Reverb – a beginner’s guide

Reverb is a must-have effect for every musician. Used properly, it can make anybody sound instantly better – its almost like having a super-power!

How reverberations work

This highly versatile effect is used in almost every instrument and genre, from adding warmth and ambience to bluesy solos or even giving rise to whole new genres of music.

In this guide you will:

  • Discover what reverb is
  • Learn the key differences between reverb, echo, and delay
  • Get to know the most common reverb effects (and some lesser-known ones too)
  • And most importantly, learn how to get the most out of your reverb effect unit and take your sound to the next level
Image credits: seier+seier [CC BY], parsacad.com

What is Reverb?

Reverb is defined as the persistence of sound after the sound is produced.

Before we delve in to the details of how to use reverb effects in music, it’s important to understand what reverb is and how its created. For that, we need to cover some basic physics.

When sound waves are generated, they generally travel outwards and away from the source in all directions until they hit some kind of surface – objects, floors, walls etc.

The reflected sounds continue to bounce around the space and multiply until they are fully absorbed by the nearby surfaces, causing a temporary build up of sound known as “late reflections”.

Reverb is essentially the combination of early and late reflections. 

In most cases the listener (or microphone, recording device, etc) detects the direct sound straight from the source, as well as the early and late reflections a short time later. 

Reverb occurs everywhere in nature and every sound you hear is affected by reverb in some way but we don’t tend to notice because our ears are accustomed to hearing it.

In fact, our brains expect it and generally only notice it at the extremes – when there is a lot of reverb such as in a cathedral, or when there is no reverb at all such as in an anechoic chamber (a room designed to absorb and eliminate all reverb).

More on early reflections and late reflections

There is some debate among reverb effect manufacturers and academics as to whether or not early reflections even exist at all, but you’ll still hear them being mentioned in conversations about reverb settings, so its helpful to understand how the rest of us think about it.

Early reflections are usually those sounds that have been reflected back once (or maybe twice). They arrive at the listener’s ear slightly (approx 5-100ms later) later than the direct sound, and are considered to be important in helping your brain determine the size, shape and other characteristics of the space.

Late reflections are the build up of early reflections before they decay so much that they can no longer be detected. In most cases, these make up the majority of the reverb tail.

Early and late reverb reflections
Source: hyperphysics.phy-astr.gsu.edu

What kind of things can affect reverb?

Sounds lose volume/amplitude as most surfaces absorb at least a portion of the sound. 

The rate of absorption and reflection can be determined by a number of factors:

  • The size and shape of the physical space
  • The size, shape and number of any objects in the space
  • The materials from which the space and and objects within it are made
  • The position of the source and the listener, relative to each other and to any other reflective surfaces

What’s the difference between Reverb and Echo?

An echo is a single reflection of a sound wave off a surface.

Echo can be heard both in open and closed spaces, and usually sound clear and distinct. For example, think about shouting the word “Echo!” into a large ravine or cave. 

Reverb is the sound created when echoes reflect back from multiple nearby surfaces, usually in closed spaces. These reflections effectively overlap or layer on top of one another, decaying over time. To your ear, they sound like a single effect.

There are some other technical differences between the two phenomena as well.

For example, an echo can only be heard when the distance between the sound source and the reflecting surface is at least 56ft (or 17 meters). Reverb does not have the same limitation and can be heard even if the refelective surface is only a few feet from the source.

Echo can also be used to determine distances between the source and other large objects by measuring the time taken for the echo to be reflected back (Sonar is the prime example). Reverb can’t do this as its impossible to distinguish between each of the reflections.

Whats the difference between Reverb and Delay?

Delay is simply an audio signal repeated one or more times.

Similar to reverb and echo, in delay the number of repeats (known as feedback) can be altered as well as the length of time bewteen repeats, to create all kinds of different effects.

The main difference is that delay tends not to decay, unlike echo and reverb.

In audio effect terms, echo is basically a subset of delay.

Using Reverb in music

So now we have a better understanding of how reverb is created, we’re ready to discuss how reverb is used in music – what reverb does and what it can be used for.

Generally speaking reverb is used in varying amounts with each instrument to add a sense of space or depth to a mix, or make some instruments feel “bigger”.

With the right equipment, you can also crank up the dials on your reverb pedal to create ethereal or other-worldly textures that can’t otherwise be achieved in nature.

Reverb and vocals

If you’ve ever sung in the shower (and who hasn’t?!), you’ll no doubt have noticed that the reverb from your bathroom tiles can make you sound a little better. It can’t do anything if your your singing is so bad it resembles an injured animal, but most people find that it can enhance their vocals at least a little.

So why does reverb make you a better singer? Well, the late reflections – or the reverb tail – almost blends in with the source signal – in this case, your voice and can mask over minor imperfections in tone and also hides any mild shakiness in your voice. 

Reverb also adds “thickness” to your tone, and acts as a sort of harmony. All of these things added together can certainly give your vocals a little boost so its always worth adding a touch of reverb to your vocals if you can. Just remember that it can’t work miracles so use it sparingly

Reverb and guitars

The rest of this article is going to focus on using reverb with guitars (because we’re a little biased here at Guitar Signal HQ) but it can apply to pretty much any instrument or musical context.

