Fiio FH9 Review

We’ve previously covered the FH5 and FH5s here on MajorHiFi, and we were happy with what Fiio had to offer. Their semi-open back IEM design that was introduced with the FH5s is a personal favorite of mine, so I was excited to see them release the latest model in this series, the FH9. Compared to their past designs, the FH9 aims to be their most high-end semi-open back IEM yet, coming in at their highest price of $599.99 Let’s see if this new IEM from Fiio has the sound and design to match it.

Fiio items

What You Get

  • HB5 carrying case*1
  • Bass ear tips*3 pairs (SML)
  • Balanced ear tips*3 pairs (SML)
  • Vocals ear tips*3 pairs (SML)
  • Foam ear tips*2 pairs (M)
  • Double-flange ear tips*2 (M)
  • SpinFit ear tips*3 pairs (SML)
  • Cleaning brush*1
  • MMCX removal tool*1
  • Magnetic clamp*1
  • Green/Black/Red audio filters*1 set
  • 2.5/3.5/4.4mm interchangeable audio plug*1 set
  • 8 strands of 224 wires each high-purity monocrystalline pure silver cable*1

Fiio single

Look and Feel

The FH9 takes after the same basic structure of the FH5s, but this time Fiio went with a housing that felt a little slimmer than its predecessors. It may be an all silver finish, but the black and silver on the FH5s may look a bit more stylish. However, the FH9 is a lot more practical and feels more natural when its body is placed within your concha. It sits more firmly and offers more support. It still feels a bit big when compared to other IEMs in this price range that are more ergonomic, but this is still a worthy upgrade and a solid improvement to the FH5s in terms of comfort.

Fiio Cable


A flagship IEM needs a flagship system, and the FH9 delivers. This titanium alloy construction houses a seven-driver hybrid system. It’s made up of a single dynamic driver, with a 13.6mm diaphragm that uses an in-house developed diamond-like carbon construction. With this design, Fiio aims to heighten rigidity to make the best out of the driver dynamic response, with a dampening coefficient to help deliver the fastest transients. Six Knowles balanced armatures are also included in order to reproduce a coherent midrange signal flow. The way the acoustic signal travels through the shell and sound tube will help eliminate unwanted resonance.

Fiio front


A semi-open design for an IEM establishes a few prior notions about the ability of the FH9’s soundstage. Considering what the FH5s did with this principle, I was looking forward to what they could do with a bit of a more high-end model. Comparatively, the FH5s might appear a bit wider at first, but listening to the FH9 for a while I could distinctly notice the expanded depth that these IEMs possess. This isn’t an IEM concerned with a linear stereo field, where the extreme left and right positions are extended past the earphone’s shell. Instead, the FH9 keeps to a space that better represents the spatial imaging of the intended mix, all while providing the soundstage with air and clear separation. The layers stack over each other well and place the sound elements in a realistic way that preserves their natural origin.

Low End

From the first track to the last track I tested, the bass always left the greatest impression on me. It’s sort of the FH9’s main meat, as it delivers an expressive low-end that protrudes outward and fills the frequency response with a gratifying heft. There’s a richness to it that will easily satisfy bass-heads, with its extended sub-bass that reaches a surface while venturing into a deep resonance. It offers a weighty presence that textures the bass frequencies in a pleasing thickness that never outstays its welcome. The mid-bass also supplies the timbre with a significant impact, producing a firm accent to the tone. Although you’ll get a good amount of detail here, there’s not exactly a ton of balance, but if you’re looking for pure fun then the bass timbre will be bound to satisfy.


After the power of the low-end, you’d expect the midrange to take a dip, but that’s not what happens on the FH9. There’s a great amount of clarity in the mids, and while they don’t obtain the body of the lows, the frequencies retain a respectable amount of neutral detail. Its timbre never suffers from the colorful extension of the bass, treating its tone with a sustainable cleanness that keeps the sound signature fairly even throughout the frequency response. Instrumentals and vocals showcase some emphasis at the bottom and top end of the midrange, but the fundamental frequency bands never suffer from their texture. At its best, the midrange can highlight some dramatic details but presents an overall smooth response.


Not all will like the treble response from the FH9, but I think it gives the sound signature a certain shine. There are some bright spots to consider, but they are handled with a respectable amount of control. They take a dominant spot in the sound signature without culminating in a distracting tone of piercing harshness. It extends well in height, offering a wealth of high-end airiness that further elevates the potential for an even grander image. They produce accents of tone when necessary, providing drive, and completing the overall timbre in an intricate way.


For the FH9 I was most surprised by the sound signatures’ consistent tightness and control over its textured response more than I was its detail and expansiveness. I think that’s a great thing to achieve for any IEM in this price range, as it tries and mostly succeeds to maximize enjoyment over anything else. The improved depth and bass extension were definite highlights of the FH9, as no fidelity seems to be sacrificed with its coloration. For $599 I think this is an excellent choice for those not necessarily looking for the purest detail, but one that will reproduce the whole of the frequency response both clearly and colorfully.

Pros  Cons
  • Spatial depth
  • Meaty bass
  • Clear mids
  • Tight highs
  • Flagship design
  • Bulky   

The Fiio FH9 is available at Audio46.

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Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.