Itsfit Fusion Review – Mystical Blend

Itsfit Fusion review featured

Itsfit is a relatively new company based in Hanoi, Vietnam that manufacture’s custom in-ear monitors (CIEMs). Despite only recently opening for business, they’re already delivering on a level you’d expect from a well-established brand in terms of product quality and user experience. In today’s review, I’m taking a look at the Itsfit Fusion, a tribrid custom earphone with a magnetostatic driver plus a dynamic, musical and immersive sound.


Itsfit website:

This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

Itsfit Fusion Review

  • Instrument separation, soundstage and imaging
  • Clarity and coherency
  • Build quality
  • Engaging bass performance
  • Detailed and resolving

  • N/A

Package and Accessories

The unboxing experience begins with a black box adorned with the Itsfit logo. This outer box was actually sealed in plastic; the first sign that I was dealing with a proper finished product and not just a branded DIY project.

Inside you’re greeted by a plastic carrying/storage case plus the rest of the accessories. What’s in the box:

  • Itsfit Fusion in-ear monitors
  • Hard carrying case
  • Carrying pouch
  • Cleaning tool
  • Cleaning cloth
  • Detachable 2-pin cable
  • Warranty & documentation

So far, it’s a fairly standard CIEM package, however, there are some things that stand out, most noticeably the uniform branding and feel of a finished product. For a company that is just starting out, there is a high level of polish here.

Build Quality and Design

Itsfit Fusion earpieces

Let’s talk about the internals before we get to the actual design. Internally, the Itsfit Fusion has three types of drivers which were chosen for their optimal performance in specific frequency ranges. A 10mm dynamic driver was naturally chosen for bass reproduction, as they excel at moving air and creating authoritative lows.

For the core and upper midrange, a dual balanced armature driver was given the task; perfect for fast transients and instrument separation. Lastly, the most exotic of the drivers, the 8mm magnetostatic, which is in charge of the high frequencies.

Magnetostatic driver info
Image courtesy of

Itsfit uses 3D-printing technology which allows them to produce the shells with more consistency and with advanced features, such as 3D acoustic chambers.

In terms of build quality, the Fusion looks and feels fantastic. The shells have a uniform thickness thanks to the 3D-printing process and they feel fairly robust, although, you wouldn’t want to drop them of course. They come with recessed 2-pin sockets for extra durability as well.

Fusion inner shells and internals

When it comes to customization, there is visual product designer software on the website that lets you choose from a variety of colours and patterns for the shells and faceplates. You can also upload your own artwork or logo and you can communicate directly with Itsfit staff for even more options.

My unit came with the “Skeleton Leaves” heritage design complimented by cyan-clear and pink-clear for the left and right sides respectively. I’m delighted with the way they turned out. The skeleton leaves design is exquisite and of course, every leaf is 100% unique courtesy of mother nature.

Itsfit Fusion in its natural habitat
Comfort and Noise Isolation

As always, the fit of your custom monitors relies on sending a good set of ear impressions. The website has a useful page with detailed instructions on how to get the best fit. It’s wise to print the instructions and share them with your audiologist.

In terms of size, my Fusion earpieces are about average among my custom monitors. They’re smaller than the LXear Pluto, slightly larger than my Empire Ears Bravado and are most comparable in size to my Custom Art FIBAE monitors.

Natural habitat 2

The shells are beautifully finished and are very smooth all over. I can wear them comfortably for hours but again, your mileage may vary and is dependant on starting with a good set of impressions or 3D scan.

Noise isolation is par for the course in regards to modern 3D-printed customs meaning they block out a good 25-26dB of external noise passively so even playing music quietly will shut out just about all ambient noise unless you’re in an extreme environment.

Itsfit stock cable

The stock cable included with the Fusion was quite a surprise, as I was expecting to find the ubiquitous Plastics1 that comes with many custom in-ears. However, Itsfit includes their own custom cable and it’s a good one too.

It’s a twisted 4-core SPC (silver-plated copper) wire with glossy black sheathing. It’s thicker than the Plastics1 cables and handles really nicely. There is very minimal microphonics and the cable drapes comfortably without any springiness or kinks.

