GrainBrain

GrainBrain — Stereo 4-Band Multiband Granular Processor

Split it. Freeze it. Scatter it. Bleed it into the next band.

GrainBrain takes your signal apart by frequency and hands each piece to its own independent 8-voice granular engine. Low end, low-mids, high-mids, and highs each get their own grain size, scatter, pitch, drive, and mix — so instead of one granular texture smeared across the whole spectrum, you get four that can move in completely different directions at once. Freeze the low end into a drone while the highs keep scattering. Reverse just the mids. Gate the top end to the host tempo while the bass stays smooth. It's a texture machine built for people who think in frequency bands, not just wet/dry knobs.

Core Signal Path

• 4-Band Split — draggable bandpass filters right on the spectrum analyzer; grab a band and move it, narrow it, or disable it entirely.
• 8-Voice Granular Engine (per band) — grain size, scatter, pitch + pitch spread, drive/saturation, and wet/dry mix, independently on every band. Reverse and Freeze modes included.
• Cross-Band Bleed — each band's output can feed into the next (Low LoMid HiMid High, wrapping back to Low), for resonant, self-reinforcing textures that a simple per-band effect can't produce.
• Stutter Gate (per band) — a BPM-synced trapezoid envelope with attack, release, and phase offset, for rhythmic amplitude patterns that lock to the host tempo.
• 7-Target LFO Matrix (per band) — modulate Center, Width, Mix, Pitch, Scatter, Size, and Gate Phase simultaneously, each with its own depth and phase.

Built to Watch, Not Just Hear

The real-time spectrum analyzer isn't decoration — band regions animate live under LFO modulation, so you can see a Center sweep or a Width pulse happening in sync with the audio. Drag directly on the analyzer to reposition a band by ear and eye.

Highlights

• Ducked, equal-power Master Mix — dry and wet displace each other instead of just stacking, so blending in granular texture never gets muddy.
• Global In and Out trim sit alongside Mix in the bottom bar — set levels in one place without hunting through four bands of per-band Gain knobs.
• Collapsible Spectrum / Gate / LFO sections, remembered per preset, so the window stays exactly as compact or as deep as the patch needs.
• Full MIDI Learn on every parameter.

What It's For

Multiband texture design, granular pads and drones, rhythmic stutter/gate effects synced to tempo, spectral freeze composition, glitch and sound-design work, and subtle "make it feel alive" granular blending underneath a mix — GrainBrain covers the gap between a delicate texture enhancer and a full sound-design instrument.

GrainBrain is donation-ware — free to use, no strings attached. If it earns a place in your workflow, a tip is always appreciated: buymeacoffee.com/brittnell

Format: VST3 (Windows & macOS) | Current version: 1.0.1.