reverb time reverbtime reverberation RT60 time room acoustics Sabine sabin sabins compute calculate calculating calculation calculations calculator converter convert
dB conversion table tables audio studio technique techniques wall walls surface ceiling floor acoustics sound pressure absorption coefficient coefficients
alpha people adults factor factors water material buldings coefficient volume area decay measurement Sengpiel sengpielaudio Berlin
| Floor Materials
| 125 Hz |
250 Hz |
500 Hz |
1000 Hz |
2000 Hz |
4000 Hz |
| |
|
|
|
|
|
|
| concrete or tile |
0.01 |
0.01 |
0.15 |
0.02 |
0.02 |
0.02 |
| linoleum/vinyl tile on concrete |
0.02 |
0.03 |
0.03 |
0.03 |
0.03 |
0.02 |
| wood on joists |
0.15 |
0.11 |
0.10 |
0.07 |
0.06 |
0.07 |
| parquet on concrete |
0.04 |
0.04 |
0.07 |
0.06 |
0.06 |
0.07 |
| carpet on concrete |
0.02 |
0.06 |
0.14 |
0.37 |
0.60 |
0.65 |
| carpet on foam |
0.08 |
0.24 |
0.57 |
0.69 |
0.71 |
0.73 |
| |
|
|
|
|
|
|
|
| Seating Materials
| 125 Hz |
250 Hz |
500 Hz |
1000 Hz |
2000 Hz |
4000 Hz |
| |
|
|
|
|
|
|
| fully occupied - fabric upholstered |
0.60 |
0.74 |
0.88 |
0.96 |
0.93 |
0.85 |
| occupied wooden pews |
0.57 |
0.61 |
0.75 |
0.86 |
0.91 |
0.86 |
| empty - fabric upholstered |
0.49 |
0.66 |
0.80 |
0.88 |
0.82 |
0.70 |
| empty metal/wood seats |
0.15 |
0.19 |
0.22 |
0.39 |
0.38 |
0.30 |
| |
|
|
|
|
|
|
|
| Wall Materials
| 125 Hz |
250 Hz |
500 Hz |
1000 Hz |
2000 Hz |
4000 Hz |
| |
|
|
|
|
|
|
| Brick: unglazed |
0.03 |
0.03 |
0.03 |
0.04 |
0.05 |
0.07 |
| Brick: unglazed & painted |
0.01 |
0.01 |
0.02 |
0.02 |
0.02 |
0.03 |
| Concrete block - coarse |
0.36 |
0.44 |
0.31 |
0.29 |
0.39 |
0.25 |
| Concrete block - painted |
0.10 |
0.05 |
0.06 |
0.07 |
0.09 |
0.08 |
| Curtain: 10 oz/sq yd fabric molleton |
0.03 |
0.04 |
0.11 |
0.17 |
0.24 |
0.35 |
| Curtain: 14 oz/sq yd fabric molleton |
0.07 |
0.31 |
0.49 |
0.75 |
0.70 |
0.60 |
| Curtain: 18 oz/sq yd fabric molleton |
0.14 |
0.35 |
0.55 |
0.72 |
0.70 |
0.65 |
| Fiberglass: 2" 703 no airspace |
0.22 |
0.82 |
0.99 |
0.99 |
0.99 |
0.99 |
| Fiberglass: spray 5" |
0.05 |
0.15 |
0.45 |
0.70 |
0.80 |
0.80 |
| Fiberglass: spray 1" |
0.16 |
0.45 |
0.70 |
0.90 |
0.90 |
0.85 |
| Fiberglass: 2" rolls |
0.17 |
0.55 |
0.80 |
0.90 |
0.85 |
0.80 |
| Foam: Sonex 2" |
0.06 |
0.25 |
0.56 |
0.81 |
0.90 |
0.91 |
| Foam: SDG 3" |
0.24 |
0.58 |
0.67 |
