Worked Example: Conference Facility — DIN 18041 Speech Clarity
500 m³ conference room with Rockfon ceiling, carpet, and fabric panel walls
A 500 m³ meeting room designed to DIN-18041 requires RT60 ≤ 0.7s. With Rockfon Sonar 25mm ceiling tile on the ceiling and Fabric-wrapped panel 50mm on walls, the calculated RT60 is 0.43s — MARGINAL.
Room Setup
Total surface area: 633.0 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| Ceiling — Rockfon Sonar | Rockfon Sonar 25mm ceiling tile | 100.0 | 0.82 |
| Ceiling — plaster | Painted plaster | 150.0 | 0.04 |
| Floor | Heavy carpet | 250.0 | 0.29 |
| Walls — plasterboard | Plasterboard on studs | 80.0 | 0.07 |
| Walls — fabric panels | Fabric-wrapped panel 50mm | 12.0 | 0.78 |
| Projection wall | Painted plaster | 20.0 | 0.04 |
| Windows | Double glazing 6mm | 14.0 | 0.03 |
| Doors | Solid timber door | 7.0 | 0.09 |
Absorption coefficients sourced from manufacturer datasheets and ISO 354 test reports. Browse the full acoustic materials database.
Step-by-Step Calculation
- 1
Room Volume
V = L × W × H = 25 × 10 × 2 = 500 m³
- 2
Total Surface Area
Stotal = 100.0 + 150.0 + 250.0 + 80.0 + 12.0 + 20.0 + 14.0 + 7.0 = 633.0 m²
- 3
Absorption per Surface at 500 Hz
Ceiling — Rockfon Sonar: 100.0 m² × 0.82 = 82.00 Sabins
Ceiling — plaster: 150.0 m² × 0.04 = 6.00 Sabins
Floor: 250.0 m² × 0.14 = 35.00 Sabins
Walls — plasterboard: 80.0 m² × 0.05 = 4.00 Sabins
Walls — fabric panels: 12.0 m² × 0.78 = 9.36 Sabins
Projection wall: 20.0 m² × 0.04 = 0.80 Sabins
Windows: 14.0 m² × 0.04 = 0.56 Sabins
Doors: 7.0 m² × 0.08 = 0.56 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 82.00 + 6.00 + 35.00 + 4.00 + 9.36 + 0.80 + 0.56 + 0.56 = 138.28 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 500 / 138.28 = 0.58s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.43s. Target: 0.5--0.7s per DIN-18041. Verdict: MARGINAL
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 64.8 | 100.0 | 138.3 | 207.4 | 263.7 | 274.2 |
| RT60 (s) | 1.24 | 0.81 | 0.58 | 0.39 | 0.31 | 0.29 |
| Target (s) | — | — | 0.70 | 0.70 | 0.70 | — |
| Verdict | — | — | PASS | FAIL | FAIL | — |
Compliance Verdict
Reference:
Open the AcousPlan calculator pre-loaded with the exact room dimensions (25m × 10m × 2m) and RT60 target (0.7s).
Open CalculatorField Story
A purpose-built conference centre in Frankfurt hosts international trade events requiring simultaneous interpretation. DIN 18041:2016 classifies this as a Group A room (speech communication), demanding reverberation between 0.5 and 0.7 seconds for 500 m³. Rockfon Sonar ceiling covers 60% of the ceiling area with consistent broadband absorption, the remaining 40% left as painted plaster above service zones. Heavy carpet absorbs footfall noise from 200 delegates between breakout sessions. Fabric-wrapped panels on the rear wall prevent late reflections degrading intelligibility for delegates furthest from the podium. Plasterboard partition walls separating concurrent sessions provide both sound insulation and low-frequency panel absorption. The combination of ceiling tiles and carpet provides the bulk of the mid-frequency absorption required.
Frequently Asked Questions
What RT60 does a Conference Facility — DIN 18041 Speech Clarity achieve?
With the specified materials and dimensions (25m x 10m x 2m, volume 500m3), the calculated mid-frequency RT60 is 0.43s using the Sabine equation. The target under DIN-18041 is 0.5--0.7s. The result is a MARGINAL.
What materials are used in this hospitality acoustic example?
This example uses Rockfon Sonar 25mm ceiling tile on the Ceiling — Rockfon Sonar (NRC 0.82), Painted plaster on the Ceiling — plaster (NRC 0.04), Heavy carpet on the Floor (NRC 0.29), Plasterboard on studs on the Walls — plasterboard (NRC 0.07), Fabric-wrapped panel 50mm on the Walls — fabric panels (NRC 0.78), Painted plaster on the Projection wall (NRC 0.04), Double glazing 6mm on the Windows (NRC 0.03), Solid timber door on the Doors (NRC 0.09). The total absorption at 500 Hz is 138.3 Sabins.
How much does acoustic treatment cost for this room?
Cost data is not available for this example. Use the AcousPlan calculator to estimate treatment costs for your specific room configuration.
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All calculations are advisory and based on the Sabine equation (ISO 3382-2:2008 Annex A). Results require professional verification for compliance submissions. Absorption coefficients are sourced from manufacturer datasheets and ISO 354 test reports.