Gear & technology
Balanced armature
Also called BA, BA driver, armature driver
A balanced armature is a tiny driver, long used in hearing aids, in which a pivoting metal reed moves a small diaphragm. Its size lets in-ear monitors pack several into one shell, each handling part of the frequency range.
Because the moving parts are so small, balanced armatures are fast and detailed in the Mids and Treble and in a sealed fit can reach deep Bass, though many listeners find all-armature bass lacks the impact of a dynamic driver. Many multi-driver IEMs use two or more, and professional stage monitors have long used them.
The shortfall in bass is why Hybrid designs pair them with a dynamic driver. All-armature IEMs are often praised for clarity and criticized for lean or "plasticky" bass; listeners disagree about which trade-off they prefer.