Brady Boettcher releases gRainbow, a free pitch-detecting granular synthesizer plugin for Windows, macOS, and Linux.
Granular synthesis is a complex and fascinating area of audio research, and it’s not uncommon to see developers push the boundaries of what is possible with it, thanks to fresh perspectives and brilliant intuitions.
It’s within this scenario that Brady Boettcher, an independent audio developer, shares with the world his open-source, cross-platform synthesizer gRainbow, a cross-platform synthesizer that uses pitch detection to choose candidates for granular synthesis or sampling.
The main goal of this project was to overcome a few shortcomings of traditional granular synths, for example, the inharmonicity generated by pitch variations in the input clip and the unwanted artifacts which are the result of extreme time-stretching.
To overcome these problems, gRainbow uses longer, pitch-diverse audio clips. It automatically produces harmonics matched for MIDI input and avoids too much time-stretching by generating harmonics that are already near their target pitch.
It works like this: when an audio file is loaded into gRainbow, a pitch detection analysis is run to segment the clip into discrete pitches over time, and each one is assigned a color (hence the rainbow visual nature of the GUI).
Next, the synth finds up to 6 pitch-matched position candidates for each note, guaranteeing harmonically agreeable grains.
Candidates are a collection of viable positions in the audio clip where the pitch is harmonic with a particular note.
Finally, the user can customize each note and its generators (i.e., changing parameters and candidates) to their liking and can save all the processing into a preset for instant recall.
The GUI is organized with the 12 notes of the chromatic scale displayed at the bottom, a neat rainbow at the center displaying the harmonic profile of the audio analyzed, and some useful global controls on the sides.
You’ll find traditional controls over the grain’s envelope, like their shape and duration, a global ADSR amplitude envelope, and a multi-mode filter with Cutoff and Resonance parameters.
Furthermore, there are some other specific parameters to customize the granular synthesis process: the Pitch Adjust, Pan Adjust, and Position Adjust, paired with their respective Spray control, which can select a range of randomization.
gRainbow is available for Windows, macOS, and Linux in VST3, AU, and LV2 plugin formats. You can download the current version (v 0.2.2) via Github.
Download: gRainbow
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