In the diagram above, the microphone and the loudspeaker are the doors in and out of the analog world. The only difference between the two is the direction of the process. Now you know why it works. The only difference is whether the membrane moves the coil or the coil moves the membrane. Well, that and the size.
Loudspeakers are much larger than microphones because they have to handle much stronger signals.
Next time you lift a speaker, remember that you're only lifting a box, some paper, and a really big magnet. Digital Recording A digital recording is simply a series of numbers representing analog waveforms. The trick is in making the measurements. Since a continuous waveform can be measured at an infinite number of places, yet we can only make and store a finite number of measurements, the result will always be approximate. The trick is to make a lot of measurements at regular intervals.