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Fiio F9 Review – Making Waves

Introduction –

Though best known for their sources, Fiio have augmented their new devices with a line of accompanying in-ear earphones that each offer sensational value at several conservative price points. I’ve personally reviewed them all, from the humble F1 to the excellent EX1 and F5. And, through aggressive pricing and partnership with audio guru Dunu, none have failed to impress with excellent price/performance ratios combined with build quality that belies their meagre asking price. The F9 is the latest extension of Fiio’s F-series in-ears and perhaps the most technically impressive to date.

Featuring a triple hybrid driver configuration, it represents a considerable step up from the Fiio’s single dynamic driver based models. In addition, the F9 retains the removable cable of the F5 but trades its shallow semi-open form factor for a meticulously sculpted monitor style housing. Combined with a balanced cable from factory, the F9 is without a doubt, Fiio’s best built and best sounding in-ear to date but also their most expensive at $100 USD. Let’s see how the F9 competes in a price range teeming with excellence.

*Of note, Fiio have released several variants of the F9. Initial batches of the F9 had tighter MMCX connectors and smooth cable connectors where newer batches have ridged connectors and slightly looser connectors. The new batches also have a larger angle between the connectors and housing which enables cables with wider connectors to be used. Fiio have also released the F9 SE which is acoustically identical but has a fixed 3.5mm cable. A higher priced Pro model with revised armature drivers is in the works and will be released at a later date.


Disclaimer –

I would like to thank Sunny from Fiio very much for her quick communication and for providing me with the F9 for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.


Accessories –


It’s almost unbelievable how far Fiio has come since their first iems. The F9 is very professionally packaged with attractive renders and a very fully featured accessory set. Inside the box is Fiio’s excellent pelican style hard case that contains the earpieces and 6 pairs of silicone ear tips. The tips are quite interesting, there are 3 pairs of regular tips and 3 eQ tips that enhance the bass response, similar to that employed by the Simgot EN700 Bass.


During listening, I found them to provide very noticeable tonal adjustments with the red tips offering my most preferred sound. A small box just above contains two cables, a regular 3.5mm cable with a 3-button smart remote and a very nice braided 2.5mm cable for use with a balanced source. It’s a nice inclusion that is very uncommon at this price point and the inclusion of a remote cable is thoughtful for those that intend to use the F9 with a smart device.


Design –

The F9 is a striking earphone with a beautiful rippled design and two-piece aluminium construction. They are easily among the best-constructed earphones around $100 if not the best with finish and solidity that matches earphones costing several times more. Further yet, their smooth satin finish serves to accentuate the fascinating quality of their undulating outer face, creating a stunning visual package that belies its asking price.


Fiio have also carefully considered ergonomics when designing the F9. Though not especially compact, the F9 is a far from a large in-ear, about the same size as the Shure SE215, with long but low-profile housings that make them perfect to sleep on. The earphones also generate little wind noise when outside despite their rippled design.


Through smooth sculpting and longer nozzles, the F9 achieves nice fit depth and great stability in the ear. They were perfectly comfortable for me even after extended listening, forming no hotspots. That said, due to two internal vents, the F9 doesn’t quite isolate as well as some competing models like the Rose Mini 2 and Pinnacle P2 but they still block more noise than the semi-open F5, K3 HD and EN700 bass and will be sufficient for public transport.


Up top, the F9 utilizes a removable MMCX cable. Fiio were quick to note that the MMCX connectors are much tighter than those on the F5 before and that newer batches of the F9 have a slightly larger MMCX connector angle that permits the use of 3rd Party cables (where initial units were a bit too tight). This enables users to swap the cable in the event of damage or upgrade to a superior unit in the future. That said, the stock cables are quite good, the remote cable is rubbery but serviceable while the balanced cable is genuinely compelling.


Both have well-formed pre-moulded ear guides that I vastly prefer over memory wire and the balanced cable has a nice loose braid that is exceptionally supple and soaks up microphonic noise. The cables also have an integrated strap that keeps everything organized. Otherwise, the cables are mostly well relieved, more so than the cables that came with the F5 and the connectors are tight without intermittency.


