The FiiO F9 has 1 dynamic driver and 2 balanced armature drivers under the hood. There are lots of hybrid designs in the market now, yet the F9’s strong suit is the price. But of course the configuration is not everything, there needs to be a good cohesiveness, good control of the dynamic driver and good precision from the BA drivers.
Does F9 tick those boxes? Let’s find out.
The FiiO F9 has good amount of bass and if you like bassy type of IEMs, there’s a good potential for you to like it. Thanks to the dynamic driver it has a good amount but it’s not something I would call “bass heavy”. On the other hand, there’s certainly a focus on low frequencies. They’re the focal point most of the time, making their presence heard, especially on bassy recordings.
Mid & subbass balance is good, altough I think the midbass is ahead in terms of quantity. It’s important to set your expectations right in this price range so I think it’s quite nice. Is it nicely controlled? Sometimes yes, sometimes no. That depends on the source and the recording but you shouldn’t expect top notch control over the bass, like Mid-Class or TOTL hybrid IEMs.
The important thing here is the midbass. Altough it’s a midbass focused IEM, the midbass hump problem is almost non existent. I say almost because it’s not perfect. There’s a small midbass hump, yet I don’t think it will bother and you can use a small amount of EQ to make it flatter. Fortunately there’s no obvious bleeding on this part, so the mids can shine if they’re asked to. Not on a high level but you can’t ask more than this for the money. So fairly good separation between bass and mids but it could’ve been a little better if you ask me. It’s positive to hear that subbass is not overpowering, but just a little flatter midbass and slightly more kick from subbass could’ve made this IEM even better in my opinion.
The bass doesn’t reach very deep and altough the texture is not too bad, again I think a little more bass kick from subs would’ve been nice. Instead, the focus usually is on the midbass. That makes the IEM just a little slow for fast paced music genres. But that part can be better or worse in proportion with the source quality. But I should say bass is not artificial and not overly elevated as a whole. This is a natural bass response, maybe a little bit better tuning can be done in the future to make it better.
This is not a mid monster and there are reasons for me to say that. The mids are slightly recessed overall, making the F9 a slightly V-Shaped sounding IEM. Mids are not too distant though, there’s still good resolution and definition in this part. Mids also contain very good tonality and naturalness so it in no way like is some entry level IEMs that sounds artificial or thin. The mids are full, dynamic, transparent and coherent. Along with good level of dynamism for the price, you won’t be disappointed but in terms of amount, if you like more forward mids in your IEMs than this obviously is not the first choice.
Mids are nicely separated from low frequencies. So despite being a little back in the stage, you can hear the good tonality and transparency across the range. I’m no way in discomfort in terms of mid presentation but I prefer more quantity from the mids. Maybe with a little less midbass presence, mids could shine more with the F9.
But for 100$, there’s no need to be harsh on this IEM really. In the past I heard worse or similar presentations with more expensive IEMs. However there’s a peak that lies down on upper mids & lower treble that needs to be equalized to some extent. Foam tips can be useful here, making them smoother and more coherent by sucking out those peaks. Is it too discomforting with sibilance? No, but it for me personally needs to be addressed. Either with foam tips or EQ.
Lower treble has some amount of peak as I’ve said, you either could face it or not, depending on the recording and source quality. But once you solve that with EQ or foam tips, you can focus on the good treble extension, resolution and detail retrieval. Treble is quite prominent, almost the same amount as the low frequencies, but not harsh except for the lower treble. The cymbals can be harsh for you so be aware. It’s good to tame down that part with EQ.
Highs have good clarity and resolution, and also can sound nicely articulated. The treble quality of the FiiO F9 is very very good and you’ll be pleased to hear the details from it, especially for this price. Highs give good lift for this IEM to sound airy and open, so it doesn’t sound congested in any way whatsoever.
Treble also has good positioning with being at the right distance and not in your face. It usually sounds quite refined and has good control on upper treble. The roll off in this part is slightly apparent but it’s not something to complain about because the roll off isn’t too much. So extension is good in my opinion. Could it be better? Well it can always be better, but not for this price level.
Overall, except the lower treble region (which you can easily sort out with giving -2/3db on 8khz) treble is very nice with the F9.