arcattackandClaude Opus 4.8 c581553a6c Audio (AUDIO_FIDELITY F14 residue): bake the authored static resonant ...

low-pass into the zone WAVs

232 zones author initialFilterFc(8)/initialFilterQ(9) (SBK 0..127) -- the
fixed resonant low-pass the EMU8000 applied in hardware; the port played
them unfiltered (flagship: the LaserLoaded charge hum, fc=57 Q=87, much
brighter/harsher than the arcade).  The extractor now applies an RBJ 2-pole
low-pass per zone: cutoff = the AWE NRPN curve (100 + fc*7900/127 Hz),
resonance = SBK Q -> 0..+12 dB peak [T3 curve, endpoints exact], designed at
the zone's baked rate so note-60 playback reproduces the hardware's absolute
cutoff (pitch-shifted notes carry the filter -- same limitation as the
rate-baked tuning).  Synthetic sweep verified: flat lows, +5.4 dB at the
authored 3.6 kHz cutoff, -22 dB @10 kHz, -46 dB @14 kHz.

Whole bake pipeline (filter -> attenuation) now runs in float with ONE int16
conversion + peak normalization: an int-per-stage draft hard-clipped 165 of
232 zones (resonance overshoot, worst 3% of samples); now only pre-existing
source-material clipping remains (14 files).  160 WAVs re-baked; the preset
table is unchanged (no engine rebuild).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

2026-07-16 15:36:44 -05:00

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