> For the complete documentation index, see [llms.txt](https://manual.minimal.audio/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://manual.minimal.audio/lucid-manual/granular-view/grain-filter.md).
# Grain Filter
### Overview
The **Grain Filter** gives every grain its own multi-mode filter, with independent modulation and drive. Because each grain is filtered on its own, tone and texture shift and evolve from grain to grain in ways a single filter never could.
***
### 1. Filter Mode and display
#### Grain Filter Mode
Select the filter type applied to each grain.
* **Lowpass.** Passes frequencies below the cutoff. Includes **Drive** for saturated, aggressive filter sweeps.
* **Highpass.** Passes frequencies above the cutoff. Includes **Drive** for added harmonic character.
* **Bandpass.** Focuses on frequencies around the cutoff. Includes **Drive**, making it ideal for vocal-like and resonant textures.
* **Notch.** Removes frequencies around the cutoff. Includes **Drive** for hollow, phasey movement.
* **Morph.** Smoothly transitions between **Lowpass**, **Bandpass**, **Highpass**, and **Notch** using the **Morph** control.
* **Comb.** A resonant comb filter with **Damping** control. When **Scale** is enabled, it functions as a tuned resonator.
* **Flange.** A short modulated comb filter with **Damping**, creating metallic resonances and per-grain flanging effects. Can also be tuned with **Scale**.
* **Phaser.** A multi-stage phaser where **Morph** controls the spacing of notches and peaks across the frequency spectrum.
* **Allpass.** A phase-shifting allpass filter chain. **Morph** spreads the phase stages to create diffuse, smeared coloration.
* **Reducer.** Combines sample rate reduction and bit depth reduction for lo-fi textures. **Cutoff** controls the sample rate, **Smooth** softens reconstruction artifacts, and **Bits** adjusts bit depth.
### 2. Filter Controls
### Scale
Quantizes the filter cutoff to the currently selected musical scale.
This allows resonant filters, comb filters, and flangers to function as tuned resonators for harmonic filtering effects.
{% hint style="info" %}
Scale does not affect the filter's internal modulation unless **Random** modulation is enabled.
{% endhint %}
### Cutoff
Sets the cutoff frequency of the per-grain filter.
When **Scale** is enabled, the cutoff snaps to notes in the active scale, transforming resonant filters, comb filters, and flangers into tuned resonators that remain harmonically in key.
### Random
Randomizes each grain's filter cutoff instead of applying a continuous modulation sweep.
This is ideal for introducing variation and unpredictability to dense granular textures.
When **Scale** is enabled, randomized cutoff values are quantized to the active musical scale.
### Mod Depth
Controls how far the filter cutoff moves during each grain's lifetime.
Every grain modulates its filter independently, creating unique movement across the texture. Negative values reverse the modulation direction.
Enable **Random** to replace the sweep with a randomized cutoff offset for every grain.
### Mod Rate
Controls how many modulation cycles occur during each grain's lifetime.
* **1.** One complete filter sweep per grain.
* **Higher values.** Faster modulation, reaching audio-rate FM-style effects with shorter grain sizes.
{% hint style="info" %}
This parameter has no effect when **Random** is enabled.
{% endhint %}
### Resonance
Controls the emphasis around the cutoff frequency.
Higher values produce a sharper resonant peak, highlighting frequencies near the cutoff. In **Comb**, **Flange**, **Phaser**, and **Allpass** modes, this parameter controls feedback intensity, creating stronger resonances.
### Drive
Adds per-grain saturation and harmonic distortion.
* **0%.** Drive is disabled.
* **Higher values.** Produce increasingly aggressive soft clipping while preserving the detail and movement of individual grains.
### Morph
Shapes the filter response. Its behavior varies depending on the selected filter mode.
* **Morph Filter.** Blends continuously between **Lowpass**, **Bandpass**, **Highpass**, and **Notch**, enabling smooth transitions between filter types.
* **Phaser & Allpass.** Controls the spacing between notches and peaks, ranging from tightly clustered sweeps to wide spectral movement.
### Damping
Available in **Comb** and **Flange** modes.
Reduces high frequencies in the feedback path, causing higher harmonics to decay faster than lower ones.
* **0%.** Bright, metallic resonances with minimal damping.
* **Higher values.** Darker, shorter resonances that resemble muted strings or damped resonators.
### Smooth
Available in **Reducer** mode.
Applies smoothing between sample rate reduction steps.
* **0%:** Raw, stair-stepped digital artifacts.
* **Higher values:** Softer aliasing and a smoother, lowpass-like character.
### Bits
Available in **Reducer** mode.
Sets the bit depth of the reducer.
* **16 bits.** Bit reduction is bypassed.
* **Lower values.** Introduce quantization noise and classic digital crunch.
### Mix
Blends the filtered and unfiltered signal for each grain.
* **0%.** Dry signal only.
* **100%.** Fully filtered signal.
### Grain Filter Bypass
Enables or disables the entire per-grain filter section.
---
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