Problem
The bandwidth of a QRD® is limited at high frequencies by the
well width and at low frequencies by the maximum depth. Additionally,
wide area coverage with periodic arrays focuses energy into certain
diffraction directions. A full spectrum diffusor offering wide area
coverage is needed.
Solution
The Diffractal® is the first diffusing fractal. It consists of
nested self similar scaled diffusors, each of which covers a specific
frequency range and offers wide area coverage without lobing effects. A
second generation Diffractal® (DFR72) contains two nested
QRD®s, thus forming a diffusor within a diffusor. Each diffusor
provides uniform scattering over a specific range of frequencies so
that the effective bandwidth is extended. The DFR72 can be nested
within a larger low frequency diffusor to provide wide area coverage,
extended low frequency diffusivity, and also minimum lobing associated
with periodic arrays. This third generation Diffractal® (DFR73)
offers low, mid, and high frequency diffusion over an extended
bandwidth, limited only by the depth available.
Performance
Diffusors essentially scatter
sound, but absorption may occur from wave resonances within the wells
when they are narrow and deep and viscous losses due to pressure
gradient induced air particle flows between adjacent wells. The
Diffractal® provides high frequency diffusion without adding
additional absorption by replacing the mid frequency QRD® wells
with nested reduced scale high frequency QRD®s.
The nested diffusors comprising the Diffractal® extend the high
frequency diffusive performance beyond that of the QRD® 734.
The graph illustrates how the Diffractal® mid frequency and
high frequency nested components essentially boot strap the uniform
diffusion from 500 Hz to 20 kHz. The diffusion coefficient is also
compared to a flat reflective panel which exhibits decreasing
diffusivity with increasing frequency.
Installation
The Diffractal® can be flush mounted into an opening or surface
mounted on a wall or ceiling.
Features and Benefits
Applications
Product Options
1200x600x230
1200x600x100
600x600x230
600x600x100
MDF
Venereed MDF