Page 235 - The Master Handbook Of Acoustics

210 CHAPTER NINE

1
1"–1 /2" Glass or
mineral fiber

1 /4"– /16" Plywood
1

1 /4"– /2" Airspace
1

FIGURE 9-24

Typical resonant panel absorber for either vertical or horizontal corner mounting.

studio. It is advisable, however, to break up the cavity behind the
poly skin with randomly spaced bulkheads. The polys of Fig. 9-25
incorporate such bulkheads.
Should the polys be empty or filled with something? Mankovsky
again comes to our rescue and shows us the effect of filling the cavities
with absorbent material. Figures 9-25D and 9-25C show the increase in
bass absorption resulting from filling the cavities with absorbent. If
needed, this increased bass absorption can be easily achieved by sim-
ply filling the polys with glass fiber. If the bass absorption is not
needed the polys can be used empty. The great value of this adjustable