acoustics5 (S3) — Design Decisions

S3 Layout Re-split

The S3 re-split moves the facility from four production rooms to three rooms plus the buffer spine. The three decisions below record why the Editing Suite was removed and its footprint merged into a widened, high-ceiling Video/Podcast room, why a new external Control Room door (D5) was added, and how the Control Room first-reflection panels are set.

TechTown B3Damascus
DecidedAugust 2026
Affects3 elements
Datasetacoustics5 / S3
01
Editing Suite removed — Video/Podcast widened
East zone · former B312-1 + B312-2 merged · new B312
4 rooms (11.23 m² video + 8.56 m² editing) 3 rooms (19.78 m² Video/Podcast)

The four-room split forced the east zone into a cramped 11.23 m² video studio and a small 8.56 m² editing suite, separated by an internal partition (Wall 7) and its door (D4). Editing is a quiet, non-critical activity (the old NC-25 target) that does not need a dedicated acoustically-isolated room — it can be performed at any workstation, including inside the Control Room or Video/Podcast space. Dedicating an isolated room to it wasted the most valuable floor area in the facility.

Removing the Editing Suite lets the entire east zone become a single Video/Podcast room of 19.78 m². Freed of the internal Wall 7 / D4 partition, the room also gains a high 3.40 m clear ceiling. A Rev2 laser survey found the true slab-to-slab at 366.4 cm — not the 340 cm assumed on the old drawings — so the height chain is now measured, not estimated: 366.4 slab − 15 cm floated floor − 11 cm compact decoupled ceiling leaf = 340 cm clear, with the hanging MEP (HVAC unit and black pipe) boxed into a perimeter bulkhead with an HVAC service hatch. The larger volume (67.3 m³) pushes the Schroeder frequency down to 130 Hz and spreads the room modes more evenly, giving a well-behaved, flexible space for multi-camera video, podcast panels, and small live sessions. Two weak partition elements (Wall 7 and door D4) are eliminated entirely.

Backdrop — curtain, not a hard cyclorama. The earlier scheme called for a plastered NE coved cyclorama (a fixed, hard, curved corner). Rev3 replaces it with a multi-colour curtain backdrop system: a motorised track on an independent secondary-steel frame hung from the structural slab on neoprene isolation hangers (never off the resilient ceiling leaf, never rigidly through to the slab, to keep the flanking path short), 40 cm off the wall, wrapping the North wall (full) plus the East wall north-half around the NE corner (≈23 m² face). It carries interchangeable heavy velour/molton curtains (≥300 g/m², ≥100 % fullness) in chroma green, white, black molton and mid-grey, plus a vinyl floor-sweep for the infinity curve. Acoustically this is the better decision: fabric absorbs, acting as the room's primary variable mid/high absorber, whereas the hard cyclorama would have added two reflective corner walls. It also frees the wall-panel count (the curtain now carries the video mid/high), so the room drops from 20 wall panels to 6. The camera still shoots toward the backdrop.

Video/Podcast — resulting geometry (acoustics5 / Rev C)
4.79 × 4.13 × 3.40 m · 19.78 m² · 67.3 m³
RT60 mid 0.284 s (flat green-screen reference) · NC-18 · Schroeder 130 Hz
Treatment: 6 wall panels · 6 deep superchunk traps (400–600 mm) · 4 membranes (≈123 Hz) · deep perimeter bass soffit · in-shot area rug (≈6 m²) · isolated Unistrut lighting grid · lean 28% ceiling cloud · multi-colour curtain backdrop (N + E-half)
Acoustic impact
Video room area
11.23 → 19.78 m²
Volume
→ 67.3 m³
Clear ceiling
2.75 → 3.40 m
Schroeder
→ 130 Hz
Elements removed
Editing Suite · Wall 7 · door D4
02
D5 — New external Control Room door
South wall · 90 × 220 cm · STC 50 · opens out
no dedicated Control entry D5 STC 50, opens out

In the four-room layout the Control Room was reached only through the buffer spine or from VO Live (D3). With the east-zone re-split and the removal of the old Editing access, the Control Room needed its own external entry so engineers can come and go without transiting VO Live or the buffer during a take. (The old buffer↔Control door D2 has since been deleted in Rev2 — Control is now entered only by external D5.)

