Custom Art is a Polish manufacturer helmed by the reigning King of CIEM Customer Service, Piotr Granicki. Having spent almost a decade in the DIY community, Piotr started Custom Art in 2012 with a clear focus towards value-for-money performance and a clinical expertise in both acrylic and silicone IEM production. Custom Art – now one of the biggest players in the CIEM industry – is looking to break new ground with their Flat Impedance Balance Armature Earphone (or FIBAE) technology. FIBAE-equipped IEMs are designed to maintain a consistent sound signature regardless of source. One of the first two out of the gate is the FIBAE 2: A dual-driver monitor that jabs far beyond its price range; delivering dynamics, musicality and engagement you’d be hard-pressed to find in the sub-$1000 market.

Custom Art FIBAE 2

  • Driver count: Two balanced-armature drivers
  • Impedance: 7.1Ω @ 1kHz
  • Sensitivity: 113dB @ 0.1V
  • Key feature(s) (if any): FIBAE technology
  • Available form factor(s): Universal acrylic and custom acrylic/silicone IEM
  • Price: €475
  • Website:

Build and Accessories

The FIBAE 2 comes in a black mini-shoebox with a Peli 1010 nestled snugly inside. The Pelican case houses the IEMs themselves along with the standard set of accessories: A cleaning tool, desiccant and Custom Art’s signature “Hi.” brochure. As I mentioned previously in my Lime Ears Aether review, these are the bare essentials for a custom in-ear monitor at any price point. Although I won’t be knocking off any points, I would’ve loved to see a microfibre cloth, an airline adapter or a cleaning spray of some sort for silicone CIEMs. At least the brochure gives it some personality.

The FIBAE 2 is my very first silicone IEM. Having owned six acrylic monitors with varying builds, fits and finishes, the FIBAE 2 is certainly a unique wearing experience. Overall, it fits slightly tighter than my acrylic Custom Art Harmony 8.2, but it forms far less breakable seals and adheres to the skin more effectively too. As a result, you get superior isolation and comfort, and a stronger feeling of seamlessness between your inner ear and the bodies of the IEM. It does take a few days to break in the silicone’s initial density and rigidity – and to learn how to properly push them in and pull them out – but they’re an absolute joy to wear and use afterwards.

Both physically and cosmetically, my FIBAE 2 is an incredible achievement. Piotr is one of the most collaborative and open-minded folks in the industry when it comes to customisation. The final design we came up with is the culmination of over 20 e-mails, and tons of effort and experimentation on Custom Art’s part. Consisting entirely of bespoke options, my personal unit bears a distinct black-and-gold theme, with elements that react differently and dynamically to light. From the mica-infused black-and-gold shell to the cut-out and laser-engraved faceplates, the FIBAE 2 is easily one of the best-looking and best-built IEMs in my entire collection.

FIBAE Technology

Custom Art’s goal with FIBAE technology is to produce IEMs that perform consistently regardless of the source’s output impedance. This was done, according to Custom Art, “By changing Balanced Armature driver character from inductive to resistive…”

As seen in the graphs above, the single FIBAE driver’s impedance remains unchanged throughout the entirety of its frequency response. Its equally-consistent electrical phase plot also affirms that the driver is – in fact – resistive in nature. Piotr has confirmed to me that the FIBAE 2 performs just as brilliantly under these conditions. Pragmatically, what this means is no matter what amp circuit you use, FIBAE IEMs will constantly output the exact same signature.

But, there is a case to be made for sound signature vs. sound quality, because they are not one and the same. In terms of frequency and CSD response, FIBAE IEMs will perform independent of the source, but the data that’s fed to them – i.e. instrumental fidelity, spatial cues, micro-detail retrieval, etc. – will be determined by the DAC’s ability to resolve that information. Theoretically, FIBAE-equipped IEMs are the most ideal linearly-scaling transducers available today. And, in the real world, this is absolutely true. I’ve listened to the FIBAE 2 on several sources – including the Chord Mojo, the Onkyo DP-X1, the Astell & Kern AK70-Kai, and the Macbook Pro – and the only differences I’ve found were with regards to soundstage accuracy, image solidity, micro-detail audibility and left-right separation. The IEM’s signature was left perfectly untouched, and I was left entertaining the prospect of a neutrally-tuned FIBAE IEM for proper gear evaluation. But, I’m getting ahead of myself; onto sound impressions.