Reverb can be used to add depth to your sound, as well as mimicking the natural reverb effects from various physical spaces – its impossible to recreate the huge expansive tone of a concert hall if you’re playing in your bedroom or small studio without using an effects pedal or plugin.

In some instances, reverb has become synonymous with certain sounds or genres – especially Shoegaze or Dream Pop.

A brief history of reverb effects

As we’ve already discussed, reverb is everywhere around us, and is especially noticeable in large man-made spaces such as halls and cathedrals.

In the early centuries of music, these spaces were used when performing (and later, recording) to produce the desired effects. Concert halls were built specifically for orchestral music and operas, while churches lent themselves very well to choral music.

Echo Chambers

Later, sound engineers created purpose-built echo rooms/chambers as a way to recreate the natural reverb of concert halls in amuch  smaller space.

In these echo chambers, the source signal/sound is played into the room via an amp placed at one end of the room and then re-recorded via another microphone placed at the other end. The resulting sound is then mixed back in with the original source, creating a reverb effect.

The type of sound generated depends on the materials used to create the room – whether metals, stone etc.

Echo chambers are much rarer these days due to cost, the amount space required (and the existence of affordable alternatives), these can still be found in high-end studios such as Abbey Road Studios in London , and Capitol Studios in Los Angeles.

Analogue Reverb Units

Over time, engineers began to develop solutions that were more affordable, practical (and often portable) than purpose-built spaces, or calling into your local cathedral.

Analogue reverb units don’t actually attempt to mimic the specific reverb physics of large spaces. However their effects do sound quite similar to the human ear, while adding their own unique qualities too.

Reverb Plates

Plate reverbs are another analogue effect and were developed to or studios that didn’t have the space for a dedicated reverb chamber.

originally created in recording studios by stretching a large metal sheet inside a frame. In plate reverbs a guitar signal is fed directly into the plate through a transducer, the metal plate vibrates adding long reverb tails with a pickup then capturing the sound.

The first ever plate reverb – the Elektro-Mess-Technik EMT-140 Plate Reverb – was developed specifically to counteract the high cost of building echo rooms.

These plate effects units (including the original EMT 140) are still used in some professional studios as they can be fine-tuned to perfection, but their sheer size and weight (6ft x 10ft, and 600lb) makes them completely impractical for most situations.

Thankfully there are plenty of digital plate reverb pedals that still sound great, while being portable and affordable, so you can easily recreate the classic reverb sounds used on albums by Pink Floyd, The Beatles and many other iconic artists.

Spring reverbs

Analogue spring reverbs were originally developed to help improve the sound of Hammond organs in the 1930’s, and they quickly became a staple addition to electric guitar amps once guitarists caught on to the benefits of being able to add reverb to their sound regardless of the acoustics of the space they were playing in.

Originally, spring reverbs were literally created using a metal spring stretched between two points, with a transducer and pickup at the either end, and running the guitar signal directly through the spring.

Still a common feature in many modern amps (most famously the Fender Twin Amp), analogue spring reverb effects are available as separate units that plug directly into the amp, as well as in a small number of specialist real spring analogue pedals.

Digital reverbs

Digital reverbs are designed to recreate traditional analogue reverb using digital circuitry – either in pedals, rack effects units, or DAW software. They offer an extra advantage in that they can also produce completely new reverb effects as well.

Digital reverbs come in two flavours.

Algorithmic Reverb

In an algorithmic reverb, traditional spaces (and plates or springs) are modelled using mathematical algorithms. They use a combination of delay lines, loops and filters to simulate the effect of sound waves reflecting off surfaces (or plates/springs).

Convolution Reverb

Essentially uses real audio samples – either from another digital simulation, or a real physical space – to produce a reverb effect. Confusingly, these effects are then controlled by algorithms.

The Five Main Types of Reverb Effect

Room

Room reverb, as the name suggests, is designed to simulate the natural sound of a small acoustic space. Because rooms are smaller than other physical spaces, sounds travel much faster through them and the decay is always quicker.

To get an idea, clap your hands in your living room or bedroom, preferably when it’s quiet. If you listen closely, you’ll notice that the first “echoes” (known as “early reflections”) are very prominent and start almost immediately. Then you’ll hear the sound decay very quickly, and has almost no tail.

Even if you’re not looking to add any real noticeable reverb, Room reverb can be used to add a subtle touch of ambience to a dry tone in Blues or Jazz music and can also give a slap-back echo effect if that’s what you’re after.

Hall

By now, you can probably guess what this one does from the name. A hall reverb provides a feeling of space and depth, and can be best suited to vocals and orchestras while also thickening the sound of an acoustic guitar.

Concert halls and even theatres are designed to produce a near-perfect environment for listening to A multitude of sounds. Their unique shape is specifically used to balance the many tones and timbre of an orchestra and to eliminate unwanted echoes.

