DIY Amplified Speakers for Your MP3 Player

There are quite a few instructables out there on making your own speakers for your mp3 player... and most of them don't use an amplifier! Without an amplifier you will barely be able to hear the music coming out of the speakers.

Here I will show you how to make your own stero speakers with amplification!

Video here:
http://www.youtube.com/watch?v=C4d4_k0mwWo

Step 1: Gather Materials

Here are the materials used:

Cardboard box - used as speaker housing, you can choose something more elegant
Drill bits - used to drill some holes
Two speakers - I chose a pair of generic 8 ohm ones lying around
Soldering equipment
Hot glue

Here are the parts for the amplifier circuit:
1x protoboard
1x TDA2822M amplifier IC
2x 100uF capacitors
2x 470uF capacitors
2x 0.1uF capacitors
2x10K ohm resistors
2x 4.7 ohm resistors (I used 3.3K and it worked fine)
IC socket
Misc. connectors

Step 2: Build the Circuit

Next step is to build the circuit. I used a TDA2822M amplifier and the schematic shown in its datasheet. You can choose to build your circuit with whatever amplifier IC you choose.

Step 3: Build the Enclosure and Install Speakers

Now, put together whatever enclosure you want. I'm heading off to camp for 3 weeks tommorow, so I rushed and chose this... cardboard box!

Next I used hot glue to glue the two speakers in.

Step 4: Test

You need to make sure you've assembled everything correctly. So test out the speakers!

The amplifiers will work up to a voltage of 18v. For testing I connected a small 4.8 volt rechargable battery.

Step 5: Put It Together

Now that it works, put it together. I used hot glue and double sided foam tape to put everything together.

I used a drill bit to drill the hole for the audio in.

I changed the power system to 6 AA batteries in series, so that at camp I could just replace the AAs instead of bringing a battery charger.

Step 6: Drill That Hole

I'm no audio expert, but you need a hole in your speaker system to let the air out.

Step 7: Add a Bottom

Finally, I added a cardboard bottom.

Step 8: Done!

You're done!

Comments

[gerwing2]

Hi, I'm new in this DIY thing and I dont know if 1/4 or 1/2 watts should i buy for my capacitors and resistors. Can someone help me

[KevinS202]

Usually with electronic devices such as preamps/amps, you can get away with 1/4 Watt components. They don't draw much current.

[Cekpi7]

Where can i put potentiometer ?? instead of 10k or 4.7 ohm resistor?

[jaccon236]

you can put a 1K-10K potentiometer between each the left and right channel of the input cable putting either terminal 1 or 3 connected to the left or right input channel and putting the other terminal to ground while connecting terminal 2 to the input of the circuit. This would create the resistance bridge from the audio input straight to the circuit as long as you make sure to connect one potentiometer on each of the left and right channel and make sure that terminal 2 in the one connected to the rest of the circuit. You cannot replace the 10K or 4.7K resistors because those resistors are part of the actual amplifier circuit and would change the operation of and may even cause issues with the rest of the circuit and cause a short.

Keep in mind this way, that I did it, means you will have 2 potentiometers, one for each the left and right channel

[Cekpi7]

ive already placed potentiometer on that amplifier

But thanks for answering :D

[billbillbill]

How many Watts are your speakers?

[Cekpi7]

10W 4Ohm
But amplifier cant give more than 3W (or 5W) in bridged configuration

[billbillbill]

What Wattage are your speakers rated?

[Arcflash13800V]

My IC got overheated and fried after three songs. Was wondering if you had to add heat sink or fan to circuit?

[jijoy sam]

I want to know that how much volts are you using in the capacitors cause i bought 470uf of 16v and 100uf of 25v is it okay will it work please tell me how much volts you have used in the capacitors so i should replace them

[sipimanify.]

im a newbie in audio electronics so prepare for my Q.
what does that "capacitor to ground" doing at the VCC input ?
ty for your time :D

[Mlagma]

It's a decoupling capacitor. In this case it's doing two things. (1) Whenever you have a power line, you'll inevitably get noise (i.e. instead of getting, say, a nice 5V power rail, you'll get some random oscillations going above and below 5V). The decoupling capacitor filters this out by passing high frequency noise to ground and temporarily supplying power when the line drops below 5V. (2 - which is more important here) As you can see, the capacitor is placed between the integrated circuit's Vcc pin and ground pin. With any IC, you have to place a capacitor between the power and ground pins. Why? There are a few reasons. The first is that the IC's pin's and wires emanating from the pins act as inductors. IC's don't (or at least rarely) draw a constant current. Instead, they "gulp" current. And they do this very quickly. Power supplies are rather slow to respond to changes in current consumption - sometimes on the order of 10us. The inductance in the wires and pins compound this problem, so the IC may not receive the power it needs soon enough, and then it doesn't operate properly. A decoupling cap can supply this need current for the short amount of time needed while also neutralizing the inductance present in the pins/wires. Another reason it's there is also due to the inductance. Between pins/wires, you have what is called parasitic capacitance. (Adjacent pins will act as a capacitor). This is bad, because you can unintentionally create an LC circuit. 1/sqrt(LC) is actually equal to 2*pi*frequency. Guess what? You now have a very high frequency resonance in your circuit (you typically can't see them on a regular scope since they can be in the Ghz to Thz range). This also wreaks havoc on IC's. By adding a decoupling cap, you can minimize these frequencies and what now. Hope that answered your question.

[sipimanify.]

Ty Mlagma :D

[spencerzzzzzz]

I have a cheap alarm clock/Ipod dock and a guitar amp that I put together. Basically I replaced the little alarm clock speakers with bigger speakers, but I cant get the speakers to play any louder then it use too. it actually sounds quiter. Can anyone tell me how i can add an amplifier to it with the alarm clocks power source? urrrrgghghh

[LucasG5]

well, you could build one (as somewhat shown above), or take one out of a different device.

either way once you have an amp take the wire that goes to your clocks speakers (output) and rout them to your new amp (input). then rout the output of the second amp to your speakers.

best of luck to you.

[olrakiinad]

what if i don't have rechargeable battery? can i use usb port to connect it direct to computer as power source?

[LucasG5]

yes, just cut the business end (the one that isn't the usb), determine what two wires are positive and negative (it varies but red and black are common).

best of luck to you.

[BLACK2017]

here is a better explained site for this http://cdselectronics.com/Kits/Stereo%20Amp.htm

[Deejean]

so this is very uninstructed, i got all the parts and went to put it together and CAN'T... isn't the point of this site to give STEP BY STEP INSTRUCTIONS? just wondering...

[xaenon]

If you don't want to play with building your own amplifier circuit, the TDA2822 circuit used in this instructable can be found at the heart of many inexpensive computer speaker setups. The module is prebuilt and very compact, and often integrates the power switch and volume control. They can easily be wired for 6VDC (four common flashlight batteries in series; I suggest 'C' or 'D' size. Most of the cheap computer speaker sets have some pretty crappy speaker drivers in them, so putting some slightly larger speakers into a larger enclosure, like in this instructable, is a definite upgrade. You'd be surprised at how much better a fractional-watt amplifier can sound when given some decent speakers to work with!