The FIBAE 2 is an IEM that’s primarily driven by dynamism and liveliness. Although it has its own specific flavour and atmosphere, how it portrays music isn’t necessarily dictated by melody, colour or tone; rather, it shines through rhythm, texture and energy. It’s akin to the contrast between a guitar solo and a drum solo. The former emotes through harmony and tonal colour, while the latter does so through pace, kinetics and flow. The FIBAE 2’s stage is more-or-less absolute, with dimensions, note sizes and temperatures that hardly ever shift from song-to-song. It’s a stage with great proportions – one of the widest, deepest and best-layered out of any 2-driver IEM I’ve heard – and one that’s bolstered by a charming richness. A musical warmth belies its instruments – endowing them with body, substantiality and weight – but, despite this, its impressively black background makes way for top-class separation as well. Instruments and vocals aren’t the most well-outlined or well-defined, but they are dead easy to locate with spatial stability and stereo imaging that’s simply unrivalled at this price point.

The FIBAE 2 carries the Custom Art house sound through-and-through. Embodied by a slightly darker tone, the FIBAE 2 attains its richness through an abundance of decay and an absence of peaks. By softening transients and allowing them to roll-off slowly over time, the FIBAE 2 acquires massive headroom, smooth dynamic performance, and tons of harmonic texture. When a cymbal is struck, most IEMs accentuate the CRASH! before dropping drastically in SPL as the cymbal sizzles out its overtones. On the other hand, with the FIBAE 2, what you’d hear is a punchy crash… followed by harmonics that linger at a similar level. What this adds to its presentation is a unique texture somewhere between smooth and coarse – almost like film grain – as well as a laid-backed-ness that associate the FIBAE 2 and its brethren with words like organic. However, where this falters is in transparency. Due to a lack of transient energy, instruments struggle to pop into the foreground of the soundscape, and the images they produce begin to blur as a result. But, its fantastic separation, stage organisation and pitch-black stage compensate for this to an admirable degree.


The FIBAE 2’s bass is the driving force behind its powerful presentation. It’s beautifully rounded, naturally accentuated, and achieves a balance of punch and tone that’s awe-inspiring at its price point. Although the FIBAE 2’s low-end is tilted towards the upper-bass, it is ultimately defined by its foundation: Luscious mid-bass warmth and vivacious sub-bass energy. Kick drums constantly sound vintage; showered in tonal richness that’s unquestionably analog, and wooly and enveloping upon impact. Bass guitars also benefit from gorgeous sub-bass texture, enriching them with grit, tension, and verve. With all that said though, due to its inclination towards impact and roundedness, the FIBAE 2’s bass isn’t the most revolved. Its saving grace, then, comes in the form of air. Because of its upper-bass emphasis and admirable extension, the FIBAE 2’s lower registers are beautifully lit; deftly juggling clarity and punch in near-equal proportions. It’s not a bass that looms over the rest of the soundscape shrouded in darkness; it’s one to be felt, heard and seen.

The key word here is electricity; the FIBAE 2’s bass is packed to the brim with spunk and sparkle, and it never fails to completely command a song’s pace, momentum and flow. But, despite its snappy nature, the FIBAE 2’s low-end is strict, disciplined and considerate from start to finish; often to an utterly impressive degree. At its price bracket – where big, brave and bold are the norm – Piotr dodges what sells, and instead caters to what engages: Linearity, balance and coherence. It neither bleeds nor blooms, perfectly recognising its place in the mix. It follows dynamic cues to a tee; growling thunderously when called upon, and simmering in patience otherwise. Even unto the midrange, the FIBAE 2’s low-end displays incredible restraint. While it does contribute slightly to note body and vocal weight, it spends most of its time sat back; letting its lower-midrange do most of the heavy-lifting. The FIBAE 2’s lower-registers embody the qualities that define a professional bass player: mature, mindful and controlled, yet exciting, engaging and downright infectious all at the same time.


