Page 198 - The Master Handbook Of Acoustics

173
CONTROL OF INTERFERING NOISE

8"

16"

8"

Construction - 8" concrete block
Weight - 30 lb/sq ft (plain)
67 lb/sq ft (plastered both sides)
Sound transmission class -
STC 45 dB plain
STC 56 dB plastered both sides

(Solite Corporation, and LECA, Norway)
FIGURE 8-5
Eight-inch concrete block construction.

The staggered stud wall and the double wall, on the basis of mass
alone, would yield a transmission loss of only about 35 dB (Fig. 8-2). The
isolation of the inner and the outer walls from each other and the use of
insulation within have increased the wall effectiveness by 10 or 15 dB.

Double Windows

Between the control room and the studio a window is quite necessary,
and its sound transmission loss should be comparable to that of the
wall itself. A well-built staggered stud or double wall might have an
STC of 50 dB. To approach this performance with a window requires
very careful design and installation. 3