Flutter Echo Attenuation Prototype Absorber #1
With a borrowed drill, mitering hand saw, and a few other borrowed tools, I was able to build my first attempt at a frame.
Without access to a table saw, my material choices are currently limited to precut measurements such as 1X4 (3/4” X 3-1/2”) or 5/4X6 (1” X 5-1/2”)
In these sizes, the two main varieties of wood planks available were framing lumber and decking boards. Decking is well finished, structural wood that is a bit heavy for this purpose. Framing lumber is not pretty but was the better option. It’s surprisingly cheap too.
Note: If using 1X4 framing lumber, look through the stack to find sufficiently straight boards as some planks were better suited for boomerangs than absorber frames. Clamping everything into place first does help with drilling the holes straight and preventing your project from becoming a parallelogram absorber.
Even then, the only way I could think to keep the boards straight was to screw a short and a long side together, making an L shape for the absorption material to sit in.
The wood screws were selected to be used on a variety of materials and sizes. #8 X 2-1/2” is probably larger than necessary for 1X4 planks. This is my guess at logical screw placement. It’s the fewest number of screws that accounted for everything. And of course we are countersinking all screws!
This screw placement attaches all sides of the wood planks with the fewest number of fasteners possible. The backing board is also screwed to the side beam at the center point to help prevent warpage.
So far so good. Because the purpose of these absorbers is to attenuate flutter echo, this frame should work well enough.
Perhaps we’ll try hole sawing the planks in some places to increase the absorption area. I'm not sure the wood is strong enough.
Both the cover fabric I have on order and the insulation itself are fireproof. These 1X4’s are the only flammable part of this prototype. If I can acquire (or get access to) a table saw, I will make the next prototype frame from a sheet of MDF instead of lumber as MDF is a lot less flammable. The center plank is intended to help hold soundproofing insulation in place as well as help straighten the frame. If you have ideas of how to improve this design, please share them.
Thank you for playing along, your feedback is appreciated.