Acoustic Foam wedges, egg crate, pyramids are effective sound absorbing for standing waves and flutter echoes, especially when used with ACOUSTIC CORNER BASS TRAPS. It also reduces slap-back and room ring when used in medium-sized areas like isolation booths, recording booths, control rooms, and sound studios. With its straight-cut sides, these Acoustic Foams can easily be arranged side by side on a flat surface area (walls).