Burlap Speakers

I want to make my own speakers out of the burlap composites, it's cheap and very strong. After some researches on how speakers work in terms of airflow and speaker placements, I quickly found out that most of them are just in boxes with different air channels. I decided to go with something less boxy looking, a speaker that shapes like an old speaker cone. Internal air chambers and corners would help you create a richer sound, I am not a sound engineer, but you can probably test out with a cardboard model.

Step 1: Mold to Lay Burlaps On

I design and printed the model with a 3D printer with a very thin wall. I will be using this as the mold to lay the burlaps on, so it doesn't need to be too thick, we are going to take it apart when de-molding anyway. I also made the base with the 3D printer, both are ready for vacuum molding.

Step 2: Burlaps + Resins

I used the laser cutter to cut out all my burlaps, the trick is not to set the laser cutter on fire by lowering the power, or have the laser at higher speed, or cut twice.

I used Johnson Wax, Release Fabric and Mann Release Technologies Ease Release (yes, all of them, might be over kill) in between my 3D printed mold and the composites layer (burlap and Epoxy Resin by Entropy Resins). The holes in the Release Fabric helps the bleed / white sponge material to absorb the extra resin. I spread the clear Entropy Resins (2 part A and 1 part B) onto each burlap and stack them layer by layer. They are extremely runny. I then vacuums it with a vacuums plastic, designed to store clothing. It was pretty easy to break the mold apart, and take out the 3D printed mold. I then trim and sand the pieces to size. All the sanding and cutting leaves the surface white and rough, so I coated it with another thin layer of resin, using it as paint. I had to wait for about 12 hours before I can do anything with it.

Step 3: Assemble

I use laser cutter to cut out the supporting material, in my case, plexiglass, for the speakers. The wiring was pretty tricky since I am working within a pretty tight space.

Step 4: Wiring

With some hot glue, the speakers are in position and ready to wired up with an Amp. The speaker wire jack makes it easy to attach and detach. You can buy different styles of wire attachment.

Step 5: Testing the Speakers & Acoustic Improvement

The speaker doesn’t have the richer bass and deeper sound that I was looking for, so I did some experiments by covering the front air vent with plexiglass. The speakers sounded a lot better after I cover the front vent, the one directional airflow makes it sound louder with much better bass.

What would I do differently
I should pay more attention with the 3D model and how it unfolds before I cut the burlap with laser cutter. I would make the speaker cone 2 times larger so it would produce better bass. I should do 2 part compression mold to get better surface on both sides with burlap composite, now it looks like dumplings ...

Comments

[RowanCant]

This instructable is like "look at me, I have a 3D printer, a laser cutter and a vacuum former". Why do I say this? because in the time it took him to carefully design his 3D model, I walked down to the $2 shop and bought some funnels. In the time it took him to create the cut file and laser cut his burlap, I had already cut them out with standard scissors. I will admit that the vacuum former is probably pretty fast, but it's not doing much that a plastic bag and a vacuum cleaner couldn't achieve.

I just thought I'd say that because the outcome is pretty cool and I'm glad you thought of these, but most of us aren't as rich.

[Dan Chen]

Good point ... not all of us have shop access, I should make a version with that in mind that you can make at home. PS: the "vacuum former" was actually just the vacuum bags for winter clothes and regular vacuum.

[Hairman]

This speaker, if it were made to be completely watertight, (if not already done so) and the creator used the "RealTree" type of burlap that is sold in hunting stores, well then this would be an excellent set of speakers for animal calls that are digitally recorded onto an MP3 type device. Hunters use these for many types of call in every type of weather. What an excellent design for this. If this takes off I will tell other hunters about your idea. I also wanted to say that you were very humnble in your reply to the comment from RowanCant. You could have taken it in a different way. RowanCant obviously never meant any insult, however people seem to explode to minute forms of critique these days, so kudos to you.

[avasselle]

Is it possible to smooth the external surface of burlap ? With grit paper or something...

Nice Instructable !

[Dan Chen]

The area that's facing the mold is always going to be smoother, in this case I had it the other way. I should make the cone larger and lay the burlap on the inside.

[KeithRichards00]

Good share.

[studleylee]

I love the idea of Burlap and Epoxy. Many uses!

Great Speakers and Idea!!!

[JON-A-TRON]

Awesome instructable! I've been wondering about burlap as an alternative to fiberglass- a small scale project like this is a great way to test it out.