Audio Distortion

Audio Distortion sits anywhere in an audio chain: source → filters → Audio Output. Connecting the Audio input splices the node into the shared AVAudioEngine graph — the cables are the engine wiring, one clock drives everything, and the node can be dropped into a running chain without a glitch.

Internally the node hosts Apple's AVAudioUnitDistortion, a multi-effect whose factory presets combine waveshaping, bit/sample-rate reduction, ring modulation, filtering, and short delays into distinct characters. The Preset port selects one of the 22 characters; the preset is loaded only when the index actually changes, so switching is cheap and performable. Pre Gain drives the signal into the algorithm in dB — more drive means harder clipping and a more saturated, aggressive result; the −6 dB default leaves headroom for reasonably hot sources. Mix blends dry (0) against fully processed (1) — parallel distortion at moderate Mix keeps the source's punch while adding grit on top.

The Audio output re-emits the processed signal as a new engine-backed snapshot, so more filters can follow and an Audio FFT can tap the chain after the distortion — heavy clipping adds dense harmonics, which the spectrum shows vividly. The Level output is a peak-decay RMS of the processed signal. Enable = false engages the audio unit's clean bypass: audio keeps flowing, unprocessed.

Outputs: Audio (the processed signal, chainable) and Level (peak-decay RMS of the processed signal).

• Lo-fi drum crush: Audio Player (drums) → Audio Distortion (Bit Brush, Mix 0.6) → Audio Output — instant crunchy texture; drop Mix to taste for parallel grit.
• Megaphone / radio voice: Audio Input (mic) → Audio Filter (Band Pass ≈ 1500 Hz) → Audio Distortion (Radio Tower, Mix 0.8) → Audio Output — live announcer destruction via the engine's realtime source bridge.
• Harmonics-reactive visuals: Audio Player → Audio Distortion → Audio Output, with an Audio FFT tapped on the distortion's Audio output — clipping floods the spectrum's upper bins, so visuals explode exactly when the drive bites.
• Riser destruction: cable Pre Gain to an LFO or fader rising from −30 to +10 dB in a chain Audio Player → Audio Distortion (Everything Broken) → Audio Output — the track tears itself apart on cue.
• Sci-fi speech: Audio Player (voice) → Audio Distortion (Alien Chatter or Golden Pi, Mix 1.0) → Audio Reverb (Plate, Mix 0.2) → Audio Output.
• Preset roulette performance: cable Preset to a Counter or Random node triggered on beats — a new character per bar; the preset only reloads when the index changes, so stepping is glitch-free.

• Mix is the tone control people forget: full-wet destruction often sounds smaller than 0.3–0.5 parallel blend, which keeps the clean transient underneath the dirt.
• Distortion massively boosts perceived loudness and adds high-frequency energy — follow it with an Audio Equalizer (cut around 3–5 kHz) or an Audio Filter low-pass to de-fizz, and an Audio Gain or Audio Compressor to level-match against the bypassed signal.
• Filter before distortion changes what gets clipped (a low-passed input distorts rounder); filter after shapes the fizz. Try both orders — the engine rewires live.
• The Echo presets (12–15) contain their own delay lines: give them space, and be careful stacking them with an Audio Delay node unless you want rhythmic chaos.
• Pre Gain reaches down to −80 dB — near-silent drive plus Mix 1.0 is effectively a mute with character; automatable as a choked-amp gesture.
• Enable = false is a clean bypass on a toggle — the honest A/B for judging whether the grit helps, since level-matched comparison is everything with distortion.