Generally on most headphone packages the companies will try to emphasize the size of the drivers in order to ‘wow’ customers into buying the product. For example you may be walking through an electronics store and you see a headphone package stating
“50MM DUAL DRIVERS”
“EXTRA BASS”
or something along those lines. However this tends to cause somewhat of a misconception. Contrary to popular belief, larger drivers don’t actually mean better sound. A pattern that is about 60-70% consistent is that larger drivers mean more bass quantity. This does not mean bass quality, but they can push more air and have a more boomy sound. However, this is either a good or bad thing because it may overpower vocals on certain tracks and some audio purists will hate that wit ha burning passion.
Smaller drivers, usually present in earphones generally have more balanced and accurate sound. The drivers inside can move faster for more accurate reproductions of sound frequencies. Again, this may have its downsides because bass quantity may not be as much as that produced from larger driver headphones. But sometimes this also means that the quality of it will be cleaner and more punchy to the ear.
There are always exceptions to these things, but it is important to know that just as if the headphone model is called “PRO” or “Studio” doesn’t necessarily mean it is good; the same applies for driver size if listed.
Larger drivers =/= Better Sound