– “Dynamic” means that the diaphragm (what makes sound) is connected to a ring of wire (also called a voice coil), would many times around a former.

– As the signals from your MP3 player pass through the ring of wound wire, a fluctuating magnetic field is created.

– Because there are small magnets in proximity to the voice coil, the fluctuating magnetic field interacts with the static magnet field created by the magnets, and this causes a force to be created.

– As the voice coil is connected to the diaphragm, the diaphragm moves, back and forth, thus creating sound.

– Most headphones operate on this principle. A few high-end headphones operate on electrostatic principles. Electrostatics are generally heralded as the most ‘airy’ or ‘open’ sounding headphones out there, but a well-designed dynamic headphone can come very close to an electrostatic design, and usually for significantly less money.