Plucked strings and sound effects
A plucked string (STK’s Plucked) and retro game sound effects (sfxr).
Pluck
Pluck(polyphony=6)A synth pluck: the short, bright, filter-snapped note of melodic techno and trance.
The analog voice with a pluck patch fixed in place: two saws a few cents apart and a square sub an octave down, through a resonant 24 dB ladder low-pass with a touch of drive. Each note opens the filter wide and snaps it shut within a couple of hundred milliseconds, while the amp envelope (no sustain) lets the note fade away on its own, so a note needs no note_off; note_off damps it in 80 ms.
lead = kiln.Pluck()
lead.decay = 0.4
lead.fx = [kiln.Delay(time=0.28, ping_pong=True), kiln.Reverb()]
for freq in (220.0, 261.6, 329.6, 440.0): # an A minor arpeggio
lead.note_on(freq)It holds polyphony notes at once (6 by default): a seventh damps the oldest. With polyphony=1 every note plucks again instead of gliding. A pluck is an analog voice, so it costs one voice of the voice budget, and a six-note chord costs six of the 24. Its patch is not editable; for another sound, use Synth.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| polyphony | int | Notes that ring at once, 1 to 16 (default 6). | 6 |
Attributes
| Name | Type | Description |
|---|---|---|
| decay | Time for a note to fall 40 dB, seconds, 0.05 to 10 (default 0.5). The filter’s snap lengthens with it, from 80 to 450 ms. | |
| brightness | Tone, 0 (a dull, rounded blip) to 1 (a bright, biting zap); default 0.5. It sets how high the filter starts and how far it opens. | |
| volume | Output level, 0 to 1 (default 0.8). |
Sfx
Sfx(polyphony=_shared.DEFAULT_POLYPHONY)Retro game sound effects, made from about twenty numbers, as DrPetter’s sfxr makes them.
play(preset) rolls a new sound from one of sfxr’s generators, a coin, a jump, a hit, a laser, …, and plays it. A seed makes it repeatable: the same preset and seed are always the same sound, so a game can give each event its own. hit() plays the current sound again.
sfx = kiln.Sfx()
sfx.play("coin", seed=3) # the same coin every time
sfx.play("laser") # a new laser every time
sfx.slide = -40.0 # tweak it: fall faster, 40 octaves a second
sfx.hit()The sound is a waveform whose pitch starts at tune, slides and wobbles, shaped by an envelope (attack, sustain with its punch, decay) and through a sweeping comb, low-pass and high-pass (kiln.sound.dsp.sfxr has the model). Each hit plays the envelope through and stops: an Sfx is a one-shot, like a drum, so a Sequencer pattern plays it at tune with no note_off. note_on(freq) plays the sound transposed to start at freq.
Every attribute below is a control: set it at any time, or use control_change(name, value). Unlike other instruments’ controls, these are queued in order with the notes: the values set before a hit are the ones it plays with, even several hits in one frame. A hit reads them once, at its start.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| polyphony | int | Sounds that play at once, 1 to 16 (default 8): one more cuts the oldest short. | _shared.DEFAULT_POLYPHONY |
Attributes
| Name | Type | Description |
|---|---|---|
| wave | “square” (default), “saw”, “sine” or “noise”. | |
| attack | Seconds the level takes to rise, 0 to 5 (default 0). | |
| sustain | Seconds it holds, 0 to 5 (default 0.2). | |
| punch | How far above full the sustain starts, falling to full, 0 to 1 (default 0; 1 starts at three times). | |
| decay | Seconds it takes to fall to silence, 0 to 5 (default 0.36). | |
| tune | Starting pitch, Hz, 20 to 12000 (default 321). | |
| min_freq | A falling pitch stops the sound here, Hz, 0 to 12000 (default 0: it never stops; the pitch rests at 3.5 Hz). | |
| slide | Pitch slide, octaves per second, -700 to 700 (default 0). | |
| delta_slide | How fast the slide itself changes, octaves per second per second, -3000 to 3000 (default 0). | |
| vibrato_depth | Vibrato, semitones, 0 to 12 (default 0). | |
| vibrato_rate | Vibrato speed, Hz, 0 to 100 (default 0). | |
| arp | A pitch jump, as a multiple of the pitch, 0.05 to 20 (default 1: none; 2 jumps an octave up), after arp_time. |
|
| arp_time | Seconds before the jump, 0 to 1 (default 0: none). | |
| pulse_width | The square’s duty cycle, 0 to 0.5 (default 0.5: square; 0.1 is thin and nasal). | |
| pulse_width_sweep | How fast the duty cycle moves, per second, -3 to 3 (default 0). | |
| repeat | Seconds after which the pitch, slide, duty and jump start over, 0 to 1 (default 0: never). The envelope runs on. | |
| phaser_delay | A copy of the sound this many milliseconds late is added, 0 to 2.9 (default 0: none, the sound doubled): a comb, sfxr’s “phaser”. | |
| phaser_sweep | How fast that delay moves, milliseconds per second, -125 to 125 (default 0). | |
| cutoff | Resonant low-pass cutoff, Hz, 10 to 20000 (default 20000: off). | |
| cutoff_sweep | Its sweep, octaves per second, -30 to 30 (default 0). | |
| resonance | The low-pass’s emphasis at the cutoff, 0 to 1 (default 0). | |
| hp_cutoff | High-pass cutoff, Hz, 0 to 6000 (default 0: only DC is removed). | |
| hp_sweep | Its sweep, octaves per second, -20 to 20 (default 0). | |
| volume | Output level, 0 to 1 (default 0.5). |
Methods
| Name | Description |
|---|---|
| control_change | Sets a named control, in order with the notes: the next hit plays with it. |
| hit | Plays the current sound. The same as note_on(self.tune, velocity). |
| play | Rolls a sound from one of sfxr’s generators, makes it the current sound, plays it. |
control_change
Sfx.control_change(name, value)Sets a named control, in order with the notes: the next hit plays with it.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| name | str | A control of this instrument, such as "slide" or "volume". |
required |
| value | The new value, clamped to the control’s range (or an option’s name). | required |
Raises
| Name | Type | Description |
|---|---|---|
| ValueError | name is not a control of this instrument, or value is NaN. |
hit
Sfx.hit(velocity=1.0)Plays the current sound. The same as note_on(self.tune, velocity).
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| velocity | float | Loudness, 0 to 1 (clamped). | 1.0 |
play
Sfx.play(preset='random', seed=None)Rolls a sound from one of sfxr’s generators, makes it the current sound, plays it.
Parameters
| Name | Type | Description | Default |
|---|---|---|---|
| preset | str | “coin”, “jump”, “hit”, “laser”, “powerup”, “blip”, “explosion”, or “random” (any sound at all, within 2 seconds). | 'random' |
| seed | int | None | Any integer: the same preset and seed are always the same sound. None (the default) rolls a new one every time. | None |
Raises
| Name | Type | Description |
|---|---|---|
| ValueError | An unknown preset. |