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 cutoff. 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 reflectiveareas. 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, 1' x 1' 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.