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The structure is exact. In all five resupply banks the first RIFF sits at HEADERLESS_DATA_OFFSET + n*2048, where 1392 is a constant this crate already had and 2048 is the XMA1 packet size: n = 8, 1, 7, 22, 29. No free parameter to tune, and the raw bytes agree -- high entropy from offset 0, then a zero run immediately before the RIFF. VOICE_D_451 is the control, its single packet being all zeros. So I made the obvious fix, emitting that region as a sub-wave, and then withdrew it on two measurements: * It does not recover audio. Coverage went 5.4% -> 89.9% for VOICE_D_453, but the emitted stream decodes through FFmpeg to 1792 PCM bytes -- silence -- while the RIFF sub-waves from the same banks decode to 150-270 KB. Byte coverage was the wrong success metric and it looked like progress. * It is not narrow. The rule matches 1524 of the 8021 RIFF-bearing entries in sound.pak, including RT* movie banks that decode correctly today. Landing it would have risked a wide regression in order to not-fix five banks. to_xma_riffs is back to its previous behaviour, verified by re-measuring: coverage is 5.4% / 9.7% again. The refuted attempt is recorded in the code beside the branch it would have changed, so the next person does not re-derive the arithmetic and re-make the change. XMA1_PACKET is kept as a named constant because the blast-radius scan uses it. Artifacts: examples/voice_bank_shape.rs (structure), voice_bank_dump.rs (sub-waves for decoding), slb_hybrid_scan.rs (the 1524 count). Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01PMRJjbxLqZtsb5Vb7KunPE