What's the difference between dynamic driver, balanced armature, and hybrid IEMs?

Single dynamic drivers (like the Sennheiser IE 200 and IE 100 Pro) tend to do bass and overall coherence well. Balanced armature drivers are small, fast, and often used for detailed mids and treble or for stage monitoring, where the UE 350's triple-BA setup is typical. Hybrid designs like the Kiwi Ears Astral and KZ ZS10 Pro combine a dynamic driver for bass with multiple BAs for mids and treble, aiming for the best of both at the cost of more complex crossover tuning.