Acoustic Absorption Panels – Part II. Assembly

21 August 2020

With all the theory out of the way, we're ready to start assembling these beautiful beasts. Here I'm going to lay out my process for the project, start to finish, summarized in 20 photos. Let's get started!

1. Buy some stuff. This is what you'll need to build 8 panels:
(with some optional parts at the bottom if hanging on the wall)

2. Find a table saw.
Use it to slice up that MDF board (dimensions given above).

3. Find a hammer.
Will be used to smash any staples that poke out.

4. Find a drill. Find a battery for the drill. Grab another battery when you realize that one's not charged.

5. Find a staple gun. Make sure it's compatible with T50 staples.

Michal "Pro Tip" — Your panels will only work if you use DeWALT products.

6. This is the frame we're building....

7. ...and this is the insulation we're putting in it.

Why construction insulation? Well, there are at least three good reasons.

8.    I.     Water Repellant: Won't get moudly and give you cancer.

9.    II.    Fire Resistant: Won't burn your house down.

10.  III.   Sound Absorbent: bingo!

We choose the insulation material primarily based on material density:
- The more dense the material, the fewer particles it sheds when being handled; but
- The less dense the material, the lighter to transport, and better at absorbing low-mids. Recall our original goal to target the low-mid frequencies (200Hz-500Hz).

For these reasons we choose...

Rockwool's Safe'n'Sound

Density: only 40kg/m³

Absorption coefficients:
0.96 at 250Hz
; 1.18 at 500Hz.

Connect the 6 pieces of the MDF frame with some wood glue and screws. The top and bottom pieces are attached to the outside edge of the side pieces; the back supports are attached on the inside.

11. Back supports are flush with the back.

12. Sides are sanded down; bevels cut along the edge.
      Michal "Pro Tip" — Get a countersink bit to hide the stupid screw heads inside the wood.

13. Rinse and repeat.

14. Landscaping fabric is laid across the back of the panel.
      This will allow sound to pass through the back as well, making for a more efficient absorber.

15. Dual-sided works best as it adds an extra layer of protection. That means less ripping.

16. Time to get acquainted with your staple gun.

Once the staples are in, we're almost there—just the fabric now! Two things to look for:
   - The more breathable the fabric, the more sound gets to the insulation;
   - The stretchier the fabric, the less noticeable the wrinkles & creases are along the folds.

With all that in mind, the ideal fabric is...

Some kind of polyester

—super stretchy
—super breathable

17. Optional — Want to take your DIY game to the next level?
Use a piece of a carpet transition strip to wedge the panel onto another carpet strip fastened to the wall. This allows for easy hanging, and for sliding horizontally along the walls to coincide better with any room modes.

18. Optional — Want a nicer looking panel?
Cover up any imperfections on the back with some multilayer duct tape.

19. Optional — Want even better acoustics?
Add some little blocks of spray painted wood or firm packaging foam to add space between the panel and the wall. Any sound that manages to pass all the way through the insulation will now have an even harder time bouncing back.

20. A job well done.