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Speaker Info

Let's take a look at the process that happens if you speak through a megaphone. The air in your lungs pushes past your vocal cords, creating sound. This sound travels through the air and strikes the diaphragm of the microphone.

The sound hits the diaphragm, causing it to move. Since the coil is attached to the diaphragm it moves too. The movement of the coil within the field of the magnet produces an electric current (click HERE to find out why this happens). This current is sent to the amplifier of the megaphone.

The electric current produced by the microphone is very small, nowhere near powerful enough to run even a tiny speaker, let alone a megaphone. The amplifier takes the current from the mic and makes it strong enough to run the megaphone speaker. The now amplified current travels to the coil in the speaker, where once again a magnetic field is produced by the flow of electricity. This field interacts with the field of the magnet, causing the coil to move. As before, the coil is attached to the diaphragm, and so moves with the coil. The diaphragm pushes on the air, creating sound.

An interesting thing to note is that a microphone is essentially the same thing as a speaker. In fact, any speaker can be used as a microphone. Due to the characteristics of modern electronics, one can't just actually use any speaker as a microphone with any amplifier, but they are the same basic device. On my to do list is making a project that demonstrates this. It is possible that the Simple Speaker could work on a powerful amplifier, like a guitar amp. If you try it, let me know!

Another interesting thing is that your ear works the same way. The sound pushes on a diaphragm in your ear, and this movement is converted to an electrical current and sent to your brain. Wow!

Think of the sequence of events when you hear someone singing on the radio. It started with air from the singers lungs pushing on their vocal cords. The sound traveled through the air, and was received by the microphone, which in turn converted the sound to electricity. This was amplified, then recorded.

When the radio station played the recording, it was again converted to an electrical signal, amplified and then transmitted through the air as a radio wave. Your radio picked up the signal, amplified it yet again, then sent this signal to the speaker, which pushed on the air to create sound. This sound travels through the air, strikes your ear, and is once again converted to an electrical signal and sent to your brain. Did I say wow?!