InEar ProMission X
Headfonics 2019

InEar ProMission X Review

The InEar ProMission X is the company’s new universal In-Ear Monitoring series flagship 10-driver IEM featuring a 4-way system and a hybrid wood design. It is priced at €2089.

Disclaimer: The InEar ProMission X was sent as a sample in exchange for our honest opinion. Many thanks to InEar for giving us this opportunity.

To read more on InEar products we have reviewed on Headfonics click here

Note, this review follows our new scoring guidelines for 2020 which you can read up on here.

InEar ProMission X
InEar ProMission X
The InEar ProMission X is lightly colored with some nice quality bass for a BA, a slightly forward midrange, and almost the perfect treble for my tastes. It also looks bloody nice out of the box with that two-one hybrid wood and aggressive contouring design.
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Reader's Score

One of our previous reviewers, Klaus, introduced the excellent InEar ProPhile 8 and the follow-up SD5 to our readers a few years back. He loved them both. We actually still have an SD5 here and I have referenced it in other reviews. Looking back, we have also covered the StageDiver SD4, so plenty of InEar reviews, just none of them from me.

The launch of the new ProMission X, however, is safely in my hands for review so this First Contact is sort of an InEar unofficial debut for me.

This is InEar’s new ‘Universal In-Ear Monitoring’ Series flagship IEM and sits on top of the pile ahead of the SD5 and ProPhile 8. Naturally, the price is higher and more or less in line with close competitors such as the Earsonics Grace at €2089.

InEar ProMission X

Tech Inside

Let’s do the dry stuff first. This is a 10 balanced armature driver universal monitor with a 4-way configuration. This is not a hybrid and, in a way, bucks the electrostatic trend for 2019 flagships.

Though the driver grouping is not officially published we would say that it is either a 2-2-2-4 or a 4-2-2-2, (lows, mids, highs). If it is 2 for the lows, they are likely to be subwoofer type balanced armature and if 4, then slightly smaller. There is a good possibility InEar is using dual vented driver designs for the mids and highs if the groupings are not lower than 2.

The ProMission X is fairly sensitive on paper at 10Ω and 120dB so it should be fairly easy to drive but my initial testing would seem to suggest it is not as sensitive as some of the Campfire Audio models I normally set the bar with. As an example, on the FiiO M11, the ProMission X was a fairly quiet pairing, (unbalanced).

One final techy note is the lack of switches on the ProMission X which the ProPhile 8 was known for. There is a single standard tuning on the ProMission X and any tweaks will come from the tips, cable, and EQ, (if needed).

InEar ProMission X

Unboxing & Accessories

For the price, I am slightly underwhelmed by the presentation. To be fair, its professional and a logistics manager’s dream being so small and tidy. However, I wish it said a bit more marketing-wise since this is a flagship IEM after all. Even a picture on the front would be a bit of a lift from the all-black and purple sticker. Make people want it without even hearing it.

InEar ProMission X

Inside, however, you do get plenty of accessories and InEar are rather good at that historically. The following is a complete break down with plenty of branded tips and two cool filter changing wheels among them.

  • 4 pairs of silicone ear tips (sizes XS, S, M, and L)
  • 3 pairs of Comply TS400 foam tips (sizes S, M, and L)
  • 4 pairs of SpinFit tips (sizes S, M, and L, and XL)
  • Gold-plated 1/4 adapter
  • 3 cleaning cloths
  • InEar hard case IE13
  • Cerumen filter set H3

InEar ProMission X

IE13 Case

The IE13 leather case looks good and smells suitably leathery also. These cases are becoming more and more common with the aluminum variants being used a lot less. The lighter materials and nicer leather finish are definitely preferable to the heavy noisy screw lid alternatives.

This is a relatively large carry case which means tons of room for the drivers, tips, and a cable or two should you prefer over the stock.

InEar ProMission X

H3 Cerumen Filter Set

The other noteworthy accessory in the ProMission X package H3 Cerumen Filter Set. These are not to be confused with sound altering filters such as you would find on an FLC8 series monitor but instead a rather tidy wax guard exchange system.

All you have to do is take off the tips, pop in the nozzle into the wheel, disconnect, push the wheel around to the next set and reconnect. There is a blue and red set for both left and right with 16 replacement filters in total per side so they should last a fairly long time.

InEar ProMission X


This is a beautiful and striking universal monitor design. What makes it striking is the use of what InEar calls a ‘hybrid wood’ build mixed in with an aggressive custom universal shaping.

Now, I am not too sure this is the exact same process as what JH Audio uses in their signature Layla Series. We had a Bacote Wood design on that Layla that has a similar consistency of wood and acrylic to the ProMission X and it is every bit as stunning.

