Grain Delay

Grain Delay Origins

The grain delay effect draws its roots from granular synthesis. It all started in 1946 when physicist Dennis Gabor published his work about applying quantum physics methods to the sound signal. With this work, he developed a system that uses a grain system to reproduce a sound. In later years, Greek-French composer and musical theorist Iannis Xenakis got in touch with Gabor's work. He used it to create a musical application based on the principle. His first works involved granular synthesis made by splicing magnetic tape into tiny segments, rearranging those segments, and taping the new string of the segments together. Inspired by Xenakis's works, Curtis Roads began experimenting with this idea on a computer shortly after. He was the first to implement granular sound processing in the digital domain. In the mid-1980s, a Canadian composer named Barry Truax began developing a way to create a granular synthesis in real-time. Since then, granular synthesis has become available to many musicians.

Granular Synthesis

Granular synthesis is a primary sound synthesis method that operates on the microsecond time scale. It works on the same principle as sampling. However, the samples are not played conventionally but are split into small pieces of around 1 to 50 ms. These small pieces are called grains. Multiple grains may be layered on top of each other. They may play at different speeds, phases, volume, and frequency, among other parameters.

Grain Size

The grain size is usually presented in Hertz (Hz) using the Frequency control. You can think of it as grains per second — higher frequencies mean larger grains and lower frequencies mean smaller grains. You can calculate the grain size in fractions of a beat at your song's tempo by dividing the tempo by 60 times the frequency. For example, at a tempo of 120 bpm, a frequency of 4Hz (four grains per second) captures a half-beat (an eighth note) per grain. But you don't need to be overly concerned with grain size. Its practical significance is that larger grains (lower frequencies) are more stable when you use feedback, pitch-shifting, or jittering with the Spray and Random Pitch controls.

Grain delays slice the input audio into extremely short segments, then delay each slice by a slightly different time. Most granular delays also incorporate pitch shifters, allowing them to change each slice's pitch. Granular delays are the most complex delay plug-ins and can warp and mangle audio into a different sound. Recently, many grain delay effects have been available on the market. Some of them contain simple control parameters, while others are very complex.