How to Build Your Own Bluetooth Speaker for Under $20

Introduction

Building your own Bluetooth speaker can be a fun and rewarding project. With just a few inexpensive parts, you can make a speaker that sounds great and works wirelessly with your smartphone, tablet or laptop. In this guide, I'll walk you through the entire process step-by-step.

What You'll Need

To build a Bluetooth speaker for under $20, you'll need just a few basic components:

Amplifier board - This is the brains of the speaker, taking the audio signal and amplifying it. You can find small, inexpensive amp boards for just a few dollars.
Speaker driver - The part that actually produces the sound. I recommend a compact 3-4 inch driver.
Battery - A rechargeable lithium-ion battery will allow the speaker to play wirelessly.Aim for at least 2000mAh capacity.
Enclosure - Any plastic box or enclosure that fits your components will work. Measure first!
Wires, switches, connectors - For connecting the components together.
Decorative materials (optional) - To customize the look of your speaker.

That's it! With just these few parts, you can build a speaker to be proud of. Now let's get started with the steps.

Step 1: Assemble the Amplifier Board

The amplifier board is the central component that will receive the audio signal over Bluetooth and amplify it to drive the speaker.

First, solder the input and output wires to the amp board. Red and black wires work well for polarity.
Next, solder on header pins or a JST connector to attach the battery's power wires.
Finally, connect the speaker wires to the output terminals, taking note of polarity.

Test the amp board with a battery to make sure the connections are good before moving to the next steps.

Step 2: Mount the Speaker Driver

Now we need to securely install the speaker driver into the enclosure we've selected.

First, cut out a hole in your plastic enclosure to mount the speaker. Make sure to leave clearance behind it.
Connect the speaker wires from the amp board to the speaker driver's terminals. Observe polarity.
Mount the speaker into the hole you've cut using hot glue or screws through the mounting holes.
For best sound, make sure the rear of the speaker is separated from the amplifier components.

Step 3: Add Battery and Controls

To make your Bluetooth speaker wireless and portable, we need to install a rechargeable battery and basic controls.

Pick a spot for your battery and secure it with hot glue or velcro. Connect the power wires to the amp board.
Add a power switch by wiring it in between the battery and amp board.
A charging port like micro USB can be wired to the battery to recharge it.
Optional: Add volume buttons, a bass boost circuit or an LED power indicator.

Step 4: Connect Bluetooth

Now for the final step - making your speaker wireless with Bluetooth!

Many amp boards have a built-in Bluetooth module. If not, you can add one.
Pair your phone to the Bluetooth module to test the wireless functionality.
Make any needed adjustments to the amp volume and audio quality.
If range needs improving, attach an external Bluetooth antenna.

Once Bluetooth is operational, your DIY wireless speaker is complete! Bring your music to life anywhere with this budget-friendly project.

Customizing Your Build

Here are some ideas if you want to take your speaker to the next level:

Add colorful LED lights that pulse and react to the music.
Experiment with different enclosure shapes and sizes for unique looks.
Install a carry handle or mounting strap for portability.
Add a cloth covering or paint the enclosure for custom styles.
Upgrade to higher wattage amp boards and speaker drivers for more volume.
Try chaining together multiple speakers for stereo separation.

So grab your tools and parts, and let's get building! Constructing your own Bluetooth speaker is an enjoyable way to learn useful maker skills. Whether you're looking to save money or just want a customizable audio gadget, this project won't disappoint. The end result will be a wireless speaker you can use and showoff for years to come.