# Filter > Low-pass, high-pass, band-pass, notch, all-pass or morphing filter with resonance, 12/24 dB slopes, curve editing and output RTA. Source: https://docs.tune.toys/nodes/std.svf/ A flexible filter that can cut highs, cut lows, isolate a band or remove one, with adjustable resonance. ## What it does The state-variable filter has a Cutoff and a Resonance (Q). Type chooses low-pass, band-pass, high-pass, notch or all-pass, or Morph, which moves continuously from low-pass through band-pass to high-pass. Slope chooses one stage (12 dB per octave) or two cascaded stages (24 dB per octave). Higher resonance emphasizes frequencies around the cutoff, up to a ringing peak. Cutoff is capped at 0.45 times the sample rate. ## When to use it Use it for filter sweeps, wah-style effects and subtractive tone shaping. Select Low-pass for a roll-off, High-pass to remove low frequencies, Band-pass to isolate a band, Notch to cut one, or All-pass to change phase. New filters start in Low-pass mode. The graph shows the response for the selected type and slope. Drag across it to set Cutoff and vertically to set Resonance; the wheel adjusts resonance too. Hover or focus the graph while playing to see the real-time output spectrum (RTA) behind the response. Patch, Properties and Frame faces use the same editor. ## Ports | Port | Direction | Signal | Lanes | | ------- | --------- | ------ | ----------------------- | | `audio` | Input | Audio | Inferred from the cable | | `audio` | Output | Audio | Inferred from the cable | ## Parameters | Parameter | Label | Range | Default | Unit | Scale | Notes | | -------------- | ---------------------- | ----------- | ------- | ---- | ------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `cutoff` | Cutoff | 20 to 20000 | 1200 | Hz | log | Filter cutoff, capped at 0.45 times sample rate. | | `resonance` | Resonance | 0.5 to 12 | 0.707 | Q | linear | State-variable filter Q. | | `mode` | Morph | 0 to 2 | 0 | | linear | Continuous low-pass, band-pass and high-pass morph. Shown when `type` is 0. | | `type` | Type | 0 to 5 | 1 | | linear | Selects the implemented algorithm. Choices are discrete and are not LFO targets. Choices: 0 Morph, 1 Low-pass, 2 Band-pass, 3 High-pass, 4 Notch, 5 All-pass. | | `slope` | Slope | 0 to 1 | 0 | | linear | One or two cascaded state-variable stages; notch/all-pass retain their response semantics. Choices: 0 12 dB/oct, 1 24 dB/oct. | | `compensation` | Resonance compensation | 0 to 1 | 0 | | linear | Reduces resonant gain as Q increases. Shown when `type` is 0 or 1 or 3. | ### Cutoff (`cutoff`) The filter frequency, from 20 to 20000 Hz on a logarithmic control. ### Resonance (`resonance`) The filter Q from 0.5 to 12. The default, 0.707, is a flat response. Higher values peak at the cutoff. ### Morph (`mode`) Used when Type is Morph: 0 is low-pass, 1 is band-pass, 2 is high-pass, with smooth values between. ### Type (`type`) Morph, Low-pass, Band-pass, High-pass, Notch or All-pass. A discrete choice. ### Slope (`slope`) 12 dB/oct uses one stage; 24 dB/oct cascades two. The notch and all-pass types keep their response meaning. ### Resonance compensation (`compensation`) When on, reduces the gain boost that comes with a high Q. It applies to Morph, Low-pass and High-pass. ## Tips - Start with a bright source such as a saw wave; filters need harmonics to remove. - Sweep Cutoff with Resonance around 4 to 8 for classic filter sweeps. - Very high resonance can be loud. Lower the level or turn Compensation on. ## See also [Low-pass filter](https://docs.tune.toys/nodes/std.lowpass/), [Drive](https://docs.tune.toys/nodes/std.drive/), [Oscillator](https://docs.tune.toys/nodes/std.oscillator/).