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Hello everyone , so in this instructable I will be showing you guys how I built this simple boombox using plywood by means of a few handheld electric tools.Building speakers as well as other small projects which I could actually use in my day to day life has always been my passion and kind of like a hobby as well.We all love that feeling which we get when we get to tell others " Yeah, I made that " ;-) .

So this is a really simple boom box that is entirely made out of plywood and MDF board. It took me 9 days to built as I only had limited tools.This boom box has 4 speakers - two subwoofers and two tweeters which gives out a total of 30 watts of power. I have used 2 different kinds of tweeters- a silk diaphragm as well as a piezo electric one.I decided to do this because I realised that the piezo tweeter covered the really high frequency notes better than the silk diaphragm tweeter.

The boombox is designed with dual rear facing passive radiators .Passive radiators acts as a substitute for bass ports.They take up less space inside the enclosure as compared to bass ports and prevents vent airflow noises as well.But what I love about them the most is to see them vibrate when the bass hits which makes the whole boombox look a lot cooler ;-) .

The boombox runs on a 12.6 volt ,3S 2600mah 18650 battery pack which gives upto 6 hours of playtime depending on the volume.You guys could use NCR 3400 mah 18650 cells for longer play time.

The boombox supports FM,USB, bluetooth,SD ,AUX and also comes with an IR remote and on-speaker buttons for easy music control and tuning.


I ordered almost all of my components from AliExpress.Most components are cheaper there but it might take upto a month or two to arrive at your place according to where you live .

1. YAMAHA TA2024 Amplifier X 1:

TA2024 is a special class T amplifier.And whats special about class T amplifier is that it offer both the audio fidelity of a Class-AB and the power efficiency of a Class-D amplifiers.Its a15 watts per channel amplifier when its running on 4 ohms load . I have used this amplifier before on an other project and was impressed by the fact that it dosn't heat up as much as other amplifiers with the same specifications, so thats why I decided to use this amp for this project.

2. 3 inch ,15 watt sub Woofers X 2:

Always choose a speaker whose impedance matches with the amplifier that you are using so that you wont face any heating issue with the amplifier.Here I have chosen a pair of 3 inch ,4 ohms woofers which according to the datasheet of the amplifier will be aperfect match.

3. DC-DC step down Buck converter X 1:

This is a module that uses the principle of switching to very efficiently step down the voltage.It is by every way better and way more efficient that any voltage regulator ICs like IC7805 . Our project needs it because we are using a 12.6 volt battery to power a 5volt audio decoder.So we need it to stepdown 12.6 volts to 5 volts.

4. Passive radiators (60X90mm) X 2

Passive radiators are a substitute for reflex or bass ports. Usually for small enclosures,production of low frequency requires a long port ,so passive radiators are used instead.Passive radiators also avoids air flow noises which usually occurs in ported speakers.The main factor affecting the performance of a passive radiator based speaker is the mass of the metal plate on the radiator . The mass should be varied for tuning.When using woofers , always try to go for a passive radiator that is the same size or bigger than the speaker(not too big).In this project I have chosen a rectangular passive radiator which I decided to place on the back of the boombox.

5. 3S 12V 18650 10A BMS X 1

A BMS (Battery Management System) is very important when connecting rechargeable batteries in series.The BMS makes sure that all the batteries are charged and discharged equally.It makes sure the same amount of current is drawn from all the batteries when in use.A BMS also limits the maximum current that can be drawn from the battery pack so that the cells wont be overloaded.The BMS dosn't have a voltage regulator , so its really important that you use a 12.6 volt charger when charging the battery pack.

6. Frequency Crossover X 2 :

A crossover usually has an Inductor (copper coil) of thick wires and a series of capacitors.So a cross over has 1 input and 2 outputs. The inductor blocks the high frequencies.The output from the inductor is given to the subwoofers. The capacitor blocks the low frequencies .So the high frequency output from the capacitor is given to the tweeters.The tweeters could blow up if the output from the amplifier is directly connected to the tweeters without the capacitor stage.

7. 12.6 volt Charger(2.1 mm pin) X 1:.

