FIIL KEY PRO REVIEW

>>I am brazilian and I speak portuguese, so forgive my english, I’ll use translation tools to help<<

INTRO:

FIIL Audio is the TWS earphone company that I have reviewed the most – to date. It is a company that focuses not only on sound and features, but also on the design of its products. The earphone that will be reviewed today – the FIIL KEY PRO – was inspired by the “Nakagin Capsule Tower” building, which was located in the Ginza district of Tokyo, Japan.

Price: $55 USD
Color: Grey/Blue or White/Purple

FIIL reviews: T2 PRO, CC PRO2, KEY, CC NANO

FIIL LINKS:

https://amzn.to/4gxjl6n

https://s.click.aliexpress.com/e/_Dkt9skt (official store)

https://s.click.aliexpress.com/e/_DDfCGql

https://s.click.aliexpress.com/e/_DDVFdqv

SPECIFICATIONS:

• (1) 10.1mm wool basin composite Dynamic Driver (DD)

– Driver frequency: 20Hz – 20kHz
– Mic frequency: 20Hz – 10kHz
– Impedance: 32Ω
– THD: <3%@1kHz
– Rated power: 3mW, Max power: 5mW
– Touch Controls
– Bluetooth 5.4
– Codecs: AAC, SBC
– Signal range: 10 meters
– ANC and Ambient sound (40dB ANC on)
– Dual-Mic A.I. ENC: ~26dB (95%)
– FIIL+ App – EQ and presets
– Low Latency Mode
– Battery time: 6.5h (ANC off), 4.5h (ANC on), 3h in calls
– Total battery time: up to 32h
– Multipoint connectivity: 2 devices
– Waterproof level: IPX5 (earphones)
– Earphones battery: 35mAh
– Charging case battery: 380mAh
– Charging time: about 1.5h
– Charging: 60min (earphones), 100min (case)
– 2C Fast Charging
– USB-C power supply: input 5V 500mA
– Case size: 5.5cm [H] × 5.5cm [W] × 2cm [D]
– Weight: 4g (one side)(without tips)
– Case weight: 34.4g (without earphones)
– Total weight (box, earphones, etc): 115.5g
– Packaging size 10cm [H] x 8.5cm [W] x 3.3cm [D]

UNBOXING:

PHYSICAL ASPECTS:

Construction: FIIL always raises the level for its products… the company managed to deliver a product of excellent quality and premium design. Aesthetically, it’s one of the most beautiful products I have ever reviewed, both the case and the earphones are very inviting parts. The product is also very lightweight and very compact, I see that except for the first version – FIIL Key – the second version is the most portable TWS I have tested, it’s perfect to carry in the pocket of a pair of shorts. It’s made entirely of plastic, but the quality is very good, I see no difference compared to other more expensive products I have tested, such as Sennheiser, Jaybird, Samsung.

Eartips: Here we have a kit that is simple, but has a difference. The Key Pro comes with XS/S/M/L eartips, but the XS size is a tip that transforms the earphone into a “semi-in-ear”, because it will not have the same isolation as an in-ear, it’s more like an earbud. There’s even a feature in the app that you can activate when using the XS eartip. I thought this feature was very welcome. The sound really is better when activated, and the bass was increased. To my ears, I think that traditional eartips are already ideal. I tested the earphones with the size L eartips.

Here is an observation about these TWSs that have oval nozzles… It may be subjective, but in my opinion, I prefer earphones with cylindrical nozzles. I think they are better for the anatomy of the ears. If I’m not mistaken, it was Apple that started this oval nozzle thing, and from there it all became a trend.

Bluetooth signal connectivity: Pairing is very fast (after the first manual pairing). Just open the case lid and the pairing is done. The signal range was very good, reaching the 10 meters recommended by the company without any interruptions in the music. Stability is also very good, I didn’t experience any signal failures or interruptions during daily use.

