Handbook for Sound Engineers

92 ChaDter 4 for the smaller ducts. For midband frequencies, a 10 ft length of ducting can account for 40 dB or 50 dB atten- uat ...

Acoustical Noise Control 93 (4-6) where, a is the absorption coefficient of the lining, Se is the plenum exit area in square fee ...

94 Chapter 4 M. Rettinger, Noise Level Limits in Recording Studios, dB the Sound Engineering Magazine, vol. 12, No. 4, pp. 41 – ...

95 Chapter 5 Small Room Acoustics by Jeff Szymanski 5.1 Acoustical Treatment Overview........................................... ...

96 Bibliography 122 ...

Acoustical Treatment for Indoor Areas 97 5.1 Acoustical Treatment Overview It is possible that there is no area in professional ...

98 Chapter 5 offering guidance), many excellent porous and resonant absorbers are available commercially. Fundamental informatio ...

Acoustical Treatment for Indoor Areas 99 typically encountered with acoustical materials that are spray or trowel applied. The m ...

100 Chapter 5 5.2.1.2 Impedance Tube Testing Methods The laboratory methods generally involve the use of an impedance tube to me ...

Acoustical Treatment for Indoor Areas 101 5.2.1.4 Absorption Ratings There are three single number ratings associated with absor ...

102 Chapter 5 5.2.1.5 Interpreting Test Results As mentioned at the beginning of this chapter, the acous- tical treatment indust ...

Acoustical Treatment for Indoor Areas 103 5.2.2.1 Mineral and Natural Fibers Of the varieties of mineral fiber, one of the most ...

104 Chapter 5 Fig. 5-7 shows the effect of air space behind a 2.5 cm (1 in) thick Owens Corning Linear Glass Board. As the air s ...

Acoustical Treatment for Indoor Areas 105 increasing number of suppliers of natural cotton absorp- tion panels. The absorption o ...

106 Chapter 5 surface area tends to increase it. Figs. 5-13 and 5-14 provide absorption coefficients for different patterns of f ...

Acoustical Treatment for Indoor Areas 107 5.2.2.3 Acoustical Tiles Acoustical tiles have the highest density of the porous absor ...

108 Chapter 5 Draperies are also porous absorbers of sound. Included in the drapery category are drapes, curtains, tapestries, a ...

Acoustical Treatment for Indoor Areas 109 absorption panels are often available as baffles as well. Absorption is reported as th ...

110 Chapter 5 results in a flexing of the fibers, and a certain amount of frictional loss results in absorption of some of the s ...

Acoustical Treatment for Indoor Areas 111 absorbers encountered in modern architecture is the gypsum wallboard (GWB) (drywall or ...