CustomArt Fibae 4

Before starting this review, I would like to share technical aspects and package details.

Also, I would like to thanks to Piotr for this great opportunity.




Single low, Single full-range, single proprietary high, single proprietary super high

Top Firing Balanced Armature Drivers

Flat Impedance technology

115dB @1kHz @0.1V

Low % THD

8.1 Ohm @1kHz (+-0.95 Ohm 10Hz-20kHz)

10Hz-21000Hz (+-20dB into IEC 60318-4 coupler)

Custom or Universal fit



Package Details:

– Carton box

– Peli 1010 case

– Zipper case

– Wax pick tool

– Drying pellet

– Warranty card

– Ear tips in 4 sizes (universal fit only)


Test Equipment:

Lotoo Paw Gold Diana

Astell & Kern AK120

Opus #1


Emotiva Big Ego


Package, Design;

Fibae 4 comes with a black box that is the same as their other products. Inside of the box, there is Pelican 1010 case and mini zipper soft carrying case with tips and cleaning tools. I’ve always been a big fan of Pelican 1010 case to store my gears, and probably I have more than 10 Peli1010 case at home. Package is not fancy and unboxing experience is not so impressive like some brands, but everything you need is in to the box.

If I have to choose only one company that has the most beautiful earphone design, I would pick the Custom Art. They make the amazing beautiful earphone; you should check them on their Instagram page. They did a fantastic job with my Fibae 4 which is the cutest, sweetest, prettiest earphone that I have ever had. It looks like a candy and I feel like I’m going to get a delicious taste if I eat it. I am hundred percent sure that all the babies want to eat it when they see. Build quality is fantastic as expected, no flow, no defect, nothing, it is beautifully made. 2 pin socket feels super solid, and it is so tight. I had a hard time to took it of the stock cable. Stock cable looks great and it is better than most of the stock cables but the only thing that I don’t like is its memory wire. Unfortunately, I don’t like memory wire and I never find good fit on it. F4 (Fibae4) doesn’t have a big shell, on the contrary it is fairly small. Its rounded edges and ergonomic design make it super comfy. I’ve used it many hours and I haven’t felt any pain or discomfort issues at all. I believe no one would complain about its comfort.



Normally, when I listen to earphone for the first time, I could understand how is the sound signature in first minutes, but with Fibae 4, it took longer than I thought and I couldn’t make any judgements. I decided to burn in like 50 hours than try to get used to its sound, and it started to give some result. The indecisions of the beginning that I faced are disappeared and I fall in love the Fibae 4’s sound. Fibae 4 sound is typical V shape, with powerful bass which hits like Thor’s hammer and relaxed smooth trebles with laid back, detailed mids. Overall sound is tad of dark but don’t let this mislead you, all the details and nuances in the music are there and easy to hear. The high frequencies are not in front of the other frequencies and are generally creamy and smooth. Mids are leaned backwards but it provides good amount of detail. Bass is the locomotive frequency of the Fibae 4. Extremely strong and deeper which dominates the overall presentation. One thing that I quite like about the bass, its articulated and natural presentation. Bass is not dry and dull tonality in despite of balanced armature drivers, on the contrary it has a very natural and organic presentation.

Fibae 4 has smooth, relaxed trebles that never harsh or sharp. It puts pretty enough space to separate the instruments and support to soundstage wideness in a good way. Although its dark presentation, it’s energetic yet detailed. It’s laid back but it never fails to show its ability to bring details. You may not clearly hear the details in the very first listening, but when you get used to it, you will notice that all the details and resolution hidden in the upper frequencies are actually there. Upper trebles missing some extension and dynamism but it makes easy to listen for long hours. This reminds me the Um Pro30 some way. But I would like to tell that some people might want more quantity, so this might not be a good option for treble-head people. Generally, trebles play well, but not as remarkable as bass or mid frequencies.

Bass frequencies might be the star of the show, but there is another hidden gem on F4 which is the mid frequencies. It is laid back and step up behind of the overall sound but it has fantastic details and pattern of the sound that produces. Layering an imagining are also great on mid frequencies. Stringed instruments are not dry and it has natural timbre. Mid bass doesn’t give any stress and it plays airy and clean. Vocals and instruments’ location are easy to distinguishable. While listening to Above & Beyond, it creates an incredible atmosphere like in the club and all the sounds spread out to the stage and vocals can be heard clearly without narrowing the soundstage. I fall in love its mids tuning with every vocal Trance track that I listened. As a result, Fibae 4 became my latest favorite EDM genres earphone. Smooth and mellow presentation doesn’t give any fatigue and although its dark sound never become muddy, ever.

Who said that balanced armature driver doesn’t have punchy bass like dynamic driver? Well, Fibae 4 will destroy those thoughts right away when you hear it. It has a huge bass that rumble of your bones and puts a big smile on your face then it pushes you to open another bassy tracks to listen it over and over and over again. Bass is super enjoyable to listen and there is a plenty of power on low frequencies and it reminds itself with every song that you listen. If I remember correctly, talking about more bass quantity than SE846. Although the bass is quite high in quantity, it does not tend to spread out or dominate the entire sound frequency, but it has some minor bleeding in to the mids that don’t bother me at all. The bass doesn’t dazzle in speed, but it still offers pretty good speed in this regard.

he soundstage is quite wide and simplifies to listen instrument and positioning. Air between instruments are great. The depth provides a good amount of space and help to improve layering an imagining. Background is not pitch black but it is pretty clean.


