All Products BAD Panel
Problem
Traditional fabric wrapped panels offer a cost effective, low profile
aesthetic approach to providing reflection and reverberation control.
However, these panels offer little sound diffusion and large area
application may lead to an acoustically "dead" space. Variable
impedance arrays offer some help, but cannot provide diffusion at mid
and high frequencies.
Solution
RPG® developed an innovative variable impedance panel by fabric
wrapping a resorptive binary template consisting of reflective areas
and holes over a semi rigid fiberglass panel. The resulting Binary
Amplitude Diffsorbor™ panel provides mid and high frequency
diffusion and low frequency absorption. The picture right shows
the BAD template mounted over the fibreglass panel, this mask is
laquered to produce a highly decorative product. The panel can be
fabric wrapped in any colour the client or architect requires.
Well balanced acoustical designs contain an appropriate combination of
absorption, reflection,and diffusion. In many applications, however,
limited budget or surface treatment thickness preclude the use of
diffusion. Absorptive, fabric wrapped panels are specified for
lack of an alternative. Unfortunately, wide area application may lead
to an acoustically "dead" environment without "air" or ambiance.
To solve this problem, RPG® developed the Binary Amplitude
Diffsorbor™: the first flat, zero depth diffusing absorber. A
BAD™ Panel simultaneously provides uniform sound diffusion at
high and mid band frequencies and crosses over to pure absorption below
the diffusive
cut-off. The energy that is not diffused is absorbed.
It's Digital!
To accomplish diffsorption, RPG® developed a new planar 2
dimensional binary reflection amplitude grating consisting of a 31 x 33
element array of 1,023 0.5 sq. in. absorptive or reflective areas. The
reflective areas (black in illustration to left) map to the "1" bit and
the absorptive areas (white) map to 0, or vice versa. The distribution
of these resorptive binary elements is based on a 2 dimensional optimal
binary sequence with a flat power spectrum. The resulting variable
impedance surface forms a binary reflection amplitude grating suggested
by James Angus. This is in contrast to RPG®'s reflection phase
gratings which use phase variation, rather than amplitude variation, to
provide diffusion. The Binary Amplitude Diffsorbor™ (BAD™)
Panel provides diffusion about an octave above the frequency whose
wavelength is twice the size of the binary element. This explains the
limitation of traditional variable impedance arrays. For example, 25mm
x 25mm panels provide diffusion up to about 1 kHz. Remaining high
frequency reflections would still corrupt speech and music quality.
The BAD™ Panel consists of a binary mask attached to the face of
a semi rigid fiberglass panel. The panel is upholstered in a decorative
fabric to completely conceal the acoustical functionality. The
BAD™ Panel extends the acoustical performance of traditional
absorptive fabric wrapped panels and allows wide area coverage without
excessive deadening. Acousticians now have a diffsorptive alternative
to traditional purely absorptive fabric wrapped panels at competitive
prices. The BAD™ Panel is ideal for any facility that needs
reflection control from a decorative, upholstered, thin, and cost
effective wall or ceiling panel.
Performance
The graph illustrates how the BAD™ Panel
offers an increase in bass
absorption over a standard upholstered 25mm panel below 1000 Hz, and a
decreased absorption above this frequency for a 15mm diameter and the
standard 12mm(approx) diameter hole. The binary template allows the
sound above 1000 Hz, which was conventionally lost to absorption, to be
uniformly diffused providing reflection control without destroying the
room's ambience.
Diffusion
The performance of a scattering surface is characterized
by the
diffusion coefficient, which is the standard deviation of the 1/3
octave angular response, shown above at 12.5 kHz. The graph illustrates
how uniformly the BAD™ Panel scatters sound across the frequency
spectrum, compared to a reflective panel, for normal incidence.
Angular scattering response
For normally incident sound, the graph illustrates the angular
response at 12.5 kHz. The flat reflector scatters sound primarily into
the 90° specular direction. The wall mounted absorptive panel has
similar response, only attenuated. The BAD™ Panel decreases
specular scattering and more closely approaches the uniform ideal
diffusion line.
Installation
Installation of the BAD™ Panel is quick and easy. Simply use impaling clips, battens or Rotofast mounts to walls or ceiling. The BAD™
Panel can also be used in any T-bar or similar mounting system.
Features and Benefits
Product Options
Any acoustically transparent fabric approved by RPG® Diffusor
Systems, Inc
6 lb. density fiberglass
Split Batten mounting or flush mount, or mount in a cavity for
increased performance
Unit Size Minimum of units is 600mm x 406mm
Units can be made with any height up to 2500mm
Units can be made with any width up to 1200mm
Units can be made with depths between 25mm - 150mm
Units can be made with flat, bevelled, angled, or radius cut edges
Note: All dimensions are allowed a tolerance of ± 2mm due to material
shrinkage and variations.