Latency test: Music mode and Game mode. The Game mode option is recommended for those who are going to use the earphone for gaming, as it has faster signal transmission. Honestly, I didn’t feel any delay with Music mode, and I didn’t see any difference with Game mode either. Both modes are perfect, the synchronization was 100% as it should be.

Touch controls (gestural touches). The area where you perform the commands is at the top of the stem, exactly where the white LED is in the center. It’s not a very large space, but it’s very easy to touch with your finger… And, by the way, you don’t even need to place your finger exactly on the circle to perform the command, just touch the edge of the area and the command is recognized. The commands were very responsive, everything worked quickly and perfectly.

Multipoint connection: With this feature, we can connect the Key Pro to two devices simultaneously. It worked perfectly here, I was able to pair my notebook and smartphone to the Key Pro. And the good news is that even if the main pairing is on the notebook, I can change the functions of the earphone (ANC, etc.) using the FIIL+ App (but the earphone needs to be paired with the smartphone as well).

FIIL+ App: The app is available for Android and iOS. The screenshots below are pretty self-explanatory, so I will only comment on what is necessary.

(Screenshots of the S22U Android 14, English App V4.1.11).

I really liked the FIIL App, it’s very clean, everything is very easy and well explained. It has what I consider an essential item for any TWS on the market, which is a bandpass equalizer. And here we have something even more positive, the equalization works “live”, that is, if you make a change in a frequency, the modification will take effect immediately. This is perfect for those who want to adjust the sound in a more detailed way.

MAF (My Audio Filters): Or the same as ANC and Ambient Sound. This is a section where the company allocated the anti noise canceling features, as well as “ambient sound” (hearing external sounds around you). In total, we can mention 5 functions: ANC Mode, Open Mode, Windy Mode, Monitor Mode, and MAF Off (feature turned off).

ANC and Windy Mode are very similar, as are Open and Monitor Mode. So basically I’m only going to talk about ANC and Open Mode. I found the Key Pro’s ANC to be very good, especially for blocking the lower frequencies, it gives a noticeable cut in the lower sounds, while the upper-mids and treble frequencies are slightly softened, and it’s still possible to hear some sounds (just like other TWS that have this technology). Open Mode is the same as what other companies call ambient sound, which in practice means opening the microphones to capture the sounds around you. Here in the Key Pro, this function really works well. Practically every TWS that has this function always performs well.

Fit and comfort: This is the standard fit of these earphones that come with the stem on the side, so there are no surprises. The earphone provide a good fit and good comfort. Before I started evaluating the Key Pro, I was using the Tanchjim Mino as my everyday TWS, and it also has the same design, so for me it was like swapping six for half a dozen. I found the isolation to be good – with the L eartips, but with the XS eartips the isolation becomes something similar to an earbud, that is, few isolation. I found the insertion to be average.

Microphone: I found the quality of the Mic to be good/ok. It can be used for trivial conversations, social media apps, etc. With a fan turned on towards my face, the Mic didn’t pick up wind noise while I remained silent, there was only added noise when I spoke (and even then, it was somewhat moderate).

Accessories: The product comes with a USB-A to USB-C cable.

SOUND ASPECTS:

I understood the sound of the FIIL KEY PRO as a U-Shape earphone. It’s a very pleasant earphone to listen to, has a very soft sound and a boost in the sub-bass. It reminded me a lot of the sound of the Tanchjim Mino, which I still have with me and I was able to compare the two side by side. The Key Pro has a little more emphasis on the sub-bass region compared to the Mino, the latter in turn, because it has fewer subs, stands out slightly more in the upper-mids region.

It’s important to remember that the KEY PRO has several EQ presets available in the App, and also 3 main equalizations that the person can choose: Bass, Original, and Treble. I evaluated the earphone with the Original preset and MAF Off (off).

Bass:

Quantitative: I think the bass of the earphone is at a moderate level. The Key Pro brings an emphasis on the sub-bass region, which ends up being the region with the greatest presence in the bass. The mid-bass is also present, but I think the focus is more on the subs. The Key Pro has a quantity that will please people who enjoy bass, especially if you use the preset feature with increased bass. Comparing it to the Buds FE, I found the bass on the Key Pro to be more balanced, the quantity on the Key Pro was more accurate, and I already see the Buds FE as earphones that have more boomy bass. I found the bass extension on the Key Pro to be very good.

