NiceHCK NX7 MK4 English Review


Fourth Time’s The Charm




Construction and Design




  • With the Gold filter the sound is quite balanced and equilibrated.
  • Good midrange.
  • Excellent ergonomics, adjustment and fit.
  • Very lightweight capsules.
  • Good accessories.




  • The tips included are too generic, at a time when every brand is making an effort to improve in this area.
  • The Black filter can be dark sounding, while the Red filter is more piercing and less natural than the reference filter.
  • The design is somewhat heterogeneous, which detracts from its appeal.
  • The sound is slightly dark and subtle, not characterised as very technical.
  • Scene and image are average.


Purchase Link


Link to the Store




NiceHCK, the AliExpress shop, persists in the continuous improvement of its products and returns to the charge with the 4th generation of its 7 hybrid driver model, consisting of a 10mm dual dynamic driver with beryllium-plated diaphragm, four BA drivers and a seven-layer PZT driver. This is the NiceHCK NX7 MK4, a small-capsule IEMS, which has «stolen» the external plate from its partner Topguy. They have three filters for fine-tuning the sound, just like their previous generations. Most importantly, NiceHCK seems to have tamed the frequency response, achieving greater linearity and balance in all ranges. The set is completed with a kit of accessories that is not new, but is the top of the range with which the brand accompanies its best creations, such as the previously reviewed NiceHCK F1. The cable is the same and the capsule consists of several parts made of different materials. The outer face is made of stabilised wood and resin, encased in an aluminium alloy rim, and the inner face is made of polycarbonate. Let’s take a look at the performance of these IEMS which are priced at just over $100.





  • Driver Type: 1DDD dual 10mm, beryllium-plated diaphragm, 4 BA drivers and 1 seven-layer PZT driver.
  • Frequency Response: 20Hz – 28kHz
  • Sensitivity: Gold Filter 112dB/mW, Red Filter 113dB/mW, Black Filter 110dB/mW
  • Impedance: 39Ω
  • Jack Connector: 3.5mm SE, 4.4mm BAL
  • Capsule Connection Type: 2PIN 0.78mm.
  • Cable length: 1.2m ± 3cm.





The presentation is very similar to that of its F1 companion. It is a white box with a real photo of the capsules in its centre. Its size is 172x127x55mm. At the top left is the brand logo in holographic ink. A little lower, in the centre and in orange, is the name of the model. There is an additional description at the bottom of the box. On the back are some of the specifications, in Chinese and English. There are also the brand’s contact details at the bottom. With the outer cardboard removed, there is a black textured box with the logo inscribed in the centre. The box opens like a book and inside a thick layer of foam are the IEMS with its cable and underneath, the classic leather box of the brand, in blue. Inside are the rest of the accessories. In a nutshell:


  • The two NiceHCK NX7 MK4 capsules.
  • One OCC-silver-plated mixed cable, with 4.4mm balanced connector.
  • 4 pairs of white silicone tips, sizes SxMxLxXL.
  • 3 pairs of black silicone tips, sizes SxMxL.
  • One branded velcro strap.
  • A blue leatherette case.
  • 3 pairs of filter tips (Gold, Red, Black). The Gold mouthpieces are attached to the IEMS.
  • User’s guide.
  • Inspection certificate.


The idea is a continuation of the previous models and still uses a good carrying case. The cable is good and soft, but I have to say that NiceHCK has more attractive cables. The set of tips is the classic one and I miss a point of innovation in this sense, as well as some foam tips. But for the price of the product, the fact that it has the same packaging and level of accessories as other more expensive products is to be appreciated.