Sound – 

Tonality –


The F9 is a clearly V-shaped earphone with a slight emphasis on treble over bass. That said, mid-bass is present, providing a solid foundation for the rest of the sound while mids are clear and extended but less forward. Lower treble is spiked creating a rather uneven high-frequency presentation though this can be altered via eQ and tip choice. Of note, I did prefer the red tips to the black ones, they were more balanced overall while the black tips murdered bass definition and sounded a little less natural within the mids and treble. Foams further smooth off the high-end though I personally prefer silicones during daily use for their convenience. I’m also not a fan of eQ since it can be hard to create a reliable experience among multiple sources. Thus, the F9 sits in-between the more V-shaped Kinera H3 and more balanced Pinnacle P2 in terms of tuning, it is a tone that possesses enough balance for the majority of genres and one that many listeners will be familiar with.


Bass –

Low frequencies are quite typical but mostly tasteful in tonality and the F9 has certainly proven to be one of the better technical performers I’ve heard around this price. Sub-bass is slightly elevated with good but not great extension, the F9 is on the looser side though impact is firm and rumble is easily discerned. They perform on a similar level to the Simgot EN700 Bass and Magaosi K3 Pro but fail to match the class-leading Kinera H3 and TFZ King in terms of overall extension and technical ability. This is followed by a modest mid-bass hump that grants the F9 with a fuller bass note but also a little bloat, and they are immediately less nuanced that the aforementioned H3 and the K3 HD as a result. Upper bass is more reserved but still well present and the F9 avoids bass spill or warming of its lower midrange as a result.

Bass texture and definition are both good though some details get buried beneath their mid-bass bloat. They also aren’t the tightest, most agile earphone around this price, easily outpaced by the competitors like the Pinnacle P2. During faster, more complex songs such as Earth, Wind & Fire’s “Boogie Wonderland”, the F9 can get a little lost and bass notes are somewhat one-note when compared to the more linear, more balanced King and Mini 2. Even the H3, which possesses greater bass emphasis, achieves a higher level of technicality through greater bass control. The F9 is certainly not a bad performer, quite the opposite, but the quality of their bass doesn’t quite match its driving emphasis within the sound. Still, those looking for great extension and impact combined with good detailing will find a very agreeable experience with the F9.


Mids –

The first things that listeners will notice is the F9’s outstanding midrange clarity that grants vocals, both male and female, with a certain glossiness and extension. As a result, the F9 does not sound particularly natural and vocals do come off as a bit thin and oddly voiced but I can definitely see a lot of listeners enjoying this presentation; the F9 really flatters pop, acoustic and well compensates for the more veiled mastering of older albums. In terms of tone, the F9 is a brighter earphone with slightly recessed male vocals preceding rising emphasis into the upper mids and treble. However, male vocals still avoid a scooped sound and the F9’s midrange sounds pretty balanced in the majority of situations. As a result, the midrange of the F9 sounds more even than the H3 with similar overall linearity to the Pinnacle P2. My main complaint stems from a sizeable lower treble/upper midrange peak that can overly emphasise sibilance and saps smoothness from the midrange.  Vocals often sound a little strident and instruments can come off as raspy.

However, from a technical standpoint, the F9 does impress, augmenting its clarity with excellent resolution that is among the highest I’ve heard around this price and even above it. The F9’s enhanced treble though not natural or refined, does notably aid space and extension of elements. Female vocals and strings, in particular, sound airy, delicate and separated making the F9 a great choice for acoustic. Courtney Barnett’s “Small Poppies” was flattered with exquisitely clear vocals, crisp guitars and great separation between elements. Furthermore, layering is very defined and the F9 is still surprisingly natural given its style of tuning. So those coming from warmer earphones like the Simgot En700 Bass might require some acclimatization to the F9’s thinner, clearer tones, however, they do reward with a mostly balanced and very technical listen.


Highs –

The F9 has been getting a few criticisms regarding its aggressive, spiked treble response. And though everyone has differing levels tolerances, to my ears, highs aren’t harsh but they do get a bit overzealous. And this style of tuning certainly isn’t something we haven’t seen before, almost all Chi-Fi iems around this price have a bumpy treble response that either serves to heighten detail presentation or create the impression of air within a less extended response. It’s called compensation because on a superficial level, these iems sound similar to more technical models but lack the actual underlying technicality to present these elements in a natural fashion. The F9, thankfully doesn’t have to compensate for too much, its high-frequency response is nuanced, detailed and clear. Treble extension is very good but not absolute, the very highest details are still a little truncated though less so than competing models. Otherwise, middle treble is a little lifted while higher notes are a little smoother and more restrained to avoid outright harshness and fatigue.

