes or worse, you give a quick try to the method i've used to teach people. clear your throat with your mouth close as normal. a "hhhHHMM-HMMmmm". do it again, get used to the sensation...
now do it with your mouth open. "HUNH-huh". at the 'NH' of it, extend that note. it'll feel like your throat robbling (weird word, but you'll see what i mean if you're doing it right).
after a while, if you can identify that sensation (which is a low/mid extreme metal growl), push it higher in the register. in other words, go from "NH" to "AA" but with the same throat sensation, you'll notice the feeling travels more towards the nose, which is actually where it's supposed to be. that's your scream.
i can go on more, but it's contained further in other threads and/or you'd rather not use my angle on things which is absolutely fair enough. it's not as simple i've put and will take much getting used to.
i don't agree with the idea of you sounding bad for the first month, frankly you can do this and sound good fairly early, but it's a matter of technique.
i hope i may have helped in some way. i'm more than happy to elaborate further as needs be.
H