DIY Bluetooth Speaker

Hello everybody

In this instructable I m gonna show you how to make a simple good-looking (and good sounding) Bluetooth speaker. I made a few speakers in the past but in this one, I made my own speaker box as well (I didn't use an existing box to put an amplifier and speaker in). And since this is a Sticky Stuff Speed Challenge I used glue to put the box together so no screws were used in this project.

This project isn't all that hard so you don't need some mad woodworking and electronic skills to make this, but I would recommend you a lot of patience. As I mentioned before that no screws were used in this project which means that the whole box is held together by glue. So for best results leave epoxy to set properly. And when epoxy sets it makes a great bond (no surprise there) so don't be fooled the box is pretty sturdy and strong. If you want to make things easier for yourself use a premade box, but if you wanna go full DIY then make your own. To make the box I used MDF (Medium-Density Fiberboard), MDF is a very dense and thick material and as such, it is pretty popular for making speaker boxes. One more benefit of using MDF is that it is easy to cut or file making it ideal for this project.

Supplies

Bluetooth module

Audio amplifier board

Li-ion battery ( and protection/charging board)

Switch

Charging connector

1 x red LED

1 x green LED

1 x yellow LED

2 x 1k ohm resistors

1 10k ohm resistor

Wire

Carbon foil vinyl wrap

MDF tiles (7,5 cm x 5,5 cm x 0,3 cm)

Epoxy

Hot glue

Tools : Soldering iron, drill, Dremel, hot glue gun, saw file pliers utility knife.

Choosing Material for a Speaker Box

A few months ago I got myself a few of these MDF tiles (7,5 cm x 5,5 cm x 0,3 cm), they were sitting on my shelf collecting dust until I decided to use them for a project.

Skip this step If you are using a premade box.

Making Speaker Hole

It is better to make a speaker hole before assembling the box.

To start trace the outline of your speaker on one of those tiles that you are using, then drill a few holes to remove a lot of excess material, and then use Dremel tool (or files) to complete the hole The diameter of a speaker that I used here is 4,5 cm.

Gluing the Box Together 1/3

To start I first glued two sides together, plan was to make a box, then put all electronics in place, and then finish the box.

I was gluing my tiles side by side, which means that I glue two of those together and then add one by one. See the photos below for it to make more sense.

Glueing the Box Together 2/3 (almost Completing the Box)

Leave one side of the box open, so that you can put electronics in place.

Electronics 1/2

Start with Bluetooth module (the one that I used here had breadboard pins which I desoldered), convert stereo to mono (because one speaker is used in this project), and to do so solder one end of 1k ohm resistor to R (Right channel), and one end of other 1k ohm resistors to L (left channel) then twist two other ends of 1k ohm resistors together (these will go on the input of the amplifier).

I added a 10k ohm resistor in series with two 1k ohm resistors so that the amplifier wouldn't overload the speaker. + side of the battery goes to the 5v input on Bluetooth and amplifier board, GND points are connected. The speaker goes to amplifier output contact points. I additionally added an indication 3mm yellow LED to know when the device is turned on (LED + goes onto LED contact point on Bluetooth decoder board and – to ground).

Electronics 2/2

To have indication lights when the battery is charged I had to modify the Li-Ion protection board.

To do so I desoldered two small LED-s and I soldered 3 wires 1 red 2 blue (three wires because both LED anodes are on the same potential which means that they are connected. Then connect battery minus to BAT-, and battery + to BAT+. That is it for the Li-ion protection board.