The RPG® Diffusor System is a fresh approach to architectural acoustics. Traditional acoustical products focus on sound absorption. While absorption is an important ingredient, effective acoustical design can only be realized with a balanced approach that uses all of the ingredients in the acoustical palette.

The Acoustical Palette
Incident sound is attenuated by absorption, re-directed by reflection, and uniformly distributed by diffusion. In 1983, RPG® introduced the first commercial reflection phase grating (RPG) surface, offering predictable wide-angle scattering over an extended range of frequencies, for all angles of incidence. In contrast to absorbing surfaces, the RPG controls sound by diffusion, in much the same way that frosted glass diffuses light instead of absorbing it. The RPG represents a milestone in architectural acoustics, because sound from any direction can now be uniformly distributed into many directions, thereby attenuating the sound interference in any one particular direction. The RPG is a modular, computer designed panel consisting of a periodic grouping of a series of wells (1D) or cells (2D) of equal width, but different depths, separated by thin dividers. When the depths are based on quadratic residue number theory sequences, the RPG is called a QRD®.

Following the introduction of the QRD®, RPG® Diffusor Systems has continually expanded the acoustical palette with new architectural acoustic products while building a reputation as the industry’s leading acoustical innovator.

Today, the RPG® Diffusor System consists of a broad range of diffusive, absorptive, variable acoustics, and performance products. These products offer aesthetic acoustical solutions for sound control as well as noise control projects.

1D Diffusion: One-dimensional diffusors contain depth variation in one dimension, thus forming linear divided wells or steps of varying depth. For all angles of incidence, the scattering is uniformly diffused into many directions. This diffusion forms a hemi-disc, which is oriented at the specular angle and covers the plane containing the depth variation. The high frequency cutoff is determined by well or step width and the low frequency cutoff is determined by the maximum well depth. 1D diffusors are useful when the diffuse scattering must be directed into specific directions.

2D Diffusion: Two-dimensional diffusors offer depth variation in two perpendicular directions, thus forming a lattice of divided cells or steps of varying depth. For all angles of incidence, the scattering is directed hemispherically. The cell or step width determines the high frequency cutoff and the maximum cell or step depth determines the low frequency cutoff. 2D diffusors are useful when the diffuse scattering is required in all possible directions.

Absorption: Absorbing products attenuate incident sound. RPG® offers both broad-bandwidth products as well as dedicated bass absorbers (bass traps) using a proprietary membrane transducer.

Variable Acoustics: RPG® offers variable acoustics products to tailor the acoustics of a space to meet changing acoustic requirements.

Performance Products: RPG® offers both passive acoustical shells and active variable acoustics performance products to satisfy the current and future needs of all performance and rehearsal facilities.

Software: RPG®’s Collaborative Holistic Acoustical Optimization System (CHAOS) offers the industry the first multi-dimensional optimization software to create aesthetic architectural shapes that complement contemporary architecture in much the same way that relief ornamentation, columns, and statuary complemented classic architecture. Critical listening room optimization software as well as room prediction and auralization software is also available.