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!
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
Here are the parts for the amplifier circuit:
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)
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!