Construction and Design


NiceHCK has made various modifications to the capsule design over the four generations. The NX7 MK4 is a somewhat heterogeneous mix. It has the same outer plate as the Topguy, made of stabilised wood and resin. Around it, there is a golden aluminium alloy rim, while the inner face is made of polycarbonate. The outer face is protected by a transparent plastic and its shape is the classic African continent shape, but with rounded edges. The inside is very rounded, transparent, not very thick. There is a hole in the centre of the DD, on the outer side. The whole is light and of medium size. On the gold rim you can read the full name of the model and the mole with the letter indicating the channel, in dark ink. There is a rectangular, shallow plate, which contains the 2PIN 0.78mm female connection. The cable is fitted to match this plate. The nozzles are gold-plated brass and the filters are screw-on. There are three, Gold, Red and Black.
The cable consists of a rather soft double braid. The material is mixed OCC copper with silver plated cores. It is soft, mouldable and shiny. The sleeves of the 2Pin 0.78mm connectors are angled, transparent pieces, with the channel letters inscribed on the outside. The sleeve of the plug is smooth, cylindrical, shiny and metallic, with a roughened strip for easy gripping. The plug is 4.4mm balanced. The splitting piece is completely smooth and the pin is a metal ring with a rough surface. It has guides on the ear, but they are soft, like the whole cable, which is very mouldable.
The mix of designs and parts already known from previous models gives it a somewhat heterogeneous look. But I must admit that the ergonomics are very good, as I will explain below.



Adjustment and Ergonomics


After having tried several IEMS that didn’t fit my morphology very well, I was afraid of losing the universality of my ears to the new models. But fortunately this is not the case with the NX7 MK4. Their rounded, depressed inner shape barely touches the outer parts of the ear. The weight is very light and I had no problem using my large, foam-filled silicone tips. The fit is precise and immediate, no additional placement is required, it adjusts right out of the box. The seal is quite occlusive. There is no movement, no rotation, the shape of the outer face contributes positively to this. The size is medium-small and gives a floating sensation although the anchorage works very well. The mouthpiece has a good slope and, although it is not very long, the insertion could be shallow to medium.
Although there doesn’t seem to be any innovation, the design works excellently in this area.







I tried the first version of these NX7s and I think that in these MK4s there is a clear idea of softening the exalted FR of those. In that sense, the current frequency response, with the Gold filter, moves in a vertical band of 10dB in almost all its totality, something that gives an idea of the smoothness and balance that this filter provides. It is a smoothed w-tuning, which presents a linear low end, starting from a slight increase in the sub-bass. The drop towards the bass is slight, as is its subsequent plateau in the upper mids. The treble starts with a small control zone, to climb into the typical PZT peak, between 6kHz and 8kHz. But, on this occasion, the treble is very controlled and moves in a narrow band of back-and-forth. In addition, it ends up with a very interesting and extended air presence, superior to many models in its price range. The Red filter is lightened in the low end, and is excited in the 2kHz and 4kHz peaks, to gain sparkle and transparency. Although I would have preferred if the Red filter had not altered the bass, but only served to raise the sense of light and closer detail. There is little difference in the treble. The Black filter lifts more in the low end and suppresses the 2kHz and 4kHz peaks, however, it gets slightly excited in the highs.
The Gold filter has a good balance, but I find it a bit soft in both the amount of light and the level of transparency. However, I find it very adequate in bass, with a presence that I consider fair. The Black filter loses this balance in favour of a more powerful bass, but at the cost of losing more illumination in that phase, which I find fair. The mid-highs become more muted and lacking in sparkle. The sound is warmer and too subtle for my taste. With the Red filter the opposite happens, the greater emphasis on those 2kHz and 4kHz excites the sound, but the sound is a bit more metallic and a bit more uncontrolled. The ideal for me would have been a mix between the Gold and Red filter. But seeing as the Mid-High filter gets a little spicy and subtly unnatural, I’ll continue the review with the Gold filter, whose compromise is good, accurate, smooth, balanced and the most well-rounded of the three.