Cable Rolling:

Effect Audio Origin:

Origin is limited budget series of the Effect Audio cables’ and I got 2 set of them when they released. To be honest, Origin doesn’t make any drastic change on Fibae 4 and its sounds almost similar with the stock cable. Bass is punchy, deep and mids are laid back. Tonality is almost same, but Origin adds some extra brightness on overall sound. The only change that I noticed is on the highs. Highs are slightly clearer and more prominent than the stock cable. Soundstage remain same or I didn’t notice any change. Overall, improvements are mostly nuance and there are no big differences between stock cable and Origin. After comparing stock cable with the Origin, I come to conclusion that stock cable is really great in terms of sound.


Rhapsodio SGD2.98 MK2:

SGD2.98 MK2 is gold plated silver cable from Rhapsodio Audio and its overall signature is warm, lush and smooth. When I try with the F4 I just realized in very few second that it won’t be a good match. F4 sound is already smooth, extra warm sauce make it dark and almost muddy in this sense. The main improvement on the bass frequencies, it hits more, goes deeper and at the same time it loses its control and bleed in to mids. Only positive improvement on the soundstage, it adds more width and depth make it more holographic. Overall, it is not good match with F4 for my personal taste.


Effect Audio Ares:

Ares is the well-known cable on the community and it deserves its good reputation. Due to its budget friendly price, it is the most popular product of the Effect Audio lines as well. F4 and Ares are not the best pair but still they have good synergy. As expected from a copper cable, bass quantity is slightly increased and feels more controlled and tighter. Mids are slightly forward and thicker than the stock cable. Trebles are same in quantity but presentation is cleaner and clearer. Soundstage is better on both width and depth and also there is more air than the stock cable. Ares matches good with F4 but still it’s not what I looking for.


Penon Audio Leo:

Leo is a pure silver cable from Penon Audio, and this is the best cable on my hand to match with F4. Bright and open presentation of the Leo makes great soulmate with smooth and warm sounding Fibae 4. Bass stays in same quantity but it is much tighter and more controlled, and also slightly faster than the stock cable. Mids are more open and natural, and also the distance between vocals are slightly more forward. Trebles are clean and clear which Leo mostly touches on high frequencies. There are noticeably more sparkle o highs and details are more audible. Soundstage is more open and wider as expected and, instrument separation is much better. Overall Leo is great match with Fibae 4 which I am using it with F4 right now.




Fibae 4 vs Fibae 2:

Both F4 (Fibae 4) and F2 (Fibae 2) looks geourgeus looking IEM. F2’s space concept design is one of my favorite and anyone who sees loves at the first second. F4 design is completely different and its super sweet colorful design hard to dislike. There is no much to say about qualities and design, both earphones are top notch in this sense. F4 body is little bit fatter and more rounded shape while F2 is slightly slimmer and also its nozzle is little bit longer. Both are pretty comfortable and no issue with the fit. These are coming with exactly same type of box and only difference is the stock cable that F4 has. Sound wise, F4 is better in every technical aspect from F2 but that is all about personal preferences. F2 has more forward and upfront presentation, while F4 has more open and V shape like sound. Bass is more authoritative and powerful on F4. It hits harder and goes deeper. F2’s bass is more controlled, slightly faster and it takes powers on the mid bass. Both are definitely bassy earphones. Mids are more forward and centered on F2 while F4 is more laid back and distance. Due to its forward presentation, F2 has more melancholic and romantic presentation while F4 has typical V shape mids, but F4 is more detailed and better on resolution. When I start to compare side by side, I felt F2 has more in treble quantity but after some couple of tests I realized that F4 has slightly more in quantity. F2 has well extended, clear and detailed trebles. Both are good in quantity and quality. Soundstage is better on F4, wider and more open while F2 has limited soundstage and its forward mids has big role in here for sure. Both earphones are great in terms of sound, build and design. As I mentioned before, it is all about preferences.



Fibae 4 vs Nocturnal Atlantis:

Fibae 4 and Atlantis shares same number of drivers, but their presentations are completely different. Let’s talk about the design and build. Both earphones are beautifully designed. Material and build quality are top notch on both, no complaint here. Atlantis has golden space design while F4 has colourful dots. Sounds are totally different on both. Atlantis has more neutral reference like sound while F4 has more fun sound signature. Bass is much more in quantity on F4 and it goes deeper than the Atlantis. Atlantis has more linear and rolled off on bass when I compare to F4. Atlantis’ bass is faster and better on decay but F4 is punchier.  Mids are more laid back and smooth on F4 while Atlantis has flatter and slightly forward. Trebles are more prominent and extended on Atlantis. Details and resolution are also slightly better. F4 is also detailed on trebles but Atlantis’ bright presentation makes it prominent and brings details more upfront. Stages are almost par and maybe Atlantis a bit of wider but hard to understand. Both earphones are great for specific genres. Fibae 4 shines with EDM, dance, pop, R&B while Atlantis better choice for Classical, jazz, country style genres.




Custom Art has a very special place in audio community and Piotr and his team create really amazing IEM in every new release. And, Fibae 4 has one of the amazing IEM that they made. Bass is so powerful yet detailed and mids are smooth as like hash brown and trebles are detailed and relaxed. Ergonomic shape of the body is great for long listening or outdoor. I don’t need to express of design, just as I said, check their Instagram page, they are building one of the best design IEM in the market. If you looking for a good IEM fantastic for EDM, Pop, R&B and also has an outstanding build quality and great comfort, I can highly recommend the Fibae 4.

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