“To reduce flutter echoes from reflective surfaces and to increase reverberation, 120 RPG® Skylines®—an omnidirectional primitive root number theory 2D diffusor—are placed on the reflective panels located on the walls, as well as on the ceiling and areas behind the loudspeaker.”

A New Laboratory for Evaluating Multichannel Audio Components and Systems
Sean E. Olive, Brian Castro, and Floyd E. Toole