What is Granular Synthesis? How it Works & How to Use it

Granular synthesis is a powerful tool for creating new sonic textures and soundscapes.

This sound production technique differs from standard synthesis methods (wavetable, subtractive, additive and FM) that work by manipulating waveforms. Instead, granular synthesis creates new sounds by breaking down existing samples of audio into tiny pieces (or "grains").

At its heart, granular synthesis is similar to sampling. Except it provides sound manipulation on whole deeper level. 

Granular synthesis lets the user manipulate the sound at a granular level by changing the pitch, shape, duration and volume of sound grains. The result: an effect that turns an existing sounds into something completely different – if done right!

The most fascinating thing about granular synthesis is its experimental capabilities. It can give you some unexpected results and can add character to any sound.

In this article we will take a look at granular synthesis and how it works, as well as some examples of its use in music.

How does granular synthesis work?

Granular synthesis is a sound design technique that works by splitting audio samples into tiny fragments (grains). Each grain is usually around 1 to 100 ms long. The fragmented audio grains are replayed with the sound, shifting in frequency, amplitude and duration over time.

This cluster of sound grains is known as a ‘sound cloud’ – a fitting name for its experimental and textural sound effects. The granular sound cloud contains the shifting, echoing sound fragments that shift around over time, resulting in a dynamic, highly textured sound.

The graph below provides a visualisation of granular synthesis. 

In the graph above, each point represents a unique sound grain. Each fragmented grain occurs at a different frequency and time. This variation in where, when and how each sound grain replays is what makes granularly synthesised sounds so unique and textured.

The user can manipulate granular synthesis parameters to alter the end sound. For example, a shorter playback delay will replay the sound grains in fast succession, resulting in a tighter sound. Whereas a longer delay would replay sound grains in slower succession, resulting in a looser sound. 

Once this new sequence of sounds has been created, volume cross-fades are applied in order to blend sound grains together. This is what’s referred to as “smoothing”. Like other granular synthesis parameters, the shape of the cross-fade can be adjusted for a smoother, or more fragmented sound effect.

Uses for granular synthesis: what does it do?

Granular synthesis can be used in a number of creative ways to add texture, movement and sonic definition to your tracks. Especially when it comees to manipulating samples.

Here are some examples of how granular synthesis can be used:

Add texture

The most common way to use granular synthesis is as a textural technique. It can be used for creating sound design elements such as ambience, textures and soundscapes.

This is a great way to add sonic definition and character, making your sounds more unique and interesting compared to other types of production methods (such as additive or subtractive). This is one of my favourite things about using granular synthesis: The end result is often very organic-sounding!

It can be used on any kind of sound, but it’s usually most effective on elements that already have some variation in them (i.e., not just single notes). 

For example, granular synthesis is often applied to:

• Drones and pads to create ambient soundscapes and textures.
• Synths to add character to lead sounds in the mix.
• Vocals to add a “digital” feel to lead vocals.
• Percussion to add width and glitchiness.
• Basslines to add movement and variation.

Create glitchy sounds

Granular synthesis is used by many experimental music producers to create glitchy sounds. As a sound design technique with endless possibilities, granular synthesis can chop up an existing sound into something truly weird and wonderful. Grains can be played back in different orders, loops, layers and lengths – resulting in a huge range of glitchy effects. This can include everything from jarring stutters and delays, to soft glitching reverbs. 

Create unique sounds

If you’re struggling to find a way to make a particular element in your mix sound less dull, then granular synthesis could be perfect. Granular synthesis is great for creating new and unique sounds that would be impossible to create with other methods of sound design. It is especially useful if you rely on sound library presets, yet want your music to sound more exciting and less ‘out of the box’. 

By applying granular processing on one or multiple elements from an existing sample library; this often results in a totally new sound that still retains elements from its source material (e.g., a drum loop processed through granular synthesis). It’s a really simple but effective way to completely warp presets into something new.

