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Custom Art Fibae 7 Review – Tempered

Pros – 

Excellent sub-bass extension, Great dynamics, Transparent tone throughout, Outstanding layering and imaging, Source agnostic

Cons – 

Forward vocals may fatigue some, Lower-treble can lack crispness by comparison to most high-end IEMs, Subdued upper-treble sparkle

Verdict – 

With technical quality parity with market leaders and a versatile tuning at a substantially reduced asking price, the Fibae 7 is a win for the enthusiast.

Introduction –

Surely those invested within the hobby will be familiar with Polish CIEM manufacturer Custom Art, who have achieved renown on behalf of their mature realisation of a variety of tonalities. And those a little more invested will surely be familiar with Piotr, the brain behind the operation and pioneer of Fibae flat impedance technology. The Fibae 7 is his latest creation, a curiosity sporting 7-drivers that sing ubiquitously from any and every source. Moreover, it is positioned as a flagship yet carries the price of a modern midrange earphone at roughly $1100 USD at the current exchange rate. With the Fibae 7, Piotr seeks to offer a no-compromise experience in addition to being his first model offered in universal. It refines the experimental qualities of models prior to craft a unique take on neutral. You can read more about the Fibae 7 and treat yourself to one here.


Disclaimer –

I would like to thank Piotr very much for his quick communication and for providing me with the Fibae 7 for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.


Accessories –

The Fibae 7 unboxing provides the same experience offered across Custom Art’s entire line-up, packaged within a solid black box and safely secured within the excellent Pelican 1010 carrying case. Also included is a small cleaning tool in addition to a desiccant pod that draws moisture from the earphones to ensure longevity and sustained performance.


Interview –

With excellent reception to his Fibae earphones and the pre-existing Harmony, I found it curious to finalise the line-up with the flagship Fibae 7. Piotr was kind enough to provide some thoughts, his design ethos alongside his plans to further expand the line-up in future, please enjoy!

Where did the idea for Fibae come from and how was it realised?

I wasn’t developed on purpose. I was playing around with a design making all sort of unusual electrical circuits and measuring them, at one point a connection I didn’t expect to make any sound measured quite normally and I started to investigate further. Once I measured impedance I knew I had a breakthrough.

What makes a flagship? Why stop at 7 drivers and €1100 when other brands charge so much more?

To me a flagship is a no-compromise sound. Flagship IEM has to perform best at any scenario and cannot present flaws when it comes to its response or electrical design. It also has to pack the latest and most innovative technology available.

We always kept our prices sane and tried to have the best quality to price ratio. Our product at €1k performs at the top tier level. We think that FIBAE 7 cost adequately to its performance even if it beats 2-3times more expensive competitors.

Do you have any plans after Fibae? What comes next!

Yes are planning a new release soon. I cannot reveal more details at the moment. But as always please stay tuned, we have some really exciting things coming.


Design –

The Fibae 7 also marks the introduction of Custom Art’s dedicated universal offerings, previously only available on individual request. As with his previous uni design, the housings are magically compact, especially considering the F7 contains 7BA drivers per side. They are almost entirely acrylic with in-hand feel to match, however, brushed aluminium faceplates showcased from beneath a gloss coat injects visual intrigue.


The housings are fairly long though they are slim, providing a low-profile fit. The nozzle is elongated and well-tapered, fitting any regular T200 size tip such as Final E-tips or Sony Hybrids. The included tips provided the most balanced sound to my ear as these are what Piotr uses to tune the unis. The fully-sealed housings provide a strong seal and stable fit in conjunction with an over-ear design. Isolation is strong, especially with foams, aided by a deeper fit depth. These will easily suffice for public transport and air travel.


Special mention goes to the new cable, the Arete from Null Audio, a 4-wire cable with UPOCC copper conductors in a Litz 3 configuration. It has a supple transparent jacket with little memory and microphonic noise. My unit was terminated with a straight 3.5mm plug with ample heat shrink strain relief. The terminations are all made from machined aluminium in a gorgeous blue/silver colour scheme. The pre-moulded earguides provide a stable, comfortable fit. This cable represents a huge step up in quality from the standard OFC cables provided with past CA earphones and most custom earphones for that matter.


