Diy Speaker
I was trying to make a analog VU meter but start having fun with the coil as a speaker. It is really enjoy turning anything to speaker, why not share it.
Supplies
Copper wire(Any thickness will work, keep it under 1mm)
Small magnets, more stronger better. I used from DVD reader reading head.
Any amplifier (amplifier will decide the coil resistance)
and Soldering supplies.
The Coil
Wrap the enamel copper wire in a tight loop. To keep maths simple, check your amp's rating for speaker, like my amp uses 3watt/4ohm speaker, so the resistance of my coil should not be much less than 4 ohm. Likewise make your coil, this way isn't that efficient but who would do math.
Electronics
Connect the coil wires to speakers section of amplifier, polarity does not matter. Connect the audio and power input wires to amplifier.
Diaphragm
Again, the stronger magnets are more preferred. Mine are from DVD reader head assembly. Now whatever you attach the magnets with will be your amplifier. I don't know why it is fun:)