Conventional acoustic treatments have relied on absorption for reflection control. Unfortunately, this can “deaden” the room and make it unsuitable for speech or music. Diffusive ceilings are one of the most effective ways to simultaneously control room reflections and provide a natural ambiance. The Omniffusor® uniformly scatters sound arriving from any direction into many directions, providing ideal distribution and coverage. It’s unique shape creates an attractive, visually interesting acoustical surface.
Specular reflections from flat, hard surfaces cause strong reflections that corrupt speech intelligibility and degrade music quality. Typically, fabric wrapped absorptive panels are used to control interfering reflections, but in some situations the deadening effect is undesirable.
The Omniffusor® is the first two dimensional QRD® sound diffuser of its kind. It offers twice the reflection attenuation of the 1D QRD®, because it scatters sound uniformly into a hemisphere. The Omniffusor® provides uniform, omnidirectional, broad bandwidth diffusion in an attractive ceiling or wall design element.
It was discovered that phase gratings, consisting of wells of different depths separated by dividers, also may provide sound absorption. The absorption is caused by viscous losses created by high particle velocity flows over the dividers, between wells of different depths and resonant frequencies. The absorption can be enhanced by placing a resistive element, e.g. fabric, near the face of the phase grating. A supplemental sound absorption data sheet illustrates the absorption performance uncovered, with fabric directly on the surface and at 2″ and 7″ above the surface.
The Omniffusor® offers significant diffusion above the diffraction limit of 565 Hz, which is determined by the dimensions of the panel. The chart displays the mean diffusion coefficient, which is the normalized standard deviation of the 1/3 octave polar responses for angles of incidence between 0° and 90°, the normalized scattering coefficient for computer modeling calculations and the A-mount absorption coefficient for reference.
Wooden Omniffusors® can be wall mounted. For wall installation, plexiglass Omniffusors™ should be flush mounted into a framed opening. Decorative trim can be added to conceal the perimeter joint.