And breaking that down a bit more reveals impressive underlying technicality. As aforementioned, lower treble is aggressive and notably accentuated though actual detail retrieval is good, roughly similar to models like the Pinnacle P2 and just below the H3 and K3 HD. That said, the F9 is very aggressive in its presentation, bringing every little nuance to the fore though without the forwardness of the King. This is augmented by very commendable resolution that grants treble elements with great clarity and immediacy. That said, texturing does suffer due to their thinner, spiked presentation that lacks the linearity to portray accurate instrument timbre. As a result, the F9 is a detailed, hyper clear earphone with nice air but also a somewhat artificial tone to instruments and the extent that this bothers the listeners will depend on preference and music taste.


Soundstage, Imaging and Separation –

As a result of their airier, hyper-crisp treble response, the F9 produces a very nice soundstage presentation that is among the best I’ve heard around this price, especially through a balanced connection. Width is great, extending to the periphery of the head and depth is notably more immersive than competing models. This is especially noticeable with vocals that extend exceptionally well on the F9. Imaging is good but not outstanding, directional cues are accurate and clear and instruments are easily located. Centre image to vocals is a bit hazy and diffuse and most elements tend to become pushed to the side of the soundstage. Separation is excellent due to their defined transition between lows, mids and highs in addition to enhanced clarity and resolution.


Drivability –


The F9 is one of the easier to drive earphones I’ve tested with a 28ohm impedance and 106dB sensitivity. Users shouldn’t want for more volume even from smartphones or portable MP3 players and those with any sort of dedicated DAP will have no trouble driving the F9 to potential. Due to its cool resolving tone, the F9 finds particularly strong synergy with warmer, more laid-back sources. I found the Chord Mojo and Shozy Alien+ both to provide extra smoothness and refinement to the F9’s excited sound in addition to a little extra body all without sacrificing detailing. My HTC 10 also provided a fine pairing with plenty of volume and the F9 was not overly affected by output impedance in my testing. Of course, the F9 can also take advantage of a balanced output, from my X7 II w/AM3 module, I noticed slightly more separation and greater bass weight and control as opposed to the regular 3.5mm output. It’s also possible that the cable itself is contributing as on the F5 in addition to greater driving power from these outputs.


Comparisons –


Rose Mini 2 ($100): The Rose and F9 couldn’t diverge much more in their tonality. Where the F9 is clear and engaging, the Mini 2 is neutral with a tinge of warmth. Bass extension easily goes to the F9 and the Fiio possesses notably more slam and impact, though the Mini 2 is much faster and considerably more defined if more reserved in quantity. Mids are far more linear on the Mini 2 and though the Rose lacks the outright clarity and resolution of the F9, the Mini 2 is a lot more natural and far more refined.

Mids are better balanced with the rest of the sound on the Mini 2, it is also more bodied and transparent with more accurate timbre. Highs are far more aggressive on the F9 and though the Mini 2 is just as detailed, it is more on the laid-back side in terms of presentation. The Mini 2 isn’t spiked like the F9 and resolves greater texture and micro-detail as a result. However, it can sound a little sedate and air is not its forte. The F9 also has a large advantage when it comes to soundstaging, though the Rose images a little better, the Fiio has greater space in all axis and notably higher separation.

Simgot EN700 Bass ($100): The Simgot is a delightfully warm, natural earphone that contrasts to the V-shaped competition. It is bassier than the F9 with a bigger mid-bass hump though it is less extended and defined. That said, the Simgot is nicely articulate and bass/midrange transition is smoother so lower mids are more natural as a result. The F9 is clearer but also much thinner, it sounds thoroughly artificial compared to the EN700 Bass if more resolving. Upper mids are clear and clean on the Simgot but even clearer on the F9.

The Simgot clearly lacks the technical ability of the Fiio, the layering and resolution isn’t quite there nor is the detailing, but they make up for it with tonal excellence, they are so much smoother and more refined. Treble is more laid-back on the EN700 Bass with average extension and air. The F9 is a lot more aggressive and extended and raw detail retrieval is appreciably better. On the flipside, the EN700 Bass is much smoother and more textured while retaining some crispness. The En700 Bass has a very nice soundstage on account of its almost semi-open design. The Fiio has less width but a little more depth and both image similarly well. Separation is a little better on the F9 due to its greater extension and more dynamic tuning.

TFZ King ($100): The King and F9 make for interesting comparison since both earphones pursue absolute technicality over tonal refinement yet through differing approach. The King is a bright, forward sounding earphone while the F9 balances its prominent high-end with greater bass quantity. Both are similarly well extended but the King’s low-end is more defined and agile. That said, low-end details can become overshadowed by higher elements, something the Fiio doesn’t suffer from. Mids on the King are considerably more forward in the mix and find a better balance between clarity and smoothness.

