FlutterFree W



FlutterFree-W is an attractive, furniture grade acoustical wood plank designed to add high frequency sound diffusion to RPG’s patented one-dimensional Waveform designs such as the Gaussian and the Spline. The combination of the FlutterFree-W with an optimized Waveform shape produces an assembly capable of very broadband diffusion.


FlutterFree-W is available in hardwoods, softwoods and painted finishes. RPG offers factory color matching on both wood finishes and paint colors. See some of the options displayed under the Finishes tab below.


FlutterFree-W is best mounted perpendicular to Waveform ribs for wall or ceiling mounting. Rib spacing should be no more than 16″ on center. The mounting can be configured to integrate low frequency absorption to further enhance the acoustical attributes for the most demanding applications. See details below under the Drawings tab.

FlutterFree is a Registered Trademark of RPG Acoustical Systems LLC

FlutterFree-W 1D Wood Sound Diffusing Plank For Curved Surfaces

FlutterFreeW Features img

The phase grating surface of the FlutterFree-W is designed to provide a more uniform ambient sound field through high frequency diffusion while the solid wood construction of the unit limits the amount of sound energy that is removed by absorption. The unique shape of the plank allows it to easily follow curved surfaces which make it able to be paired with RPG’s optimized Waveform shapes such as the Spline and the Gaussian. When combined, the FlutterFree-W Waveform system offers broadband diffusion, the performance of which is only rivaled by the Modfractal. The FlutterFree-W can be simply attached to wooden RPG Waveform ribs in the field, creating a variable depth cavity that can be utilized for low and mid frequency absorption. Its durability and broad selection of finishes make it a logical choice for music education facilities, auditoriums and performing arts facilities. FlutterFree is available in a wide variety of finishes, including natural hard and soft woods, stains and painted finishes to match any manufacturer color code.


Interfering reflections that degrade sound quality can be controlled by absorption and/or diffusion. When absorption alone is used to control reflections it creates “dead” sounding spaces that lack the benefit of late order reflections which can greatly enhance the acoustic performance of a space.


FlutterFree-W is the first sound diffusing plank designed to follow curved surfaces. Rather than remove the energy that strikes key surfaces in a space, FlutterFree-W preserves the energy by uniformly distributing the energy back into the space. The onset of significant diffusion for FlutterFree-W occurs at approximately 4000 Hz; when paired with the RPG Waveform shapes the onset of diffusion can occur as low as 250 Hz.


  • Offers high frequency sound diffusion in a decorative, solid wood plank.
  • Comes in a variety of finishes, including natural hard and soft woods, stains and custom paint colors.
  • Easily follows curves.
  • Can be paired with RPG Waveform shapes to create very broadband diffusive surfaces.
  • Can be slotted to provide mid frequency absorption
  • Can be mounted to provide low frequency absorption
  • Comes standard 1-1/16″ depth, 2-3/4″ width and up to 12′ in length.
  • Simple installation direct to wall surface, on furring strips or on RPG provided Waveform ribs.

RPG Wood Products can be manufactured to match most commercially available and custom hard and soft woods.

Common Wood Species

Ash 1

Stocked product samples are typically manufactured using common wood species – no products are available at any one time in all of the above species. Please check with your local rep or contact RPG.