Scratch Built Acoustic Absorbers for Bedroom Studio

Hey everyone! I'm in the process of converting my bedroom into a bedroom studio for music recording and production, so I thought I would teach Y'all how I made my acoustic absorbers!

Step 1: Materials & Supplies

Materials

Wood(in my case I used spare plywood)

Foam(I had some extra memory foam from an old mattress)

Exacto Knife

Table Saw

Chop Saw

Drill

Screws

Staple Gun

Fabric to cover the frames(Landscape fabric for the backing and nice fabric for the front)

Step 2: Ripping the Wood Sheet Into a Usable Size

In our case, we had a small sheet of plywood left over from an old project, so we figured we could build both frames out of it. We first started by cutting the memory foam so we could build a frame around it. Foam is a pain to cut, but with some patience and a sharp knife, it can be done successfully. Once we had cut two foam pieces in the dimensions 2 feet 5 inches by 3 feet, we began to rip the wood on the table saw. We cut each wood strip out of the sheet of plywood to be 3 inches in thickness. We ended up with a total of 14 wooden strips, 7 for each frame. Four of them being for the outside frame, and three for the inside support.

Step 3: Cutting the Wood Strips to the Correct Length

We then began to cut down the strips we had ripped from the table saw to the correct lengths. Since I was making two acoustic frames, I cut four in the length of 3 feet, and 10 in the length of 2.5 feet using a chop saw.

Step 4: Constructing the Frame

For this step, we used 2-inch screws to attach the whole frame together. We predrilled holes in the sections of wood that were 3 feet long, and then in the final assembly, we predrilled holes in order to prevent blowout and tearing from the screws.

Step 5: Sanding and Attaching the Landscaping Fabric

We first started by sanding the entire frame to prevent the sharp edges from puncturing the fabric. Then, we cut out the landscaping fabric in the size of the frame and attached it to the back using staples from a staple gun.

Step 6: Inserting and Covering the Foam

We held the foam in place using staples that gripped onto the wood beams behind the foam. When we began to cover the absorbers, we made sure to stretch the fabric tight for a clean finish. To hold the fabric in place, we used staples from a staple gun. In our case, the fabric we used was extremely thin, which led to a lot of tears from the staples.

Step 7: Attaching the Absorbers to a Wall

For this step, we used a system of hanging called a French Cleat. Here is a great example of how to use one: https://www.instructables.com/id/French-Cleat/

For mine, we used a scrap 2x4 for the system of attaching it.

Step 8: Done!

Thanks for checking out this instructable!! I hope you enjoyed this one!!

For those curious, the links for my music are down below!

https://soundcloud.com/kurt-wokoek

https://open.spotify.com/artist/55lZKGjKOJQ62xD9U4...

Thanks for checking this out!!

Comments

[auto13142828]

You're still going to hear the neighbors, cars, and their dogs barking.

[Killawhat]

Great idea to use leftover ply wood for the frame and ingenious use of weed matting for the back. Not too sure whether the foam matress would have too much effect as it's quite dense. You wants something with air pockets in it (like rockwool or similar). Also, sit them off the walls a little bit more.

[Penolopy Bulnick]

These are great! I didn't know something like this would be so easy to make :)

[JamesA41]

Check out this instructable and this Hackaday for more detailed info on more effective builds I'm thinking (not that this one is bad... I have been wondering what the space foam material performance characteristics are and the instructable was well done):
https://www.instructables.com/id/Mic-Surround-for-...
https://hackaday.com/2018/12/14/build-your-own-ane...

I thought this was kind of neat showing a room style with the wall also creative with a different material:
https://www.instructables.com/id/Computer-Drawer/

[macasoft]

You mean sandwich foam in a container?

[Penolopy Bulnick]

Exactly ;)

To be fair, I didn't know what it would take to make thses in the first place, but now I know and it seems so easy :)

[sundvl76]

I built acoustic panels for a piano room, using these: https://www.homedepot.com/p/Auralex-Auralex-Studiofoam-Pyramid-Panels-2-ft-W-x-2-ft-L-x-2-in-H-Charcoal-Half-Pack-12-Panels-per-Box-2PYR22CHA-HP/203468292 and they worked very well. Research acoustic absorption and you will find you don't need to cover the entire surface, but placement can be critical. I simply glued these panels, using spray-on adhesive, to 1/8" thick tempered hardboard then attached loop hangers to the back sides.

[JamesA41]

Awesome, I didn't realize Home Deport has acoustic foam. Two layers of drywall come to mind however for residential code... I forget if that code is in general or some places. Thanks for the link!

[Humble Handyman]

They look nice but I'm not sure how they :absorb" sound.
With foam that dense and only the dents caused by stapelling I'm struggle to find the Helmholtz resonators needed.
Perhaps you could substitute the dense foam with something that has the required resonant spaces?

[zanod]

What were you actually trying to achieve? - reduced reflections in the room (reduced reverb), or reduced transmission of noise through the wall (improved neighbour relations)? In either case, what tests did you do to check the effectiveness of these dampers? They seem to cover a relatively small percentage of the wall area, so even if they were 100% effective, I would expect them to reduce reflections/transmission by only that percentage. However, 100% effectiveness is usually pretty hard to achieve, so I don't suppose they would be as effective as that.

Can you share your test setup and the results?

[JeffB184]

Try using an electric carving knife for cutting foam. Same kind you might use for carving meat or slicing bread.

[yrralguthrie]

Without including your enthusiasm, for a project you have invested in, how effective are these? I ask because I didn't know memory foam was particularly effective in sound dampening and you don't cover a lot of wall. And I believe the foam would be more effective without a cover.

[macasoft]

Not sure what the purpose is? You have a lot of straight wall surface left. I mean cover all or nothing. What do I miss?

[Belgarion115]

The entire wall does not need to be covered in order to effectively reduce standing waves and first-order reflections. I think the threshold is somewhere around 30-40% but it's been a while since I did that kind of thing.

[debbitoo]

I need to make these for my cathedral ceilinged family room that echoes. Would they work for that and how do I determine how big they need to be and where to position them for best effect?

[smartrem]

That's a full time job. Acoustics is very hard and it depends of so many factors. According to my experience, you should hang cubes up in your ceiling (https://www.doxacoustics.be/fr/produits/solutions-acoustiques/design-elements-ludiques/cube-cone). If you ask a retailer of this kind of products, I think they can advise you

[captinvidio]

Cutting foam is made more easy if you are using a electric carving knife it will give a clean cut

[Spaycemuuse]

Why did you choose to use memory foam as opposed to Roxul, for example?

[ich666]

Have you measured how much dB it get's down the noise or something?

[GaryV11]

I was thinking the exact same about dB levels, but this instructable was designed for a studio in which its purpose is to deter unwanted echo. On the other hand should this be used for a restaurant/bar atmosphere speech is greatly improved and sound intensity levels can be simultaneously reduced. People tend to speak louder to overcome the echo which in turn makes the echo even worse. It is bothersome (for those already hearing impaired) when a local restaurant remodels and totally forgets about dB levels.