Wengwei 2 Pack 24 X 48 X 2 Blue Acoustic Foam Egg Studio Absorbs Sound Insulation And Fills With CushionThey have an egg-carton like surface, hence the name, and are a cheap way to control acoustics The uneven surface of these acoustic shingles allows them to absorb a wider range of frequencies and sound waves, and the thicker the shingles, the mor..