A Simple DIY Bluetooth Speaker - Complete Build Instructions

I've been wanting to build my own Bluetooth speaker for a while now, and I finally did it using some really cheap components I found online. It actually sounds pretty good. No fancy case or battery pack yet, but it works great plugged into a USB charger. Let me show you how I put this together.

Here's everything I used for this build:

1. JDY-62 Bluetooth module - This little board handles all the Bluetooth 4.2 stuff and outputs audio
2. PAM8403 amplifier board - A tiny stereo amp that runs on 5V
3. Two 2-watt 8-ohm speakers - Any small speakers in this range work fine
4. 22-24 AWG wire for signal connections
5. 18-20 AWG wire for the speakers (thicker is better here)
6. Soldering iron and solder
7. 5V power supply - I used an old phone charger

The JDY-62 and PAM8403 boards are super common and cheap. You can grab both online for pretty affordable prices. The speakers were the most expensive part for me, but you could salvage these from old electronics too.

Before jumping into wiring, let me quickly explain what each part does. The JDY-62 is your Bluetooth receiver. When you pair your phone to it, it outputs audio on two pins - one for left channel, one for right. But this audio signal is really weak, way too quiet to drive speakers directly. That's where the PAM8403 comes in. It's a Class-D amplifier that boosts that weak signal enough to actually move the speaker cones.

The JDY-62 has four pins you care about:

1. VCC goes to 5V
2. GND goes to ground
3. L OUT is your left audio channel
4. R OUT is your right audio channel

The PAM8403 has a few more connections:

1. VCC to 5V
2. GND to ground
3. L IN connects to the Bluetooth module's left output
4. R IN connects to the Bluetooth module's right output
5. L OUT goes to your left speaker
6. R OUT goes to your right speaker

Some PAM8403 boards have volume pots already on them, which is really handy. Mine did, so I could adjust volume without needing my phone.

I started by laying out all my components on the workbench to plan the wire routing. Here's how I connected everything.

Power connections first. I cut two pieces of red wire and two pieces of black wire, each about 3 inches long. I soldered the red wires to the VCC pins on both the JDY-62 and the PAM8403, then twisted them together and connected them to the positive terminal of my 5V supply. Same deal with the black wires to GND - soldered to both boards, twisted together, connected to negative.

Make sure these solder joints are solid. A cold solder joint on the power lines will cause all kinds of weird problems like crackling audio or the modules randomly disconnecting. Heat the pad first, then add solder, then add the wire and let it flow.

Audio signal connections. This is where things get a bit fiddly because the wires are small. I used 24 AWG wire for these. Cut two pieces about 2 inches long. Solder one wire from the L OUT pad on the JDY-62 to the L IN pad on the PAM8403. Solder the other from R OUT to R IN.

Keep these wires as short as you can while still being comfortable to work with. Long audio wires can pick up interference, which shows up as hum or buzz in your speakers.

Speaker connections. The speakers were easy. Most small speakers like this have two terminals or two wires coming off them. Polarity technically matters for speakers (so they're in phase with each other), but honestly at this power level you probably won't notice if you get it backwards.

I soldered wires from the L OUT terminals on the PAM8403 to my left speaker, and R OUT to my right speaker. Used thicker 18 AWG wire here because speakers draw more current than the signal lines. Strip about 1/4 inch of insulation, tin the wire with solder, then attach it to the speaker terminals.

If your speakers just have wire leads instead of terminals, twist the wires together and solder them. Cover the connection with heat shrink tubing if you have it.

Before buttoning everything up, I wanted to make sure it actually worked. I plugged in my 5V power supply and watched for the LED on the JDY-62 to start blinking. That blinking means it's in pairing mode and ready to connect.

I grabbed my phone, went into Bluetooth settings, and looked for "JDY-62" in the available devices list. Tapped it, and it connected immediately. The LED on the module went from blinking to solid, which means it paired successfully.

Then I opened Spotify and hit play on a song. Sound came out of both speakers right away. It wasn't super loud, but it was clear and had decent stereo separation. I messed with the volume pot on the amplifier board and could control the loudness from barely audible to reasonably loud.

No sound at all. First time I powered it up, I got nothing. Turned out I had the L IN and R IN wires swapped with each other. They were connected to the wrong channels. Once I fixed that, it worked fine. Also double-check that your amplifier is actually getting power - some PAM8403 boards have a tiny power LED that should light up.

Only one speaker working. This happened when I accidentally broke one of the thin signal wires while moving things around. Resoldered it and both channels came back. If only one speaker works, check the solder joints on both the audio input side (JDY-62 to PAM8403) and the output side (PAM8403 to speaker).

Crackling or distortion. Usually this means you're pushing the amplifier too hard. Turn down the volume on both your phone and the pot on the amplifier. The PAM8403 can only put out about 3 watts per channel at 5V, so if you crank everything to max it'll distort. Also check your power supply - if it can't deliver enough current (aim for at least 2A), you'll get distortion when the volume is up.

Won't pair with my phone. The JDY-62 should go into pairing mode automatically when powered on. If it doesn't show up, try power cycling it. If it still won't pair, make sure you don't have it connected to another device already - it can only pair with one thing at a time. Also some older phones don't support Bluetooth 4.2, though that's pretty rare now.

This basic build sounds okay, but there's a lot of room for improvement. The biggest limitation is volume - the PAM8403 running at 5V just doesn't have much power. If you want it louder, you could upgrade to a PAM8610 board and run it at 12V instead. That'll give you 10 watts per channel, which is a huge difference. You'll need a beefier power supply though, something that can do 12V at 3A.

Better speakers help too. These little 2-watt jobs are fine for a desk setup, but 5-watt or 10-watt speakers will give you better bass and overall sound quality. Just make sure the impedance matches - stick with 4 or 8 ohm speakers. And bigger speaker drivers (40mm to 100mm diameter) move more air, which means better bass response.

The other thing that makes a massive difference is building an enclosure. Right now my speakers are just sitting on the desk, and a lot of the sound is canceling itself out because the front and back of the speaker cone are producing opposite waves. A simple sealed box for each speaker fixes this and makes the bass way punchier. You don't need anything fancy - even a cardboard box helps. For a more permanent solution, cut some MDF or plywood and build proper enclosures sized to your speaker specs.

Adding a battery would make this truly portable. A USB power bank works great since this whole thing runs on 5V. Get one rated for at least 10,000mAh and it'll play for hours. You could also use 18650 lithium cells with a charging circuit if you want to get fancy.

One last thing - if you want this to automatically reconnect to your phone, the JDY-62 will remember the last device it paired with. So after the first pairing, it'll connect automatically whenever it's powered on and your phone is nearby with Bluetooth on. Pretty convenient for a daily-use speaker.

This DIY Bluetooth speaker project that cost barely anything and taught me a lot about audio circuits. The speaker won't blow anyone away with its sound quality or volume, but for background music at a desk or workbench it's perfect. And there's something satisfying about using a speaker you built yourself instead of buying one.

If you've never done a project like this before, this is a great place to start. The circuit is simple, the components are cheap, and you don't need any programming or complicated tools. Just a soldering iron and some wire. And once you've got the basics working, you can keep improving it - better amp, bigger speakers, a nice wooden case, battery power, whatever you want.

The whole build took me maybe an hour including testing and fixing my mistakes. Most of that was just careful soldering and making sure the connections were solid. If you want to build something similar, grab the components and give it a shot. You'll have a working Bluetooth speaker by the end of the day.