Speaker success

I mentioned earlier that we tried to make a speaker for a weekend project (and also as a part of the kids education). It didn't work at all and I figured we needed more power. We were using ceramic magnets, so I ordered some more powerful neodymium magnets to play with. We also used more wraps (250) with thinner (32 gauge) wire to get a more powerful electromagnet coil to push and pull the magnet. These were glued to two plastic plates and one plate is supported over the other by springs. When it is hooked up to a battery you can see the top plate being pushed or pulled by the magnetic field interactions. We stripped a 1/8" audio cable and hooked it to our speaker then plugged it into the computer and played a song. It worked! Sort of. The sound was very faint, but if you listened closely you could hear the audio coming from the top plate. If you touch the plate you can clearly feel the vibrations.


We also plugged it into the microphone port and tried recording. It makes a very bad microphone but it does work to an extent. You have to lean close and speak loudly. There is a lot of hissing and so on but you can recognize a voice in the background. Here is a picture of the raw recording using Audacity.


Below I've amplified the signal and labeled places where T said "testing one two three."