In a post a few days ago (Mixing Mono) I talked about getting all the inputs lined up in the mix like actors along the front of a stage. In the studio or when mixing down recordings of live events though, mono isn't ever a consideration (read the other post to see why it should be though). Here's how you can do so much more than just pan your inputs left to right on the sound stage.
Reverb has many uses. With just a touch you can create a little sparkle or air on a vocal or drum. But what it really does is create the impression of space. Reverb is the result of multiple reflections of sound in a room, so many reflections that the human ear can't tell them apart and blends them all together. Your ear can tell a lot of things about the size, shape and materials of the room by the way it hears those reflections. There are plenty of good articles about early reflection, diffusion and damping and you should go look those up. This isn't an article about styling your reverb, but how to put it to use.
It might help if we take the visual metaphor of a stage that we've been using and exchange it for a fully three dimensional one. Think of volume moving an input up or down, pan moving it left or right, and reverb moving it toward or away from you. A vocal with no reverb at all on it, be it a shout or a whisper will seem like it's right in your face. That can actually be a pretty difficult trick to pull off. Usually there's some amount of room sound on a track. The more reverb you add, the farther off it seems.
There's quite a few things you can do with this. Just adding reverb to a signal will start to put it more and more into the artificial space. You can go a step further and lower the volume of the original while you continue to add reverb. That actually starts to push the track back quite significantly. Quite useful when doing a call and response that's actually just a single track. You can literally make the vocal jump all around in space.
It's a common technique for backing vocals as well. In addition to taking off a little high end so they don't step on the lead vocal, a little reverb will help soften things up a little further. With a very intimate (meaning close up) lead vocal you can have sort of a boring stage going on. Placing the backing vocals with panning and reverb can create a lush landscape without loosing the intimacy of the lead vocal.
So you can start to see how reverb should be thought of as much more than just an effect that you smear on a mix like mayo on a sandwich. It's really a powerful spatial control that even in small amounts can create a huge difference in perception over a dry track. Which leads me to one last thing.
There is one particular type of reverb that stands out in my mind as doing just what I just mentioned and it comes in handy sometimes. Again you can find a million articles on the different types of reverb and you should go read them. This is just a trick from my arsenal that I'd like to share. Plate reverb is often overlooked for not sounding natural or nice. But it's the one I always reach for when I have a potentially muddy mix and still want to put some space in it. For some reason plate reverb sits in the mix almost like another discrete input. To put it simply, instead of having four background singers floating in some verb, it's almost like you have a fifth input that you can sneak in there without muddying up the mix.
That's my bit on reverb. I'm interested to hear what the rest of the Brethren of the Knob and Fader have to say on the subject. Leave some comments or hit us up on Facebook or Twitter.