AudioChainsDB
FiiO

FH5s

headphones

$250

Used market: $195*

Manufacturer datasheet

Specifications

3 of 6 values have a recorded source
Connector
expanded MMCX, swappable 2.5 / 3.5 / 4.4 mm plug·
Form Factor
In-Ear·
Impedance ohms
40✓
Transducer Type
Dynamic·
Detachable Cable
yes·
Sensitivity dB mW
106✓

Expert Audio Engineering Commentary

Tonal Profile

A 2+2 hybrid: 12 mm and 6 mm beryllium-plated dynamics with a Knowles TWFK-30017 compound armature above them. FiiO also publishes a maximum power input of 100 mW, which at 40 Ω is 2 V — a real ceiling, not a formality.

Gain Staging Advice

40 Ω is high for an in-ear and it helps: the same source output impedance that tilts a 16 Ω hybrid barely moves this one. 106 dB/mW here is about 120 dB/V.

* Estimated with the depreciation fallback (~78% retained value). · checked on 8/5/2026