What is Reverb?
Learn all about reverb, the audio effect that simulates the behaviour of real sound in a room as it reflects off multiple surfaces and builds into a wash of sound. You’ve definitely heard reverb before, but would you have known to call it that?
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What is Reverb? Adding Space and Depth to Your Mix
If there’s one audio effect that impresses non-audiophiles and professional mixing engineers alike, it’s reverb. This effect can be found on almost every recording, whether it was created artificially or recorded happening naturally. It’s a staple in the toolbox of guitarists and of studio engineers, and there’s an army of software developers aiming to both perfect the sound of reverb and to push the boundaries of what it can do.
So what is reverb, exactly? Put simply, it’s the sound of sound echoing in a space. It’s the sound you hear when a loud noise happens in a large space and rings on for a few seconds. And it’s the sound that no music would be without, from rumbling drums to epic vocals and dramatic guitar solos.
You could say that reverb is the sound that happens after the sound – reverberating in the space around it. Here’s a great example of reverb on both guitar (subtle) and vocals (more extreme)…
Now that you know more about the sound of reverb, in the remainder of this article, we’ll get deeper into why reverb happens, how it’s controlled or otherwise, and how to take command over it to put its mysterious, echoing powers to best use in your own music.
How Reverb Occurs in the Real World
Imagine a space you’ve been in that was very reverberant (full of reverb). The chances are, it’s a large space such as a church, a cave, an atrium or a train station, where sounds from in the distance seem to ring out everywhere around. Let’s tune into the details and look at exactly what’s happening.
You’re in a large space with four walls, a ceiling and a floor. When something makes a sound – any sound – the behavior of that sound is to radiate out in all directions, as shown in the image below.
While sound radiates out in all directions, some of it comes in your direction. That part of the sound travels in a straight line right to where you are, and this marks the first time you hear the sound.
Remember, sound is far slower than light, so much that we’re able to perceive differences.
Only a small portion of the sound has reached us, but the rest will make its way to us sooner or later, because it will be reflected off the surrounding walls, ceiling or floor.
In the image above, some of the sound reflects off a surface, maybe two, three or four. Because of the longer travel distance, it reaches us later. Each reflection usually means a sound takes a little longer to reach us, and also loses some power (IE, volume) by the time it does arrive.
With more reflections arriving, the sound builds up more and more until all these oncoming sounds blur into one. We’ve reached the long, reverb tail at the end of our ‘reverb experience’. Below is how the reverb reflections that have reached our ears look when they’re arranged in time, from when the sound was made until a number of seconds later.
That’s how reverb works in the real world, and whether we’re in the studio, playing through a guitar amp or mixing music on headphones, that’s the effect we’re emulating. There are a lot of ways that engineers have found to mimic these sonic reflections, and next we’ll discuss how to use them yourself and dial them in.
Core Reverb Settings
Here are some of the most important parameters to get to grips with when trying to understand reverb.
Reverb Time (RT60)
A reverb’s Time or often its ”Decay” or “Size” is the main parameter for shaping the overall sound of the reverb signal. In use, this parameter controls how long the reverb lasts, and therefore how ‘impressive’ or ‘complex’ the reverb comes across as.
In technical terms, the reverb time is referred to as the RT60, which means the time it takes for the reverb to die down by 60dB (so not to complete silence). You’ll rarely find this specific control name in a reverb plugin, but its effect will technically still be measurable.
Pre-Delay
When using a reverb, unless it’s set to 100% wet, you’ll hear the input sound first before the reverb kicks in based on the parameters you’ve selected. But with Pre-Delay activated, there’s an extra stage of delay added to hold things up, by the amount you’ve dialed in.
Turning up Pre-Delay means there’ll be a delay between the original sound (the ‘direct sound’) and the first simulated reflections of the signal.
If your reverb environment is relatively ‘small’ (like a room or studio reverb), then this should be perceived as adding more presence to the sound, letting it ‘breathe’ before the reverb kicks in to swamp it. If your reverb settings give you a large environment, like a hall or church, pre-delay might have the effect of making the sound source appear to be further away than it really is.
Diffusion and Damping
Every reverb has its way of making the tail – the part the sticks around longest – diffuse and ‘cloudy’. Your reverb’s Diffusion properties determine how this acts, while its Damping parameters will put the brakes on the reflections, making the tail last less time, be more subdued or similar. These reverb settings can be a great way of creating depth and contrast in your reverb sound.