What do you know! But the NX7 MK4s with the Gold reference filter are even a little dark. It’s that darkness mixed with warmth, a characteristic that adds creaminess to the low end, generating a more unctuous and pleasant bass. But this ability is not at odds with the quality of presentation, nor is it at odds with the speed of execution. The hit feels complex, tight and concise, the execution is beautifully executed with good roughness. The sound is natural and the test of the very low frequency pure tones is remarkably well executed, with an uncoloured timbre and a quite pleasant and adequate sonority. The recovery feels relatively fast and there is little sediment left behind. You can tell this is a specialised bass driver because the recreation of the lower range feels very complete, while the properties of the beryllium try to contain its controlled power. As a result, the bass is round, solid, full, physical, full-bodied, powerful, punchy and very appealing. They have a sweet spot that encourages you to turn up the volume and enjoy the fullness of the range. Even in these situations, the bass doesn’t get out of control, but fills the sound and adds a beautiful depth. It is agile in complex situations and able to execute unfiltered bass without distortion. It withstands high sound pressure situations, being adept at recreating multiple bass lines and layering separate layers.
Without being perfect or the most defined bass, it feels pleasant and improves with analytical sources, because it perhaps compensates for the thickness of the lower range.




That subtly dark aspect lends a touch of dryness to the mids, but without any loss of sweetness or richness. There is a good balance between physicality, fullness and density, without the sound of the first half of the mids feeling totally near or close. The combination of the first half and the second half is very well achieved, resulting in a compensated and balanced midrange. I think this Gold filter generates a nuance in the sound that makes it more analogue, that mix of darkness that softens the momentum of the BA drivers, to give them a more pleasant, silky and velvety sonority. It seems to lose precision or definition, but it gains in musicality, in a more harmonious and melodious sound, which gains in exuberance, but without losing transparency, separation or resolution. In this way, the midrange is quite full, rich and present, but without being opulent or bold. The vocals are very well combined with the bass area, as well as being well separated. They know how to stay behind the low end when the song so presents itself, or get ahead of it when the opposite is the case. There are no overbearing outbursts and the blend is quite natural, with that subtle patina that smoothes out the rough edges. The equilibrium and good tuning prevents any hint of muddiness, nor is there any sibilance. And from all of this comes that feeling of an analogue, yet rich and rounded sound.
The midrange, without being spectacular, has everything I could ask for to enjoy for hours, for listening that is not too critical. Not too clear, but still maintaining a level of transparency and detail that is quite natural and pleasing.





In the treble you can feel that control zone or roll-off at around 5 or 6kHz. It is clear that NiceHCK has learned from its mistakes and has forced the first treble to be more shaded. I think that instead of improving the quality of the BA drivers or refining the PZT driver, they’ve agreed on a link between the tuning and the filters, to soften the high end and move it away from the excess of that first version. You can feel the layer of shade in the early treble and how it affects the definition of the highs. I can feel that they are not free, but I still prefer them, because they move away from a more metallic or over-emphasised sonority, which would not bring naturalness to the sound. I don’t think the choice of the word «natural» is the most convenient either, but it is true that no faults are shown. The high range starts securely and extends with the virtue of the PZT driver, educated in its 8kHz hot spot and stretched all the way to 15khz. There is ample presence throughout the treble, but with that characteristic focus on not exceeding a red line of presence that makes flaws in the sound visible. The result is a sound that parades on a thin sonic line that avoids making missteps, but also doesn’t reflect reality to an audiophile degree. It is an attempt to sound with a lot of definition and resolution, but without achieving genuine fidelity. But it’s true that many amateurs won’t be affected, because the treble integrates quite well with the tuning of the lower ranges. In addition, it has a limited sparkle capable of providing good macro detail and some more exposed micro nuances.



Soundstage, Separation


The subtly dark and shaded analogue sound mix prevents a certain expansiveness. The scene lacks a more visible three-dimensional feel, although the laterality and stereo sensation reaches 180º, but does not exceed this limit. Recreation is frontal, of average height, though good depth. The sound is perceived as cohesive, musical and silky, something that binds its exposition together. It’s not a tight scene, but it doesn’t stand out in this respect either. Separation is good, this is not a technically adept IEMS in this respect, but it is not flawed either. It is a good all-rounder, it can be used for hours on end and on a daily basis without overwhelming. The level of transparency is adequate, good for providing a good level of definition, but without being analytical or overly expressive. It gets to a point and the tinted layer prevents more resolution. Perhaps the red filter offers more detail, but with a risk in sonority and timbre.
The image is good, but without being explicit in a totally precise and distinguishable location. Nor does the size of the scene help in this respect.







