By Anderton |
Create ethereal, unusual reverb effects with phase reversal
by Craig Anderton
Reverb hasn’t changed a lot over the years: you emulate a gazillion sound waves bouncing off surfaces. But if you’re a gigging musician, one thing that may have changed is how you hear reverb. Back when you were in the audience, you heard reverb coming at you from all sides of a room. Then when you graduated to the stage, reverb started sounding different: you initially heard the sound of your amp or monitors, and then you heard the reverb as it reflected off the the walls, ceiling, and other surfaces. The effect is a little like pre-delay at first, but as the reverb waves continue to bounce, you hear a sort of “bloom” where the reverb level increases before decaying.
Controlling reverb to give this kind of effect can produce some lovely, ethereal results. It also has the added bonus of not “stepping on” the original signal being reverberated, because the reverb doesn’t reach its full level until after the original signal has occured It’s not hard to set up this effect; here’s how (Fig. 1).
CREATING ETHEREAL REVERB
You’ll need two sends from the track to which you want to add reverb that go to two reverb effects buses. These should have the same settings for send level, pan, and pre-post. Insert your reverb of choice into one of the effects bus returns, and set the reverb parameters for the desired reverb sound. For starters, set a decay time of around 2 seconds.
Next, insert the same reverb into the other effects bus return, with the same settings. If you can’t do something like drag/copy the existing reverb into another track, save the first reverb’s settings as a preset so you can call it up in the other reverb. The returns should have identical settings as well. Assuming the sends are pre-fader, turn down the original signal’s track fader so you hear only the reverb returns (Fig. 1).
Fig. 1: The yellow lines represent sends from a guitar track to two send returns; each has a reverb inserted (in this example. One return also has a plug-in that reverses the phase.
Now it’s time for the “secret sauce”: reverse one of the reverb return’s phase (also called polarity). Different DAWs handle this in different ways. Some may have a phase button, while others might have a phase button only for tracks but not for send returns. For situations like this, you can usually insert some kind of phase-switching plug-in like Cakewalk Sonar’s Channel Tools, PreSonus Studio One Pro’s Mixtool, or Ableton Live’s Phase.
Reversing the phase should cause the reverb to disappear. If not, then there’s a mismatch somewhere with your settings—check the send control levels, reverb parameters, reverb return controls, etc. Another possibility is that the reverb has some kind of randomizing option to give more “motion.” For example, with Overloud’s Breverb 2, you’ll need to go into the Mod page and turn down the Depth control. In any event, find the cause of the problem and fix it before proceeding.
Finally, decrease the reverb decay time on one of the reverbs (e.g., to around 1 second), and start playback. When a signal first hits the reverbs, they’ll be identical or at least very similar and cancel; as the reverb decays, the two reverbs will diverge more, so there will be less cancellation and the reverb tail will “bloom.”
Because the cancellation reduces the overall level of the reverbs, you’ll likely need to compensate for this by increasing the reverb return levels. However, note that the two reverb returns need to remain identical with respect to each other. I find the easiest way to deal with this is to group the two faders so that adjusting one fader automatically adjusts the other one. If you’re using long reverb times and there’s not much difference between the two decay times, the volume will be considerably softer. In that case, you may need to send the bus outputs to another bus so you raise the overall level of the combined reverb sound,
Because it takes a while for the reverb to develop, this technique probably isn’t something you’ll want to use on uptempo songs. It’s particularly evocative with vocals, especially ones where the phrasing has some “space,” as well as with languid, David Gilmour-type solo guitar lines. But I’ve also tried this ethereal reverb effect on individual snare hits and a variety of other signals, so feel free to experiment—maybe you’ll discover additional applications. Happy ambience!
Craig Anderton is Editor Emeritus of Harmony Central. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.