In terms of its sound characteristics, hall reverb has later early reflections than rooms and chambers, with a long, warm decay and a prominent tail, meaning it takes a few milliseconds longer to hear the reverb, with the effect lasting longer once its in play. The result is a beautifully rich and lush reverb, but use sparingly (or at least shorten the decay parameter) as the long decay times can often muddy your overall mix.

Variations such as Church and Cathedral reverb also fall under this category, and as you might expect, offer similar characteristics but often a little more extreme. They’ll both have even later early reflections and longer tails, giving a really expansive, almost heavenly quality to your playing.

Chamber reverb

In the early days of sound recording, almost every recording studio across the world (at least those that had the space) created their own echo chambers.

These rooms were specially-designed to provide maximum sound reflection and usually involved setting up a guitar amp at one end, with a mic at the other to capture the sound that was created.

Chambers offer a good degree of flexibility, as the reverb qualities can all be affected by the shape of the space, the materials used for the walls and ceilings, and the placement of the mic and amps.

Chamber reverb tends to have a longer tail than a room, but offers much greater clarity than a hall.

Plate reverb

As we’ve covered before, original plate reverbs are large and expensive which makes them inaccessible to most, and generally impractical. God luck getting one to a gig unless you travel with a full road crew!

Thankfully plate reverb can be achieved through digital plugins and effects pedals, many of which do a great job at replicating those lush tones.

Another limitation of analogue plates is that they have limited decay times (the EMT-140 had a maximum decay of 5 seconds), but digital units can offer much longer decays, giving more flexibility.

Spring reverb

Spring reverbs were designed to be the most portable of the analogue reverbs and were first used in guitar amps. But real spring reverb tanks can also be found in guitar pedals. Naturally, these tend to give the truest spring reverb sound available, but most digital reverb pedals these days offer faithful recreations while being more flexible, and only the most sensitive ears would be able to them apart.

Its also a highly versatile effect. Its bouncy style is part of the unmistakable classic sound of surf rock, vintage rock ‘n roll and rockabilly, and it’s also one of the most common reverb effects for blues guitar.

Interestingly, you might also notice how the spring reverb sounds unnatural and maybe even dark and brooding. This is because of how the signal interacts with the springs, making the low-end frequencies audible before the high-end, which is not natural.

Other types of reverb

Those are the most common reverb effects you’ll come across, but there are literally dozens available. These include variations on the traditional room, chamber, hall, spring and plates, as well as some creative new effects that can add an extra dimension to your sound. Some of our favourites include:

Modulation

The modulation setting can add extra effects – such as chorus, vibrato, phaser, and flanger- to the reverb tail but leaves the dry signal intact, giving it subtle extra flavour which can sound great when playing chords.

The range of effects that can be added are almost limitless, but some further examples of modulated reverb that you might find in some higher-end units include rotary speaker, tremolo & vibe.

Pitch Shift - AKA Halo or Shimmer

These are really another specific type of modulation effect but are so popular they’re worth their own mention – Halo or Shimmer reverb adds an extra layer to the tail, and then pitch-shifts that layer, often going up an octave giving a surreal, otherworldly vibe.

Gated reverb

Noise gates are often available as their own dedicated pedal, and help cut unwanted noise from your signal once your playing volume drops below a certain level. You can also find this built in to some guitar reverb pedals, to reduce the reverb effect between notes when you stop playing.

The gated reverb effect is not generally associated with guitars. In fact, it was originally discovered by accident by Phil Padgham, while recording Phil Collins’ drum part on Peter Gabriel’s 1980 song “Intruder”, and became almost synonymous with 80’s pop/rock.

Not generally associated with guitar, gated reverb produces a thick, dynamic and punchy effect with the tail decaying quickly, but that’s not to say that you won’t perhaps find a new sound by adding some gated reverb to your mix.

Reverse Reverb

As simple as it sounds – reverse reverb reverses the signal and quietly swells, building up to full volume.

Typically, reverse reverb is used to sparingly in a mix, generally in the lead up to new sections of a song or on vocals.

Understanding reverb effect parameters

Dry/Wet or Mix/Level – Affects the amount of reverb sound relative to the original signal

Attack – Determines how quickly reverb effect begins

Decay (aka reverb time) – Controls how long the reverb tail lasts

Tone – Adjusts the brightness of the reverb sound

Shimmer/Modulation/Sway – Controls how much pitch shift is added to the reverb effect

Dampen – Reduces the high frequencies in the signal, which produce a more natural reverb

Pre-delay – Sets the length of the early reflections

Size – controls the size of the “room”  or “space” and generally lengthens the decay time

Shape/Diffusion – adjusts the “complexity” of the room the reverb takes place in

Reflections

See what I did there?!

For most guitarists, reverb should be one of the first effects on your pedal board due to its versatility, and general ability to enhance your sound. 

A word of caution – as a general rule of thumb, be subtle with your use of reverb. Too much reverb make your instrument sound “muddy” and make it harder to distinguish the individual parts in a mix.

That said, its ok to go wild and experiment like crazy! With the huge array of reverb effects available you may find a whole new sound or even discover a new genre of music

Before you go...

My three favourite examples of reverb are:

Please let me know your favourites in the comments below.

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