InEar ProMission X Review


The definition of the mids is very very successful and the spaciousness in the mid-region is present despite the general warm presentation of the IEM. This demonstrates the success of PMX in imaging and a clean background. Instrument separation and general instrument definition and clarity are some of the features I appreciate the most.

The clarity and transparency in this area are impressive, while at the same time the timbre and overall mid-presentation in the PMX are quite vivid and realistic. The resolution performance in the mids also allows you to extract every detail from the music. While the quality of your source device is of course decisive here, it shows very clearly what the PMX can do great with a good source.

I can say that the realism in the mid-region is the most similar to the presentation of a Hi-Fi system. PMX offers a very impressive performance especially at the point of tonality. True tonalty is not an easily accomplished subject in IEMs, but the realism and note size in some of these high-level IEMs really impress me. PMX is one of them. It is an IEM that I would give 10 out of 10 for general tonality. I have to point out that this is a very rare thing.

InEar ProMission X


PMX has good extension performance on top, with a very clean and airy presentation. Treble is very refined and not digitized to create a bright upper zone like many IEMs. The treble here is very successful and the treble contains a high level of detail. Especially the micro details in the cymbals reach your ears with everything. Of course, let me emphasize again that the source quality is very important.

With the combination of the spacious and airy structure in the treble and the fact that the IEM does not lose control even in the complex passages and the treble does not stick together, a very satisfying treble presentation emerges. Overall there is no shortcoming that I can find in this part.

The PMX’s treble resolution and transparency are hovering at the highest levels and it’s very admirable. Despite the clear and distinctive, well-defined treble presentation, there is no aggression or a piercing presentation.

InEar ProMission X

Technical Performance

The staging of the PMX also once again gives a Hi-Fi system atmosphere. Although the stage is not very wide and deep, there is no feeling of squeezing since it plays quite spacious and airy. The soundstage may differ slightly depending on the cable attached and the source device paired, but I cannot say that it has an incredibly huge sound-stage.

However, staging and instrument placement is quite realistic. In positioning, the PMX has a great performance and owes this performance somewhat to its very high definition ability. It is also difficult not to pick any instrument in the presentation of the PMX, which does a great job with background blackness. Generally, we witness that the IEMs with a warm presentation lack when it comes to transparency. But despite the PMX is a bit warm and has a good reproduction of note size, the resolution and transparency are top-notch. In my opinion, there are not many IEMs that can melt these two flavors in one pot.

InEar ProMission X


InEar ProMission X is a very very sensitive IEM. Therefore, a good source with ideal output impedance should be chosen. DAC / Amplifiers or portable amplifiers with very high output power may bring some hissing or channel imbalance. I think it pairs well with all kinds of devices as DAP. Thanks to its technical performance, PMX reflects the characteristics of the source you match in general.

In terms of presentation, I have not come across any equipment that is clearly incompatible. Although this review was written with Hugo 2, I have also tried the IEM with many devices such as Dethonray DTR1, Oriolus DP100, Astell & Kern SP2000SS, and iFi Hip-Dac. While the compatibility with DTR1 and Hugo 2 is at the optimum level, I can say that the stage expands with SP2000SS.

In my opinion, the IEM is so successful that it continues to be impressive at all times unless you connect a very poor quality source.

InEar ProMission X


As a result, the InEar ProMission X takes its place among the best in-ear monitors I’ve ever heard. Frankly, the presentation, balance, tonality, and technical performance of the IEM, which I cannot find a point to criticize, have been magnificent.

Of course, with the eye-watering price of the PMX, this performance can be called “only normal”, but among the IEMs I listen to in this price scale, there are some products that do not really reflect their huge prices. To be clear in this hobby, the fact that an IEM has a very high price tag does not make that IEM directly successful. I’ve experienced this many times.

However, PMX is not one of them. InEar did not surprise me, frankly. There were some issues with the sound of the old SD3 model, but all the other IEMs they’ve released have always been impressive in terms of pure sound performance. With the PMX, they even achieved a better performance than the Prophile 8 and frankly, it truly deserves the title of a “flagship IEM”.



A keen audiophile and hobby photographer, Berkhan is after absolute perfection. Whether it is a full frame camera or a custom in-ear, his standpoint persists the same. He tries to keep his photography enthusiasm at the same level with audio. Sometimes photography wins, sometimes his love for music takes him over and he puts that camera aside. Simplistic expressions of sound in his reviews is the way to go for him. He enjoys a fine single malt along with his favourite Jazz recordings.

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