Custom Art FIBAE 5 Review

Custom Art FIBAE 5 Review

Today, we review the Custom Art FIBAE 5 which is a new hybrid multidriver custom in-ear monitor using the company’s flat impedance technology. It is priced at €1100.

Disclaimer: This sample was sent to us for our honest opinion. Headfonics is an independent website with no affiliate links or status. We thank Custom Art for this opportunity.

To read more about Custom Art products previously tested on Headfonics click here.

Note, that this 3-page article follows our latest scoring guidelines which you can read here. 

Custom Art FIBAE 5 Review
Custom Art FIBAE 5 Review
The Custom Art FIBAE 5 is a tribrid driver monitor that hits a bit differently. We are talking about excellent physical planar tweeter highs, a surprisingly spacious midrange, and a low-end that digs deep but is not overbearing or full of bloom.
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Superb treble performance
Accurate fitting
Attractive Design
Lacks mid-bass punch
4.4mm terminated cable would be preferable
Reader's Score

Until now, five was a missing number in Custom Art’s long-running FIBAE monitor series. We even had two editions of FIBAE 7, (including Unlimited), and the discontinuation of some of the older smaller numbers before Piotr and the team launched the new FIBAE 5.

What makes the FIBAE 5 special is twofold. The first is that it is the company’s debut wholly-owned and developed hybrid IEM. If you remember back a few years ago they had collaborated with AAW on a project called 4+2 which we felt was a very good value monitor.

The second reason is that this is not just a regular hybrid IEM either but a unique tribrid design. You get a mix of dynamic, BA, and planar making it relatively unusual in today’s earphone market that normally goes for EST drivers. 

Custom Art FIBAE 5 Review

Tech Highlights

The Custom Art FIBAE 5 is a Tribrid 5 driver in-ear monitor. You can buy it in either a universal or custom design format with both using the company’s patented FIBAE or flat impedance technology.

The tribrid moniker comes from a blend of three different drivers; a 10mm dynamic for the lows, dual BA for the mids, and a dual planar tweeter for the highs and super highs. There is no specific mention on the website but we do know the FIBAE 5 uses a 4-way crossover. 

Like the FIBAE 7 Unlimited, the crossover is combined with a dedicated 3D-printed special waveguide to up the sensitivity as well as improve the high-frequency performance of those planar tweeters. 

The FIBAE 5 is rated at 10Ω and 109dB @1kHz SPL so on paper it would seem to be relatively sensitive and easy enough to drive but not so sensitive to play havoc with higher amplification noise floors. 

One final note is the small bag inside the supplied kit which includes a small impedance filter that slots right into a small opening on the side of the FIBAE 5 shell. This will primarily target the elevation in the bass response from the dynamic driver, reducing it by around 2.5 dB. 


For those of you new to the concept, this is more than just a fancy name for Custom Art’s monitor lineup.

FIBAE stands for Flat Impedance Balanced Armature Earphone. Custom Art created this patent-pending design in 2016 and since then has released various IEMS with this technology at the core of each monitor.

The technology promises to eliminate the issue of output impedance dependency by providing flat impedance and phase using a variety of specifically designed balanced armatures.

Why is that important? In essence, each headphone jack has an output impedance value that influences your IEM’s tonality to some extent. With a sub 1Ω impedance becoming increasingly common, manufacturers have made efforts to lower this as a factor in their DAPs and amps.

This isn’t always the case, though. Some balanced outputs have a higher resistance rating such as the FiiO M17 which is between 1-2Ω.

FIBAE should render that impedance variance moot by switching balanced armature designs from inductive to resistive to cancel out potential impedance mismatching which could skew the FIBAE 5 sound signature.

Custom Art FIBAE 5 Review


This particular FIBAE 5 sample is a custom design, of which Custom Art has a ton of beautifully unique options depending on your preferences. The universal version is a fixed design so you cannot change it but the black 3D printed shell and attractive purple wavy patterned faceplate do look very attractive. 

This particular custom build is a purple transparent shell with an Amaranth plate which has more of a slight reddish-rose color with a subtle grain. I feel it is still in keeping with the FIBAE 5 universal theme but fits better with my preference to have purely complimentary colors for a CIEM design rather than a two-tone version. 

The aesthetic is subtle rather than overt but very clean to my eyes with no imperfections such as stray bubbles in the acrylic resin or messy finishing around the connectors and venting port.

Because of the minimalist patterning, this was also one of those custom designs that suit the CA logos being on the top of the shell rather than on the side. 

Custom Art can also give you some variation on the build around the nozzle. For this sample, I asked for a long “pro” stem to get the bore exits as deep as comfortably possible into the ear canals. I tend to find the level of isolation and resulting performance to sound improved over shorter more relaxed custom nozzle fittings. 

