Between the FH19 and IER-M9, the FH19 comes out ahead in sensitivity and impedance, while the IER-M9 wins on several specs. Overall, the FH19 scores 72.9 and the IER-M9 scores 54.5 on our Mars Score.
Which should you buy?
The FH19 is the clear pick on raw spec strength, leading by 18.4 points on the Mars Score. The margin is wide enough that the underdog only makes sense if its individual strengths line up with what you specifically need.
Pick the FH19 if you care most about sensitivity and impedance. The biggest gaps in its favor are sensitivity, impedance, driver count.
The IER-M9 similarly doesn't carry a headline advantage on the popular specs — look at the full table for category-specific deltas.
Both ship with comparable detachable cable, so those specs don't separate the two — focus on the differences below.
Bottom line: the FH19 is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why FiiO - FH19 wins
- ▲Sensitivity — 8.74% more. 112 dB vs 103 dB.
- ▲Impedance — 6.00 Ω less. 12 vs 18.
- ▲Driver count — 5.00 more. 10 vs 5.
Why Sony - IER-M9 wins
- No decisive advantages.
Spec comparison
Drivers
| Spec | FiiO - FH19 | Sony - IER-M9 |
|---|---|---|
| Driver count | 10lead | 5 |
| Driver types | 1DD + 8BA + 1BC Hybrid | 5 Balanced Armature |
| Impedanceⓘ | 12 Ωlead | 18 Ω |
| Sensitivityⓘ | 112 dBlead | 103 dB |
Build
| Spec | FiiO - FH19 | Sony - IER-M9 |
|---|---|---|
| Detachable cable | true | true |
| Connector | MMCX | MMCX |
Spec-level deep dives
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