The Abffusor® is the industry’s first absorption phase grating. It is an extension of RPG®’s research on the reflection phase grating (RPG) which provides sound diffusion from a series of divided reflective wells of equal width and different depths. The depths of both the reflective wells of the RPG and the absorptive wells of the Abffusor® are based on mathematical number theory sequences. The Abffusor®’s absorption efficiency extends below that of a traditional flat porous absorber because it utilizes two absorption mechanisms.
The first is the traditional dissipation of sound energy into heat by frictional losses in the pores of a porous absorber. The second is the viscous losses due to high particle velocity flows across the well dividers induced by the pressure differences in adjacent wells. This pressure gradient mechanism results in additional low frequency absorption. The absorption phase grating topology also offers efficient glancing angle reflection control and near field diffusion to create a natural sounding, attractive room treatment.
Problem
There is a need for a surface treatment that controls strong first order reflections over a wide range of frequencies and angles of incidence which also offers near field scattering to provide a natural ambiance.
Solution
The Abffusor® accomplishes solves these problems by using two absorption mechanisms in addition to diffusion. Absorption extends to lower frequencies than flat porous absorbers due to the QRD® pressure gradient mechanism. Near field QRD® diffusion provides additional sound control.