Audit acoustic graph DSP model

state/spine.yaml

@@ -1,6 +1,6 @@
 project: AquaSynth
 spine_version: 1
-updated: 2026-05-28T07:15:00+01:00
+updated: 2026-05-28T07:45:00+01:00
 
 prime_directive: >
   Build coherent synth machinery. References exist to reveal missing structure,
@@ -46,6 +46,7 @@ current_mechanism:
   pink_trombone_parity: docs/pink-trombone-parity.md
   pink_trombone_dsl_parity_plan: docs/pink-trombone-dsl-parity-plan.md
   physical_voice_modeling_research: docs/physical-voice-modeling-research.md
+  acoustic_graph_dsp_audit: docs/acoustic-graph-dsp-audit.md
   physical_voice_modeling_packet: research/physical-voice-modeling
   parameter_contracts: src/AquaSynth.Core/Model.cs
 
@@ -124,6 +125,7 @@ live_invariants:
   - PT utterance metrics now include cross-utterance separability because log-mel parity alone hid the user's actual listening failure. Artifact `artifacts/parity/pink-trombone-utterance-logmel/20260527T225833392` shows `mama/papa` candidate collapse: reference log-mel similarity 0.3791 versus candidate 0.6069, with candidate envelope similarity 0.8885. Interior source terminals no longer decide topology or node area/reflection; they attach to existing graph nodes and inject energy, while non-source terminals own geometry. Keep this source/topology cut even if other broken layers get louder.
   - Generated lip radiation terminals no longer bake first-frame lip opening into terminal `area_scale`; lip opening owns live path area plus radiation aperture. This removes a stale initial-state authority where words starting with closed lips kept closed-lip admittance. Static PT graph artifact `artifacts/parity/pink-trombone-logmel/20260527T231611586` passes, while utterance artifact `artifacts/parity/pink-trombone-utterance-logmel/20260527T231056242` still fails `mama/papa` collapse and silent `thrombosis`. Next work remains source/reservoir/radiation coupling, not restoring terminal-scale double gates.
   - Graph voice repair pass on 2026-05-28 fixed four model-level ownership leaks: glottal excitation is source-normalized with local `tanh`; segment propagation loss is area-dependent so closures absorb instead of ringing forever; generated nasal side-port area maps velum diameter squared directly instead of through the old hidden 0.15 damper; generated tract lips use live path-end geometry as the aperture owner and no longer double-gate radiation opening/boundary flow. Utterance artifact `artifacts/parity/pink-trombone-utterance-logmel/20260528T070759312` passes smoke and no longer collapses `mama/papa` (`referenceLogMel=0.3791`, `candidateLogMel=0.3651`); `thrombosis` improves to cosine 0.4366 but remains weak/quiet. Static artifact `artifacts/parity/pink-trombone-logmel/20260528T071240442` passes with `closure-release` demoted to sealed-static evidence (`peak=0.000005`). Next pressure is true graph-native closure reservoir/release through the scattering path.
+  - `docs/acoustic-graph-dsp-audit.md` is the current Jenga audit for graph voice DSP. It says the path graph, typed terminals, KL/PT two-port and nasal branch scatter, source/topology separation, velum side-port area, generated lip geometry ownership, area-dependent segment loss, and utterance separability should stay. It flags the generic connection fallback pressure/admittance blend, unowned radiation constants, unowned segment loss constant, turbulence/release scalar constants, and nearest-node source attachment as suspect. Next coherent build is a passive general N-port junction plus graph-native closure reservoir, then a named radiation impedance primitive.
   - Graph source lowering now names per-node incident pressure and node-local source sums inside the recursive graph loop. Generated tract injection source banks now use cell-centered positions and `1 / sections` index scaling, so turbulence/release energy is born inside tube cells rather than directly on graph/radiation nodes. Latest source-position artifact under `artifacts/parity/pink-trombone-utterance-logmel/20260527T172949293`: mama/papa/thrombosis cosine 0.6654/0.7746/0.5522, rmsRatio 3.0010/2.5712/2.4943, articulation 0.1444/0.1177/0.1193. Static closure-release RMS improved to 1.0078 under `artifacts/parity/pink-trombone-logmel/20260527T172843945`, but papa articulation worsened; keep the cell-centered source placement because it is the correct graph-level source geometry, not because metrics liked it.
   - TurbulenceJet now includes a release-timed burst-noise component in addition to the deterministic pressure pulse, but a stronger trial barely moved papa; the source is not the main remaining articulation bottleneck. Graph radiation now mixes 30% raw boundary flow with 70% high-passed flow after local admittance weighting, down from the over-bright 15/85 blend. Latest radiation/source artifact under `artifacts/parity/pink-trombone-utterance-logmel/20260527T174236049`: mama/papa/thrombosis cosine 0.6578/0.7692/0.5585, rmsRatio 3.0006/2.6153/2.3488, articulation 0.1437/0.1173/0.1191. Static `closure-release` under `artifacts/parity/pink-trombone-logmel/20260527T174139661` has rmsRatio 0.9900 and speechBandRatio 0.0842. This is still not speaking; next pressure is true tract resonance/passive scattering and pressure storage, not more burst gain.
   - Same-path two-port area discontinuities now emit `graph_area_energy_in_*` and `graph_area_energy_out_*` probes alongside the three-port branch `graph_connection_energy_*` probes. Use these to inspect passivity and formant-body failures at the scatter sites rather than judging only final output loudness.