0.91 |
0.96 |
0.99 |
| Foam: SDG 4" |
0.33 |
0.90 |
0.84 |
0.99 |
0.98 |
0.99 |
| Foam: polyur. 1" |
0.13 |
0.22 |
0.68 |
1.00 |
0.92 |
0.97 |
| Foam: polyur. 1/2" |
0.09 |
0.11 |
0.22 |
0.60 |
0.88 |
0.94 |
| Glass: 1/4 plate large |
0.18 |
0.06 |
0.04 |
0.03 |
0.02 |
0.02 |
| Glass: window |
0.35 |
0.25 |
0.18 |
0.12 |
0.07 |
0.04 |
| Plaster: smooth on tile/brick |
0.013 |
0.015 |
0.02 |
0.03 |
0.04 |
0.05 |
| Plaster: rough on lath |
0.02 |
0.03 |
0.04 |
0.05 |
0.04 |
0.03 |
| Marble/Tile |
0.01 |
0.01 |
0.01 |
0.01 |
0.02 |
0.02 |
| Sheetrock 1/2" 16" on center |
0.29 |
0.10 |
0.05 |
0.04 |
0.07 |
0.09 |
| Wood: 3/8" plywood panel |
0.28 |
0.22 |
0.17 |
0.09 |
0.10 |
0.11 |
| |
|
|
|
|
|
|
|
| Ceiling Materials
| 125 Hz |
250 Hz |
500 Hz |
1000 Hz |
2000 Hz |
4000 Hz |
| |
|
|
|
|
|
|
| Acoustic Tiles |
0.05 |
0.22 |
0.52 |
0.56 |
0.45 |
0.32 |
| Acoustic Ceiling Tiles |
0.70 |
0.66 |
0.72 |
0.92 |
0.88 |
0.75 |
| Fiberglass: 2" 703 no airspace |
0.22 |
0.82 |
0.99 |
0.99 |
0.99 |
0.99 |
| Fiberglass: spray 5" |
0.05 |
0.15 |
0.45 |
0.70 |
0.80 |
0.80 |
| Fiberglass: spray 1" |
0.16 |
0.45 |
0.70 |
0.90 |
0.90 |
0.85 |
| Fiberglass: 2" rolls |
0.17 |
0.55 |
0.80 |
0.90 |
0.85 |
0.80 |
| wood |
0.15 |
0.11 |
0.10 |
0.07 |
0.06 |
0.07 |
| Foam: Sonex 2" |
0.06 |
0.25 |
0.56 |
0.81 |
0.90 |
0.91 |
| Foam: SDG 3" |
0.24 |
0.58 |
0.67 |
0.91 |
0.96 |
0.99 |
| Foam: SDG 4" |
0.33 |
0.90 |
0.84 |
0.99 |
0.98 |
0.99 |
| Foam: polyur. 1" |
0.13 |
0.22 |
0.68 |
1.00 |
0.92 |
0.97 |
| Foam: polyur. 1/2" |
0.09 |
0.11 |
0.22 |
0.60 |
0.88 |
0.94 |
| Plaster: smooth on tile/brick |
0.013 |
0.015 |
0.02 |
0.03 |
0.04 |
0.05 |
| Plaster: rough on lath |
0.02 |
0.03 |
0.04 |
0.05 |
0.04 |
0.03 |
| Sheetrock 1/2" 16" on center |
0.29 |
0.10 |
0.05 |
0.04 |
0.07 |
0.09 |
| Wood: 3/8" plywood panel |
0.28 |
0.22 |
0.17 |
0.09 |
0.10 |
0.11 |
| |
|
|
|
|
|
|
|
| Miscellaneous Material
| 125 Hz |
250 Hz |
500 Hz |
1000 Hz |
2000 Hz |
4000 Hz |
| |
|
|
|
|
|
|
| Water |
0.008 |
0.008 |
0.013 |
0.015 |
0.020 |
0.025 |
| People (adults) |
0.25 |
0.35 |
0.42 |
0.46 |
0.5 |
0.5 |
| |
|
|
|
|
|
|
1 ounce / square yard = 0,0339 kg/m2 or 1 kg/m2 = 1,6388 oz/yd2
More tables and charts of absorption coefficients:
http://www.bobgolds.com/AbsorptionCoefficients.htm
http://www.ptb.de/en/org/1/17/173/datenbank.htm
http://www.bobgolds.com/Sabin.htm