In this tutorial we will be building a simple boombox speaker that plays loud music and has great quality.
To build this speaker , the materials you will need are as follows:
LM386 (low power audio amplifier)
10 kohm potentiometer
10 ohm resistor
2 x 10 µF capacitor
0.05 µF (or 0.1 µF) capacitor
250 µF capacitor
2 x 5 ohm speakers
1 PCB from https://www.pcbway.com/
To obtain your parts first you will need to design and order your PCB. Luckily i have done all the designing already so you can simply use my design
Once you have downloaded the Gerber file from the google drives link , you can order your PCB from pcbway.com
To order the board you will first need to enter the dimensions of the board and the amount you would like and select the quote now button. If you are using the design i provided, simply copy the information used in the picture below.
After pressing order now, it will take you to the page in the picture below. You have the option to choose various specifications. Everything should be auto filled correctly if you entered the correct information in the previous step so there is no need to change anything in this step. Simply enter your email address, choose your shipping method and press add to cart.
The next step simply asks you to upload your gerber file. Download the gerber file here and upload it where it says add gerber file. After this, it will prompt you for payment information and your address and then the pcb will be on its way.
Once the pcbs arrive you also need to get the other materials to start building the project. To make a loud speaker all we need to do is build an amplifier to amplify the music signal coming from your phone or laptop. The signal will need to amplified around 100x so that the signal will have a large enough amplitude to play music loud. The parts in the picture below are all it takes to build our amplifier circuit. the 8 pinned integrated circuit chip is an operational amplifier and it amplifies a signal based on the relationship between impedance at the input and impedance at the output. Impedance is a combined resistance and capacitance, therefore all we need is a large resistor and capacitor at the input of op amp and a small resistor and capacitor at the output. We also need 2 more capacitors to filter out DC components at the input and output. Below is all the parts you will need as well as a schematic of the design
The PCB has the indicators to where each part goes. Put the capacitors and resistors in their respective places and solder them in. Capacitors only work if the polarity is correct. Be sure to refer to the pcb to see if the polarity of the capacitor is correct.
Now we need a power source to power our Op Amp. For that i attach a 9v battery clip to the + and – of the Pcb. we will also add in a variable resistor to be used as volume control. We also need to provide the amplifier with an input signal to amplify. That input signal will come from the auxiliary port that we attach to it To finish off We will also add the 2 speakers to the output of the board
The speaker is now done and can be tested. To finish the project off, we will need to create a case. Our case will be made of cardboard. This step is a flexible part of the project so i encorage you to be creative and make the case out of anything you would like and experiment what type of case would provide the best sound quality.
To finish off we will simply mount all of the electronics in the case and add a back to it. The speaker can now be tested out. To use it, plug in a battery, plug in an AUX cable to the speaker and connect it tou the device that will be playing music. The variable resistor can be used to change the volume of the music. The speakers had amazing quality and can be heard in this video
