Reverb — an abbreviation for "reverberation" — is the reflected sound that bounces back to your ears from surfaces in your environment. It's what gives massive cathedrals their characteristic, echo-laden sound.
Reverb, whether it be from a plug-in, digital rackmount unit, or tailor-made physical space, is an essential studio tool. It's what we use to give depth and dimensionality to our mixes. Used properly, reverb will create a spacious soundstage for your mix, imbuing it with a realistic, three-dimensional quality. Used incorrectly, reverb will submerge your mix under an avalanche of disorganized sonic reflections.
Few things scream "amateur mix" more than poorly applied reverb. So, how do you keep reverb from overwhelming your mix? In this blog, we'll explore different methods for making ambient effects fit unobtrusively into your mix.
Use the Right Reverb
Even if you only have a bare-bones plug-in collection, you probably have hall, chamber, room, plate, and spring reverbs at your disposal. Indeed, most modern DAWs come equipped with a sizeable cache of reverbs right out of the box.
Newbie engineers often dial up the densest, lushest reverb in their toolkit and apply it — liberally — to every individual track in their mix. This is not an advisable practice (unless you're producing avant-garde ambient soundscapes or '90s-era shoegaze; if that's the case, have at it).
While these in-your-face reverbs can sound amazing in isolation, you can't apply such a pronounced effect to all your tracks without cluttering up your mix.
When you have a near-unlimited arsenal of reverbs at your fingertips, it's important to understand which tool is right for your application. After all, you don't want every track in your mix swimming in über-thick ambience!
Different kinds of reverb
Hall reverbs mimic the sound of a concert hall. Because of their huge size and long decays, halls are ideal for thickening and adding space to strings and pads.
You definitely don't want to overuse hall reverb. Slathering too much of this effect on a track will wash it out and effectively bury it.
Chamber reverbs deliver a lush, hall-like sound, but with more clarity. Chambers are great for vocals, strings, acoustic guitar, and cavernous-sounding drums.
Based on the sound of an old-school echo chamber, these reverbs deliver a vintage-tinged sound you can't get any other way. If you dig the vibe of classic R&B and rock, fire up a chamber reverb.
Room reverbs are almost always a safe choice — they fit seamlessly into just about every mix. Room reverbs sound excellent on vocals, guitars, pianos, drums, and pretty much everything else you run through them.
If you want to add dimension to a track while maintaining its intimacy, room reverbs are the way to go.
Plate reverbs replicate the sound of a vintage mechanical studio device — think classic Abbey Road recordings. This type of reverb produces a very conspicuous effect, and it can sound magical on vocals and snare drums if applied correctly.
If you want to replicate the vibe of classic Beatles and Pink Floyd albums, you'll love what plates add to your mix — but use them sparingly!
Spring reverbs, which are standard issue for guitar amplifiers, produce a clean, bright, occasionally trashy sound. If you're aiming for vintage-inflected guitar tracks, these are the right effects for the job.
Want to have some fun? Slap the side of a guitar amp or spring reverb unit, and it will produce a dramatic thunderclap-like sound.
Applying the correct type of reverb to your tracks will go a long way into making them sound right.
Use a Sensible Wet/Dry Balance
If you only glean one nugget of information from this article, this is the bit you'll want to remember: the more reverb you add to a track, the further away it sounds. If you drown every track in reverb, your entire mix will sound weak and distant — subtlety is where it's at.
If you want a track to sit in the background, apply more reverb to it. Conversely, if you want a track front and center, apply less reverb to it.
It's important that you adjust your reverb levels in context — with your entire mix playing — rather than while soloing each track. What sounds appropriate by itself can easily devolve into a cacophonous storm of echoes when you bring in other reverb-treated tracks.
It's easy to overestimate how much reverb a track needs — even seasoned mix engineers do it. That's why after you have everything dialed in, you should cut each track's reverb level by an additional 1–2dB.
Use Stereo Buses
While you'll likely have specific reverbs for certain applications (i.e., a favorite vocal plate), resist the urge to place a different reverb on each track. Doing this not only gives your mix a scattershot, haphazard sound, it will also eat up precious CPU cycles.
You're better off instantiating a global room reverb on its own stereo bus and routing the majority of your tracks through the same plug-in via sends. Note: make sure the wet/dry mix on the reverb plug-in is set to 100% wet.
This will create a cohesive-sounding mix, because you're placing most of your mix elements in the same virtual space. And you'll take some strain off your CPU while you're at it.
Another way to make a reverb fit into your mix is by placing an EQ before the reverb. Note: this only works if the reverb is on its own bus; it won't work if the reverb is on a track insert.
Instantiating an EQ plug-in before your reverb enables you to control how much of each frequency hits the reverb. Settings will vary from project to project, but deploying a 450–500Hz highpass filter and 10–12kHz lowpass filter is a great place to start.
You'll be shocked at how well this works — it's almost like magic. Low-frequency mud will disappear, and your mix's high end will sound lucid and intelligible.
Use an Appropriate Decay Time
Long reverb tails may sound lush and lovely, but once you start piling on reverb-treated tracks, things can get cluttered rather quickly. Slow-tempo ballads can typically accommodate longer reverbs; however, upbeat songs will degenerate into a vat of sonic mud after a couple of beats once the tails start cascading together.
Using shorter reverb decay times is an easy way to keep things clean. A good rule of thumb is to aim for reverb tails that drop off before the next beat.
Alternatively, you can deploy a noise gate to aggressively chop off the reverb's decay instead of shortening its decay. This is a time-tested technique for adding a bit of pizazz to snare drums; but use it conservatively unless you want your drum tracks to sound like outtakes from 1985.
At times, you'll want to add dimension to something without pushing it to the back of your mix. That's where pre-delay comes in.
If you add 50ms of pre-delay to your reverb, the effect will sound 50ms after the onset of the track. This enables the track's initial attack to cut through before the reverb kicks in.
Adjusting your reverb's pre-delay is a great way to add space to your mix's central elements — vocals, snare drums, guitars — while ensuring that they remain front and center.
Use Delay Instead
Using a delay in lieu of reverb is another great way to add dimension to a track without cluttering your mix. What's more, it maintains an up-front sound, all while adding a sense of space to a track.
To get started, try dialing in around 100–500ms of delay with a conservative number of repeats. Less than 100ms tends to sound smeared and cluttered; more than 500ms can sound disconnected from the rest of the track. That said, there are no hard-and-fast rules — experiment!
Delays are ideal for lead vocal and instrument tracks. It keeps them from sounding dry and boring, yet it doesn't push the elements further back in your mix.
You can even insert a subtle — basically subliminal — amount of reverb after the delay to give it a nice, polished sheen.
As far as mixing goes, reverb is a basic food group. And learning to apply it the right way is an important element of achieving pro-level mixes.
When applied correctly, reverb will give your mix depth, dimensionality, and polish. But if you abuse it, it will transform your mix into a cluttered, distant-sounding mess.
As with any mixing-related topic, this article merely scratches the surface. That said, applying these concepts is a surefire way to elevate the quality of your mixes.