Exactly what Diffusion and Damping parameters do varies by the individual reverb. In Baby Audio’s Crystalline Reverb Plugin, Damping consists of high-pass and low-pass filter options, as shown below.
Main Reverb Types
Most reverb plugins will be of a certain type, or will contain multiple types of reverb within them. Those types are based on reverb’s history as a hardware unit, and emulate specific environments or equipment that is used to create reverb, each with its own sonic personality.
Room
A classic and ‘standard’ reverb type that basically equates to “nice sounding recording studio”. A room reverb is a great first choice, because we’re all so used to hearing sound inside rooms. Add to that the fact that almost all classic recordings have taken place… inside rooms… and you have a good reason to reach for a room type reverb.
Room reverbs are great for drums, vocals, guitars and keyboards. You may not want to run epic strings or similar orchestral sounds through a small room, though.
Hall
This type of reverb equates to a ‘concert hall’ or can even offer a ‘live music hall’ experience to emulate a sweaty, beer-soaked gig venue.
Vocals, orchestral instruments and pianos sound great in halls. A hall reverb might be overkill for drums or instruments you want to have an intimate feel.
Plate
A plate reverb comes from a hardware simulation of a reverb ‘environment’. Within a physical box, a metal plate was excited by sound from the channel input. That sound would reverberate around the plate in a similar way to how it would do so in a room, and then the resulting reverb sound would be picked up as an output.
Plate reverbs have a haunting, resonant sound that works great on vocals, can complement drums or particular drums very well, and can surprise you as to which sources they will and won’t work wonders on.
Spring
This kind of reverb was an early type that would fit into a guitar amp or small studio box. Inside, a real spring would carry the sound, which would be reflected at the ends, and sound waves travelling through the spring would also hit each other and interact.
Spring reverbs are predominantly useful for guitar sources, and are mostly associated with the very particular sound of surf guitar. A spring reverb can serve well on vocal sources, certain drums, and piano too, depending on the context.
Convolution
This type of reverb is purely digital, and derives its sound from a literal recording of a real reverb response from the physical world. By loading an Impulse Response into a convolution reverb, you can literally recreate the sound of the space it was recorded in, making your convolution reverb as strong as the collection of impulse responses you use it with when it comes to creating depth..
Reverb Mixing Techniques
Although it’s a mixing tool itself, reverb can also cause its own problems in a mix. Since it adds a ‘layer’ of sound to your project, this layer itself sometimes has to then be dealt with as a part of the mixing with reverb task list. Here are some reverb tips specifically for mixing.
Use Reverb as a Send or an Insert
A lot of audio effects are dropped straight onto a mix channel to process its output. Reverb can do this, but it’s slightly more flexible to use it on a ‘bus’ or ‘Return’ or ‘Aux’ effect by running it in parallel with your instrument’s channel. To do this, set your reverb plugin to 100% Wet, and use the dedicated reverb channel’s fader to balance the whole effect.
One reason a reverb send tends to work better than an insert is that it allows multiple channels to be routed to the same reverb processor, gelling them together in the same virtual space. Another reason is that here you can add effects to the reverb signal alone, without processing the original track, as we’ll see below…
EQ Before or After Reverb?
If your reverb is placed on a send, you’ll be able to place an EQ before or after to change the reverb signal. Your reverb may also contain an EQ processor as part of its processing architecture. You should always ensure your mix channels are tonally balanced, and EQing after reverb means you’ll have an extra chance to pay attention and discover any harsh or overloaded frequencies that weren’t there before the signal was sent through the reverb processor.
Reverb Automation
Automating particular parameters in your DAW is a great way to make your song evolve as it goes on and stand out. One simple example is the spot reverb: automate your reverb’s send level (IE the input into the reverb) to flick on suddenly for one moment – the best example is the last word in a vocal lyric. This way, the sound will have a sudden and impressive reverb effect to keep the energy and interest going into the next section of the song.
Common Reverb Mistakes
There are some ways you should avoid working with reverb if you’re aiming for quality results in music production. Take our advice with these reverb tips, and avoid the following…
Overcooking the Reverb
Too much reverb is a bad thing. If overused, reverb can overpower the original sound, and can even start to compete with other elements in the mix. Since reverb lasts longer, it can get in the way if its parameters aren’t set with the whole mix in mind.
