This is how to build a tiny pair of speakers that simply clips onto your ipod/mp3 player, and are surprisingly loud.
Word of caution: If I were you, i would not use these with mp3 players that use hard disk drives (as opposed to flash memory, like many newer ones) because there is a chance that the magnets in the speakers could mess up the data on the disk, and brick your player.
So i built this, not knowing how well it would work, and when I finished, I realized that I should have taken photos so I could make an instructable about it. So I have whipped out my trusty tablet, and recreated all the steps by drawing them out in painter 6. If anything is confusing, please tell me so i can clarify.
Step 1: Materials
2 smalll rectangular speakers. I got mine from an old and broken dell latitude cp that was about 10 years old
8mm male audio jack
Sheet aluminum. I just used aluminum flashing, which is extremely thin, and can be cut with scissors
Step 2: Wiring
Cut the audio cable about two inches from the end, and strip off the plastic around the bundle of wires. There will be 3 wires inside: a ground wire, a wire to the left speaker, and a wire to the right speaker. The ground wire probably will not be coated in plastic, or it will be black. Strip the plastic off the wires to the left and right speaker, and twist the two wires together. This will make the signal to the speakers only one channel, and it will make it a little bit louder. Connect one wire from each speaker to the joined signal wire, and the other wire on each speaker to the ground wire on the jack. Once you have done this, go ahead and plug it into your music player to see if it works.