VO Live
B304 — Voiceover recording booth — The quietest room in the facility
Use Cases
Voiceover recording, vocal takes, singing, spoken word, podcasting, ADR (Automated Dialogue Replacement).
VO/singing hybrid mode: Manual acoustic curtain on south wall (over OW-1 glazing) switches room character. Curtain RETRACTED = VO default (panels exposed, RT60 0.20s, NC-12). Curtain DEPLOYED = warmer singing/narration character (RT60 0.27s). Both inside the 0.15–0.30s acceptance band; mid-state 0.217s is the published figure.
Requires NC-12 — the strictest noise criteria in the facility. This room is designed for the most noise-sensitive content where even subtle HVAC hum would be audible on recordings.
Room Data
| Parameter | Value |
|---|---|
| Room code | B304 |
| Width | N 336.6 / S 293.5 cm |
| Depth | 133 cm |
| Area | 4.24 m² |
| Volume | 11.66 m³ |
| Ceiling AFF | 275 cm [AC] |
| Flooring | Vinyl |
| NC target | NC-12 |
| RT60 achieved | 0.217s (broadband) |
| Schroeder freq | 273 Hz |
| IDU | IDU-04 (dedicated) |
Floor Plan Position
VO Live occupies the northwest corner of the zone. Bounded by the concrete north wall (W1 — the only concrete wall, street behind), the EXISTING GYPSUM diagonal on the west (W2 — lined with a NEW independent inner stud leaf), the NEW-BUILD buffer spine (W5) on the east, and the NEW-BUILD VO/Control partition (W6) on the south.
The observation window OW-1 (STC 50) is located in the south wall (W6), providing visual contact with the Control Room.
Room Footprint
Acoustic Treatment
| Element | Qty | Specification |
|---|---|---|
| Absorption panels | 5 | Rockwool RWA45 50mm, 1200×600mm, NRC 0.90 |
| Corner bass traps | 3 | Rockwool RWA45 150mm, 300mm corner, full-height floor-to-ceiling |
| 125Hz membrane traps | 3 | 4mm ply + 100mm cavity + 50mm RWA45, 1200×600, f0≈123Hz |
| QRD diffusers | 0 | — |
| Ceiling cloud | 28% | Rockfon RWA45 cloud, 28% floor-area coverage |
| Manual curtain | 1 | 450g/m² velour, ceiling C-rail, dead/live positions |
RT60 Analysis
| Band | Target (s) | Achieved (s) | Status |
|---|---|---|---|
| 125 Hz | 0.25 | 0.24 | ✓ Pass |
| 250 Hz | 0.22 | 0.23 | ✓ Pass |
| 500 Hz | 0.20 | 0.22 | ✓ Pass |
| 1 kHz | 0.20 | 0.21 | ✓ Pass |
| 2 kHz | 0.20 | 0.22 | ✓ Pass |
| 4 kHz | 0.20 | 0.22 | ✓ Pass |
Room Modes
| Mode | Frequency |
|---|---|
| Length (L) | 53.8 Hz |
| Width (W) | 128.9 Hz |
| Height (H) | 62.4 Hz |
| Schroeder | 273 Hz |
Noise Criteria
Target: NC-12 — the quietest achievable rating for this room type.
| Octave (Hz) | 63 | 125 | 250 | 500 | 1k | 2k | 4k | 8k |
|---|---|---|---|---|---|---|---|---|
| NC-12 limit (dB) | 51 | 40 | 33 | 26 | 22 | 19 | 17 | 16 |
Boundary Build-ups
| Wall | Type | Lab STC | Field | Assembly |
|---|---|---|---|---|
| North (W1) | Concrete (street — the only concrete wall) | 65 | 58–62 | 300mm concrete + RSIC-1 + 50mm RW + 2×gyp |
| South (W6) | Partition (NEW BUILD) | 53 | 47–51 | NEW-BUILD VO/Control partition at y=280 (obs. window OW-1 here) |
| East (W5) | Buffer spine (NEW BUILD) | 55 | 49–53 | NEW-BUILD double leaf (W-07): 2×12.5mm gyp+GG + 100mm studs+RW + 2×12.5mm gyp+GG |
| West (W2) | Existing gypsum diagonal + NEW inner leaf | ~60 (class) | 55–60 | Existing gypsum wall (kept, NO fixings into it) + ≥25mm air gap + independent 70mm stud leaf w/ RWA45 + 2×12.5 SoundBloc + GG (PW-02) |
| Ceiling | Rockfon cloud | — | — | 28% coverage, NRC 0.90, 275cm AFF |
| Floor | Float | — | — | Vinyl finish + 15cm Sylomer buildup |
HVAC — Silencer Run A
| Parameter | Value |
|---|---|
| IDU | IDU-04 (dedicated to VO Live only) |
| Silencer | Run A: 1500mm, 40dB attenuation |
| Max velocity | 1.5 m/s |
| NC contribution max | NC-12 |
| Risk R1 | IDU-04 self-noise must be verified at min fan speed [AC] |
NC-12 demands ≤35 dB SPL at 4kHz octave band. IDU-04 supply and return ducts MUST have inline rectangular silencers (minimum 900mm length, 50mm Rockwool lining). Without silencers, IDU-04 alone will produce approximately NC-28 at the diffuser — 16 dB above target. This is non-negotiable for the NC-12 specification.
Design Constraints [AC]
- [AC] NC-12 is achieved ONLY if IDU-04 runs at minimum fan speed — verify at commissioning
- [AC] Perimeter gap 10mm → backing rod → Tremco MUST NOT be bridged
- [AC] 3 full-height corner bass traps (300mm) required in corners — cannot be removed
- 3× 125Hz membrane traps for low-frequency modal control (lower wall band) — confirm effect by measurement
- Manual curtain allows dead (0.20s, retracted) vs live (0.27s, deployed) mode switching
- Observation window OW-1 (STC 50) is the weakest acoustic element in Wall W6 (STC 53)
- [AC] SNK-1 (BOQ SN-01): 8ch XLR multicore VO Live ↔ Control (dubbing/talkback + spare pairs) — Neutrik XLR wall plates both ends, SLEEVED crossing through the W6 partition (SN-03 kit: packed, sealed both faces, putty pads); all channels land on the Control 48-pt patchbay (SN-04)