3D PRINTED BLUETOOTH SPEAKER
APRIL 2021

For my individual discovery project, the outcome was not always clear in my mind. What I knew is that I wanted to create something useful. As an amateur DJ, I first wanted to build a mixer. After outlaying the general steps, I decided that it was too complicated and demanding for this course. I finally decided that I wanted to build a Bluetooth speaker from scratch, mostly because I needed one. After researching about the project, I found that I would need skills in 3d printing, laser cutting, soldering, as well as some basic circuit design. Achieving the project would require walking through many steps, and therefore, in order to facilitate the flow of operations, I came up with a checklist of what I needed to do, and I set to myself deadlines. I first needed to check that I could find all the resources I needed on campus. From 3D printing and laser cutting at the Invention studio, to soldering at the Hive, everything was ready for me. After 3D printing the body of the speaker in PLA using Cura3 on a FDM printer, I designed the wooden side panels using JobControl X and laser-cut them on the Trotec Speedy 400. Parts I needed for the circuit are an 8 ohm 3.3’’ full range speaker, an amplifier, a Bluetooth board a power supply, and a step-down converter. I was generously offered a 12V power supply at the Hive, as well as a step-down converter that would convert the 12V of the supply to the 5V needed for the Bluetooth board (which I ordered online). I also ordered an “Adafruit” 3” diameter, 8-ohm speaker, a TPA3116 D2 Dual channel audio amplifier, as well as a Bluetooth amplifier module online. Once the body, side panels, and electronic parts were ready, I only needed to assemble everything. First, I started with the soldering. I encountered some difficulties with the Bluetooth board, since it required precise work and it was my first-time soldering. At the end I was however able to properly wire the components. I was very lucky that everything worked from the first try: I plugged the power supply, the amplifier and Bluetooth board turned on, and I was able to connect my phone and play music. At this point, before placing the electronics inside the body, I needed to isolate some parts of the circuit: I did so by using electric tape. After testing the circuit one last time, it was time to put it inside the speaker body. Using hot glue, I fixed the Bluetooth board, amplifier module and step-down converter at the back of the body. I also screwed the driver, or speaker at the front, and glued the side panels. It was now time to test the performance of the speaker. I noticed that for songs with low levels of bass, like the guitar intro in “Snow” by Red Hot Chili Peppers, the sound quality is great, even at maximum volume. However, when I played “What’s The Difference” by Dr. Dre, at high volumes the quality of the sound was lost. We can attribute this poor performance to the poor quality of driver that I used: it cost me $4. We can expect a much better experience with a $15 driver of the same size, which I am considering to use. All in all, this project was one of the most fun I came up with, since it allowed me not only to learn a lot in 3d printing, design, laser cutting, soldering, but also to discover my campus. I also got a Bluetooth speaker for less than 10$ at the end.