- NewBank creates 11 layers from ClassFreqConfigs, one per TrafficClass
- RenderWindow transforms WindowSnapshot into SamplesPerWindow stereo frames
- GainPerLayer (1/11) applied per layer guarantees no clipping with all layers at max
- PanGains applied per layer for constant-power stereo positioning
- EMA amplitude smoothing provides temporal convergence across windows
- 7 bank tests: layer count, output length, silence, non-zero, no-clip, stereo pan, EMA convergence
- synth/config.go: FreqConfig, HarmonicDef types; ClassFreqConfigs for all 11 traffic classes
with frequencies in 60-800 Hz using musical intervals; pan positions per D-12
- synth/oscillator.go: phase-accumulator oscillator with additive harmonic synthesis
and phase subtraction wrap (not math.Mod) per D-05
- synth/layer.go: EMA amplitude smoothing with tau-based alpha; whisper floor (0.03)
prevents silence once class has been seen; UpdateTarget/AdvanceSample interface
- All 12 tests pass (TestAllClassesHaveConfig, TestFrequenciesUnique, TestEMAAmplitudeRise, etc.)
gurix