Sheet Metal 2.38 mm Round, No MLV
Same panel and MLV state, insulation product varied.
Tests
4
Effect of Insulation
Rw range
1–17dB
spread 16 dB
Highest Rw
17dB
GW 90 mm R2.7
Largest ΔRw vs first
+17dB
GW 90 mm R2.7
Sound reduction index
R′ from the 2270, re-referenced to the 0.9216 m² specimen area (−0.35 dB). Grey lines: reference bounds.
Single-number ratings
Open in explorer| Varies | Test | Rw | C | Ctr | ΔRw vs first | ΔRw vs open | Mean R | |
|---|---|---|---|---|---|---|---|---|
| No Insulation | Project043 | 1 | 0 | 0 | ref. | +1 | 1.2 | |
| GW 45 mm R2.5 | Project044 | 7 | 0 | −1 | +6 | +7 | 6.0 | |
| GW 90 mm R2.5 | Project045 | 12 | −1 | −2 | +11 | +12 | 10.4 | |
| GW 90 mm R2.7 | Project046 | 17 | 0 | −3 | +17 | +17 | 16.4 |
Rw, C and Ctr per ISO 717-1 over 100–3150 Hz. ΔRw fits the reference curve to the band-by-band difference curve, which is not the same number as subtracting two separately rounded Rw values. Mean R is the arithmetic mean over the 16 rating bands.