Reverbs are essential for creating space, depth, and a dimension of interest into a track, either creatively or technically. Programming reverbs in particular ways is a simple way to locate elements within a mix, to establish a near-to-far soundstage, and to help prevent the mix from getting muddy – but reverbs used incorrectly will actually contribute more to the “mud.” Some plugins will allow you to select a location within the soundstage for the reverb to originate from, such as Convolution Reverb within Max4Live. Let’s dive into a few specific aspects of reverb programming and use cases to give you an overview of how to use this effect to its full potential.
Pre-Delay is one of the first parameters to have dialled in. This timing tells the reverb how long to wait before the echoed and dispersed sound returns, which we hear as distance. There are two ways to determine how long to set the pre-delay time. First, as is becoming more popular in current electronic music styles, is to time the pre-delay as a note fraction, You can get this exact time by using a delay calculator, and plugging in your current track bpm. You can select any time based on a note fraction for this method, knowing that any time selected will drop the reverb in on time relative to the effected sound. Keep in mind that super-long delay times will start to sound very artificial. The other way to determine the time is simply by deciding how far away you want the reverb to come from, or how big the virtual room should be. The longer the delay time, the further away the reverberation comes from and the bigger the perceived space is. Again, as with the other technique, super-long times will sound very unnatural.
Early/Late reflections can also change our perception of the space in which the reverb exists. Early reflections are more discrete, much like a delay echo. These are the first parts of the sound reflected back to the source. Late reflections are less discrete and more muddied, as reverb usually is. These are the waves that mix together within a space and come back to the origin a little later. Combined with the pre-delay selection, the specific mix of Early/Late reflections will help to better locate the element within a mix. Use to taste and to how the sound interacts with the chosen reverb style and plugin.
Reverb time is probably the aspect most focused on when programming a reverb, and it is very important to keep the mix tidy as well as properly convey the creative sense of depth and space. Long reverbs can sound nice in isolation, but a lot of the time, they also take up way too much space in the mix and can really kill dynamics and definition when you are not careful. Carefully timed reverb decays can blend perfectly into the timing of a track when for example, a reverb tail drops just below audible just before the sound plays again and re-triggers the reverb tail. This can also be timed using a delay calculator, or simply by ear. Huge tails have their place too, but in my experience, it is best to reign these in a little, I usually do so with an eq on the reverb tail or a gentle sidechain compressor. The compressor can be side-chained into a kick, clap, high hat, or any other rhythmic element which makes sense and works in the mix. A fun way I use to add a little groove is to set up a large, airy reverb on my open hats, and sidechain compress them from the snare track, so every few hats the reverb tail is cut out for a short time, usually timed to correspond with a note division at the track’s bpm.
Finally, the last thing I will cover this week with reverb is the common question: track insert or return channel? As with any other mixing based question, it really depends on what you are trying to accomplish with the effect in each specific case. Track insert effects give you individual control over what happens with each element and effect, but depending on the plugins used, how many tracks you have, and your computer’s capability, you can quickly encounter cpu throttling issues; reverb can be especially hard on cpu usage. Using just one reverb in a return channel helps with this, but you lose the customisability over each instance and how it is adjusted. Using a combination of both is often the answer, using a return for background depth and reverb, and the main sense of space within the mix and separate reverb inserts to draw attention to an element or locate it somewhere else within the mix. The return reverb instance could be set to somewhat average settings, with other track inserts using blends of near/far location or short/long tail length. Of course, most of this falls into the realm of creative decisions, so it is always good to have more tools in mind when it comes to expanding the stereo image of a mix and keeping things interesting with effects.