Acoustic Diffusers | Sound Diffusers | Diffusion Panels | Sound Scattering Panels
RPG FLUTTERFREE PLANKS
Problem and Solution
Repetitive reflections from hard parallel surfaces produce flutter echoes that are
timbre coloration and degrade sound quality and speech intelligibility. Absorptive surfaces are
often used to control this annoying problem, with the unfortunate side effect of making the
FlutterFree is the first acoustical hardwood molding that controls
flutter echo by
diffusion, maintaining the natural ambiance of the room. When adjacent panels are
spaced and mounted
with an air cavity, low frequency absorption can also be achieved.
When FlutterFree panels are mounted 1/16" apart, the graph can be used to determine the spacing from the mounting wall for the desired absorption frequency. For example, to achieve bass absorption at 100 Hz, follow the vertical 100 Hz frequency line until it intersects the leftward sloping fractional open area line. Follow the horizontal line to the 8" intersection point.
The absorption coefficient data on the left is for non-slotted FlutterFree in a Hemlholtz mounting. Surface mount refers to a C mounting with fiberglass on the boundary. The Cavity mount refers to a D mounting with a cavity depth of 3.5" (89 mm). The spacing between FlutterFree strips is 0.063" with a fractional open area of 0.015.
RPG Flutterfree Absorption 3
The absorption coefficient data on the left is for slotted Flutterfree and was measured without any spacing between the FlutterFree planks. Surface mount refers to a C mounting with fiberglass on the boundary. The Cavity mount refers to a D mounting with a cavity depth of 3.5" (89 mm). For extended low frequency absorption the FlutterFree Helmholtz mounting may be used in conjunction with the slotted planks.
RPG Flutterfree Diffusion
The graph illustrates how FlutterFree® provides useful diffusion above
limit of roughly 3400 Hz compared to a flat reflective surface. The chart represents
diffusion coefficient, which is the normalized standard deviation of the 1/3 octave
for angles of incidence between 0° and 90°.
RPG Flutterfree Installation
FlutterFree strips are molded on a 5 head wood molder from hardwood that is kiln dried to
6-8% moisture content.
All information contained in these details is given in good faith but without warranty.