Auralex VersaTile

The VersaTile combines a visually distinct absorptive panel with engineered internal air cavities for more low-frequency pull than a same-thickness flat foam panel. Bridge it across a corner to create a sizable air pocket, or mount it flat on a wall or ceiling with either face out.

Each panel measures 2 x 16 x 24 in; a 6-pack covers 16 sq ft and needs about one tube of Tubetak Pro adhesive. It's also sold in a 24-pack for larger rooms, in Charcoal or Purple.