| Materials |
Coefficients |
| |
125Hz |
250Hz |
500Hz |
1000Hz |
2000Hz |
4000Hz |
| Brick, unglazed |
.03 |
.03 |
.03 |
.04 |
.05 |
.07 |
| Brick, unglazed, painted |
.01 |
.01 |
.02 |
.02 |
.02 |
.03 |
| Carpet, heavy, on concrete |
.02 |
.06 |
.14 |
.37 |
.60 |
.65 |
Same, on 40oz hairfelt or foam rubber
|
.08 |
.24 |
.57 |
.69 |
.71 |
.73 |
Same, with impermeable latex backing on 40oz hairfelt
or foam rubber
|
.08 |
.27 |
.39 |
.34 |
.48 |
.63 |
| Concrete Block, light, porous |
.36 |
.44 |
.31 |
.29 |
.39 |
.25 |
| Concrete Block, dense, painted |
.10 |
.05 |
.06 |
.07 |
.09 |
.08 |
| Fabrics: |
|
|
|
|
|
|
| Light Velour, 10oz per sq yd,
hung straight, in contact with wall |
.03 |
.04 |
.11 |
.17 |
.24 |
.35 |
| Medium Velour, 14oz per sq yd,
draped to half area |
.07 |
.31 |
.49 |
.75 |
.70 |
.60 |
| Heavy Velour, 18-oz per sq yd,
draped to half area |
.14 |
.35 |
.55 |
.72 |
.70 |
.65 |
| Floor: |
|
|
|
|
|
|
| Concrete or Terrazzo |
.01 |
.01 |
.015 |
.02 |
.02 |
.02 |
| Linoleum, asphalt, rubber, or
cork tile on concrete |
.02 |
.03 |
.03 |
.03 |
.03 |
.02 |
| wood |
.15 |
.11 |
.10 |
.07 |
.06 |
.07 |
| Wood parquet in asphalt on concrete |
.04 |
.04 |
.07 |
.06 |
.06 |
.07 |
| Glass: |
|
|
|
|
|
|
| Large panes of heavy plate glass |
.18 |
.06 |
.04 |
.03 |
.02 |
.02 |
| Ordinary window glass |
.35 |
.25 |
.18 |
.12 |
.07 |
.04 |
| Gypsum Board, 1/2-inch, nailed
to 2x4's 16 inches o.c. |
.29 |
.10 |
.05 |
.04 |
.07 |
.09 |
| Marble or glazed tile |
.01 |
.01 |
.01 |
.01 |
.02 |
.02 |
| Plaster, gypsum, or lime, smooth
finish on tile or brick |
.013 |
.015 |
.02 |
.03 |
.04 |
.05 |
| Plaster, gypsum, or lime, rough
finish on lath |
.14 |
.10 |
.06 |
.05 |
.04 |
.03 |
Same, with smooth finish
|
.14 |
.10 |
.06 |
.04 |
.04 |
.03 |
| Plywood Paneling, 3/8-inch thick |
.28 |
.22 |
.17 |
.09 |
.10 |
.11 |
| Water surface, as in a swimming
pool |
.008 |
.008 |
.013 |
0.15 |
.020 |
0.25 |
| Air, Sabins per 1000 cubic feet |
.09 |
.20 |
.49 |
1.20 |
2.90 |
7.40 |
| Open doors and windows |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
1.00 |
| Values below are given in Sabins
per square foot of seating area or per unit |
| Absorption of
Seats and Audience |
125Hz |
250Hz |
500Hz |
1000Hz |
2000Hz |
4000Hz |
| Chairs, metal or wood seats,
each, unoccupied |
.15 |
.19 |
.22 |
.39 |
.38 |
.30 |
| People in a room, per person,
(do not use for auditorium calculations |
2 |
3 |
4 |
5 |
5 |
4 |
| Audience, seated in upholstered
seats, per square foot of floor area, for auditorium calculations |
.60 |
.74 |
.88 |
.96 |
.93 |
.85 |