Mixing With Reverb

Reverb is a powerful way to add depth, atmosphere, and variety to your mixes. It can fill out your songs and make them sound more cohesive.

To benefit from reverb, you have to implement it properly. Making your reverb impactful but not overwhelming can be tricky, but having the right process can make it simple. 

Definition

When sound is generated inside a physical space, it is partially reflected off of the walls, floor, ceiling, and furniture in that space. These reflections are called reverberation, or reverb for short. 

Figure 1: Reverb created by reflecting sound waves

A common type of reverb is an echo. The first musical reverb was created by using small, highly reflective echo chambers that purposely reflected as much sound as possible. Modern day reverb plugins emulate conditions similar to this digitally. 

For any sound with reverb added to it, there are two parts: an initial sound (like a drum hit) and a reverb “tail” that follows. The contents of the reverb depends on the physical space the initial sound was generated in, whether it be a real or emulated environment.

Figure 2: Kick drum waveforms without and with reverb

Uses of Reverb

There are two primary ways to use reverb in music. The first, and most useful way, is as a mixing effect. 

When you add reverb to a track, it can become softer, more airy, more spacious, and further away in space. Subtle reverb can help fill out your mix and make your song feel more three dimensional.

Reverb can also create separation in your mixes, preventing all of your tracks from competing for attention at the same time. It can move your tracks back in the mix, allowing for more space up front and more contrast overall.

The second way to use reverb is for sound design. Reverb can be used to transform the sound of individual tracks in major ways. For the purposes of this article, we will focus on using reverb as a mixing effect and not as a sound design tool.

Choosing Where to Apply Reverb

Deciding where to add reverb in your mix depends on several factors. Typically, reverb is added to tracks that play supporting roles in your mix or that can benefit from a more atmospheric, less direct sound.

For example, backing vocals are a great candidate for reverb. Reverb will help move these vocal tracks into the background to support and accompany your lead vocals instead of competing against them. 

Another great use of reverb is for drums. Reverb is often added to drums to lightly add texture and cohesion to the overall drum sound. Instead of sounding like a series of disconnected samples, reverb can help bring your drums together and integrate them into the greater mix while adding character to their overall sound.

Regardless of where you add reverb, it is important to add it conservatively. Too much reverb can start to bog down your mix, creating a muddy, unfocused sound. Not all of your tracks need reverb, and tracks that do need reverb probably don’t need very much.

To add reverb to your tracks, you can follow a simple four step process.

Step 1: Setup The Signal Path

In most cases, the best way to add reverb to your songs is through a dedicated auxiliary channel. While many plugins are added to individual tracks, routing your tracks through a reverb channel is useful for a few reasons.

Cohesion

Sharing a single reverb plugin (and a single set of reverb parameters) will create cohesion within your song. Instead of sounding like different instruments recorded in multiple locations, reverb will allow your arrangement to sound more like it was recorded in the same space. It adds a shared attribute across your instruments, creating a more unified sound.

Simplicity

By sharing the same reverb settings and characteristics, the reverb in your song will sound more consistent and less varied. Reverb should be treated like another track in your mix. Pooling your reverbs together results in one reverb track, which is easier to mix than multiple reverb tracks. 

CPU Management

One final benefit of using a reverb channel is to save CPU resources. Reverb plugins can require a lot of computing resources to operate, so using one reverb plugin instead of several will help your computer run smoother and more productively if needed.

Figure 3: Reverb is setup on an auxiliary channel with sends pointing towards it

You don’t always have to send your tracks to a reverb channel. Adding reverb directly to a track makes sense if you are using reverb for sound design, if you need reverb for only one track, or if you need to use reverb in two or more distinct ways.

When routing your tracks to your reverb channel, transfer the signals through Sends, not as channel outputs. You want your tracks to send their original signals to the main output channel and a copy of their original signals to the reverb channel for optimal control.

On your reverb plugin, set the output to be 100% wet and 0% dry. This channel will only represent the reverb sounds and not your original tracks. You can mute and solo this track to get an understanding of how reverb is effecting your full mix.

