Auto Filter
Semantic type: AutoFilter · Category: modulation
Provides Auto Filter sweeps, Envelope Filter response, and Auto Wah movement with a resonant state-variable filter.
Contract
- Seeded: no
- Catalog sample rates: not declared; this does not mean unsupported
- Assets: none
- Catalog-declared latency: zero
| Semantic name | Python constructor keyword | Type / count | Default | Unit | Range or values |
|---|---|---|---|---|---|
mode |
mode |
string / 1 | "LFO" |
Not declared in catalog | LFO, Envelope |
filterType |
filter_type |
string / 1 | "Low-pass" |
Not declared in catalog | Low-pass, Band-pass, High-pass |
minimumFrequency |
minimum_frequency |
number / 1 | 200 |
Hz | 20 … 20000 |
maximumFrequency |
maximum_frequency |
number / 1 | 4000 |
Hz | 20 … 20000 |
resonance |
resonance |
number / 1 | 1.5 |
Q | 0.5 … 20 |
mix |
mix |
number / 1 | 80 |
% | 0 … 100 |
rate |
rate |
number / 1 | 0.5 |
Hz | 0.05 … 20 |
waveform |
waveform |
string / 1 | "Sine" |
Not declared in catalog | Sine, Triangle |
stereoPhase |
stereo_phase |
number / 1 | 0 |
deg | 0 … 180 |
sensitivity |
sensitivity |
number / 1 | 24 |
dB | 0 … 60 |
attack |
attack |
number / 1 | 20 |
ms | 1 … 500 |
release |
release |
number / 1 | 250 |
ms | 10 … 2000 |
direction |
direction |
string / 1 | "Up" |
Not declared in catalog | Up, Down |
EffeTune app documentation
The following section is reproduced from the English EffeTune app documentation. Its parameter names and values describe the app UI and can differ from semantic API parameters through transforms or value maps. The generated contract above is authoritative.
Auto Filter
Auto Filter moves a stable state-variable filter automatically. LFO mode repeats a sweep; Envelope mode follows the music’s level, covering the familiar Envelope Filter and Auto Wah uses. It reports zero algorithmic latency.
Sound Enhancement Guide
- For gentle tonal motion, choose LFO, Low-pass, a wide frequency range, low Resonance, and Mix around 30–50%.
- For an Auto Wah response, choose Envelope, Band-pass, raise Resonance, and adjust Sensitivity until accents open the filter without holding it fully open.
- Use a slower Attack to soften the reaction to percussion; use a longer Release for a smoother return between notes.
Parameters
- Style — loads a complete factory setting for every parameter. Choices are Auto Filter Sweep (LFO), Stereo Filter Sweep (LFO), Envelope Filter (Envelope), Auto Wah (Envelope), and Reverse Auto Wah (Envelope). Changing an individual parameter switches Style to Custom.
- Mode — LFO sweeps periodically; Envelope follows signal level.
- Filter Type — Low-pass retains frequencies below the moving cutoff, Band-pass emphasizes the region around it, and High-pass retains frequencies above it.
- Minimum Frequency / Maximum Frequency (20–20,000 Hz) — set the sweep limits. If supplied in reverse order, EffeTune sorts them; equal values hold the filter stationary. Processing also keeps the cutoff safely below Nyquist.
- Resonance (Q 0.5–20) — higher values emphasize the moving cutoff more strongly.
- Mix (0–100%) — blends dry and filtered sound; 0% is transparent dry.
- Rate (0.05–20 Hz), Waveform (Sine/Triangle), and Stereo Phase (0–180°) — control LFO speed, trajectory, and the offset within each stereo pair. They are used only in LFO mode.
- Sensitivity (0–60 dB), Attack (1–500 ms), Release (10–2,000 ms), and Direction (Up/Down) — control how strongly and how quickly the envelope moves, and whether louder sound raises or lowers the cutoff. They are used only in Envelope mode.