Another thing I love about granular synthesis is that it allows me field record sounds from my everyday life – things like frying bacon or running water – and then use those recordings as source material for more complex sounds later on down the road.

Examples: granular synthesis in action

In order to understand exactly how granular synthesis sounds, it’s helpful to hear some examples. It’s a variable tool with a lot of experimental scope, so the end result of using granular synthesis can be dramatically different each time, depending on how the sound grains are manipulated. 

I’ll be using Soundtoys Crystallizer to make some granularly synthesised sounds.

Here is a raw synth sound without granular synthesis applied: 

Now, here is the same sound with varying types of granular synthesis applied. Notice how each version sounds completely different in texture:

Example 1: the ambiance of the sound has thickened

Example 2: the sound grains have become more fragmented and distanced, and have also heightened in pitch and frequency

Example 3: the grains are softer with more attack, they sound fragmented, but less jarring than the above example

Example 4: the sound grains echo in quick succession after the original sample, and also change in frequency

Example 5: the sound has a lower pitch and the repetition of sound grains give it a thicker texture

Examples of granular synthesis can be heard across a variety of genres. Most notably, it is recognised as a staple of experimental and glitchy music.

Take Arca for example, a musician known for producing experimental sounds inspired by IDM, hip hop, ambient, avant-pop and other music genres. Her sounds have been described as complex and unique, with a recognisable character – many of which have been created through granular synthesis techniques.

Listen to Arca’s Mutant, for instance. The song begins with 2 minutes of granularly synthesised percussive, kick and synth elements:

You can also hear subtle touches of granular synthesis being used in the song Anoche. Subtle sound grains help surround the synth sounds with texture and warmth, which is what makes them sound so emotive and ethereal.

How to use granular synthesis

As a more experimental music production technique with many possibilities, there are a range of approaches to granular synthesis. This will also depend on the type of plugin you use. 

Although, most granular synthesis plugins share the same common techniques to manipulate sounds. This includes parameters such as:

• Grain length: the size of each individual grain in milliseconds (ms)
• Grain frequency: the frequency of the grain in hertz (Hz)
• Grain position or delay: where the grain is located in relation to the playback of the original audio sample, usually measured in ms or note division
• Number of grains: the amount of sound grain layers that are micro-sampled
• Sample segment: the part of the sample you wish to use
• Grain direction: whether sound grains replay in reverse or forwards
• Smoothing: the amount of crossfade between grains
• Distance: the gaps of time between sound grains in ms, this can be increased or decreased
• Randomisation: this is a common tool found in granular synths. Whereas wavetable synths tend to work best with smooth modulation that ‘morphs’ the sound from one table to another, granular synths can create ear-catching effects using both subtle and overt randomisation. This can be a great way to create sounds that change in an unpredictable and unusual manner.

Granular synthesis sounds best with experimentation, so don’t worry if you aren’t sure exactly how each parameter will impact the sounds, or if the granular synthesis tool you’re working with doesn’t have all of these parameters.

The best thing to do is start experimenting with granular synthesis in your music.

Tools for granular synthesis

It’s clear how fascinating granular synthesis can be, making it a powerful sound editing tool for any producer or sound designer. That being said, here are some popular software granular synthesisers:

• Granulizer 2
• Portal by Output
• Fragments by Efx
• FRMS by Imaginando
• Fracture XT by Glitchmachines
• Crystallizer by Soundtoys
• Absynth by Native Instruments

Conclusion

Granular synthesis is one of the most powerful and creative tools in music production, but doesn’t get half of the attention it deserves. 

With this technique, you can create new entirely unique sounds from scratch or transform existing ones into something completely different. Its versatility makes it a great tool for almost any genre, but is mostly heard in experimental, ambient and glitchier styles of music. 

The endless possibilities of granular synthesis make this hidden gem of a tool an important technique for any music producer to experiment with.

To learn more about types of synthesis, read our complete guide to types of sound synthesis.