At the top are gunmetal-coloured 2-pin connector housings followed by heat-shrink ear guides. A small metal Y-split and plastic chin slider are next and the cable terminates in a straight 3.5mm plug. Each of the components is the same colour and have Itsfit branding on them. This is easily one of the nicer stock cables I’ve seen with a CIEM but I would love to see Itsfit add options for 2.5mm and 4.4mm balanced terminations as well.

branded cable components


Portable sources used: Shanling M5s / Sony NW-ZX300 / Soundaware M2Pro.
Desktop source: Windows PC > Foobar2000 > FiiO K3.

Alright, let’s get down to the meat of this review: the sound. The Itsfit Fusion’s defining characteristics are its clarity, timbre, tonal balance and staging. Too vague? Stick with me here, I’m getting to it. The overall presentation is one of balance, where the trinity of bass, midrange and treble are all on equal ground. A touch of warmth is added for intimacy and naturalness which combined with the staging and cleanliness makes for one very interesting performance.

Technically, Fusion can go toe to toe with the best of them and surpasses many of those that are similarly priced. It’s supremely confident in its presentation without being brazen, not like the new kid on the team with something to prove but more like a player at the top of their game.

Itsfit Fusion right earpiece

Itsfit have chosen a 10mm dynamic driver for the bass reproduction and it pays off handsomely. The bass is boosted a little north of neutral but governed and balanced with the mids and highs. There’s plenty of force in reserve when required though and the Fusion has sufficient impact to work across any music genres.

The Fusion’s bass is simply among the best I’ve heard on a CIEM. It seems to dig down forever but it’s not sheer grunt that makes it special; It’s the depth of its extension coupled with its resolution and definition. It also comes from the naturalness in its weight and tone plus the clean leading edge and the relaxed but never loitering speed of its decay.

Listening to Hans Zimmer’s “Gotham’s Reckoning“, Fusion recreates the dark foreboding tones of the synth bass with a physical rumble and the potent drums of war with all their vast grandeur while sustaining just enough restraint to keep them in check.


The Fusion’s midrange is a mix of clarity, body and naturalness. It has pristine cleanliness but blends it with a musicality rich with detail and nuance. Instruments are neutral in size so they never sound thick or clammy nor are they analytically thin. Stage positioning is also neutral, allowing you to take in the full scene but keeping you close enough to feel immersed in the sound.

Vocals are rich yet articulated, whether male or female, the Fusion’s midrange is rendered evenly without any area taking precedence in the overall presentation. Perhaps the midrange’s greatest asset though is it’s natural timbre. That cleanliness has an underlying warmth that is ever so inviting but never cloying. Fusion’s mastery of midrange timbre is evident in tracks like Above and Beyond’s “Sun & Moon – Live At The Hollywood Bowl“, where it renders the instruments, vocals and the crowd with vivid naturalness.


So now it’s time to see what the fancy magnetostatic treble driver can deliver; Is it merely marketing buzz or does it really add value to the sound? Well, I’m a believer, let me tell you. Fusion’s treble is crisp and lively with a light halo that adds a touch of softness and body. A brilliant extension gives it abundant airiness while its tastefully even presentation keeps it smooth and fatigue-free.

There’s sufficient sparkle and shimmer but thankfully no sign of sizzle or sibilance. Given its calm delivery, it’s striking how it can still be so precise, detailed and accurate. There’s no evidence of compression or steeliness either – timbre is another box the Fusion’s treble ticks off with zeal.


Fusion’s soundstage is stately in its dimensions and very stable by nature. While that in itself is an achievement, it’s made even more extraordinary by maintaining instrument and vocal note size and density. The result is a stage that is not only large but is holographic with precise imaging and spatial cues. Stellar instrument separation and a black background give the Fusion tangible layers of width, depth and height.


M-Fidelity SA-50

Fusion vs SA-50

The SA-50 (review here) has long been one of my personal favourites. With 5 BA drivers per side, it has a balanced signature with great end to end extension and superb detail retrieval. SA-50’s bass is still my top pick for an all BA bass – it sounds so natural and carries itself with imposing authority. That said, it can’t bring the same level of impact as the Fusion’s dynamic driver although it does get very close.