I’ve said before that I like to compare IEMS with similar tunings and similar prices. This time it’s the TRI KAI x HBB, a premium looking model, made of aviation grade aluminium alloy level 7. They can now be found for just under €100, while the NX7 MK4 is around €125.
The Kai’s packaging is pared down, without much in the way of frills or accessories. It does, however, come with a good cable and a good case. In this respect, both are similar, although the NiceHCK package is larger. Looking at the looks of the two, I wouldn’t choose either for a design contest. I wouldn’t choose the Kai for its gold colour, nor the NX7 MK4 for its heterogeneous mix of flavours.
In terms of ergonomics, the NX7 MK4s are a blessing, while the TRIs are not bad in this respect, but the weight and size penalise, comparatively speaking.
Sound-wise the difference is in the nuance. The Kai’s seem freer and clearer, while the NX7 MK4’s have that layer of softness that limits their exposure. Also in the bass area, you can feel the depth and better definition in the low end, as well as the bass shift towards the LFOs. The NX7 MK4s have more rounded bass. The result is an abyssal bass in the Kai’s, which is absolutely stunning. While the comparison is watered down when you switch to the NX7 MK4s. They don’t have the resonance, the texture, the punch or the physicality. The NiceHCKs just show more dryness and a more compact tendency.
While it might seem that the mid-range of the NX7 MK4s would be fuller, the Kai is no slouch in this respect. In addition to better clarity, there is also more transparency and a less nuanced sound. This gives the TRIs a little more texture, but also a point of richness, with more surface detail and descriptiveness. The level of brightness and sense of dynamics is also greater in the Kai.
Despite the arsenal of drivers, the Kai’s highs seem more coherent and natural. Although the control zone is deeper and wider in the TRIs, their simplicity works in their favour. More extension and more air in the NiceHCKs, but with that ambivalence of the PZT timbre.
The technicalities are more evident in the TRIs, as opposed to the opacity and relative darkness of the NiceHCKs. The greater illumination, clarity and transparency of the Kai offers a more explicit sense of definition, resolution and detail, as opposed to the velvety smoothness and nuance of the NX7 MK4. In this way, the Kai’s scene feels wider and more expansive, as well as possessing a clearer and more evident image, with more obvious and precise positioning. In the same vein, separation is also more perceptible and despite the verve it possesses, it is also a little more refined in these abilities.





NiceHCK has managed, after four iterations, to make its NX7 sound pretty good. As with previous versions, it is a tri-hybrid with a 10mm dual 1DDD, beryllium-plated diaphragm, 4 BA drivers and 1 seven-layer PZT driver. It also incorporates 3 pairs of tuning filters, to adjust the sound to our taste, of which the Gold series filter stands out. With these, the sound is quite balanced, equilibrated, without any unpleasant treble, even smooth and slightly shaded/dark. The result is a pleasant IEM, quite all-round and suitable for everyday use. The design combines the beautiful outer sides of the TopGuy and a polycarbonate inner part. The mix is a bit heterogeneous and detracts somewhat from the overall attractiveness. The accessories are still the best of the house and that brings that premium character that NiceHCK gives to its best creations.
Possibly, these NiceHCK NX7 MK4 are one of the most comfortable IEMS, with the best ergonomics and fit of the last models I have reviewed. They fit like a glove and it’s extremely easy to find the best sound in them, using any tip on the market.
But the crux of the matter is that, for price, they fit in a range where the competition is simply brutal and where every day there are qualitatively tremendous models on the market. Thus, despite being a remarkable model, it is very difficult to stand out among them all. But what is really positive is that NiceHCK has achieved a good and pleasant tuning. Now it only remains to improve on the technical side. I’m sure it will succeed.



Sources Used During the Analysis


  • Aune X8 XVIII Magic DAC + iFi Zen Can.
  • TempoTec Serenade X + iFi Zen Can.
  • Earmen Angel.
  • TempoTec Variations V6.
  • ACMEE MF02s.
  • xDuoo XD05 BAL.