Fiio F9 Pro In-Ear Headphones Review

Author: Tech Merit Reviews

Review from:samma3a

→→ Read the original article on samma3a:>> Click here

FiiO F9 Pro Pros&Cons 


  • Price-point

  • Comfort

  • Almost great sound

  • Value


  • Treble peak

FiiO F9 Pro Specs

Impedance: 28Ω

  • Driver configuration: Triple hybrid (9.2mm Dynamic driver + 2 Balanced Armature drivers)

  • Frequency response: 15 Hz ~ 40 kHz

  • Sensitivity: 106 dB/mW

  • Cable length: 120cm

  • Weight: 21g


As we’ve come to expect and appreciate, Fiio packages the FiiO F9 Pro in a very familiar packaging style (similar to that of the F5 and EX1 2nd Gen) and practically identical to that of the regular F9. A mostly black coloured box proudly displays an image of the F9 Pro on the front, along with the familiar Hi-Res Audio logo. Fiio have also taken it upon themselves to advertise the fact that the F9 Pro features a Knowles BA-driver package.

The sides of the box are entirely blank, whereas the rear only has the name of the product, it’s description, and the model number of the Knowles driver that was employed. However, no further specs are shown.

f9-pro-boxWhat’s in the box?

  • FiiO F9

  • HB1 Waterproof storage case

  • Soft carrying/storage case

  • 9 x Pair of silicon eartips

  • 3 x Pair of foam eartips

  • 1 x 3.5mm single ended MMCX cable

  • 1 x 2.5mm Balanced MMCX cable



For the F9 Pro Fiio have upped the number of accessories included. Most notably is the fact that we now get a total of 12 pairs of eartips, whereas the regular F9 only came with 6.We still get both a 3.5m(1/8-inch) single ended cable within in-line remote and mic, as well as a 2.5mm balanced option.


Another new inclusion is an additional storage/carrying case. Whereas both the regular F9 and F5 shipped with Fiio’s HB1 waterproof case included in the packaging, the F9 Pro has both the HB1 case as well as a soft carrying/storage pouch which is much more compact than the HB1. Of course you will forgo the HB1’s waterproof capability if opting for the soft case. But, other than that, the rest of the accessories remain the same.


Read: Fiio EX1 2nd Gen In Ear Headphones Review


The F9 Pro’s design is slightly different to that of the regular F9. Well, actually, Fiio decided to make a few design changes to the regular F9, which means that, whilst the F9 Pro’s design is slightly different to the initial batch of regular F9s, it’s design is almost identical to that of the subsequently updated version of the regular F9. The only differences here lies with the cable, the colour of the shell, a newly-added left and right marking, and one of the internal components.


Just like the regular F9, the F9 Pro’s design is well-thought-out and attractive in its looks. The slight design change of the shell does seem to make it sit a little more securely in the ear, but the main reason for the change was so that the shell could accommodate a larger number of aftermarket cables.

Fiio also said that, with the F9 Pro, they would have changed the stiffness of the MMCX connection. Where the F5 had a pretty poor connection, the regular F9’s just seemed too secure, which meant that swapping cables required quite a lot of effort. Unfortunately, things don’t seem to have changed with the F9 Pro. It’s still a really stiff connection, which actually prompted yours truly to have to use a pair of pliers to grip the cable securely enough in order to be able to apply enough force to disconnect the cable from the shell. The F9 Pro’s cable is better, though, as the added texture does allow you to grip it more easily. Perhaps after a few removals and insertions the connector will loosen up a bit.

Fiio also added a new little left and right markings in the form of red and blue markers. On the actual shell, close to the MMCX connection, they’ve added a little red marker to indicate right, whereas the other shell has a blue marker to indicate left. And there also correspond with newly-added coloured rings on the cable, Pretty darn neat!


Another change to the cable is that it now has a beefier right-angled plug which also features a more robust strain relief.

However, the most anticipated change for the Pro is with what lies inside.

The F9-series is based on a triple-hybrid design, consisting of both a dynamic driver, as well as a dual BA-driver package. For the Pro version, Fiio have swapped out the dual BA-driver in favour of a Knowles TWFK-30017-000 driver (which is still a dual BA-driver). This was supposedly done to “refine” the F9’s sound signature (hence the Pro moniker).


Interestingly enough, though, is that Fiio published the exact same frequency response graph, impedance, THD, and SNR figures for both the regular and the Pro version of the F9. Surely if one of the drivers are changed there should be a change to at least one of those parameters (especially the frequency response graph). When comparing the regular to the Pro version, though, it was clear that the F9 Pro was a bit more power hungry than the regular F9, suggesting that, despite Fiio publishing the same impedance and sensitivity figures for both iteration, in reality the F9 Pro either has a higher impedance, a lower sensitivity, or a combination of both. Or, perhaps this might be due to additional acoustic dampening instead.

Using the Shanling M2s as a source and a white noise test track to get an overall volume level, a measured volume match was on volume level 65 for the F9 Pro, and volume level 62 for the regular F9.

Read: Fiio F9 In-Ear Headphones Review


Perhaps the biggest question on everyone’s lips is whether or not the driver change has indeed resulted in an improved sonic performance.
arguably the biggest flaw with the regular F9 was a pretty dramatic treble spike at around 7kHz. Now, sibilance occurs between around 4kHz and 9kHz, which means that a sharp peak within any part of that range could result in a lot of unpleasantness.

Once again we have to thank Brooko on Head-Fi for publishing the below frequency response graph which showcases the differences in the frequency response between the regular F9 and that of the F9 Pro.


As we can see from the graph, the F9 Pro’s frequency response is pretty much identical to that of the regular F9 withing the bass region all the way through the mids. It’s only in the Upper mids that we start to see that the F9 Pro has a bit more presence.

