Stud Wall STC Comparison
Compare a caller-supplied single-stud and double-stud laboratory STC pair, return the signed point difference, and preserve each test reference without treating the result as a universal construction rule.
Description
Stud-wall ratings describe particular assemblies and test conditions.
Stud-wall ratings describe particular assemblies and test conditions. Decoupling benefits must be tied to matched records.1
Compare a caller-supplied single-stud and double-stud laboratory STC pair, return the signed point difference, and preserve each test reference without treating the result as a universal construction rule.
When to use Stud Wall STC Comparison
Use this tool to compare a caller-supplied single-stud and double-stud laboratory STC pair, return the signed point difference, and preserve each test reference without treating the result as a universal construction rule.
Choose a supported reference topic, run an input-free reference with an empty object, or prepare the measured values and caller-supplied test records requested. Keep acoustic metrics, frequency, units and test conditions consistent.
How to use Stud Wall STC Comparison and understand its results
- Choose a supported reference topic, run an input-free reference with an empty object, or prepare the measured values and caller-supplied test records requested. Keep acoustic metrics, frequency, units and test conditions consistent.
- Enter comparisons, queryComparisonId using the field table and calculation rules, then run the tool.
- Read caveat, higherRatedConfiguration, selectedComparison, stcDifferencePoints. The explanation below defines the units, signs, ordering and any flags or placeholder values.
- If the tool reports an input issue, correct the values and run it again. Apply the stated assumptions when interpreting a successfully returned result.
| Input field | Meaning | Value type; see rules below | Requirement |
|---|---|---|---|
| comparisons | Stud comparison table | list of object; minimum entries: 1; maximum entries: 200 | Required |
| queryComparisonId | Comparison identifier | string; minimum length: 1 | Required |
| comparisons[].comparisonId | Field in comparisons record | string; minimum length: 1 | Required in each record |
| comparisons[].doubleStudAssembly | Field in comparisons record | string; minimum length: 1 | Required in each record |
| comparisons[].doubleStudStc | Field in comparisons record | number; minimum: 0 | Required in each record |
| comparisons[].framing | Field in comparisons record | string; minimum length: 1 | Required in each record |
| comparisons[].ratingBasis | Field in comparisons record | string; one of "estimated", "manufacturer-claim", "tested" | Required in each record |
| comparisons[].singleStudAssembly | Field in comparisons record | string; minimum length: 1 | Required in each record |
| comparisons[].singleStudStc | Field in comparisons record | number; minimum: 0 | Required in each record |
| comparisons[].source | Field in comparisons record | string; minimum length: 1 | Required in each record |
| comparisons[].testMethod | Field in comparisons record | string; one of "ASTM E90/E413", "ISO 10140-2/ISO 717-1", "manufacturer-method" | Required in each record |
| comparisons[].testReference | Field in comparisons record | string; minimum length: 1 | Required in each record |
Supply 1–200 comparison records and an exact queryComparisonId. Require unique raw IDs, finite nonnegative ratings and all assembly/framing/source/test fields. Select the matching row and return it, signed points, double-stud/single-stud/tie by sign and caveat.
difference=doubleStudSTC−singleStudSTC Units, indexing, boundary conditions and exceptional cases are defined in the calculation rules above.
| Output field | Meaning | Value type |
|---|---|---|
| caveat | caveat | string |
| higherRatedConfiguration | Higher-rated configuration | string; one of "double-stud", "single-stud", "tie" |
| selectedComparison | selectedComparison | object |
| stcDifferencePoints | STC difference (STC) | number |
| selectedComparison.comparisonId | Field in selectedComparison | string; minimum length: 1 |
| selectedComparison.doubleStudAssembly | Field in selectedComparison | string; minimum length: 1 |
| selectedComparison.doubleStudStc | Field in selectedComparison | number; minimum: 0 |
| selectedComparison.framing | Field in selectedComparison | string; minimum length: 1 |
| selectedComparison.ratingBasis | Field in selectedComparison | string; one of "estimated", "manufacturer-claim", "tested" |
| selectedComparison.singleStudAssembly | Field in selectedComparison | string; minimum length: 1 |
| selectedComparison.singleStudStc | Field in selectedComparison | number; minimum: 0 |
| selectedComparison.source | Field in selectedComparison | string; minimum length: 1 |
| selectedComparison.testMethod | Field in selectedComparison | string; one of "ASTM E90/E413", "ISO 10140-2/ISO 717-1", "manufacturer-method" |
| selectedComparison.testReference | Field in selectedComparison | string; minimum length: 1 |
{
"input": {
"comparisons": [
{
"comparisonId": "published-examples",
"doubleStudAssembly": "CEMCO 2-1/2 in double steel-stud rows, 1 in separation, four layers total",
"doubleStudStc": 62,
"framing": "steel",
"ratingBasis": "tested",
"singleStudAssembly": "ClarkDietrich single steel-stud wall with RC-Deluxe on one side",
"singleStudStc": 54,
"source": "Independent laboratory reports supplied by the caller",
"testMethod": "ASTM E90/E413",
"testReference": "CEMCO NOAL-19-1045; ClarkDietrich TL18-302"
}
],
"queryComparisonId": "published-examples"
},
"output": {
"caveat": "A double-stud or resiliently attached assembly is not automatically superior. Compare only caller-supplied rows with equivalent framing, mass, insulation, fasteners, test conditions, and rating method; laboratory STC does not predict field isolation without flanking and workmanship checks.",
"higherRatedConfiguration": "double-stud",
"selectedComparison": {
"comparisonId": "published-examples",
"doubleStudAssembly": "CEMCO 2-1/2 in double steel-stud rows, 1 in separation, four layers total",
"doubleStudStc": 62,
"framing": "steel",
"ratingBasis": "tested",
"singleStudAssembly": "ClarkDietrich single steel-stud wall with RC-Deluxe on one side",
"singleStudStc": 54,
"source": "Independent laboratory reports supplied by the caller",
"testMethod": "ASTM E90/E413",
"testReference": "CEMCO NOAL-19-1045; ClarkDietrich TL18-302"
},
"stcDifferencePoints": 8
}
}Limitations and assumptions
No test report is fetched or authenticated. The ISO method option normally concerns Rw rather than STC; the tool preserves supplied field names without establishing cross-standard equivalence. A result is not a universal construction rule.
Numeric inputs, where present, must be finite. Follow the calculation-specific rules for overflow, underflow and exceptional cases. Extremely large text inputs are rejected. Missing required fields, extra fields, wrong value types and violations of the calculation rules are input errors.
Alternative or Complementary methods
Use Resilient Channel STC Comparison: Look up the caller-supplied STC change from direct board attachment to a specified resilient-channel assembly, preserving channel, spacing, test, and manufacturer caveats. For a complementary task, use STC and NIC Metric Classifier: Classify a caller-supplied ASTM or ISO airborne-sound record as laboratory STC, field NIC, apparent ASTC, or the corresponding distinct rating without equating the metrics.
References
-
Stud Wall STC Comparison — tool.io
Similar or alternative tools
- Resilient Channel STC Comparison
Look up the caller-supplied STC change from direct board attachment to a specified resilient-channel assembly, preserving channel, spacing, test, and manufacturer caveats.
- STC and NIC Metric Classifier
Classify a caller-supplied ASTM or ISO airborne-sound record as laboratory STC, field NIC, apparent ASTC, or the corresponding distinct rating without equating the metrics.