{"abstract":"The sum of source gains is applied to the sum of signals, introducing cross terms.","category":"Audio channel mixing","checks":4,"contract":"Mix equal-length source arrays with one corresponding scalar gain per source; output is unsaturated.","contract_signature":"sources, gains","evaluation_group":"xaud-mix-gains-per-source","failed_approach":"A common first-source gain ignores independently configured source levels.","family":"xaud-mix-gains-per-source","id":"FA-10901","implementations":{"attempt":{"sha256":"32e30a2d8532020f1e77f7297fdb9df0fe4ff8aa08def11e051d9f56ac2b8ae6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(sources, gains):\n    return [sum(frame)*gains[0] for frame in zip(*sources)] if sources else []\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 0], [0, 1]], [0.25, 0.75])),[0.25, 0.75])\ncheck('fixture 2',solve(*([[1], [1]], [0.5, 0.5])),[1])\ncheck('fixture 3',solve(*([], [])),[])\ncheck('fixture 4',solve(*([[2]], [0])),[0])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"dc4483ea00679fe3d0c07a39b8cf044d2b9dbd9442cf91161de3dc1b90457ff4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(sources, gains):\n    return [sum(frame)*sum(gains) for frame in zip(*sources)] if sources else []\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 0], [0, 1]], [0.25, 0.75])),[0.25, 0.75])\ncheck('fixture 2',solve(*([[1], [1]], [0.5, 0.5])),[1])\ncheck('fixture 3',solve(*([], [])),[])\ncheck('fixture 4',solve(*([[2]], [0])),[0])\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":" This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"xaud-mix-gains-per-source","generated_at":"2026-09-29T14:38:43.154417+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.","root_cause":"The sum of source gains is applied to the sum of signals, introducing cross terms.","sha256":"657eca433adff136fb7999d85391892cd781c3908f294d14ae672f7363493bf8","title":"Mix gains per source · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":38.201,"exit_code":1,"observations":[{"actual":[0.25,0.25],"check":"fixture 1","expected":[0.25,0.75],"passed":false},{"actual":[1.0],"check":"fixture 2","expected":[1],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0],"check":"fixture 4","expected":[0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [0.25, 0.25], \"expected\": [0.25, 0.75], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [1.0], \"expected\": [1], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0], \"expected\": [0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.767,"exit_code":1,"observations":[{"actual":[1.0,1.0],"check":"fixture 1","expected":[0.25,0.75],"passed":false},{"actual":[2.0],"check":"fixture 2","expected":[1],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0],"check":"fixture 4","expected":[0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1.0, 1.0], \"expected\": [0.25, 0.75], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [2.0], \"expected\": [1], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0], \"expected\": [0], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}