Sound –

Tonality –

Piotr provides a visual scale that summarises his earphones and provides a sound taste of what one can expect. Many have dubbed the Fibae 7 as neutral, however, I couldn’t agree more with Piotr’s own description; that the Fibae 7 prioritises naturality. Surely, Piotr has achieved excellent balance from bottom to top, however, this descriptor fits due to a lightly warmed bass counterbalanced by clear, lightly vocal forward mids. Meanwhile, highs impress with both neutrality and linearity with only a touch of additional crispness. Contrasting to the majority of high-end IEMs, the F7 has subdued sparkle within the upper-treble. As such, though technically proficient without a doubt, the F7 won’t immediately drop jaws with its micro-detail and extension. Rather, it is a delicately tuned and tonally brilliant earphone that focusses on excellence throughout the spectrum.


Bass –

What a curious low-end, Piotr implements aspects of his former designs such as the ME, that imitated the qualities of a dynamic driver in-ear, in order to realise bass that is dynamic and involving but also balanced and well-paced. Lows are reaching and extended, not quite dynamic driver-esque but certainly providing an excellent weight, slam and rumble for a BA earphone. Mid-bass is slightly enhanced, providing a touch of warmth and this light emphasis continues through the upper-bass to provide a linear and lightly warm presentation.

As such, bass isn’t hyper-transparent nor is it lightning-fast or outstanding in its definition. In fact, the Fibae 7 has slightly longer decay, providing a natural rendition of bass notes that is more commonly witnessed from dynamic driver in-ears. Of course, it isn’t executed to quite the same effect, however, the Fibae 7 does effectively combine excellent dynamics with high control that reels in its enlarged low notes. The result is a low-end that feels natural, expansive and well-weighted while also retrieving buckets of detail even if this isn’t immediately apparent due to a smoother texture.


Mids –

Alluring, delicate, transparent. Mids are delicate with a slight bias towards vocals on behalf of a centre midrange bump and pronounced upper-midrange. As such, the Fibae 7 isn’t especially organic or dense, however, it retains what I would consider to be a natural vocal reconstruction. Vocals have ample size and are well-positioned so as to not overwhelm the outstanding presentation. The warmer low-end imbues a touch of additional body ensuring that vocals never sound a touch hollow or thin.


As the upper-midrange, especially the 4KHz region, has been enhanced, the Fibae 7 has excellent vocal extension. This contrasts to the majority of modern flagships that have tended to attenuate the upper-midrange, however, as the Fibae 7 has a well-metered lower-treble, this is not necessary. It is smooth and refined in addition to boasting superb clarity and presence. That said, vocals do sound a touch shouty and nasal if avoiding rasp, sibilance and over-articulation in entirety. The midrange is the spotlight of this IEM and though balance and tone are superb, timbre isn’t perfect, but tastefully augmented.


Highs –

A focused foreground well-integrated into an extended background delivers atmosphere, range and vivid instrumentation. The lower-treble is refined and very well-tuned so as to delicately balance a sufficient vocal smoothness and instrument clarity. Due to the slightest hint of 6KHz emphasis, foreground details are both well-present and crisp; detail retrieval is excellent but there isn’t a hint of thin or brittleness. This is so as middle-treble is well-integrated, accurate in emphasis and linear from the lower-treble, creating a background that is clean and a presentation that has clear layers but also impresses with its cohesiveness. As treble extends very well and there is no middle-treble attenuation, the Fibae 7 delivers heaps of headroom and a satisfying amount of air.

Shimmer and decay is accurate as is instrument body, this is one of the most realistically rendered treble presentations I’ve encountered in a long time. As has been mentioned in a few other reviews, however, there is a distinct lack of sparkle. On behalf of strong extension and a linear tuning, both background and micro-details are very well-resolved, however, it lacks the top-end energy and perhaps lucidity of most high-end earphones such as Campfire Audio’s Solaris. As such, it is not a leader of technical ability within its price class and its large resolving power isn’t as immediately apparent as some competitors. Nonetheless, the Fibae 7 has been tuned with mastery; its composition and cleanliness on the most complex of tracks combined with immensely accurate instrument body and positioning make this a performance nothing less than TOTL.


Soundstage –

With a well-extended and impressively linear treble, the Fibae 7 creates a spacious stage that extends easily beyond the head in all axis. Its stage appears especially wide on behalf of its more forward vocals, however, depth impresses with its ability to project forwards with other content. Imaging is outstanding with accurate positioning, a strong centre image among the best layering I’ve encountered. This is aided by strong separation with plenty of air and space between each element. It is easy to discern fine details, as a result, and the presentation is thoroughly immersive. There is a reduced upper-octave sparkle, however, this grants the earphone a slightly cleaner background that enables more contrast between foreground and background without overwhelming with brightness in the slightest.


