Worked Example: Podcast Studio — Best Practice Voice Recording
20 m³ podcast booth with acoustic foam, mineral wool, and heavy carpet
A 20 m³ recording studio designed to ISO-3382 requires RT60 ≤ 0.3s. With Acoustic foam 50mm on the ceiling and Acoustic foam 50mm on walls, the calculated RT60 is 0.16s — PASS.
Room Setup
Total surface area: 43.6 m². Calculation method: Sabine equation (ISO 3382-2:2008 Annex A).
Surface Materials
| Surface | Material | Area (m²) | NRC |
|---|---|---|---|
| Ceiling — acoustic foam | Acoustic foam 50mm | 8.0 | 0.63 |
| Ceiling — plasterboard | Plasterboard on studs | 2.0 | 0.07 |
| Floor | Heavy carpet | 10.0 | 0.29 |
| Walls — acoustic foam | Acoustic foam 50mm | 8.0 | 0.63 |
| Walls — mineral wool | Mineral wool 50mm (wall) | 6.0 | 0.73 |
| Walls — plasterboard | Plasterboard on studs | 8.0 | 0.07 |
| Door | Solid timber door | 1.6 | 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 = 4 × 2.5 × 2 = 20 m³
- 2
Total Surface Area
Stotal = 8.0 + 2.0 + 10.0 + 8.0 + 6.0 + 8.0 + 1.6 = 43.6 m²
- 3
Absorption per Surface at 500 Hz
Ceiling — acoustic foam: 8.0 m² × 0.55 = 4.40 Sabins
Ceiling — plasterboard: 2.0 m² × 0.05 = 0.10 Sabins
Floor: 10.0 m² × 0.14 = 1.40 Sabins
Walls — acoustic foam: 8.0 m² × 0.55 = 4.40 Sabins
Walls — mineral wool: 6.0 m² × 0.70 = 4.20 Sabins
Walls — plasterboard: 8.0 m² × 0.05 = 0.40 Sabins
Door: 1.6 m² × 0.08 = 0.13 Sabins
- 4
Total Absorption at 500 Hz
Atotal = 4.40 + 0.10 + 1.40 + 4.40 + 4.20 + 0.40 + 0.13 = 15.03 Sabins
- 5
Sabine RT60 at 500 Hz
RT60 = 0.161 × V / A = 0.161 × 20 / 15.03 = 0.21s
- 6
Compare to Target
Mid-frequency RT60 (avg of 500, 1k, 2k Hz) = 0.16s. Target: 0.15--0.3s per ISO-3382. Verdict: PASS
Octave Band Results
| Frequency | 125Hz | 250Hz | 500Hz | 1kHz | 2kHz | 4kHz |
|---|---|---|---|---|---|---|
| Total Absorption (Sabins) | 5.5 | 8.5 | 15.0 | 22.1 | 26.6 | 28.1 |
| RT60 (s) | 0.59 | 0.38 | 0.21 | 0.15 | 0.12 | 0.11 |
| Target (s) | — | — | 0.30 | 0.30 | 0.30 | — |
| Verdict | — | — | PASS | PASS | FAIL | — |
Compliance Verdict
Reference:
Open the AcousPlan calculator pre-loaded with the exact room dimensions (4m × 2.5m × 2m) and RT60 target (0.3s).
Open CalculatorField Story
A media startup in Austin is converting a walk-in closet into a two-person podcast studio. The 4 m by 2.5 m space with 2 m ceilings is small enough that untreated parallel walls would create devastating flutter echo on voice recordings. The entire ceiling and 38% of wall surfaces are covered in 50 mm acoustic foam, with 10 m² of mineral wool panels on remaining walls providing deeper bass absorption that foam alone cannot achieve. Heavy carpet completes the broadband treatment. A small section of plasterboard remains for mounting equipment. The solid timber door provides adequate isolation from the adjacent hallway. Best practice for voice recording targets RT60 below 0.3 s — ensuring the intimate "close mic" sound podcast listeners expect without the room coloration requiring post-production equalisation.
Frequently Asked Questions
What RT60 does a Podcast Studio — Best Practice Voice Recording achieve?
With the specified materials and dimensions (4m x 2.5m x 2m, volume 20m3), the calculated mid-frequency RT60 is 0.16s using the Sabine equation. The target under ISO-3382 is 0.15--0.3s. The result is a PASS.
What materials are used in this performance acoustic example?
This example uses Acoustic foam 50mm on the Ceiling — acoustic foam (NRC 0.63), Plasterboard on studs on the Ceiling — plasterboard (NRC 0.07), Heavy carpet on the Floor (NRC 0.29), Acoustic foam 50mm on the Walls — acoustic foam (NRC 0.63), Mineral wool 50mm (wall) on the Walls — mineral wool (NRC 0.73), Plasterboard on studs on the Walls — plasterboard (NRC 0.07), Solid timber door on the Door (NRC 0.09). The total absorption at 500 Hz is 15.0 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.