The FiiO FH19 is FiiO's current flagship hybrid in-ear monitor, succeeding the critically acclaimed FH9. Developed in collaboration with Tokyo Onkyo Co., Ltd. in Japan and Knowles in the USA, the FH19 represents the culmination of FiiO's IEM engineering experience and builds significantly on the FH9's balanced, musical character while addressing listener feedback on midrange density and bass texture.
Driver Architecture
Each earpiece of the FH19 houses eight drivers arranged in a four-way crossover configuration. Bass duties are handled by a push-pull dual dynamic driver unit, co-developed with Tokyo Onkyo and comprising two 13.7mm dynamic drivers with PU+DLC composite diaphragms mounted in an opposing push-pull arrangement. This doubles the driving force, improves phase consistency, and halves the required diaphragm displacement compared to a single driver, reducing intermodulation distortion and resulting in tighter, more controlled low frequencies.
Mid-frequencies are reproduced by four custom Knowles enhanced midrange balanced armature drivers, grouped as two stereo pairs. FiiO worked with Knowles to add acoustic vents to the rear cavity of these drivers, increasing sound energy density and producing richer, more present vocals without sacrificing resolution. High frequencies are handled by two Knowles SWFK treble balanced armature drivers, arranged coaxially with an acoustic guide tube and crossed over using Rubycon audiophile-grade film capacitors, which achieve a 0.1% accuracy rate versus the 1% typical of ceramic capacitors. This combination delivers extended, detailed treble with precise phase alignment.
Acoustic Design
A key innovation in the FH19 is the mid-frequency notch filter: a dedicated resonant cavity device that physically attenuates the 8kHz peak produced by the midrange balanced armature drivers. This eliminates sibilance, smooths the crossover transition between mid and high-frequency drivers, and allows each driver to operate within a clearly defined frequency band. The FH19 also employs FiiO's patented S.Turbo acoustic design, a turbine-shaped internal structure inspired by supercharger engineering that enhances bass extension and energy while filtering out excess mid-to-high frequency content from the dynamic driver section.
The earphone shells feature a semi-open design, retaining the hallmark of the FH9 lineage and combining it with FiiO's front-and-rear cavity balanced pressure relief technology. This results in a wide soundstage, natural presentation, and comfortable long-session listening without eardrum pressure.
Construction and Materials
The FH19 shell is constructed from 7000 series aerospace aluminium alloy, which provides structural rigidity and resistance to everyday wear while keeping weight low. A titanium midframe adds a premium tactile quality and further durability to the section of the earphone most frequently handled. The suspended voice coil design of the dynamic drivers routes the coil leads from beneath the diaphragm, eliminating adhesive loading and enabling more uniform diaphragm movement.
Cable and Accessories
The FH19 is supplied with a high-purity monocrystalline sterling silver cable consisting of 8 strands and 224 individual wires, each enamel-insulated and arranged in a Litz braid. The outer sheath is a transparent, eco-friendly TPU that resists yellowing and remains supple in cold conditions. The cable uses stainless steel expanded MMCX connectors for a secure, reliable connection, and terminates in a straight twist-lock swappable audio plug system supporting interchangeable 3.5mm and 4.4mm balanced plugs (4.4mm pre-installed).
The FH19 ships with an extensive accessory set befitting its flagship status: 22 pairs of ear tips across four types (foam, bass, balanced, and vocal in S/M/L, plus SpinFit CP series, HS18, and HS20 silicone), three sets of swappable audio filters (red, black, and green, tuning bass emphasis and treble character), an HB7 carrying case, a magnetic cable clip, MMCX quick-release tool, and a cleaning brush.