Now, pretty much everyone was wondering if (or perhaps hoping) that the updated driver configuration would get rid of the treble spike that plagued the regular F9. Unfortunately this does not seem to be the case, but the severity of the spike was indeed reduced, and it has also been shifted to roughly the 8kHz mark. So no, the spike is not gone, but it definitely is reduced.

Of course, a frequency response graph only tells us so much, it does not indicate if the new driver configuration has perhaps resulted in better distortion figures or a impulse response, for example.

It should also be noted that the F9 Pro’s frequency response will be altered depending on which eartips are used (as is the case with all IEMs). Fiio did post up an explanation of the differences between the various included eartips, but I personally found that my all-time favourite aftermarket eartips, the JVC Spiral Dots, seemed to work best for comfort and subjective sound quality. Thus, the below sonic impressions are based on the F9 Pro with the Spiral Dot eartips.

In listening to the F9 Pro and comparing it to the regular F9, the increased upper mids is apparent. This gives the Pro version a bit more attack and presence to vocals and string instruments. Where these sounds on the regular F9 can be a little recessed, the Pro brings them more forward, giving them a touch better clarity. But, for the most part the regular F9 and F9 Pro sound pretty much identical. Since that sharp treble peak has been reduced in level and also moved to the 8kHz mark, it does tend to be less noticeable, but not completely gone as many of us had hoped would be the case for the Pro version.

Compared to a far more neutral set of IEMs like the HiFiMAN RE-400, the F9 Pro’s v-shaped signature does become apparent. The neutrality of the RE-400 just sound more natural, and never do you get the sense that one part of the frequency spectrum is trying to compete with another. Despite that v-shaped response, though, the F9 Pro can still be said to have a reasonably well-balanced signature.

Of course, the way we enjoy music is entirely subjective. Thus, the F9 Pro’s sound has arguably the more widely accepted “enjoyable” sound. Because of the increased bass, the F9 Pro, just like the regular F9, has more thump and slam, but it certainly cannot hope to portray the bass notes with the sheer accuracy and texture that the RE-400 can.

The thing is, though, that the F9 Pro isn’t obnoxious. Its lack of neutrality doesn’t come across as being a particularly troublesome character trait, but rather just a tasteful flavouring.

Think of it like this – for me, roasted lamb lamb is delicious. But, add a little bit of a mint sauce, and it’s a friggin’ amazing meal. Add too much, though, and you totally lose the flavour of the meat. Of course, this meal won’t be to everyone’s taste, so, objectively, just like the signature of the F9 and F9 Pro, not everyone will agree with it. As such, if you prefer a neutral signature, the F9 Pro probably won’t appeal to you. But, if you’re looking for a something that just has a bit more flavour than neutral, the F9 Pro’s signature may very well be right up your alley.

But then again, the same rules apply for the F9 Pro as those that applied for the regular F9 – with a little EQ work you can almost entirely get rid of the “colouration”.

Read: Fiio F5 In-Ear Headphones Review

So, at a $40 higher MSRP compared to the regular F9, does the F9 Pro hold a higher bang-for-buck value? Erm, somewhat. At this price, the F9 Pro is in direct competition with, for example, the MEE Audio M7P. To be perfectly frank, the M7P doesn’t stand a chance against the F9 Pro. Heck, it couldn’t measure up to the regular F9 for that matter. So when taking that into account, yes, the F9 Pro does hold quite a lot of value. Of course, the reason for the higher price as compared to the regular F9 is because of the additional accessories and change in configuration of the BA-drivers. There’s a very good chance that you might not end up using any of the included eartips, in which case the extra eartips are of absolutely zero value to you. So really, all we’re left with is the extra little soft case and the slightly improved sonic signature. From that perspective, the Pro doesn’t quite match the same bang-for-buck value as the regular F9.

However, if you do not already own the regular F9, and you’re currently deciding between the regular and Pro version, then the Pro version would likely be the better choice. But current F9 owners really shouldn’t feel obliged to “upgrade”.


The TECH MERIT rating system is designed to take as many aspects of the device into account as possible. As such, we have a basic rating, as well as a final rating. The basic rating rates the product purely as a high quality portable audio device, and is generally a good indicator of how it stacks up to its rivals in terms of standard features and specs. The final rating, however, grants bonus points for any extra features and specs that aren’t quite as common, and is a great way to judge the product as a complete package.


Look and feel: 8 / 10

Included Accessories
More than 3 pairs of eartips included: YES
Protective case: YES

Quality control: 9 / 10
Seems durable: YES
Microphonics: 9 / 10
Comfort: 10 / 10

Relatively balanced signature: YES
Soundstage: 8 / 10
Detail retrieval: 9 / 10
Sibilance: 9 / 10
Instrument separation: 9 / 10
Isolation: 7 / 10
Hiss: 8 / 10

Small size: 9 / 10
Relatively low power required: 8 / 10
Weight: 10 / 10

Competitive price-point: YES
Relative value: 9 / 10

Basic Rating: 8.8

Bonus points
Removable cables: YES
Number of cables included: 2
Premium cables: YES
Pairs of eartips above 3 pairs: 9
How premium the case looks and feels: 8 / 10
Battery life above 8 hours: –
Bluetooth: –
Apt-X: –
Volume/remote controls: YES
Metal body: YES
Interchangeable filter system: –
Premium look and feel: YES
Use of exotic materials: –
Bluetooth connection quality: –
1/4” adapter included: –
Cable management: YES
Aircraft adapter: –

Final Rating: 9.5

The Competition:

Westone UM1 In Ear Headphones

Shure SE215 Headphones

 MEE Audio M7 Pro