FiiO FA19

The FA19 is an all-balanced-armature IEM with ten Knowles drivers per earpiece: four bass drivers that Knowles made to FiiO's design with more airflow for more low-end energy, two Knowles ED drivers for the mids and four SWFK drivers for the treble. Balanced armatures are small, precise drivers; using several per frequency band gives more output and lets each one work in its own range, split here by a physical and electronic three-way crossover with Rubycon film capacitors. The 3D-printed resin shell guides bass energy into a rear chamber (FiiO's negative-feedback bass system), and a notch filter at the mid drivers tames an 8 kHz peak to avoid sibilance. A switch on the back of each earpiece chooses between Monitor mode, which FiiO describes as clean and detailed for audio production, and HiFi mode, which adds mids and bass. At 10 Ω and 106 dB/mW it is easy to drive, and it comes with a 224-wire pure silver cable with expanded MMCX connectors and swappable 3.5 and 4.4 mm plugs.

• 10 Knowles balanced armatures per side
• Monitor/HiFi switch on each earpiece
• Pure silver cable with 3.5/4.4 mm plugs