Problem: Mounting drywall on resilient metal furring does not sufficiently reduce sound and noise transmission.
Cause: Resilient metal furring between two layers of drywall, forming a small air space with a solid connection of the inner layer to the studs.
Do not mount two layers of drywall or any other solid sheet material, so that there is a thin air space between them; it fails to act as a fully resilient separator. Place the resilient metal furring directly on the studs or joists to avoid rattling, and then apply the drywall as shown in Figure 3a and 3b. Twenty-four gauge or thinner steel studs are resilient enough tin themselves, so that no special measures are needed to isolate the layers of the wall form each other.
Figure 3a - Incorrect Method Of Applying Metal Furring With Two Layers Of Drywall