The tone is quite different on the ProMission X, however. This is a collage of jet-black violet wood/acrylic in a shimmering mother-of-pearl sky blue swirl just under. For my eyes, it is more of a purple than blue but the effect is nonetheless exotic and quite attractive. Because it is wood that does mean each finish will be entirely unique since no grain on a piece of wood is ever the same.

InEar ProMission X


The ProMission X comes with a 1.2m 4-wire black jacket OFC “Plastics One” type stock cable. It is terminated with a small form-factor right-angle 3.5mm TRS gold-plated jack and 2-pin 0.78mm connectors. The splitter is composed of the same stiffened rubber as the jack barrel and strain relief is good at both ends.

The good news is that this cable is as about as light as you can get outside of a Linum SuperBax aftermarket variant. It is also very pliant and has no memory retention properties with a fairly microphonic free response.

The not so good news is that I tend to find cables like these to be a little too resistive and do not offer the best dynamic range. I am pretty sure InEar knows that already so this is more of a “get you out of the box and running’ stock cable.

This was fine a few years ago but as of 2019 a lot of companies are putting in a decent cable into their best offerings. Perhaps a missed opportunity here when something like the $199 Effect Audio Grandioso will give a huge lift in dynamic range.

InEar ProMission X

In The Ear

Of all the custom universal designs out there, I happen to think InEar is the most committed to this philosophy. The contours are so extravagant and combined with what seems to be a super short nozzle you could be forgiven for thinking the ProMission X simply won’t fit well into your ear.

Well, in actual fact, with the right tip, it works amazingly well with well above average levels of passive isolation. The comfort is excellent also with that aggressive contouring avoiding plenty of ridges and bumps in my outer ear.


Just one note, however, the ProMission X is actually deceptively deep. That means quite a lot of the ProMission X can come into contact with your ear so picking the right tip will not only make a big difference on the seal but will push the main shell out a shade and reduce pressure on the ear.

I found using the supplied SpinFit tips, even with the largest one, to be a little on the shallow side and inviting more pressure on my ear. They also didn’t really isolate that well for me.

The foam tips gripped earlier in the canal, pushing out the shell a bit more, reducing pressure, and enhancing the seal. YMMV on this one depending on your own ears but the fit was perfect with the Comply TS-400s.

InEar ProMission X

PMX Sound Impressions

(Impressions were done using a Sony 1Z, Lotoo PAW Gold Touch, and the stock cable).

The ProMission X has a degree more coloration than the ProPhile 8 but it is not as warm or bottom-heavy as the SD5. This is an articulate, pacy but natural sound. I do detect a gentle u-shape with an extended low-end and a bit of mid-bass elevation, maybe just shy of 4-5dB over neutral.

The low-end is offset or balanced out with a 1-2k bump that teases out some very nice and dare I say it fairly pure sounding vocals performances. What is impressive is the upper treble of the ProMission X.

There is a bump around 8k but it doesn’t produce a lean or tizzy overtone on the high-pitched instruments. Instead, there is just enough to tease out an excellent harmonic balance and a nice sense of instrumental clarity with some good headroom.

The ProMission X has a BA timbre no doubt with its slightly lightish but very detailed response and a lack of heavy-hitting dynamic driver type bass decay and quantity. This is a presentation that is going for excellent balance, way above average clarity and detail, and a lack of top-end harshness.

Comparative Hunches

The ProMission X competes well with CTM’s Da Vinci IX or perhaps even the X. The IX is also fairly natural but it doesn’t extend quite as well as the ProMission X whereas the X is the more neutral of the two. 

I also prefer the tuning to the Earsonics Grace. The ProMission X is not as rich or as warm, it has more of a hi-fidelity sweet overtone and slightly forward vocal sound. That is more to my taste than the recessed mids of the Grace.

InEar ProMission X

Our Verdict

I have a few 10 driver offerings that came in the door in the last year with the likes of the Grace, LSXC from Lark, and CTM’s Da Vinci X. All of them sound very different from each other and the ProMission X is probably the most complete sounding of that group.

If I have to draw a parallel, then the ProMission X is closest in tone to the Da Vinci X than the two former, albeit warmer and richer offerings.

The ProMission X is lightly colored with some nice quality bass for a BA, a slightly forward midrange, and almost the perfect treble for my tastes. It also looks bloody nice out of the box with that two-one hybrid wood and aggressive contouring design.

The supplied cable might get relegated though. I think the ProMission X can scale with a better gauge of wire in all honesty.

ProMission X Specifications

  • ProMission X
  • Headphone type: In-ear
  • Drivers: 10 Balanced armature
  • Frequency response: 10Hz to 20kHz
  • Impedance: 10Ω
  • Sensitivity: 120dB / mW

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