Tests
2
Effect of MLV
Rw range
19–31dB
spread 12 dB
Highest Rw
31dB
MLV
Largest ΔRw vs first
+9dB
MLV
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 MLV | Project068 | 19 | −1 | −3 | ref. | +19 | 19.2 | |
| MLV | Project067 | 31 | −2 | −6 | +9 | +30 | 28.6 |
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.