Independent Acoustics and Noise Control Expertise Custom Audio Designs Ltd 

RPG BAD Panel-Thin flat acoustic diffsorberRPG BAD Panel-Thin flat acoustic diffsorberRPG BAD Panel-Thin flat acoustic diffsorberRPG BAD Panel-Thin flat acoustic diffsorberRPG BAD Panel-Thin flat acoustic diffsorber

Acoustic Diffusers | Sound Diffusors | Diffusion Panels | Sound Scattering Panels


  • Simultaneous diffusive and absorptive sound control in a thin
    decorative, cost effective panel.
  • Recording Studios.
  • Post Production Studios.
  • Practice Rooms.
  • Home Theatres.
  • Mastering Studios.

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  • Wide range of wood finishes .
  • Can be surface or flush mounted.
  • Custom Sizes and depths.
  • Attractive fabric finish.
  • Curved BAD-Arc option.
rpg BAD Panel
RPG B.A.D Panel Diffuser
  • 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 the Binary Amplitude Diffusor/Absorber simultaneously provides uniform sound diffusion at high and mid band frequencies and crosses over to pure absorption below the diffusive cutoff. The energy that is not diffused is absorbed.
rpg BAD Panel Grid Image 

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 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, 1' x 1' panels provide diffusion up to about 1 kHz. Remaining high frequency reflections would still corrupt speech and music quality.

BAD Panel Assembly Image 

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.

Problem and Solution


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.


The B.A.D. panel is an innovative variable impedance fabric wrapped acoustic panel with a 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.


rpg bad panel image       

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The graphs above illustrate how the BAD Panels can offer an increase in bass absorption over a standard upholstered 1" panel below 1000 Hz, and a decreased absorption above this frequency. The binary template allows the sound above 1000 Hz to be uniformly diffused providing reflection control without destroying the room’s ambiance.

BAD Panel Diffusion Graph, Select For Detail


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.

BAD Panel Polar Graph, Select For Details

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.


For wall mounting a split batten is fixed to the wall. The acoustic panel is offered up to the wall brackets and simply lowered in place. The split batten on the back of the panels allows easy removal as well as providing an additional airspace behind the absorber for improved acoustic absorption.

For flush mounting wall panels the metal Z clip system can be used if specified in advance.

For ceiling mounting the female Z clip is fixed to the ceiling. Again the panel is simply lifted up and dropped down onto the ceiling clip.

Metal impaling clips are screwed into the wall. Adhesive is applied to the panel and the wall. The panel is then offered up against the wall spikes and fixed in place. This method does not allow easy removal of the panels.


BAD Panel diffusers are now also available with a curved front panel for improved diffusion. Contact Custom Audio Designs for further information and costs.
RPG curved BAD-Arc panel RPG expo BAD panel in oak veneer RPG expo BAD panel in oak veneer

RPG expo BAD panel powder coated grey with grey fabric rear RPG expo BAD panel powder coated bronze with red fabric rear RPG expo BAD panel antique powder coated grey with black fabric rear

All information contained in these details is given in good faith but without warranty.
Custom Audio Designs reserves the right to alter the specifications of any product without notice.
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