01
MLV is the biggest single lever
Adding the mass-loaded vinyl layer to an insulated build raised the rating by +9 to +19 dB ΔRw across 7 matched pairs (median +18 dB), taking perforated linings to Rw 29 to 36 dB.
See the controlled pairs →Honours 2026 · Reverberation-room transmission loss
How much sound gets through a perforated lining?
65 transmission-loss measurements of a 960 × 960 mm specimen between two reverberation rooms: perforated plasterboard and sheet metal, seven insulation products, and mass-loaded vinyl, across 24 third-octave bands from 50 Hz to 10 kHz. Every curve is here, rated to ISO 717-1, with the same numbers as the analysis workbook.
Highest Rw measured
36dB
Project057 and Project060: perforated plasterboard, 90 mm R2.5 glass wool and MLV.
Tests
65
63 unique builds + 2 repeats
Comparisons
69
one-factor sweeps
CH.00 · Every spectrum at once63 tests · R, dB · 1/3 octave
Colour = Rw036 dB
What the data says
ΔRw is ISO 717-1 fitted to the band-by-band difference curve.
02
Flow resistivity beats R-value
On all 5 builds tested with both, 90 mm R2.7 glass wool (σ ≈ 33.6k N·s/m⁴) out-rated the thicker, higher-R 100 mm R5 (σ ≈ 8.8k) by +11 dB ΔRw (Rw 7 to 9 dB higher). In these tests the acoustic ranking follows airflow resistivity, not thermal rating.
Plot rating against flow resistivity →03
A bare perforated board is nearly transparent
With nothing behind them, the 9 perforated panels rate Rw 1 to 9 dB, against 23 to 29 dB for unperforated plasterboard. Almost all of the performance comes from what sits behind the holes.
Compare the bare panels →04
Insulation does the work behind the holes
Across 8 bare perforated panels, the best insulation added +7 to +17 dB ΔRw. Holding the insulation fixed and changing the plasterboard perforation moved Rw by at most 6 dB (5 insulation products compared).
Open the panel × insulation heatmap →05
Repeatable rig; orientation matters only with MLV
The 2 repeat tests landed within 1 dB Rw of their originals. Without MLV, reversing the assembly left Rw unchanged (2 pairs), but with MLV it moved Rw from 30 to 29 dB: −5 dB ΔRw, mean R −2.9 dB.
See the orientation sweeps →06
The scrim is worth a few decibels
On the bare 12 mm round board, the scrim backing moved Rw from 3 to 7 dB (+4 dB ΔRw): consistent with the fabric adding flow resistance across the open area.
See the scrim pair →02
Explorer →
Overlay any tests. R, ΔR against any baseline, T60, Sabine absorption, and the ISO 717-1 fit drawn on the curve.
03
Sweeps →
69 one-factor comparisons as small multiples, each with its own chart and rating table.
04
Insights →
Controlled pairs, a panel × insulation heatmap, correlation plots and a full ranking.
Data: Master_Acoustics_Consolidated.xlsx and Acoustic_Metrics.xlsx, built 2026-09-27. Tests 059 and 063 are excluded as faulty measurements, as in the analysis.