Please be aware that this is speaker is more for demonstration purposes of how speakers work. Don't expect anything loud, or has amazing sound.
If anything goes wrong, such as it sets on fire (possible) or damages equipment, I do not take any responsibility. Make at your own risk. If you feel it getting hot, turn it down or off, and don't blow up your sound equipment!
Step 1: Components
You will need some:
-Sellotape (sorry, I don't know what you would call this in other countries, but basically any tape will be good)
-a good magnet (preferably a strong one like a neodymium rare earth magnet, sorry, forgot to put in picture)
-either a copper wire spool or just an old transformer (very common to find in unwanted electronics. There are other instructables on how to safely extract the wire from these. This is what I'll be using.) IT HAS TO BE INSULATED, some people call it "magnet wire.
-and a plastic dish, container etc, used to amplify the sound.
you will also need a lighter for burning off the end of insulation on the wire
Step 2: Lets Start!
Unfortunately for me, my wire broke, so I'll have to make do with only some of it wound (it should still work)
Now lightly burn the ends of both wires, so the insulation comes off
Step 3: Wire It Up!
Warning, may get hot, make sure it doesn't get too hot, but it isn't too dangerous. If anything, it may just burn the tape or melt the cap (unless you have flammable tape).
To amplify it ( it makes a HUGE difference, just use some tack and stick it to the plastic tray, or hot glue it or something, just try not to use something that will adsorb the sound.
Oh, and cut off the extra tape so it doesn't look as bad as mine
If you want to know how it works...
Basically, you have just made an electromagnet. As the music "pulses" through the coiled wire, a magnetic field is created, that will attract and repel from the magnet. This creates vibrations. They are amplified through the cap, and the plastic tray. You could even use a wall or a rigid piece of furniture to amplify through.
If you want to improve:
-experiment with different size wires, thinner is more annoying to coil, but it may have a better effect.
-placement of coil, I've noticed that winding the coil around different part of the cap gives it a different tone.
-you could also use the bottle as the amplifier
Please tell me if I've made any mistakes or if you found a way to make it work better.