The midrange of the SA-50 is more in line with its bass and treble as its whole presentation is very linear across the board. Vocals are more upfront on the Fusion and they’re positioned more forward too – the SA-50’s stage position is further back.

Both iems share a similar treble quality with excellent timbre and airiness. The SA-50’s treble sounds slightly more feathered and the Fusion extends a touch further. When it comes to stage dimensions, the SA-50 is wider but not as deep. Therefore, stereo imaging is stronger on the SA-50 but the Fusion has more clearly defined layers.

Itsfit’s Fusion is the first custom monitor that has challenged the SA-50 for the top position in my collection. Thankfully it’s different enough to compliment the SA-50, rather than having to compete directly with it.

LXear Pluto

Fusion vs Pluto

The LXear Pluto (review here) is a 4BA iem and has a bold and upfront presentation with a strong emphasis on bass. Tonally, it’s much warmer than the Fusion due to the underlying bass colouring the sound from top to bottom. How the Pluto performs really depends on the amount of bass in each individual track. In bass-heavy songs or music, it tends to become congested and stuffy while the Fusion is able to maintain its lightness and separation regardless of the recording.

Both iems have a similarly upfront vocal presentation but the Pluto doesn’t have the same separation or layering ability and as a result, it has a less convincing stage that is surrounded by heavy, rounded bass notes.

It’s a similar situation in the treble too. Even though Pluto’s lower treble is more forward it’s mainly there to compensate for the powerful bass and the stage still ends up being darker than the Fusion.

These have starkly opposing approaches and each one would no doubt appeal to different listeners. The Pluto would be ideal for musicians as a stage monitor or people who want a more upfront performance with a wow factor. The Fusion, on the other hand, has more of what is commonly known as an audiophile tuning that concentrates on details and nuances rather than sheer fun factor.

Empire Ears Bravado

Fusion vs Bravado

The Empire Ears Bravado (review here) is a dual-driver hybrid with one dynamic driver and one balanced armature. Its sound signature is more L-shaped and less mids-forward than the Fusion. Its extra bass presence brings with it more warmth and body. In contrast, the Fusion’s bass is tighter and has better definition but has less overall impact.

Bravado’s midrange sits further behind the bass and goes for more smoothness over absolute clarity. Furthermore, the treble is more laidback and doesn’t have the extreme extension that the Fusion has.

A direct result of the relaxed treble and rounder bass is the Bravado’s smaller stage, although it is still excellent for such a warm iem. The Fusion has more pinpoint imaging thanks to its detailed treble and tighter bass plus clearer air between notes gives it stronger instrument separation.

Itsbit Fusion left earpiece


I have to admit that I was not expecting to be affected in such a manner by the Fusion. While it’s not unheard of for a new brand to enter the market with an excellent product, it is uncommon for one to manifest with such a level of completion. The Itsfit Fusion feels whole in every sense; from the coherency and maturity of its sound to the branding, packaging and build quality.

The Fusion has a golden ratio of bass, midrange and treble that creates the perfect mystic blend. No single IEM is going to please everybody as personal preferences in tuning and musical tastes vary too much but it’s hard to imagine most people not loving the Fusion. Not only does it excel on a technical level but it has a tuning that is lavishly musical and impassioned. With its fun but tight bass, liquid midrange and spectacular treble, it is simply outstanding.

  • Driver configuration: 1 Magnetostatic driver, 2 Balanced Armature drivers, 1 Electro-dynamic: low
  • Freq. Response: 4Hz – 40kHz
  • Sensitivity: 98 dB/mW @ 1kHz
  • Impedance: 13.1Ω @ 1kHz
  • Isolation: -26dB
  • Price $950
  • Website:

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Founder of Prime Audio
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Danny Chu
Danny Chu
4 years ago

Do you have a frequency measurement of Fusion? Thanks

Tim S
Tim S
4 years ago

I would love to hear these in Bangkok or Singapore. doesn’t look like they will be here anytime soon.

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