Qualitative: The bass has authority, weight, mass, body, and strength! Fortunately, the right quantity is what makes the earphones play so well, because the bass isn’t exaggerated. The impact is strong and full-bodied, but it’s worth remembering that it’s not excessive (in my opinion). The bass has a lot of texture, and also good definition. The physicality of the bass is also another striking feature here on these earphones, and once again I think it doesn’t go overboard, it delivers what is satisfactory. For example, when you’re using a bass drum, you feel more vibration and mass in the sound of the instrument. I think the Key Pro is a pair of earphones that will play the most fun genres well, or those that need a little more bass, such as EDM, Hip-Hop, Metal, Rock, Reggae, POP, etc.

Midrange:

Quantitative and qualitative: The midrange is slightly recessed, giving a smoother, “softer” feel in the presentation. This characteristic of the midrange makes the sound in this region “warmer”, and I think this is great for those looking for earphones that avoid hearing fatigue due to harsh/aggressive midrange. The Key Pro is very calm in this sense, zero fatigue. The more recessed the midrange is, the less clarity you’ll have in the presentation, right? Now, fortunately, this relation between recessed and clarity was well done here in the Key Pro, because the earphones still deliver an interesting amount of midrange in their sound.

Voices: The Key Pro certainly delivers better performance for voices with lower timbres. The sound of the earphones in general has a warmer side, which makes baritone and low voices more engaging, with more textured, and more natural. I think that it will benefit those people who have a music library with more male/low voices. Obviously, for voices with higher timbres, the Key Pro will also deliver good sound, although the performance won’t be the same as that of lower voices (in my opinion).

Treble:

Quantitative: I found the treble to be moderate to low. At times the treble will be more present, and at others, you will feel that it could have a little more. You can see there in the frequency response graph that around 9kHz the treble has a vertiginous drop, so we certainly know that we will have some sounds that will sound softer, lower in the presentation. Now, the good thing is that it didn’t affect the treble extension. As I said in the midrange paragraph, I can also make the same statement here, the Key Pro’s treble won’t make you feel hearing fatigue or discomfort.

Qualitative: We will have treble that is smooth, controlled, soft, silky, comfortable, and has good definition. I think the detail is ok, almost all TWS have this level of detail, perhaps only the Earfree i3 is one that has a slightly higher level of detail. The airy is also ok. The sparkle is very polished and discreet. I didn’t hear any shrillness, harshness, piercing, or sibilance. In my opinion, after hear to the treble, it’s possible to draw a sound profile and say that the Key Pro goes very well with more lively genres, such as extreme metal, since it’s a genre that has a lot of activity with instruments like hi-hats or cymbals, so the earphones make the presentation more “soft”. Anyway, if you’re looking for more performance for genres like jazz, classical music, instrumental acoustic music, then the Key Pro might not have the best treble.

Soundstage and Imaging: I found the soundstage to be average, which means it’s good but not the biggest I’ve ever heard, especially when compared to wired earphones. The soundstage we have here is the standard for the presentation to sound, neither compressed nor spatial. For a TWS, I think it’s good. I also found the imaging to be average. You can hear everything with good definition, but it’s the separation standard I’ve been hearing in most TWS earphones.

Driver flex test: I didn’t hear any driver flex when inserting the earphones into my ears.

Amplification: Unlike wired earphones, this is just to talk about the product’s volume level. During my use, I found that the Key Pro reached a sufficient volume for my ears and still had 2 volume steps left on Android (13 out of 15 levels). I confess that although it was enough for me, the Tanchjim Mino managed to reach a volume higher than the Key Pro presented, in fact, there is still 2 more volume steps (approximately).

PROS AND CONS:

GRAPHS BY YOSHIULTRA:

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