I usually have a small or mid room as an external bus on the whole mix bus that gets
printed to jel the whole mix together, usually with a very low settings so it is not much
Peter Tangtren (probably my favorite metal producer) adds quite a
bit dark reverb but in such a subliminal way that it doesn't add the 80s dated sound to
the mix but beefs it up and makes it bigger. Check out Hypocrisy to see what I mean.
Personally on some mixes I'd also do short to mix room and feed them opposite for
bigness. If guitar is panned hard left I pan the verb hard right and vice versa. I've been
known to add big room or concert hall settings in some instances and get away with it if
you mix it "subliminally". What I mean by that is if you hear the reverb, you've applied
Another thing you can try is reamp or feed through monitor speakers
and capture the room with a big concender or maybe two in stereo configuration and feed
that back in as your guitar reverb.