Driveability –

The Fibae 7 is a very efficient earphone with a 113dB sensitivity and low 5.9ohm impedance. Despite its high-driver count, its low-impedance is of no issue due to Custom Art’s flat impedance technology that ensures an identical sound signature regardless of source output impedance. This was confirmed to me when ABing the 10-ohm Hiby R6 and sub-1-ohm DX220, where there were differences in soundstage positioning, however, little difference in tone and overall frequency balance. This is a huge advantage over the vast majority of multi-driver IEMs as it enables parity from both high-end dedicated sources and


Comparisons –

Hyla CE-5 ($915): The Hyla features a very unique hybrid setup with 3-driver types and produces a more V-shaped sound than the Fibae 7. The Hyla offers increased sub-bass extension and increased sub and mid-bass, creating larger bass notes. The Hyla has slightly slower decay but similarly excellent control, and it offers the same level of definition and detail with considerably more quantity, no small feat. As the Hyla has a sharp dip in its upper-bass, its tone is only medium warm and it avoids flab, bloat and bloom as a result. Through the midrange, the Fibae 7 is more natural and balanced where the Hyla is vocally recessed with a considerably attenuated lower-midrange that counteracts its bass emphasis. Both earphones climb to a 4KHz primary emphasis, however, the Fibae 7 is more linear, especially through the centre midrange so its timbre is more accurate and its vocals are better balanced with instruments.

The Hyla has a more emphasized lower-treble, specifically the 5KHz region before a trough from 6KHz through to 8KHz where it has a small peak for air and clarity. The result is a very crisp treble that doesn’t have much body. Meanwhile, the Fibae 7 is smoother and its midrange has more accurate articulation on top. It lacks the same crispness and foreground detail presence, however, it resolves a little more background detail and is more coherent. Meanwhile, the more engaging Hyla has appreciably more foreground detail in addition to being more aggressive in its presentation. The Fibae 7 offers slightly more treble extension and a larger soundstage where the Hyla has more distinct layers between foreground and background.

 Campfire Audio Andromeda ($1099): The Andromeda is more W-shaped compared to the Fibae 7 and it represents a more engaging sound. Both earphones have very similar sub-bass quantity, however, the Fibae 7 has appreciably more extension, delivering more slam and rumble. The Fibae is also more linear through the bass where the Andromeda has slightly more mid and upper-bass emphasis, lying on the warmer side. The Fibae 7 has more natural decay and it has a more aggressive texture. As it has the more linear tuning, it delivers appreciably more detail and definition. The Fibae 7 has a more distinct centre midrange push than the Andromeda which is debatably U-shaped with a slight dip in vocal presence as compared to the forward Fibae 7. Regardless of the Fibae 7’s greater vocal forwardness, the two represent very different voicings; the Fibae 7 being thinner in body and clearer, the Andromeda being warmer and more organic. As the Andro has a slightly attenuated upper-midrange, it is substantially denser and smoother which also helps timbre given its more present lower-treble.

Compared to the Fibae 7 it lacks the same sense of transparency and clarity, exchanging these qualities for a smoother and fuller vocal presentation. It does so while still upholding a high level of clarity and strong balance when heard in isolation. Within the treble, the two also differ greatly, with the Andro boasting an emphasized lower-treble, specifically around 6KHz and the Fibae 7 having a more neutral to smooth presentation here with more emphasis in the middle-treble. At the very top, the Andro offers similar extension if not a hair more and its extension is more apparent on account of its enhanced sparkle which grants it great atmosphere, air and treble energy. The Andromeda has the larger and more separated soundstage with immediately more air while the Fibae 7 has a more distinctly layered presentation and slightly more coherent imaging.


Meze Rai Penta ($1099): The Rai Penta offers a similar style of sound but, being a hybrid, offers that more naturally decaying, warmer dynamic driver bass. Extension is superior and rumble and slam can’t be matched by the Fibae 7. The Rai Penta has a similar bass tuning with just a hint more upper-bass creating a slightly warmer tone. As its sub-bass extension is superior, it also sounds a bit bassier despite having similar quantity when measured. The Fibae 7 has a touch more control, with a hint more definition while the Rai Penta offers more natural decay while upholding high definition. The Rai Penta also has a fairly large centre midrange emphasis that brings vocals to the fore. As its bass is slightly more present, it sounds more balanced. This impression is reinforced by its upper-midrange that tapers off naturally into a similarly attenuated lower-treble where the Fibae 7 continues emphasis through the upper-midrange before a sharper drop.

