You’ve all seen portable speakers becoming popular right now, but most of them are pretty expensive, so I’m going to show you how to make your own with a minimum of parts. It only takes 1 hour to build and test, and will run on any common USB charger. So, let’s get started!
Step 1: Get Parts and Tools
Required parts:
- Amplifier Circuit/Op Amp Circuit (I used a PAM8403 Class D 2 channel amplifier circuit.
- Project case or an old speaker with space inside for the circuit
- auxiliary cable
- some wires
- micro usb adapter (if you want to play with normal charger)
- Ordinary USB data cable
- required tools
- iron
- Solder wire
- hot glue stick
Step 2: Know the Circuit
The circuit is very simple; just connect two wires to the amplifier IC’s VCC 5V and ground pins. Connect one speaker to the +L -L channel output and the other to the +R -R output. These are the outputs for our speakers.
For the input to the amplifier, strip one end of an aux cable and carefully expose the three separate wires. To identify the ground wire, put the multimeter in continuity mode. Connect one lead to the ground pin and the other lead to the three wires one by one. The wire that produces sound is the ground wire. Now, carefully connect the wires.
Solder the ground wire to the ground input point, and the others to the left and right channel inputs (it doesn’t matter which input pin is connected to the left or right channel).
With our circuit now complete, test it using a 5V DC power supply for the input and play some music. If everything works well, it’s time to move on to the evaluation stage.
Step 3: Solder the Components Together
Solder the components following the described schematic.
Step 4: Place the Circuit in the Enclosure
In my case, the speaker enclosure itself served as the casing for my speakers. You can also employ differential calibration for your speakers. The approach you take will depend on your usage, but the underlying concept remains consistent.
Once you’ve soldered the circuit, carefully place everything inside the casing. Secure them in place using a glue gun or by applying hot glue with a soldering iron. Always remember to clean any excess solder right after using the hot glue stick.
Step 5: Adding a Power Supply
You can use this circuit directly with any standard 5V power supply or opt for a micro USB female adapter (as I did).
I salvaged a micro USB female jack from an old power bank and utilized its case for added durability (since it’s quite fragile).
To salvage an old power bank circuit, remove the battery and connect the +ve wires to the positive side of the power bank’s battery connector and the -ve wire to the negative side. I removed the battery to save space.
Step 6: Secure the Case
Now, securely close the speaker enclosure. If possible, use screws to seal the enclosure, as this will make any future troubleshooting easier.
Step 7: Testing
It’s time to test your creation. Plug it in, connect the AUX cable to your phone, iPod, or other device, and check if it works.