The F9 pushes clarity a step further but also sounds a little harsher and less refined. As such, though both have excellent resolution and layering, the King is a bit more linear with better background detail retrieval. The King has a similarly spiked high-end though its emphasis lies in the middle rather than lower treble. As a result, it is airier but splashier with a similar lack of body and the F9 is more separated and detailed without the overbearing brightness of the TFZ. The F9 has a larger stage, especially depth in addition to appreciably better separation though imaging is more accurate on the King.

Kinera H3 ($100): The H3 is the more engaging counterpart to the F9 and P2 with a notably more visceral bass response combined with a similarly clear midrange and high-end. Sub-bass extension is better on the H3 and bass is greater in emphasis with a more deep bass over mid-bass focus. As such, though the H3 is bassier, it is more defined, controlled and articulate. Mids are more recessed on the H3, lower mids sound a bit scooped compared to competing models though clarity and body are both excellent. And though the F9 is more balanced throughout, the H3 is almost as clear but warmer and more bodied. The H3 actually matches the F9 on resolution but it is also slightly more natural with greater definition of layering.

Highs are actually brighter on the H3 but also more resolving and separated which acts to counteract some of its peakiness. Both are very aggressive yet well-detailed earphones, the H3 a little more so since its treble emphasis extends a little further up. As such, the H3 doesn’t overshadow as many higher details and instruments sound a little more linear if pushed forward in the mix. The F9 once again has the larger soundstage, especially depth which provides vocals with an immersive character. Separation is better on the H3 while imaging is similar on both.

Meeaudio Pinnacle P2 ($100): The P2 pursues almost identical tuning to the F9 but with better balance throughout, this is probably the most pertinent comparison of the bunch. Bass is similar on both, the F9 has a hair more extension and greater emphasis throughout though the tuning is similar. The P2 is considerably faster but also tighter and more defined, it has a touch more upper-bass quantity that grants mids with a slightly warm tone as opposed to the thinner, cooler F9. Both possess a clarity driven midrange though the P2 is smoother and more refined, less affected by the sibilance and peakiness of the F9. The P2 is also slightly more balanced, though still lightly v-shaped overall.

Resolution is slightly higher on the F9 though the P2 is more detailed due to its greater body and more natural presentation. Highs are also similar, lower treble is spiked on both, the P2 to a lesser extent. As a result, the P2 has less aggression but also sounds smoother and more detailed, cymbals are more textured and notes are less raspy in general, female vocals are also less strident. The F9’s soundstage has greater depth and a little more width than the P2 though it is the less coherent sounding earphone with inferior imaging. Both separate very well, the P2 more so since it is less peaky and more balanced.


Verdict –

Fiio’s lower F- series earphones were sensational. They were priced competitively, built better than competitors and were tonally brilliant to top it off. However, unlike these models, the F9 sits within a price range overflowing with competition, some that strive for great balance and some greater engagement. There is no doubt in my mind that the F9 offers a great sense of value but what a lot of listeners and critics fail to acknowledge is that $100 buys you a lot of earphone these days and this is demonstrated by models like the Rose Mini 2, Kinera H3 and Meeaudio Pinnacle P2. As a result of this fierce competition, I would argue that even these mostly affordable in-ears can no longer be fully excused for treble peaks, unnatural voicing and uneven bass tuning, at least, not to the extent shown here.


Because, like the K3 Pro, the F9’s sculpted tones come with several inherent caveats that some competing models don’t suffer from. The Meeaudio Pinnacle P2 serves as a great example, that earphone fits better, isolates more and pulls off the same kind of sound but with greater balance and refinement. However, with the right material, the F9 sings like few others around this price with class-leading resolution and clarity within a well-featured and beautifully shaped housing. And at the end of the day, tonality is a preference and though the F9 doesn’t fit mine, those that prefer a clear, resolving V-shaped sound and don’t mind the treble, will find a delightfully technical listen. This technicality also makes them an excellent choice for those who like to experiment with eQ, they are indeed very response with great potential lying beneath wonky tuning.

Verdict – 7.75/10, The F9 is not an outstanding earphone but one that firmly deserves its asking price. For a reasonable price, Fiio provide buyers with an excellent housing, balanced capability and a resolving V-shaped sound. However, while technically impressive, that sound lacks the tonal refinement to stand above the rest.

The Fiio F9 is available from Amazon (US) for $99 USD and Penon Audio (International) For $109, please see my affiliate link for the most updated pricing, availability and configurations.

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