Page 258 - Master Handbook of Acoustics

FIGURE 12-12 The density of glass-fiber absorbing material has relatively little effect on absorption
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in the range of 1.5 to 6 lb/ft . The material is mounted directly on a solid wall.

Open-Cell Foams

Flexible polyurethane and polyester foams are widely used in noise quieting of automobiles,

machinery, aircraft, and in various industrial applications. Foams also find application as sound
absorbers in architectural applications, including recording studios and home listening rooms. Figure
12-13 is a photograph of one form of Sonex, a foam product contoured to simulate the wedges used in
anechoic rooms. These are shaped in male and female molds and come in meshed pairs. This material
can be glued or stapled to the surface to be treated.