Speaker on denim

In this assignment i've created a soft speaker on a piece of denim. I've solded a mono amplifier with a jack connector that is connected to the soft speaker. For the best audio results i should have a resistance between 4 and 8 ohm.

I did this together with Summer.

Summer folded the blue and the orange wires to the jack plug. Picture: Andrei Motian

In this case the blue wire is + and the orange wire is -. We wrapped some tape on eacht wire and wrote + and -. The + (blue wire) should be soldered on the short side of the jack plug and the - (orange wire) on the long side of the jack plug.

Pins soldered on the bottom of the amplifier. Picture: Andrei Motian.

I've soldered the pins on the bottom from the amplifier. With these pins we will provide power and amplify the sound from the speaker.

This is how I should look like from the top. Picture: Andrei Motian

For connecting the speakers to the amplifier, make sure to solder the part (with the two screws on top) with the two holes pointing on the outside of the amplifier. Connect the two crocodile wires with the amplifier by stripping the coating (5mm will do), stick each in a hole and secure them with a screwdriver on the topside.

The amplifier is done for now and i'll continue with the denim after the recessweek.

For the design of the speakers we wanted to use a piece of denim. We will lasercut a square (10cm x 10cm) and inside the square we are going to sew the coil that is also a square but turned 45 degrees.

The coil that I am going to make will be made of steel conductive wire

This is how the steel conductive wire looks like. Picture: Andrei Motian

Beforehand I did not measure exactly how much resistance the wire had because I wanted to solve it later. I wasn't sure yet how many centimers i actually need.

IIn Illustrator I made a design for laser cutting on a piece of denim. I have experience with the laser cutter, but since it was my first time to do this on a piece of denim, I asked a supervisor from the Makerslab if it was possible.

There was no preset for denim on the lasercutter and it worked out by using the presets from cotton. Because this was a preset i do not know what the actual settings are for lasercutting cotton and denim.

Make sure to save the file as an Illustrator 8 file for lasercutting.

The design I've made in Illustrator. Picture: Andrei Motian.

The link for the Illustrator file: https://drive.google.com/file/d/1VxzwrsgKnVtR5iwDGME11UZh4vQVc9_9/view?usp=sharing

Preparing the file for lasercutting. Picture: Andrei Motian.

I've marked the outline with red and the inside where the coil is going to be black. I did this because the lasercutter will cut out the red lines and the black lines are going to be dotted.

I have setted the dotted line 4mm apart from eachother.

Preparing the piece of denim inside the lasercutter. Picture: Andrei Motian

The lasercutter does its job. Picture: Andrei Motian.

Now I will embroider the pattern with the thread that will guide the current. In the beginning I often had to look back at the design so that I would not get stuck in the wrong place.

Preparing the denim, thread and needle. Picture: Andrei Motian.

Here I am halfway and start to follow the dots to the outside again. Picture: Andrei Motian.

Here I was done with the embroidery part. Picture: Andrei Motian

This was the hardest and most frustrating part for me because I stabbed myself in my fingers a few times, sometimes, I was tied up a few times and also broke the thread a couple of times, so I had to pull the thread through the entire denim again that I had enough thread to continue sewing.

Now I am going to see with a multimeter how much ohm it will indicate. For the assignment I want to be between 4 and 8 ohm.

The multimeter indicates 64,6 ohm. Picture: Andrei Motian

The multimeter indicates 64.6 ohms. That is too much resistance and I have to think of a way to solve this so that it has less resistance. Loes Bogers told me that if I made the wires thicker, it could conduct more current, so that the resistance would also be lower. Instead of taking the whole thread out and starting over with a thikker thread i'm going to sew a new layer of thread on top of the current one. It might work but I don't know for sure yet.

Here I'm sewing the second layer on top of the first one. Picture: Andrei Motian

This went much faster because I only had to follow the first thread. When I was completely done again I tested it again with a multimeter to see how much ohm it would indicate.

The multimeter indicates 15,7 ohm. Picture: Kai

With the 2nd layer that I have embroidered, the multimeter indicates 15.7 ohms. My plan worked out and this would also be enough to be able to hear something if I connect it to the amplifier and hold it above a cup according to Kai.

Testing the speaker on a red cup with some assistance from Kaz. Picture: Andrei Motian

I connected the denim with the amplifier and tested with magnets if I could hear music. Connect the crododile wires from the amplifier with the thread on the denim. Do that on the two sides where you've cut the thread on the denim. Connect the jack plug to a telephone of laptop with music and make sure to turn the volume all the way up.

It worked and there was music, you could only hear it if you keep your ear next to the cup.

The end result. Picture: Andrei Motian

I did not manage to get between 4 and 8 ohms for the assignment. I didn't have enough time to embroider a third layer on the denim. Hereby the resistance would be lower because the wire is thicker and provide more current so the music coud be heard louder.

An application as wearable for a soft speaker could be in a beanie. You wear it on your head and the music is played in your ears.

Sketch for an application for the speaker inside a beanie. Picture & sketch: Andrei Motian