As you apply reverb, you can use a feature called Sends on Faders in your DAW to adjust how much or how little signal is routed from your tracks to your reverb. If you want less reverb for one track, lower the Send fader. If you want more reverb added, raise the Send fader.

Figure 4: Sends on Faders set to generate different amounts of reverb

Step 2: Select a Reverb Type

Reverb can be customized in many different ways. Luckily, many reverb plugins have various presets to give you lots of options up front. If you find a preset that sounds good, don’t stress too much about modifying the individual settings as well.

Since reverb is all about sound reflecting off of surfaces, reverb is commonly designed to emulate different shapes, sizes, and types of recording spaces. The most common types of spaces are rooms, chambers, and halls. 

Room reverb is usually short and fast, dissipating quickly after it is triggered. It is useful for adding tonal improvements to your tracks, such as drums.

Chamber reverb is bright and punchy. Think of this reverb as coming from a tiled bathroom or other space where the surfaces are very reflective. 

Hall reverb is more spacious, slower, and drawn out. It is meant to replicate a large auditorium or concert space. Hall reverb is best used as a more atmospheric effect that can move your tracks into the background of your mix.

Two other forms of reverb that you might run into are plate and spring reverb. These varieties emulate early mechanical reverb devices where a large metal plate or a spring was vibrated to create reverb. 

Plate reverb is warm, dark and dense sounding, while spring reverb is bright, bouncy, and metallic. Spring reverb is most commonly associated with guitars, and many guitar amps have spring reverb onboard. 

Step 3: Fine-Tune The Settings

Many reverb plugins have a wide variety of room presets that you can use to find the perfect reverb sound. Once you find a preset that you like, you can fine-tune the reverb. 

Figure 5: Logic’s main reverb plugin

Not all reverb settings need to be adjusted each time. Pick and choose the adjustments that will be most beneficial for each scenario. 

Pre-Delay

Reverb is generated as soon as the effect’s input signal produces a sound. Pre-delay is used to postpone the start of that reverb. 

For longer sounds (like a guitar chord), pre-delay can be used to position the reverb towards the end of the sound or after the sound is competed, avoiding overlap between the sound and its reverb.

This overlap can make the sound of the track muddy. Delaying the reverb prevents this and also makes better use of the entire reverb duration. 

It is important not to increase the pre-delay too much, or the reverb will start to become detached from its source, like a distinct echo.

Decay

The decay parameter determines how long the reverb tail is. A short decay means that the reverb stops quickly, while a long decay means that the reverb will continue for a longer time. Use shorter decays for a cleaner, tighter sound, and use longer decays for a more drawn out, atmospheric effect. 

Make sure your reverb’s decay doesn’t cut into the next note in your track. You want to keep your reverb in between the notes, not competing with them.

Density

Reverb density dictates how thick the reverb is for a track. Higher densities will emulate more reflective spaces (like a chamber), while lower densities will emulate less reflective spaces. You can adjust density to control how impactful and noticeable the reverb is.

Size

The size parameter provides added control over the size of your reverb space. A smaller space will have faster, shorter reverb, while a larger space will have a slower, longer reverb. 

Distance

The distance parameter determines how far away the reverb sounds in the mix. A large distance will make it sound like the instrument is further away and softer, while a shorter distance will sound closer, crisper, and more like the original sound.

Step 4: Mix The Reverb

Just like any other track, reverb is a distinct sound that needs to be properly mixed into your song.

The first and most important way to mix your reverb is by adding EQ. Many reverb plugins even have output EQ built-in to make this easy.

Reverb EQ should almost always include a high pass filter, and quite often a low pass filter as well. Reverb in these extreme frequencies can add muddiness, so isolating the reverb within the middle frequencies is best. 

Figure 6: Typical EQ for Reverb

Beyond EQ, you can consider adding other effects like compression to mix your reverb into your song. This is another benefit of using a dedicated reverb track – you can add your effects right to it like it’s another instrument.

Final Thoughts

Reverb is a great tool for mixing. It can add depth, variety, and atmosphere to your mix, fill out your songs sonically, and build cohesion.

Make sure to always add reverb gently and conservatively. Too much reverb can quickly kill your mixes if you aren’t careful!

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• Category: Mixing