Introduction: DIY Bluetooth Speaker
I have an old DVD home theater set that i use only for listening to music from my cell phone. Unfortunately, a few months ago, the DVD Player of that set was stolen by the thief and the subwoofer has become rat nest, but i still got 4 fully functional satellite speakers. So in this instructables, i decide to make a bluetooth speaker using the remaining satellite speaker drivers.
Step 1: Drivers
The driver that i got was 2 inch 4 Ohm 10 Watt speaker with double magnet rings. Hmm, looks promising...
Step 2: Components
All components I used :
- PAM8403 2x3W Class D Amplifier Board for power amplifier, powered by 5V DC. It's ideal to use 10W amplifier board based on the speaker's spec, but I only had this, so I used it.
- Bluetooth Audio Module, also powered by 5V DC.
- 3x1500 mAh 18650 lithium batteries, connected in parallel. Batteries connected in parallel don't need Battery Management System board (BMS).
- TP4056 1A Lithium Battery Charger Module.
- 2A Boost Step Up Module, for boosting voltage from battery pack (4.2V) to 5V for powering the amplifier and bluetooth board.
- Passive Radiator. Similar to speaker but without coil. I use 2 x 2 inches passive radiator.
- A Switch.
Step 3: Case/Enclosure
I used 200 x 120 x 75 mm plastic waterproof outdoor enclosure. Drilled according to the size of the drivers and passive radiators.
Step 4: Connection
The setup is quite simple. The key connection is :
- The voltage from the battery (3.7V - 4.2V) is boosted by boost module to 5V through the switch. The boost module gives power (5V) to both bluetooth audio module and the amplifier board.
- The TP4056 Charger module charges the battery through the built-in micro-USB Port. The positive lead on the battery is connected to B+ on the charger module, same with negative lead.
- The audio signal from Bluetooth Audio Module output is connected to the amplifier board's input (Right (R), Left (L), and Ground (G).
- The two speakers is connected to the output of the amplifier board. Mind the right polarity of the amplifier and the speakers, otherwise, both speaker will produce the opposite phase and the bass quality will be very poor.
-The switch is connected between battery and the boost module so if the switch is off, all the module will not powered, so there is no part consumes the battery power.
Step 5: Assembly
Now it's time to put all the components into the enclosure.
I glued the passive radiator directly to the enclosure using all-purpose glue.
For the speakers, I used bolts and nuts.
The switch can be screwed to the case.
The charging port (built in with the charger module) is secured with hot glue.
And all the remaining components is secured to the case by thick foamed double sided tape.
Make sure the enclosure is air tight (there is no air leak through the bolts or switch). If there is no leak, passive radiators will work perfectly.
Step 6: Testing
Here is the video of making this bluetooth speaker (in Indonesian language (Bahasa)).
Skip to 8:31 for testing section
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