For charging the battery BMS system

8. XL6009 DC Adjustable Step up boostconverter X 1:

This module also works on the principle of switching.Its a step up module.Here we are using it so that we get a constant 12.6 volt at the amplifier's power input even when the battery voltage goes below 12.6V

9. Tweeters X 2:

The tweeters cover the all high frequency notes in music. Here we are using a piezo electric as well as a magnetic silk diaphragm tweeters.I tried different combinations and I was most satisfied when I used both at the same time.Always make sure yoy are using a filter capacitor or a crossover brfore using a tweeter.

10. DC Jack(2.1 mm) X 1:

For the charging port

11. Bluetooth Audio Decoder X 1:

For getting input from different sources like USB,AUX,FM,Bluetooth ,SD etc

12. 18650 battery(capacity of your choise) X 3:

Our power house.There are 1000s of different manufacturers for 18650 cells . Be sure to get one from a good manufacturers . 18650 cells could get dangerous if it has defects and not charged properly.I have attached the links of two types which I have personally bought and found that its good and safe.

13. DC toggle Switch X 1:

14. Connecting wires

15. 4000uf (or higher) , 16 volt capacitor

16. Wood glue

17. Spray Varnish

18. Wood sealer

19. Sand paper

20. 3mm LEDs

21. Thick double sided padding tape

22. All the necessary screws

23. 18 mm plywood sheets.

24. 5mm plywood

25. M3 and M4 nuts and bolts

comatlinc3 months ago
I ljke ur procedure
comatlinc3 months ago
Pls after u ran the taste, does the speaker produced good bass quality and can fill a room?
dshydro11 months ago

In the supply list the tweeters are the same but in the assembly photos they look different. Why is that? This thing is really cool and I want one! Thanks.

patrick panikulam (author)  dshydro11 months ago
I just swapped one of the tweeters with a piezoelectric tweeter . The other one is the same as in the supply list . I have mentioned why I did this in the introduction and also among one of the comments .
The different tweeter I used is just a low cost automobile tweeter which is awailable almost in any automobile accessories shop . So you won't have any trouble finding those

A masterpiece in itself great!!!!!

Thankyou so much :-)
Gadisha11 months ago

I like the way it looks, also interesting to see how you build it, thanks!

patrick panikulam (author)  Gadisha11 months ago
Thankyou :-)
ToddW_0011 months ago

Just curious, what's the total amp draw off the batteries and how much run time do you get?

patrick panikulam (author)  ToddW_0011 months ago
Not sure about the current drawn .
But I am getting 4 to 6 hours of play time depending upon the type of music and volume.
AspireS311 months ago
What is the purpose of 4700mf capacitor.. And crossover?
patrick panikulam (author)  AspireS311 months ago
The boost converter works on switching principle. So the output actually switches really rapidly , so a capacitor is added to supply energy during this "off" period . They have already provided a small SMD capacitor on the boost module , but is is always a good practice to add an external one with heavy loads

The crossover seperates the amplifier output into high and low frequency channels . Which means it has 1 input and 2 outputs . One of the outputs (high frequency) goes to the tweeters and the other (low frequency) goes to the woofers . You could damage the tweeters if the output from the amplifier is directly connected to the tweeters without a crossover or a filter capacitor in between .
Alex in NZ11 months ago

This looks really good. Thank you for sharing :-)

patrick panikulam (author)  Alex in NZ11 months ago
gm28011 months ago

Nice design and execution. I see you used Aliexpress for most of your parts including the speakers. Have you ever looked at Parts Express? The sell tons of quality speakers with all the data of each speaker one could ask for. I built shop speakers using their products and they sound amazing. Your wood box enclosure looks very nice. Have you disconnected one of the tweeters at a time to see if you could hear any difference? Just wondering.

patrick panikulam (author)  gm28011 months ago
I am from India , so I guess the parts would get really expensive once the shipping charges are added if I order stuff through parts express

And yup , first I used 2 magnetic tweeters , but I was not satisfied.So before finally closing everything up ,I just swapped one of the magnetic tweeter with a piezoelectric one . And There was a huge difference . Usually magnetic tweeters are the best , but I don't know what happened in this case , I guess the ones I had was not of good quality.