Using Reverb on Bass or Low Frequencies
It’s usually not good to use reverb on low frequencies like bass or kick, unless you know what you’re doing. If your reverb settings don’t have a ‘bass safe’ mode, you can use an EQ plugin before the reverb (if it’s placed on a send) to remove the bass from the signal before it gets processed in the first place.
Forgetting to Filter Reverb
Reverb can get harsh, making you notice all these sounds that didn’t stick out before, especially when applied to vocals (“Ess” and “T” sounds, for example). Removing bass and treble frequencies from reverb was once standard practice, but it’s not a shoe-in today. However, it’s worth considering whether limiting the wideband nature of your reverb would be a benefit to your mix as a whole.
Recommended MuseHub Reverb Plugins
It’s free, it’s simple, it might have everything you need
Sometimes you don’t need such deep customization from your reverb – just a quick sense of space. With the MuseFX Reverb, all you need to do is choose a reverb algorithm (Plate, Hall, Room etc) from a choice of nine, and turn a single dial to taste.
MuseFX Reverb is part of the wider MuseFX package, which contains ten other effects too.
A fresh way to look at reverb, and a great depth of sound
Crystalline isn’t quite like any other reverb you’ll ever find. Its square buttons are actually more often dragged to set their parameters, and the shapes respond to help you dial in your ideal reverb sound. There’s a lot of the controls you’d expect from a work-a-day reverb here, but you may also discover some new tricks like Shimmer, Ducking and Warp.
A very creative and inspiring way to wash your sounds in spacious atmosphere
At the start, you’ll operate Borealis by adjust those geometric shapes you can see on the interface. It might have a very abstract control set, but there’s a lot more power once you start exploring this plugin. You’ll find the ability to modulate and morph even parameters like Room Size – this is a reverb that literally gets the room pumping.
A free option for creative reverb that should hit the spot
The LE version of the full Borealis operates using only a single reverb algorithm – the ‘Sanctuary’ – to create its reverb. Credibly, you get the full control set of modulators, macros, EQ and limiter, and other controls. The only drawback is the lack of reverb types, but that’s why it can justify its presence as a free plugin.
Final Thoughts on Reverb
Reverb is an essential effect in music production, whether for mixing or sound design. Reverb has its roots in the real world, and is a key part of our perceptions, whether we know it or not. There are many ways to make reverb in your DAW, but some of the best known ways are room, hall, plate and spring reverb plugins.
There are a few considerations to make when mixing with reverb, such as whether you place it as an insert (quick) or on a bus (flexible). Overall, it’s your reverb plugin that will have the most effect over the reverb sound you can create. There are many different options out there, including free ones. You can check out reverb plugins on MuseHub, along with many other types of music production tools.
FAQ
Here are some of the most common questions about reverb, answered:
What’s the difference between reverb and echo?
Echo (delay) employs discrete ‘repeats’ of a sound, while reverb tends to build up more into a diffuse tail. Reverb seeks to simulate sonic reflections in a real space, while echo (delay) repeats sound based on your parameters.
Is too much reverb bad?
Yes, that’s why they call it ‘too much’ reverb. Overly soaking a sound in reverb means the original sound loses definition, and its long reverb tail can start to compete with other instruments in your project.
What’s the science behind reverb?
Sound reflects off surfaces in a room before reaching you. Simple reflections reach you quicker, while sound that takes a longer path will reach you later. The measurement of the ‘decay’ of a reverb response is called its RT60, and this figure describes how long it takes for the reverb signal to drop in level by 60dB.
Should I put reverb on bass?
Generally not. Bass frequencies are harder to manage while mixing, and reverb will add sustain and ‘blur’ the sound in ways that might not be obvious on all playback systems. When you hear your music back on a large sound system, you could be in for a nasty surprise if you don’t know the ins and outs of putting reverb on bass frequencies.
Why do people use reverb?
Reverb gives a sound a simulated sense of space, making it sound like it’s in a real environment. Since we hear real sounds in real environments, we’re used to hearing reverb, and it sounds more natural to our hearing system.
Does being in the shower make you a better singer?
No, but the hard, close surfaces mean sound reflects very quickly and low frequencies reinforce.