SGS Acoustic Certificate Art Collection
The acoustic felt used for every piece in our Art Collection has been tested by SGS in accordance with EN ISO 354:2003 (measurement of sound absorption in a reverberation room) and rated in accordance with EN ISO 11654:1997. SGS is the world’s leading testing, inspection and certification company.
Report: CZIN2406000121CM01 · Date: 9 July 2024 · Sample: Acoustic Art
Test set-up
| Material | acoustic felt, 9 mm thick |
|---|---|
| Test sample | 2420 × 1220 mm |
| Surface density | approx. 1.39 kg/m² |
| Mounting | type E — 200 mm air cavity behind the panel |
| Reverberation room | 260 m³, test area 11.82 m² |
| Testing period | 28 June – 9 July 2024 |
Absorption coefficient per frequency (αs)
| Frequency (Hz) | αs |
|---|---|
| 100 | 0.15 |
| 125 | 0.29 |
| 160 | 0.33 |
| 200 | 0.52 |
| 250 | 0.60 |
| 315 | 0.74 |
| 400 | 0.82 |
| 500 | 0.82 |
| 630 | 0.80 |
| 800 | 0.69 |
| 1000 | 0.61 |
| 1250 | 0.73 |
| 1600 | 0.79 |
| 2000 | 0.82 |
| 2500 | 0.81 |
| 3150 | 0.84 |
| 4000 | 0.87 |
| 5000 | 0.90 |
Practical sound absorption coefficient (αp)
| Frequency (Hz) | αp |
|---|---|
| 125 | 0.25 |
| 250 | 0.60 |
| 500 | 0.80 |
| 1000 | 0.70 |
| 2000 | 0.80 |
| 4000 | 0.85 |
What does this mean? An αw of 0.80 means the felt absorbs roughly 80% of incoming sound in the speech frequencies instead of reflecting it. Class B is the second-highest absorption class. NRC is the average of the values at 250, 500, 1000 and 2000 Hz.
The test was carried out with a 200 mm gap behind the panel. The same applies to our acoustic wall art: the more space between wall and felt, the better sound is captured on both sides.