Pyramid foam is a long-lasting, high-performance solution to your sound-deadening needs at an affordable price. Pyramid foam’s unique design offers slightly different performance characteristics than other cuts, with its greater surface area. The four sides, rather than the two of the wedge, provide extra diffusion but slightly less absorption for different usage styles and needs.Pyramid foam is a long-lasting, high-performance solution to your sound-deadening needs at an affordable price. Pyramid foam’s unique design offers slightly different performance characteristics than other cuts, with its greater surface area. The four sides, rather than the two of the wedge, provide extra diffusion but slightly less absorption for different usage styles and needs.