Audio Engineering

104 Chapter 3

Table 3.4 : Continued

Materials Coeffi cient

125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz

Fiberboards, ½-in. normal soft, mounted

against solid backing

Unpainted

Some painted

0.05

0.05

0.10

0.10

0.15

0.10

0.25

0.10

0.30

0.10

0.3

0.15

Fiberboards, ½-in. normal soft, mounted

over 1-in. air space

Unpainted

Some painted

0.30

0.30

0.15

0.15

0.10

0.10

Fiberglass insulation blankets

AF100, 1 in., mounting #4

AF100, 2 in., mounting #4

AF530, 1 in., mounting #4

AF530, 2 in., mounting #4

AF530, 4 in., mounting #4

0.07

0.19

0.09

0.20

0.39

0.23

0.51

0.25

0.56

0.91

0.42

0.79

0.60

0.89

0.99

0.77

0.92

0.81

0.93

0.98

0.73

0.82

0.75

0.84

0.93

0.70

0.78

0.74

0.80

0.88

Flexboard, 3/16-in. unperforated cement

asbestos board mounted over 2-in. air space

0.18 0.11 0.09 0.07 0.03 0.03

Floors

Concrete or terrazzo

Linoleum, asphalt, rubber, or cork tile

on concrete

Wood

Wood parquet in asphalt on concrete

0.01

0.02

0.15

0.04

0.01

0.03

0.11

0.04

0.015

0.03

0.10

0.07

0.02

0.03

0.07

0.06

0.02

0.03

0.06

0.06

0.02

0.02

0.07

0.07

Geoacoustic, 13 1/2 in. 13 1/2 in.,

2-in.-thick cellular glass tile installed

0.13 0.74 2.35 2.53 2.03 1.73

Glass

Large panes of heavy plate glass

Ordinary window glass

0.18

0.35

0.06

0.25

0.04

0.18

0.03

0.12

0.02

0.07

0.02

0.04

Gypsum board, 1/2 in. nailed to 2 in.

4 in., 16 in. o.c.

0.29 0.10 0.05 0.04 0.07 0.09

Hardboard panel, 1/8 in., 1 lb/ft^2 with

bituminous roofi ng felt stuck to back,

mounted over 2-in. air space

0.90 0.45 0.25 0.15 0.10 0.10

Marble or glazed tile 0.01 0.01 0.01 0.01 0.02 0.02

(Continued)