STC Comparison — All Elements
Wall Schedule
| Wall | Name | Lab STC | Field STC Est. | Thickness |
|---|---|---|---|---|
| W1 | North concrete (street — the only concrete wall) | 65 | 58–62 | variable |
| W2 | West diagonal — existing gypsum + NEW independent inner stud leaf (PW-02) | ~60 (class) | 55–60 | existing leaf + ≥25mm gap + 70mm studs/RWA45 + 2×12.5 SoundBloc+GG |
| W3 | East — existing gypsum leaf to B313 SERVER ROOM + NEW decoupled stud leaf (PW-04) | 62 | 55–59 | 16cm new stud leaf + 100mm existing air gap (kept UNFILLED) = 26cm total buildup |
| W4 | South — existing gypsum partition lined/rebuilt to STC 50 (PW-03; D1/D5 framed openings, steel subframes) | 50 | 44–48 | 15cm |
| W5 | Buffer spine — NEW BUILD (W-07) | 55 | 49–53 | 15cm |
| W6 | VO/Control partition | 53 | 47–51 | 12cm |
Door & Window Schedule
| Element | Location | Lab STC | Field STC Est. |
|---|---|---|---|
| D1 | South entry → Video/Podcast | 50 | 44–48 |
| D3 | Control ↔ VO | 45 | 40–43 |
| D5 | Control external (opens out) | 50 | 44–48 |
| OW-1 window | Observation | 50 | 44–48 |
Technical Notes
Mass-Air-Mass (MAM)
Two gypsum layers with air gap — the gap resonance frequency must be above 200Hz for audible range effectiveness. Below this frequency, the double-leaf system can actually perform worse than a single leaf of equal total mass.
Green Glue
Constrained layer damping compound — adds 5–8 STC points vs single-layer gypsum. Applied wet between two rigid layers, it converts vibration energy to heat. Used on the South lining/rebuild (W4), buffer spine (W5), the VO/Control partition (W6), and the new west (W2/PW-02) and east (W3/PW-04) inner stud leaves.
RSIC Clips
Resilient sound isolation clips decouple gypsum from structure, eliminating direct vibration path. RSIC-1/A237R clips are used on the NORTH concrete wall only (W1) — the west, south and east walls are gypsum (S3-SITE-TRUTH), so they get independent/decoupled stud leaves instead of clips-on-mass.