Audio Architecture

1. Overview

Oh My Ondas is a 4-source, 4-channel mixer with per-channel FX processing. The four sources — microphone, sampler, synthesizer, and internet radio — each feed into a dedicated mixer channel with independent gain, 3-band EQ, and a full FX chain (delay, glitch, grain). All channels merge through a master EQ, master FX stage, and master gain before reaching the audio output and analyser.

2. Signal Flow

Each source follows an identical path through its channel strip. The per-channel FX sit between the channel EQ and the master bus, allowing independent effects processing without affecting other sources.

3. Per-Channel FX

The ChannelFX class provides three effect types per instance. Five instances are created: one per channel (mic, samples, synth, radio) and one master.

Delay

Variable-time delay (0–2s) with feedback loop and dry/wet crossfade. At 100% mix, the dry signal is attenuated to 50% rather than muted, preserving transient definition.

Glitch

Probability-based slice effects running on a 100ms check interval. Three modes: stutter (rapid volume chops), reverse (feedback burst simulating reversal), and jump (random amplitude spikes).

Grain

Simplified granular texture using the delay line. Grain density maps to delay feedback, grain size maps to delay time. Freeze mode sets feedback to 0.98 for near-infinite sustain of the delay buffer.

Routing via MangleEngine

The MangleEngine acts as a routing manager. Its currentRoute property (default: 'master') determines which ChannelFX instance receives effect parameter changes. Direct per-channel control is available via setChannelDelayMix(channelName, percent) and similar methods.

4. Soundscape Analysis

The SoundscapeAnalyzer taps a high-resolution AnalyserNode (FFT size 2048) into the mic channel gain node in parallel. The tap is non-destructive — it doesn't alter the mic audio path.

Analysis Pipeline

• Spectral frames collected every 50ms over a configurable duration (default 3s)
• RMS amplitude computed per frame from time-domain data
• Transient detection via amplitude spike ratio (1.8x threshold)
• Average spectrum computed across all frames for peak and centroid analysis

Metrics

• dominantFreqs — top 5 frequency peaks by magnitude
• spectralCentroid — brightness center frequency (Hz)
• brightness — energy ratio above 2kHz (0–100%)
• transientDensity — amplitude spikes per second
• avgAmplitude — mean RMS level
• envelope — level over time array

Classification

• amplitude < 0.01 → quiet
• transients > 4 AND brightness > 50 → chaotic
• transients > 2 → rhythmic
• brightness > 40 → noisy
• centroid > 500 → tonal
• otherwise → ambient

AI Integration

When generateFull() runs, it calls listenToEnvironment(2000) first. If the soundscape has meaningful amplitude (> 0.05), the classification overrides GPS-based vibe selection: rhythmic→urban, tonal→nature, ambient→calm, noisy/chaotic→chaos. Transient density and brightness also adjust the density and complexity parameters (+15 and +10 respectively). Dominant frequencies below 10Hz are used as tempo hints.

5. Creative Source Roles

The SourceRoleManager breaks from the assumption that samples = drums, radio = plays straight, synth = notes. Any source can serve any of four roles:

• RHYTHM — percussive, pattern-driving elements
• TEXTURE — ambient, atmospheric layers
• MELODY — pitched, melodic phrases
• MODULATION — real-time parameter modulation from source amplitude

Role Distribution by Vibe

• calm — 2 rhythm / 3 texture / 2 melody / 1 modulation
• urban — 4 rhythm / 1 texture / 2 melody / 1 modulation
• nature — 1 rhythm / 4 texture / 2 melody / 1 modulation
• chaos — 3 rhythm / 2 texture / 1 melody / 2 modulation

Strategy Pattern

Each role+source combination has a strategy function that configures the track. Examples:

• _rhythmFromSynth — short decay + filter P-Locks for percussive character
• _textureFromRadio — delay + grain P-Locks for ambient layer
• _textureFromMic — heavy grain P-Locks for processed ambient
• _melodyFromSampler — pitch P-Locks on pitched kits
• _modulationFromMic — amplitude-to-parameter modulation route

Modulation Routing

Modulation-role tracks set up real-time parameter routes. Each sequencer tick, processModulation() reads the source channel's RMS amplitude and maps it (scaled) to a target channel's FX parameter. For example: mic amplitude → synth delay mix.

6. P-Lock Integration

Per-step parameter locks now include an fxRoute field that determines which channel's FX receives the P-Lock values. The resolution order is:

• Explicit pLocks.fxRoute (set by role strategies or manually)
• Track's source channel (sampler→samples, synth→synth, etc.)
• Master (fallback)

This allows a single pattern to apply delay to the radio channel on step 3, grain to the synth on step 7, and leave all other steps targeting master — per-step, per-channel FX automation.

7. File Reference