As such, the Fibae 7 has more clarity and a more forward presentation while the Rai Penta is a touch warmer and considerably denser with fuller vocal body. The Fibae 7 has slightly more lower-treble that gives its foreground instruments more bite and increases its detail presence in general. Meanwhile, the Rai Penta is more relaxed and smoother, lacking the same focus and crispness. Both earphones have a middle-treble bump to increase clarity and headroom, the Fibae 7 offers more treble extension and background detail while the Rai Penta sounds slightly cleaner and more composed. Neither earphone possesses much sparkle or upper-treble energy, however, both are very well-layered and nicely spacious earphones with accurate imaging; invariably delivering similar soundstage presentations with their similar signatures, the Penta being just a little more relaxed and laid-back.

Noble Audio Katana ($1850): Pursuing more of a diffuse-field neutral signature, the Katana offers less bass, a slightly denser midrange and slightly brighter treble. Bass extension is immediately stronger on the Fibae 7 and bass is more present throughout, creating a warmer signature. The Katana represents a more typical BA low-end, it has a surprisingly weighty sub-bass, however, the Fibae 7 offers more dynamics, a punchier mid-bass and more natural decay. Meanwhile, the quicker decaying and more neutral Katana offers more definition and detail retrieval at the cost of depth and impact. Through the midrange, we see an interesting exchange. Both are slightly vocal forward due to centre midrange emphasis centering around 3KHz focus, the Fibae 7 to a greater extent. However, where the Fibae 7 offers an emphasized 4KHz region that enhances clarity and extension, the Katana rather attenuates this region.

This creates a smoother and denser presentation that isn’t quite as clear but is, to my ear, more immediately natural and accurate in timbre. That said, as the lower-treble of the Katana is more present, it is clearly more prone to over-articulation where the Fibae 7 lacks any semblance of rasp despite lying on the slightly thinner side in terms of vocal body. The Katana also offers emphasized middle-treble to a similar degree to the Fibae 7, however, as it is a wider band emphasis, the Katana has a brighter background. Though foreground details are not overshadowed on behalf of its emphasized lower-treble, it does come across as distinctly brighter. Both offer expansive soundstages, the Fibae 7 is more layered while the Katana is wider.

Hidition NT-8 ($2500): The NT-8 and Fibae 7 resemble each other a fair amount, however, the Fibae 7 is slightly less linear with a more forward midrange while the NT-8 has a more present treble. Within the bass, the Fibae 7 has slightly more sub-bass extension and more mid-bass presence, creating a slightly warmer presentation. Meanwhile, the NT8 is almost dead neutral which, combined with faster decay enables it to retrieve more detail and definition. The Fibae 7 has a bit more depth and is more dynamic on the other hand. Through the midrange, both are similar in presentation, featuring clear, forward vocals. The NT8, however, attenuates the 4KHz region, creating a denser presentation.

As its bass is less present, both sound similarly vocal forward, despite the NT8 possessing less centre midrange emphasis. The difference in upper-midrange tuning is palpable, however, the Fibae 7 providing more extension and a touch more clarity, the NT8 sounding smoother. Both earphones also have a slightly smoother lower-treble with middle-treble emphasis. The NT8 is the brighter earphone while the Fibae 7 is more linear here, providing more natural instrumentation. Both earphones have heaps of headroom and air, the NT8 has a touch more sparkle in the highest registers and both have excellent extension. The Fibae 7 has a more layered presentation while the NT8 offers a slightly larger stage and even more air.


Verdict –


When forging a traditional Japanese sword, master smiths spend countless hours hammering imperfections from the steel to create a perfected product. The 7 is Piotr’s magnum opus Fibae earphone; forged with the dynamic bass decay and extension of the ME and folded with the clarity and balance of the 2 and 3 to deliver distinct qualities that sing in unison. This is another flagship that trades immediate sonic impact for a presentation that thrives under longer-term scrutiny. Chiefly, its upper-treble is fairly subdued and its forward vocals will not suit every listener. However, this is an earphone that strikes immense balance elsewhere, delivering superlative bass, treble and overall tone and note body. The addition of Fibae technology that ensures the 7 sounds sweet regardless of source is a fine addition to such a finely tuned signature. Compared to other TOTL monitors, Piotr’s latest earphone doesn’t take the top spot in any regard. However, as he intended from its inception, the Fibae 7 provides a highly versatile and minimally compromised experience that excels across essentially all genres of music. Alongside technical traits that achieve parity with other market leaders at a substantially reduced asking price, the Fibae 7 is a win for the enthusiast.

The Fibae 7 can be purchased from Custom Art for ~$1100 USD. I am not affiliated with Custom Art and receive no earnings from purchases through this link.

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