“Mastering reverb? No way!” That’s the gut reaction of most people who are into audio engineering at least a little. Is using a reverb in the mastering stage really evil? Well, in most cases, it’s unnecessary. It’s just easier and gives better sounding results when you plant your reverbs during mixing. There are some tutorials out there where the “engineer” goes through all the built in sections of the Izotope Ozone plugin. Including the reverb. It results in rendering a completely nice and full sounding mix lifeless, harsh and artificial sounding. So what’s the deal with drenching the master in reverb?
Fix the mix with reverb
It’s there when you need to fix things. The keyword is glue (what else). There are two main reasons when a mix lacks glue. The first one is when it’s way too dry and it results in too much empty space between the sounds. It’s important to point out the latter, because in itself, a completely dry mix is not a problem. Not if it grooves like crazy and there aren’t weird sounding parts that feel unfilled.
The other case is when the mix isn’t dry, but the sounds are annoyingly inhomogeneous. WTF does that mean? It means that the elements sound like they were recorded in different spaces. Again, it’s not a problem in itself, but if it makes you feel upset upon listening, you need to do something about it. It’s often the case when the elements (usually samples) are just thrown together, without much thought put into the process.
Trick the unconscious during mastering
So when one of the above cases, or both of them are present, you can reach for your psycho-acoustic weapon: mastering reverb. But what kind of reverb? And what settings? Well, don’t forget that we don’t want to change the overall nature of the music much. What we need is those precious tails to fill out the emptiness, following the sounds like tiny shadows. That will create some cohesion. It’ll also get sort of superimposed over the different reverbs of those pesky samples and amateur bathroom/living room recordings.
Set it up
For this, room settings work perfectly in most cases; it’s easier to make a room reverb almost unnoticeable than fighting the top end of a plate or the lushness and length of a hall. Either go with no predelay or the couple ms predelay of the preset. You don’t want to turn the whole mix into a rockabilly slapback fest. You’re gonna need to roll off the top end (from about ~5kHz), so it won’t sound so obvious. What about the low end? That’s where it gets tricky. Because we still want to pull the whole thing together with it. If you high-pass it too much, the lower sounds will remain dry and unconnected. Play around with it, and go as high as you can without losing the cohesion. Now scroll to the point where there are lead vocals or solo instruments playing. Quickly AB between the dry and the reverbed sound, and listen to how the reverb changes the sound’s character. Pull the master reverb level back until this character change disappears almost completely. When you’re done, you’ll hear magically connected elements that only sound imperceptibly more distant than the original ones.