Probably the best thing about this particular design is the cost. The base price of the FIBAE 5 is €1100. With the purple transparent shells and amaranth plates with the CA logos on top, it costs an additional €30 only or €15 per side. That is a fair markup for a nice finish. 


You might have noticed a large hole on the side of the FIBAE 5 in the picture and you would be right in guessing this is for venting the dynamic driver. However, it also serves as a filter socket of which CA supplies two tiny metal filters to decrease the bass output by 2.5dB. 

And when I say tiny I mean very tiny indeed so when you want to push them in or take them out do so under good lighting with a tray with a lip in case they fall out and roll away. You only get two of them so lose one and both are rendered useless.

I would have liked to have seen a spare filter included in case that happens. However, if you do lose one CA will help you replace it if you reach out to them. Alternatively, this is a standard Knowles damper (orange 3300 ohm) so you can buy it cheaply from AliExpress, Mouser, or Digikey. 

Fitting is simple enough. Just lightly apply the end of the tool into the opening of the filter to attach it, (magnetic), and then gently push the filter into the shell hole until its flush with the shell. 

Custom Art FIBAE 5 Review

Comfort & Isolation

Since this is a custom design, the FIBAE 5 should and does fit perfectly. An accurate mold with a good cutting process should render gaps and ill-fitting shells null and void. 

Having said that, I did have a chat with Piotr regarding the fit and we both realized that my scans dated back to almost 2015.

Keep your scans up to date or at least a refit after every 2-3 years is advised so I sent them an updated digital STT scan with the resulting FIBAE 5 a slight improvement over the original FIBAE 7 version and on par with the recent Unlimited shells.

That slight improvement translated into a more secure hold in the ear or a little more pressure on the sides of the ear canal. No gaps formed in the ear when in both an open or closed jaw position.

However, the new fitting does not translate into an improved level of isolation because the FIBAE 7 and 7 Unlimited are both all-BA designs with no venting which the FIBAE 5 has. 

A rough comparison is an isolation performance on par with the UM MEXT which is also a vented hybrid design. Venting tends to let a little more lower frequency noise in comparison to non-vented versions, for example, air-con rumble. 

You can improve the isolation considerably though by inserting the filters which bring it very close to the CA BA non-vented custom monitors. If the resulting tuning from using the filters is your preferred sound signature then it’s a win-win situation.

Custom Art FIBAE 5 Review


Whilst not as premium as the FIBAE 7 Null Audio Arete stock cable, the FIBAE 5 1.2m SPC 8-core cable is still a definite step up on the old P1 wires that tended to be shipped with Custom Art monitors a few years back. 

It’s a relatively weighty cable with its aluminum barrels, splitter, and chin cinch but the cable itself is soft, very pliant, and very low on microphonics. It’s a pleasure to handle it in all honesty with very little looseness from its excellent braiding build. The chin cinch also feels flexible but grippy enough to keep its position when in use.

Visible strain relief is minimal and low profile with just a small amount of silicone from the main jack barrel and nothing at the connector barrels save for a soft springy memory-wire coating to keep the cable in position over your ear.

The default termination for this 8-core cable is a 2-pin connector with a SE 3.5mm jack. CA uses 2-pin for all of their IEMs so there are no MMCX-type alternative connectors on offer. You can also get it in a balanced 2.5mm and 4.4mm jack when checking out on the main website

What you can buy instead though is a Null Audio Ethos with a mic and remote module or a 2-pin wireless Bluetooth adaptor instead of the stock SPC 8-core cable. The Ethos is a 28AWG Litz 5 UPOCC Silver-plated copper wire worth around $100 in its own right.

Custom Art FIBAE 5 Review

Packaging & Accessories

The FIBAE 5 packaging closely resembles the FIBAE 7 Unlimited version which was both an aesthetical and physical upgrade over the classic shoe box and Pelican case offering that CA has used for years. It is similar to the Go One packaging also so I would say this is CA’s standard packaging right across the IEM lineup for 2023.

You get an external blue box that is clean, functional, and branded well. Inside, everything is neatly packaged and arranged in a sizeable but nicely finished zipper carry case and wrapped in some recycled brown paper.

The case itself is too big for the pocket but small enough to slide into a travel bag. Personally, I would like to have seen a small pouch thrown in there for more flexibility.

On the plus side, there is plenty of room to fit the FIBAE 5 drivers and cable. The accessories can be safely tucked away in the roof netting with plenty of foam contouring to protect the drivers also.

Accessories include the usual Custom Art welcome pamphlet, a small cleaning tool to keep the wax and dirt out of your FIBAE 5 bores, and a silica puck to combat any humidity. You also get a small plastic bag with the 2 filters and a screwdriver for fitting them.

Click on page 2 below for sound impressions and pairings.

Click on page 3 below for our selected comparisons.

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