For the death metal bellow...
I wonder if it helps or not to use what I call the "hip-hop" or "wrong" vocal mike technique of holding the mic by its capsule (like "choking up" on it) so that the lower half of the capsule is wrapped by the singer's fingers and palm.
This would accentuate bass response and may help to turn a yelp into a bellow.
Maybe?
-r
|