Headphones most typically have dynamic drivers, whereas earphones might have dynamic drivers or balanced armature drivers. Especially in headphones, dynamic drivers are the most common because a larger dynamic driver—which the ear enclosure for a pair of headphones can accommodate—can get louder and produce more bass depth than alternatives. In earphones, the dynamic drivers have to be much smaller; this can often affect bass response. Many manufacturers, especially those in the business of making custom-molded in-ear monitors for musicians and engineers, turn to balanced armature drivers instead. Balanced armatures have the advantage of being tiny, which allows the earpieces to be smaller. Or, in the case of the aforementioned custom in-ear monitors, the earpieces can be quite large—freeing up room internally for several balanced armatures per ear, with each driver handling a specific frequency range. Generally speaking, it's possible to get excellent audio—or poor audio—from both dynamic and balanced armature drivers, although the two styles have dedicated fan bases. In both headphones and earphones, the planar magnetic driver continues to gain ground slowly. Headphones with these drivers are typically (much) more expensive. But the advantage of planar magnetic drivers is that they, ostensibly, produce a more precise sound because of the flat, larger-than-a-dynamic-driver film that vibrates between two magnets to create sound. Electrostatic speakers and headphones are similar to planar magnetic models in that they use a large, thin surface area to deliver the audio. But we see far fewer electrostatic headphones than any other type—they are typically through-the-roof expensive and best for home use. Microelectromechanical systems (MEMS) tech is also starting to appear in the form of silicon-based, solid-state drivers. These can produce faster transients and are very precise. Additionally, manufacturers can ensure a more consistent driver-to-driver build since they don’t rely on multiple moving parts.