Portable Bluetooth Speaker (From Old Car Speakers) for $10-20

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Recently, we had noticed a couple problems with the bass speakers in our car. We went ahead ordered a new pair and replaced them. About to throw the old speakers away, I realized all the potential they had. All that might have been wasted. I immediately took a chance and kept the speaker to myself. I wanted to make a surround sound like experience for my desk setup, only to soon realize the limitations of only having one speaker. Then it hit me, a Bluetooth speaker! That's what I would modify this into. That's what this would become.

Also, you may notice quite a few changes in speakers in this instructable (2 different speakers in total. All of them were from the car but I realized I preferred the silver ones over the black ones in the end as they were more lightweight.

THE SCIENCE:

A speaker in and of itself can not produce the amount of sound required for the average person to listen properly. Even high wattage speakers cannot be amplified loud enough. I would need an audio amplifier board to accomplish this. On top of that, we would also need to make this Bluetooth, in turn, we needed some sort of Bluetooth chip and compatible microcontroller. On top of that, we (or at least I) preferred this fairly lightweight speaker to be taken on the go with me. If it's wireless, why would I want to designate it to one room? I would need a portable power source. Finally, some sort of case to keep everything neat and tidy as well as add an element of aesthetics to my project. With all the planning out of the way, I got into the build.

Materials:

Speakers* (The amplifier is rated at 20-25 watts, perfect for the thirty-watt speakers in the car: When looking for amplifiers make sure to find one that is rated for your specific speaker's wattage)

9 V Battery with snap connector (This is only the snap connector, not the battery)

Audio amplifier with Bluetooth

DC plug

Wires

Cardboard box

Tools:

Soldering iron

Solder

*Unless you too are planning to rip out your car speakers for this project, I would suggest you buy speakers of your own.

Using a cardboard box is, admittedly, not the way I expected to put this project together. It was, however, the easiest, strongest, and most efficient way to do it. On top of that the cardboard box provided many benefits being as they are universal, and easy to mold to your own project.

You may notice the 2 different speakers. At this stage, I was experimenting as to which speaker I preferred.

1) Cut a hole (or square, or any shape really) big enough to be able to comfortably put your hand through on the bottom. This is meant purely if you need to fix anything up inside.

2) Cut a hole or 2 depending on the amount of speakers you have at the top. Smaller than the diameter of the speakers though. Just big enough to hold the speakers around the whole edge. Then hot glue your speakers to the cardboard for a tight fit.

3) Cut a square and insert the Bluetooth board on the outside. I would normally put it on the inside, tucked away, but since there are buttons and other useful features outside, I would leave them outside. T

4) Put the DC jack into the DC port on the amplifier. Don't attach the snap connector or the battery to it yet.

There are only 3 different parts (or if you are using 2 speakers, there would be 4 different parts) to this project. The speaker(s), the bluetooth audio amplifier, and the power source (9 V battery). First we would need to connect the speaker(s) to the audio amplifier.

1) Take 2 long strands of wire - I color coded mine (red for + and teal for -) and correspondingly connect them to the + and - on the speakers. Due to lack of solder I simply wrapped my wires around anything that required solder.

2) Put the speaker back into the hole we made for it, and notice the wires sticking out.

3) Now connect these 2 wires to the + and - on one of the speaker ports (the green terminals). The + to the + and the - to the -

4) Repeat the process for a 2nd speaker

You will notice that the DC jack has one long hooked-ish end, and one shorter stub.

1) Solder or wrap the positive wire of the snap connector to the shorter stub of the DC jack.

2) Solder or wrap the negative wire to the longer stub of the DC jack

3) Everything is now connected. The only thing left is to place the 9 V battery in place.

You will notice the amplifier start flashing Blue LED's if you did it correctly. You will also hear a noise from the speakers. It will signify that your circuit is working, and the speaker is on.

After this, we'll connect the speakers to Bluetooth on any device. Go to the Bluetooth settings on any device and you will notice a new thing pop up with the name "INSMA Audio". Add this and test something from your song library.

Your speaker is done. It is a portable - loaded with customizable features - Bluetooth speaker, made for less than 10$. (At least for me, considering I had most of the parts on me)

Check out my video below as well: The video and audio were recorded separately, but the audio is from the speaker.