---
title: Audio effects
layout: ../../layouts/MainLayout.astro
---

import { MiniRepl } from '../../docs/MiniRepl';
import { JsDoc } from '../../docs/JsDoc';

# Audio Effects

Whether you're using a synth or a sample, you can apply any of the following built-in audio effects.
As you might suspect, the effects can be chained together, and they accept a pattern string as their argument.

# Filters

Filters are an essential building block of [subtractive synthesis](https://en.wikipedia.org/wiki/Subtractive_synthesis).
Strudel comes with 3 types of filters:

- low-pass filter: low frequencies may _pass_, high frequencies are cut off
- high-pass filter: high frequencies may _pass_, low frequencies are cut off
- band-pass filters: only a frequency band may _pass_, low and high frequencies around are cut off

Each filter has 2 parameters:

- cutoff: the frequency at which the filter starts to work. e.g. a low-pass filter with a cutoff of 1000Hz allows frequencies below 1000Hz to pass.
- q-value: Controls the resonance of the filter. Higher values sound more aggressive. Also see [Q-Factor](https://en.wikipedia.org/wiki/Q_factor)

## lpf

<JsDoc client:idle name="lpf" h={0} />

## lpq

<JsDoc client:idle name="lpq" h={0} />

## hpf

<JsDoc client:idle name="hpf" h={0} />

## hpq

<JsDoc client:idle name="hpq" h={0} />

## bpf

<JsDoc client:idle name="bpf" h={0} />

## bpq

<JsDoc client:idle name="bpq" h={0} />

## vowel

<JsDoc client:idle name="vowel" h={0} />

# Amplitude Envelope

The amplitude [envelope](<https://en.wikipedia.org/wiki/Envelope_(music)>) controls the dynamic contour of a sound.
Strudel uses ADSR envelopes, which are probably the most common way to describe an envelope:

![ADSR](https://upload.wikimedia.org/wikipedia/commons/thumb/e/ea/ADSR_parameter.svg/1920px-ADSR_parameter.svg.png)

[image link](https://commons.wikimedia.org/wiki/File:ADSR_parameter.svg)

## attack

<JsDoc client:idle name="attack" h={0} />

## decay

<JsDoc client:idle name="decay" h={0} />

## sustain

<JsDoc client:idle name="sustain" h={0} />

## release

<JsDoc client:idle name="release" h={0} />

# Dynamics

## gain

<JsDoc client:idle name="gain" h={0} />

## velocity

<JsDoc client:idle name="velocity" h={0} />

# Panning

## jux

<JsDoc client:idle name="jux" h={0} />

## juxBy

<JsDoc client:idle name="juxBy" h={0} />

## pan

<JsDoc client:idle name="pan" h={0} />

# Waveshaping

## coarse

<JsDoc client:idle name="coarse" h={0} />

## crush

<JsDoc client:idle name="crush" h={0} />

## shape

<JsDoc client:idle name="shape" h={0} />

# Global Effects

## Local vs Global Effects

While the above listed "local" effects will always create a separate effects chain for each event,
global effects use the same chain for all events of the same orbit:

## orbit

<JsDoc client:idle name="orbit" h={0} />

## delay

<JsDoc client:idle name="delay" h={0} />

## delaytime

<JsDoc client:idle name="delaytime" h={0} />

## delayfeedback

<JsDoc client:idle name="delayfeedback" h={0} />

## room

<JsDoc client:idle name="room" h={0} />

## roomsize

<JsDoc client:idle name="roomsize" h={0} />

Next, we'll look at strudel's support for [Csound](/learn/csound).