D5 is a new STC 50 acoustic door (90 × 220 cm) on the south wall. It matches the STC 50 perimeter-shell/entry standard (same as D1), so it introduces no weak link in the envelope. It opens outward for clean egress and to avoid any swing conflict with the console and the side-wall first-reflection panels inside the room. Routing Control traffic through its own door reduces footfall-borne disturbance in VO Live and the buffer spine during recording.

D5 specification (acoustics5 / S3)
90 × 220 cm · STC 50 acoustic door set · south wall (x = 90)
Swing: outward · Role: dedicated Control Room external entry
Impact
Door STC
50 dB
Swing
Outward (egress)
Envelope weak link
None (matches shell STC 50)
Benefit
Control access without transiting VO / buffer
03
Control Room — Side Wall Absorption Panels
East wall + West wall · First reflection points · B311
0 flat panels 3× 1200×600mm panels

A corners-only Control Room treatment — bass traps in all corners, QRD diffusers on the rear wall, ceiling cloud — would meet the RT60 target of 0.30s without any flat absorption panels on the side walls. The RT60 number would be correct. However, RT60 does not capture early reflections.

In a nearfield monitoring environment, the primary acoustic concern after RT60 is the first reflection points — the spots on the left and right walls where direct sound from the monitors bounces once before reaching the mix position. Untreated, these reflections arrive 5–15 ms after the direct sound, causing comb filtering that colours the frequency response and compromises stereo imaging. This is audible on every mix as a smeared centre image and unreliable low-mid decisions.

Three panels — at the first reflection points on the east and west side walls (~120 cm AFF, positioned by mirror method from the mix position) plus an absorptive/splayed front — eliminate this artefact without over-damping the room. The room is too small for a time-based reflection-free zone (ITDG under 15 ms), so the RFZ is achieved by absorbing the E/W first-reflection points directly. The resulting mid-band RT60 of approximately 0.307s sits in the preferred range for broadcast monitoring. Heavier flat absorption was rejected: it would over-damp the larger 6.97 m² Control Room and lose the natural reverb tail needed for mixing judgment.

Panel specification + positioning
1200 × 600 × 50mm · Rockwool RWA45 · fabric-wrapped · NRC 0.90
Position: east wall + west wall first reflection points + splayed/absorptive front
Height: 120 cm AFF (bottom edge) · located by mirror method from mix position
Acoustic impact
Panels added
RT60 mid
~0.307s
Still within target range
Yes (target 0.30s)
Effect
Eliminates comb filtering · improves stereo imaging
Element Location Previous acoustics5 / S3 Key benefit
Editing Suite East zone (B312-2) 8.56 m² isolated room Removed — merged into Video/Podcast Frees the east zone; editing needs no isolated room
Video/Podcast East zone (B312) 11.23 m² · 2.75 m ceiling 19.78 m² · 3.40 m high ceiling (measured) Larger, better modes (Schroeder 130 Hz); flexible for video + podcast
Wall 7 + D4 Video ↔ Editing partition STC 48 wall + STC 48 door Removed entirely Two weak partition elements eliminated
D5 Door (new) Control · south wall STC 50 · 90×220 · opens out Dedicated Control entry without transiting VO / buffer
Control Room Side walls E + W + front 0 flat panels 3× 1200×600mm Eliminates first-reflection comb filtering
[AC] Acoustic Critical — Cannot be modified without written approval from the acoustic consultant.    [HP] Hold Point — Stop work and obtain sign-off before proceeding to next phase.    [DEC] Decorative — Can be customized within the stated constraints (color, texture, finish).