# Low-pass filter

> A gentle one-pole filter for warmer edges.

Source: https://docs.tune.toys/nodes/std.lowpass/

A simple filter that lets low frequencies through and softens high ones. It is the quickest way to make a sound warmer or darker.

## What it does

A one-pole low-pass filter reduces everything above its cutoff gently, at about 6 dB per octave. It has no resonance, so it never rings or whistles. It is applied to every channel of the incoming audio.

## When to use it

Use it to take the edge off a bright source, to tame a harsh distortion or to darken feedback inside an echo. When you need resonance, a steeper slope or other filter types, use the [Filter](https://docs.tune.toys/nodes/std.svf/).

## Ports

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| Port    | Direction | Signal | Lanes                   |
| ------- | --------- | ------ | ----------------------- |
| `audio` | Input     | Audio  | Inferred from the cable |
| `audio` | Output    | Audio  | Inferred from the cable |

<!-- ports:end -->

## Parameters

<!-- parameters:start -->

| Parameter | Label  | Range       | Default | Unit | Scale | Notes                                                                     |
| --------- | ------ | ----------- | ------- | ---- | ----- | ------------------------------------------------------------------------- |
| `cutoff`  | Cutoff | 40 to 18000 | 3200    | Hz   | log   | Sets the low-pass cutoff frequency. Lower values soften high frequencies. |

<!-- parameters:end -->

### Cutoff (`cutoff`)

The frequency, from 40 to 18000 Hz, above which the sound is gradually reduced. The control is logarithmic, so each step covers a similar musical distance.

## Tips

- Cutoff is a gradual slope, not a wall: sounds well above it are quieter, not gone.
- Place it before an effect to darken what feeds the effect, or after to darken the result.
- For a sweep with a peak, use the [Filter](https://docs.tune.toys/nodes/std.svf/) instead.

## See also

[Filter](https://docs.tune.toys/nodes/std.svf/), [Drive](https://docs.tune.toys/nodes/std.drive/), [Delay](https://docs.tune.toys/nodes/std.delay/).