Custom Art FIBAE Black – The Black Siren

The Black is appart in the FIBAE lineup, in that it’s based on a radically different design pattern - from the ground up. There is a lot of work into the technical design, especially in acoustics and it shows. It might be priced as an entry level custom IEM (and a mid priced universal) but it sure doesn’t sound like one! The Black's mids are probably my favorite mids regardless of price or driver tech.


  • Superb midrange with soulful timbre both for instruments and vocals
  • Leading class black background
  • Fun mid bass tuning
  • Refined treble presentation
  • Very low distorsion
  • Superb fit and build, Isolation is as good as it comes
  • Tremendous value for money / competitive pricing Cons


  • Not the fastest balanced armature
  • Mid bass can be a bit too much on some tracks, especially compared to the universal Black
  • Limited sub bass and treble extension

Price : 450€
Product page :


Strangely, the Black is my first Custom Art IEM. I had heard a lot of good things about the FIBAE 3 and a few testimony of the uniqueness of the Harmony 8.2 but for some reason it neither seem to complement my IEM collection at the time.

When the Black came out, I was very much intrigued by the technical implementation as well as the signature description : « Designed as a statement, breaking rules and going against the current. (…) Natural smooth sound with fast-paced deep bass, forward mids and smooth extended highs. Tuned for correct tone and enjoyment without sacrificing extension on both ends. It’s one of our most versatile IEM yet combining musicality and precision ».

I must admit, I have a weak spot for people who are going against the current in general (the Warbler Prelude was also high on my list by the way), for smooth musical signatures, and for single driver implementations. Combine that with a very agressive pricing – and one of the few manufacturer still allowing transfer and decently priced reshell options – and I was instantly in for a pair of custom Black!

I had to check the claims stated above and it was the perfect excuse to jump aboard the Custom Art train. Let’s see how this turned out!

The FIBAE Black are the first 3D printed CIEM from Custom Art (always with perfect fit!)


The Black is the first IEM in Custom Art lineup that is 3D printed and also my first 3D printed custom IEM. I have had some of the finest built custom IEM in the VE8, and since other 3D printed IEMs in the EM64 and… FIBAE 4. The Black have a superb fit, with perfect seal and isolation. The fit of the Black is the tightest I have had the finish is superb and the transparent faceplate is a nice way to enjoy the Black engineering. I don’t have a problem with tighter fit but I gather some people were not as comfortable and that might be why when I received my FIBAE 4 based on the same prints the fit was just a hair more relaxed while retaining great seal and isolation.


The build of my FIBAE Black is superb at any price point. I just wished that Custom Art adopted a horn bore design, like my Phantom and VE8 and Custom Art very own FIBAE 1, as it prevents spending time cleaning up the wax at the bore exits. But I am nitpicking, and it’s probably much more complex to implement with 3D printing.

The FIBAE Black transparent faceplate highlight the superb engineering


The Black feature a very smooth signature, with a nice mid bass boost that provide good rhythm, good lower mids presence that infuse a definite but not overdone warmth. The midrange is linear with a gentle and well thought out bump in upper mids to provide articulation and just a touch of lower treble to provide excitement. Upper treble is where things are quite subdued but convey nuances and air avoiding any congestion which is tricky with richer and smoother signatures. Although it’s on the more intimate side with an average width, the depth and height stand out as well above average and the soundstage is more expansive than one would think and very balanced in its distribution : the work on acoustic design certainly paid off there. I found the stage image to be very good and accurate.

The softer attack and smooth decay overall making for a fatigue free but engaging listening experience. The exceptionnally black background (wait, was there a hint in the name to begin with?) helps provide a lot of contrast, where other IEMs will rely on detail retrieval and treble presence. This is a key item of what makes the Black special in my opinion and possibly a benefit of the Helmholtz resonator tech that Custom Art used to build the FIBAE Black. Another benefit is very low distorsion, and I found myself pushing the volume with great pleasure on some tracks.

We often focus on the frequency range but the Black is a good example of the limitations of describing sound quality based on the frequency range and distribution across bass, mids and treble.

Now that I have said that, I’ll precisely do it nevertheless 😉


As I have hinted above the FIBAE Black feature a signature with limited bass extension there isn’t much sub bass to talk about. The focus is clearly on its mid bass with a generous boost that gives it a definite toe tapping factor. The bass line has good presence and percussions are deep and full, but the Black won’t provide the kick factor that a sharper attack would provide.

As I have had the opportunity to audition the universal FIBAE Black as well, this is one key difference with the custom form. I found the universal Black more balanced than the custom : note that the full seal of the custom is not the only thing that came into play as I had custom art silicon custom tips to try out the universal. I am wondering if the sound tube of the universal is not a tad bigger than the custom there… I found the bass less prominent in the universal Black making for a more balanced presentation overall.


This is where the magic happens, maybe also because it’s the Black primary focus and extension either way doesn’t distract you from their mesmerizing mids. Let’s say it, the Black are probably my favorite mids regardless of price, driver tech or anything else… yeah well I am a romantic, blame me! And the Black mids are as romantic as it gets, full sounding with rich textures and a soulful timbre that is north of neutral but who cares? Music is emotion first, isn’t it?

