Abhay and Akshay here!
Today we are going to make a speaker using PAM8403 Audio Amplifier that is powered using 18650 Lithium batteries and can be connected to audio source using AUX connection. It outputs a good bass and sounds very clear as well as punchy.
So now let's make this build.
You can scroll down and follow the steps or just watch this video for it.
The list of the components needed -
- 2 x Speaker drivers (4 ohm) - https://amzn.to/2IMyiUV
- 1 x 100K ohm Potentiometer - https://amzn.to/2xc57UH
- 2 x 1uF Capacitors - https://amzn.to/2xc57UH
- 1 x PAM8403 Audio Module - https://amzn.to/2xc57UH
- 1 x TP4056 Charging Board - https://amzn.to/2xc57UH
- 1 x Switch - https://amzn.to/2xc57UH
- 1 x 18650 Lithium Cell - https://amzn.to/2xc57UH
- 2 x 1 ohm Resistors - https://amzn.to/2xc57UH
- Shielded Wire - https://amzn.to/2xc57UH
- 1 x AUX Male Audio Port - https://amzn.to/2xc57UH
- MDF Board/ Any other preferable case material - https://amzn.to/2xc57UH
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Step 1: Cut Some MDF to Form the Case for the Speaker
If you are wondering about the dimensions of the speaker, we roughly created three 15*15 cm^2 squares and two 15 side length equilateral triangles. Then we just marked one square into four equal pieces and cut speaker holes in them. You also need to design and cut holes for charging port as well as an On/Off switch.
Step 2: Hot Glue the Speaker Drivers in Their Place With All Other Components
Then take the case pieces and hot glue the speaker drivers as well as all other components in the case. We initially thought to add a potentiometer for volume control but afterwards thought it to be lame as for a wired speaker as you can always control the volume from your respective device and therefore removed it.
Step 3: Solder the Wires to Everything and Complete the Circuit
The amplification IC that we are using is PAM8403 as it is a cheap yet powerful speaker driver. It outputs 2*3W output at a very low distortion rate. In the initial prototyping we found out that speakers of 4 ohm impedance suits better.
We are using two 8 ohm 1.5W speakers in parallel to create a 4 ohm output of 3W each for left and right. If you don't have 4 ohm speakers or too many 8 ohm ones, you can use single 8 ohm ones but remind that the speakers will sound a little less loud and punchy. We also soldered a 1uF capacitor in parallel to the speaker outputs which creates a low pass filter that lets only the frequencies lesser than 16 KHz pass. If you don't have 1uF cap or need to cap another level of frequency check out the formula here ( circuit can be found here ). More information on how to make RC Low Pass Filters can be found in these links below--
Step 4: Hot Glue the Case
Now after you have completed the circuit ( it's easy to make and if you have any problems shoot us with them in the comments section ), hot glue the case in its place. Then carefully take help from your colleague/friend, to hold the sides while you hot glue them. Then carefully also hot glue the triangle sides to the body.
Step 5: Cover the Whole Case With Newspaper and Then Fabric
After making sure everything is hot glued and rigid and the circuit works, we covered the speaker with newspaper and then a black piece of cloth. Make sure that the speaker drivers are not covered with newspaper but with only fabric.