Can you create energy using magnets?

A speaker and a microphone are almost the same - except one uses electricity to make sound (the speaker) and the other uses sound to make electricity (the microphone). A speaker can actually behave like a microphone, if the sound waves coming at it manage to move the speaker cone. The speaker has a magnet inside, and a coil of wire. If the speaker cone moves due to the sound waves, it forces the coil to move, and this generates electricity, because the coil is moving through the magnetic field. Make sense ? The thing is, you had to put energy in to make the electricity - something had to make the speaker cone move.