Vocals are a special highlight of the Black. Male vocals are firmly seated in the lower mids presence and provide a sense of power while remaining smooth no matter what, some will say it lacks a rougher edge that does exist on certain tracks and they wouldn’t be wrong but it’s not the point of the Black tuning. Similarly female vocals are sweet and enticing with again beautiful textures that pop against that very special dark background, the smart upper mids and lower treble tuning provide engagement but again some might find that it doesn’t go far enough to reflect some female performers ability to go to the edge.

The Black has its own interpretation, as in it will smoothen the edges but within those smooth edges lie the beauty of their soulful timbre and rich, detailed textures, both for vocals and instruments : the strings (especially the double bass), brass and woodwinds are of special note. I found myself surprised at how good the Black are with jazz, instrument separation is very good and the Black handles complex passage quite well.

Quick comparison to the customs : the universal feature a tad more upper mids furthering the differences between the custom and the universal which is indeed more articulate and balanced.


The Black treble are interesting : what they lack in extension and upper presence shouldn’t fool you into thinking that this is a strictly speaking descending signature : it’s more complex than this.

The Black don’t extend very far but they have more energy and detail retrieval ability in the lower treble region than most would give it credit for on a quick listen. Snare and cymbals have good presence, with the necessary energy to punctuate tracks adequately. The black might be smooth, but they don’t lack energy, the delivery will just remain smooth obviously avoiding any harshness by design due to limited extension and smoother note attack. The fact that decay is on the longer side will keep note lingering a tad more, but it’s not overdone and decay is very natural.

As for upper treble, the Black won’t scratch the itch for detail retrieval and maximum excitement but it has enough presence to provide air and the Black never sound congested unless the master itself is poorly done.


The Black is appart in the FIBAE lineup, in that it’s based on a radically different design pattern – from the ground up. There is a lot of work into the technical design, especially in acoustics and it shows. It might be priced as an entry level custom IEM (and a mid priced universal) but it sure doesn’t sound like one!

I took my sweet time writing this review, because really I often got lost into the music, which usually is a good sign of an engaging IEM. In the case of the Black I’ll go as far as saying a mesmerizing IEM, highly engaging with a lot of facets. That’s the second aspect of why it took me a bit of time, both because I found myself absorbed into its smooth and beautiful portraying and because it’s not that easy to « analyze » and try to depict how its « magic » works.

The mids are the star of the show and among the best rich, full, smooth mids you’ll ever find while not sacrificing articulation and separation. That’s the easy part of the review.

But what was hidden in plain sight because you can’t see it until you don’t hear it elsewhere, the FIBAE Black has an exceptionally black background that does a lot for contrast. Notes pop against that background and a lof of the perceived detail retrieval that comes from this makes for a very special experience that a whole bunch of upper treble won’t provide in the same way. In the same spirit, the notes softer attack won’t provide shimmer or bite, but the Black more than makes up for it by providing a delicately beautiful presentation of the music. I am pretty sure both my blood pressure and heart rate was much lower thanks to the Black 

This became apparent when I started switching with other IEMs which took me a while because I was « stuck », enthralled in the mesmerizing voice of the Sirens…or should I say Black Siren, pun intended as I must say the super heroin is neither my favorite character of the « Arrowverse » neither does it represent the FIBAE Black very well (given its special power is to disable enemies by defeaning them which is the total opposite of the FIBAE Black). I just thought it was a catchy title, as to me the FIBAE Black are just as enticing as a Siren and well, they have this amazing black background!

Beware my friend, of the song of the Black Siren, deafening beauty might just lull you into a second state!

This review was initially published on :

Custom Art FIBAE Black review on frontpage

I have happily purchased and paid the full (pre-order) retail price for the FIBAE Black, this is not a sponsored review.

This review is based on over 200 hours listening to the Black, sources were Hiby R6 Pro and iDSD Micro BL, and the iPhone XS Max with dongle all with the stock cables. I tried several cables with the Black : Hansound Zen 8 wire balanced 4.4 and ALO Superlitz balanced 2.5 with 4.4 adapter with the Hiby and 3.5 with micro BL. Of note is the fact the Black is not as source dependent as other IEMs and the FIBAE tech really works well : the IPhone dongle with stock cable already provides 90% of the great qualities of the IEM.


The FIBAE Black in custom form comes with a solid black plain card box which contains a black Pelican 1010 hard case with a transparent lid itself containing a small blue pouch with a cleaning tool.


  • Single proprietary Balanced Armature
  • Pressure Optimizing Design
  • 108.5dB @1kHz @0.1V
  • 5.2 Ohm @1kHz (+-0.8 Ohm 10Hz-20kHz)
  • 3D printed acrylic shell
  • 10Hz-16000Hz (+-10dB into IEC 60318-4 coupler)
  • Custom or Universal fit

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