The FIBAE 2’s midrange is stunning at its price. Again, compared to the rest of the competition, the FIBAE 2 does not deserve a midrange this engaging, musical or multi-faceted. But, Piotr is no stranger to defying expectation, and he’s gone for gold here; delivering instruments that seduce with ease, and captivate with richness, depth and detail. The FIBAE 2’s vocal presentation is bolstered by a hefty lower midrange. While it isn’t the most substantial in thickness or weight, it ultimately prevents voices from becoming overshadowed by the bass and lower treble. And – despite a slight lack of forwardness – vocals are imbued with strong dynamic energy; displaying a persistent and powerful presence no matter how busy the entire ensemble becomes. Authority also impresses here. The FIBAE 2’s lower midrange sports great solidity and texture; male baritone vocals, grand pianos and cellos throb with aplomb and resonate without restraint, all whilst maintaining a deep, open and pitch-black background in the process. Bravo, Piotr. Bravo.

Although the mids are mostly linear, the FIBAE 2 does exhibit a modest hump just before its upper-midrange. While the more typical upper-mid peak would’ve given the FIBAE 2 greater articulation, it would’ve been at the cost of tonal balance. This bump, instead, serves as a compromise of both; benefitting both natural continuity and detail retrieval. Plus, what this pre-upper-mid hump provides is a shift in dynamics. In drums, instead of focusing transients on cymbal crashes, the FIBAE 2 directs them towards snare shots. This beautifully enhances the interplay between the kick and the snare with liveliness and fun, whilst also preventing the former from dominating the percussive ensemble. However, this bump does have side effects of its own. Although most female vocals sound just as natural and smooth as male vocals do, some may find this tuning unflattering. Vocalists like Renee Olstead and Nikki Yanofsky – who sing with a brighter timbre – can end up sounding throaty and hoarse. But, overall, this is a small price to pay for a key component in the FIBAE 2’s addictive signature; an engaging midrange that balances richness and clarity like a pro, and does so with impressive gravitas, tenacity and depth.


The FIBAE 2’s treble is what fuels its impressive detail retrieval. Admirable articulation, openness and texture all compose a top-end that brilliantly blends clarity and smoothness. Extension and linearity are its strongest suits; allowing transients to decay with excellent grace and further solidifying the richness that runs throughout its entire signature. The FIBAE 2’s treble is attenuated, but it is a tad bright in tone, adding sufficient liveliness and air. Although, despite its modesty, the FIBAE 2’s top-end isn’t the most forgiving. Hotly-mastered recordings may sound just sizzle-y enough up top, that they risk entering unnatural territory. That’s not to say the FIBAE 2 has a harsh treble, though; it’s tonal balance in this specific range is just so fragile, that immersion can quickly fall apart when its top-end is properly provoked. Nevertheless, with most competent recordings, the FIBAE 2 runs like a dream. Dynamic performance – as usual – astounds; complementing its low-end like bolts of lightning that precede a guttural thunderstorm. If the track allows, the FIBAE 2’s treble will remain behaved, but you can never take away its enthusiasm and energy; neither to its benefit nor its detriment.

Here’s where the FIBAE 2 showcases its most notable strength: Stereo separation and imaging. Although I touched on this in Presentation, it’s a feature worth revisiting because of how impactful it is to the listening experience. Thanks to the FIBAE 2’s impressive top-end extension, its resulting soundscape is about as good as a blank canvas. But, where it differs from the rest of the competition is in its ability to produce individual canvases for the left and right channels. Absent is any cross-feed between the two extremes, and the presentation you get in the end is effortlessly segregated, spatially transparent and as rock-solid as the Eiffel Tower. Hi-hats, ride bells, percussive embellishments, rhythm guitar plucks, secondary stringed instruments; these are all tertiary sounds that produce higher-pitched micro-details typically panned to either side of the stage. But, where they’d usually get lost in favour of the centrally-focused leads, the FIBAE 2 reproduces them with utmost care. As a result, the FIBAE 2 is my weapon of choice when it comes to mixing channel balance. Levelling overhead mic’s, rhythm guitars, and back-up vocals are easier to do here than on my Empire Ears Zeus-XR! It’s a phenomenon that can easily be overlooked, but it is what makes the FIBAE 2 unquestionably special, and it really shows how far a mid-tier IEM can go with a little bit of treble extension up its sleeve.

Select Comparisons

Unique Melody Miracle v1 (now discontinued; the v2 retails at $1049)

The Unique Melody Miracle proves an interesting foil to the FIBAE 2. It has thrice the drivers, twice the price, and it was once the reigning champ of the bang-for-the-buck TOTL market. Comparing the two – more than anything – was a test to see just how far we’ve come when it comes to driver efficiency, tuning sophistication and value-for-money. Can 2017’s David truly slay 2014’s Goliath? As we always do, let’s start from the bottom.

