diff --git a/website/public/img/strudel-signal-flow.png b/website/public/img/strudel-signal-flow.png new file mode 100644 index 000000000..c5099c917 Binary files /dev/null and b/website/public/img/strudel-signal-flow.png differ diff --git a/website/src/pages/learn/effects.mdx b/website/src/pages/learn/effects.mdx index 89f36fe96..517eb658f 100644 --- a/website/src/pages/learn/effects.mdx +++ b/website/src/pages/learn/effects.mdx @@ -11,6 +11,129 @@ import { JsDoc } from '../../docs/JsDoc'; 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. +# Signal chain + + + +The signal chain in Strudel is as follows: + +- An sound-generating event is triggered by a pattern + - This has a start time and a duration, which is usually + controlled by the note length and ADSR parameters + - If we exceed the max polyphony, old sounds begin to die off + - Muted sounds (one whose `s` value is `-`, `~`, or `_`) are skipped +- A sound is produced (through, say, a sample or an oscillator) + - This is where detune-based effects (like `detune`, `penv`, etc. occur) +- The following will occur _in order_ and only if they've been called in the pattern. Note that all of these are + single use effects, meaning that multiple occurrences of them in a pattern will simply override the values + (e.g. you can't do `s("bd").lpf(100).distort(2).lpf(800)` to lowpass, distort, and then lowpass + again) + - Phase vocoder (`stretch`) + - Gain is applied (`gain`) + - This is where the main (volume) ADSR happens + - A lowpass filter (`lpf`) + - A highpass filter (`hpf`) + - A bandpass filter (`bandpass`) + - A vowel filter (`vowel`) + - Sample rate reduction (`coarse`) + - Bit crushing (`crush`) + - Waveshape distortion (`shape`) + - Normal distortion (`distort`) + - Tremolo (`tremolo`) + - Compressor (`compressor`) + - Panning (`pan`) + - Phaser (`phaser`) + - Postgain (`post`) +- The sound is then split into multiple destinations + - Dry output (amount controlled by `dry` parameter) + - The sends + - Analyzers + - These are used for tooling like `scope` and `spectrum` and their setup usually happens behind the scenes + - Delay (amount controlled by `delay` parameter) + - Reverb (amount controlled by `room` parameter) +- The dry output, delay, and reverb are joined into what is called the "orbit" of the pattern (see more in the section below) + - The `duck` effect affects the volume of all signals in the orbit + - The orbit is then sent to the mixer + +## Orbits + +Orbits are the way in which outputs are handled in Strudel. They also prescribe which delay and reverb to associate with the dry signal. +By default, all orbits are mixed down to channels `1` and `2` in stereo, however with the "Multi Channel Orbits" setting +(under Settings at the right) you can use them as individual 2 channel stereo outs (orbit `i` will be mapped to +to channels `2i` and `2i + 1`). You can then use routers like Blackhole 16 to retrieve and record all of the channels in a DAW for later processing. + +The default orbit is `1` and it is set with `orbit`. You may send a sound to multiple orbits via mininotation + + + +but please be careful as this will create three copies of the sound behind the scenes, meaning that if they are mixed +down to a single output, they will triple the volume. We've reduced the gain here to save your ears. + +⚠️ There is only one delay and reverb per orbit, so please be aware that if you attempt to change the parameters on two +patterns pointing to the same orbit, it can lead to unpredictable results. Compare, for example, this pretty pluck +with a large reverb: + + + +versus the same pluck with a muted kick drum coming in and overwriting the `roomsize` value: + + + +This is due to them sharing the same orbit: the default of `1`. It can be corrected simply by updating the orbits to be +distinct: + + + +## Continuous changes + +As all of the above is triggered by a _sound occurring_, it is often the case that parameters may not be +modified continuously in time. For example, + + + +Will not produce a continually LFO'd low-pass filter due to the `tri` only being sampled every time the note hits +(in this case the default of once per cycle). You can fake it by introducing more sound-generating events, e.g.: + + + +Some parameters _do_ induce continuous variations in time, though: + +- The ADSR curve (governed by `attack`, `sustain`, `decay`, `release`) +- The pitch envelope curve (governed by `penv` and its associated ADSR) +- The FM curve (`fmenv`) +- The filter envelopes (`lpenv`, `hpenv`, `bpenv`) +- Tremolo (`tremolo`) +- Phaser (`phaser`) +- Vibrato (`vib`) +- Ducking (`duckorbit`) + # Filters Filters are an essential building block of [subtractive synthesis](https://en.wikipedia.org/wiki/Subtractive_synthesis).