HolyCross FLFR e1513181733328


FlutterFree is an attractive, furniture grade acoustical wood plank designed for high frequency sound diffusion.


FlutterFree 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 is best mounted perpendicular to wood battens for wall or ceiling mounting. Batten spacing should be no more than 16″ on center. The mounting can be configured to integrate both mid and low frequency absorption to further enhance the acoustical attributes for more demanding applications. See details below under the Drawings tab.

Flutterfree is a Registered Trademark of RPG Acoustical Systems LLC

FlutterFree 1D Wood Sound Diffusing Plank

FlutterFree Features FLFR

The phase grating surface of the FlutterFree 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. It has become a classic shape in architectural acoustics; from its beginnings over 20 years ago it can now be found in church, theater and recording studio spaces all over the world. Its durability and broad selection of finishes also 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. It can be mounted to virtually any surface and can be configured to offer low frequency absorption.


FlutterFree Features Species
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 is the first and most applied sound diffusing plank in the world. Rather than remove the high frequency energy that strikes key surfaces in a space, FlutterFree preserves that energy by uniformly distributing it back into the space. The onset of significant diffusion for FlutterFree occurs at approximately 4000 Hz.


FlutterFree Features Slotted Species
  • 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.
  • Comes standard 1-1/16″ depth, 3-15/16″ width and up to 12′ in length.
  • Simple installation direct to wall surface or on furring strips for required cavity for low frequency Helmholtz absorption mounting or mid frequency slotted plank mounting.

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

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.