In terms of bass quality and quantity, the Miracle can’t hold a candle against the FIBAE 2’s visceral low-end. The Miracle has a lean, gentle and feather-like bass that lacks any real texture or weight. The FIBAE 2, by contrast, has a superior sense of tangibility, physicality and power. Despite the Miracle’s cleanliness and finesse, the FIBAE 2 answers back with greater authority, restraint and extension. With impact, resolution, and tonal balance all comfortably in its back pocket, modern technology has obviously propelled the FIBAE 2 forward, where the Miracle unfortunately falls behind.

The Miracle poses a better contest in the midrange. Due to its more neutral tone, the Miracle is equipped with greater clarity and sophistication. Although the FIBAE 2 performs better technically – with superior resolution, layering and separation – it has a distinct richness that it can’t shake off because of how it presents harmonics and decay. The Miracle also presents vocals more linearly. Because it has a leaner lower midrange and the more traditional upper-mid peak, it reproduces instruments with superior transparency, but without much power either. Despite a similar lack in forwardness, the FIBAE 2 betters it here through stronger dynamics and a more engaging presence.

Both IEMs have attenuated top-ends, but where they differ is in tone and dynamics. The Miracle has a softer, warmer and more forgiving treble; it relies instead on its upper-mids for clarity, The FIBAE 2 commits to the opposite, where it uses its brighter, zingy-er treble to induce excitement into the overall experience. The FIBAE 2 also presents higher notes with a more palpable sense of energy, and a greater emphasis towards imaging accuracy and stereo separation. The Miracle chooses not to bother, allowing its treble to properly conclude its signature without much in the way of theatrics.

Astell & Kern/JH Audio Rosie ($899)

The JH Audio Rosie is a rather underrated IEM. Although it was once the entry-level of Jerry Harvey’s Sirens Series line-up (now superseded by the Michelle), the Rosie is yet another Goliath to the FIBAE 2’s David. With triple the drivers and (almost) double the price, the FIBAE 2 again finds itself the underdog of the match-up.

The Rosie is equipped with a mid-bass-focused low-end. Defined by a brighter tonality and a drier texture, the Rosie excels when it comes to bass articulation and definition. However, like the Miracle, it lacks the guttural-and-visceral-ness that the FIBAE 2 possesses. The FIBAE 2 – though similar in extension – possesses a more powerful sub-bass, as well as a musical warmth throughout its lower registers.

The Rosie presents its midrange similarly to the Miracle. It’s clean, airy, transparent and largely focused on the upper-midrange. Vocals and instruments sound more clean and crisp here than on the FIBAE 2, but they lack proper presence and weight. The Rosie’s midrange is also pushed further back, while the FIBAE 2 compensates with lower-midrange heft, endowing its voices with richness, strength and allure.

Again borrowing comparisons to the Miracle, the Rosie has a more polite treble than the FIBAE 2. Although they are similarly bright in tone, the Rosie’s top-end rolls off quicker than that of the FIBAE 2. But, it has a more accentuated treble, which contributes air to the rest of its presentation at the cost of naturalness and warmth. Spatially, the Rosie impresses with its diagonal imaging. Instruments aren’t only presented at the left, centre and right of the stage; the Rosie also places instruments at 10 and 2 o’ clock with astounding accuracy. However, when it comes to stage stability, resolution, and strict left-right separation, the FIBAE 2 still comes out on top.


Without question, the Custom Art FIBAE 2 is an absolute knockout; not just for its performance, but also for what it represents in the industry as a whole. Amongst the current crop of IEMs – where exorbitant prices run wild and driver counts rise by the second – the FIBAE 2 is a product that confidently challenges the norm; delivering stellar sonics and groundbreaking technology in an extraordinarily small package. From lowest lows to highest highs, the FIBAE 2 skilfully balances clarity, dynamics and musicality; crafting an endlessly engaging, beautifully bombastic and superbly separated soundscape that’ll leave you on the edge of your seat from start to finish. Whether it’s playing out of a mobile phone or a $3,000 DAP, you won’t be able to resist the odd head-bang every now-and-again as its two “measly” drivers serve punch, after punch, after punch.  At €475, the FIBAE 2 blows its competition out of the water; effectively setting a new standard for mid-tier IEMs to strive for, and proving that driver count in the modern age is only but a number.