Today’s virtual synths can open up doors into brand new sonic territories, and while common subtractive synths are great for bread-and-butter tones, true creativity lies within the more esoteric virtual instruments enjoyed by only the most adventurous of sound designers.
Continuing our exploration of various synthesis types and the tools that create them, this month’s Toolkit is all about the mystical universe of granular synthesis. Although there’s a lot of complex theory, the concept is simple: an audio signal is broken down into tiny ‘grains’, then these sound fragments are played back and recombined in various ways. On a functional level, this technology powers the timestretching and pitchshifting algorithms found in DAWs, samplers and vocal-tuning programs – so, playing back minute segments of an audio file will extend or shorten its length without altering pitch.
Functional uses aside, this technology can be used to creatively shatter apart and remerge a sample, generating entirely new timbres. Use a granular synth to play back one small ‘grain’ of an audio file as you alter the grain’s size/length, and a single repeating ‘stutter’ is created. Then, by increasing the number of grains and playing them back simultaneously, you end up with a fluffy ‘grain cloud’ effect. Tone can be altered further by slightly (or overtly) randomising the pitch and playhead position of the grains in relation to each other. Clicks, crunches and distortion can occur at crossing points between grains, so granular synths offer some kind of crossfade parameter, which applies a small volume fade to the start and end of each grain, the shape of which greatly influences the resulting grain cloud’s timbre.
The end result obviously depends upon your source material, and generally works best with audio samples that feature some kind of timbral change over time, ultimately creating shimmering, evolving musical timbres you’d never normally come up with using more traditional sampling techniques. Load a vocal phrase into a granular synth, for instance, and you can tweak the sound into a floating ethereal soundscape with a hint of the original voice. This illustrates the power of granular synthesis as a remixing tool: granulise all manner of recognisable sounds into something new.
Over the next few pages, we’ll introduce you to today’s most powerful granular instruments, and run you through the basics of their operation. Logic Pro X users arguably get the best deal of all, seeing as former Camel Audio synth Alchemy is included off the shelf. We’ll check that one out later on, before looking at Audio Damage’s ace new instrument Quanta, which buries complex granular synthesis tech behind easy-to-use subtractive controls.