EZAudio D4 English Review

V of Victory





  • Clear and crunchy V sound.
  • Great bass response with the bass-mod performed.
  • Comfort
  • Cable to the splitter.
  • Transport box.
  • Value for money.
  • Size




  • Cable after splitter.
  • It’s necessary to make a simple mod to obtain more bass.
  • Somewhat sunken lower mids and emphasized higher mids.



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  • Driver Type: 10mm Dynamic Driver with titanium diaphragm
  • Frequency response: 20-20000Hz
  • Sensitivity: 99dB / mW
  • Impedance: 32 Ω
  • Jack connector: 3.5mm
  • Cable length: 1.2m
  • Microphone




The D4 comes in a white cardboard box with the brand logo on the front. On the back are the specifications with Chinese legends. Inside is a zippered case identical to other NiceHCK products, but with the EZAudio logo. Once opened you can find the IEMs tied with a velcro tape, 6 S-M-L tips and a small carabiner.

The tips are made of black silicone with a wide diameter at the top.

The content and presentation is almost the minimum required.



Construction and design


The design of the IEMs is the typical lightweight metal cylinder, but small in diameter and length. A plastic ring surrounds the IEM and also serves as a cable connection protector. The nozzles are short, have a metal grille and a hole in the base. There is also another hole in the back of the IEMs.

The cable to the splitter is covered with a cloth mesh, I like this kind of detail in cheap headphones because it gives them more wear resistance. On the other hand when splitting the cable is only coated with plastic and not excessively thick. Here is the weak point of these IEMs on a constructive level. In addition, on the right-hand cable, there is the button-free microphone.

The 3.5mm jack plug is L-shaped, small, functional and rigid enough.

According to the specifications the dynamic driver used is 10mm with titanium diagram.

Overall the D4, beyond its price, do not surprise or stand out in this section.



Adjustment and ergonomics


They are surface insertion IEMs, with the right eartips they fit quite well and do not move. Once they are in place, they are not very noticeable and it is remarkable how little weight they have. In my case, the stock eartips are useless to me at all, neither for fitting nor for sound. I have a quite wide channel and I use L size eartips filled with foam, made by me. With these eartips I get the right fit. I don’t need to readjust the IEMs over time. I consider the D4 to be suitable for long listening.

Using my hybrid eartips with a flexible inner diameter, I can push them against the base of the cylinder, covering the existing hole at the foot of the nozzles. In this way, you get an enhancement in the bass, something totally necessary to satisfy my personal preferences. The negative point is the undesired Driver Flex effect, whose frequency is higher than desired, as it is very common to happen when I fit the D4.





The following analysis has been performed using my hybrid eartips, with the base hole of the nozzle covered (Bass-mod).

Personally, after a lot of IEMs behind me, I’m running away more and more from V-profiles. But it is true that it is difficult to escape the market tendency.





The D4s have a mid-high enhancement. With the bass-mod, more presence is achieved in the lower zone, getting a cold trend V profile.





Bass-mod, in my opinion, enhances the sub-bass part more than the bass. From 40Hz the sound has a very good impact, texture and depth. The bass is fast and gives a thin feeling, but this detail benefits their precision. Still the bass range has a fairly complete presence.





I find the lower mids sunk, far away. This is the negative point of the D4, their V-profile makes this area is under represented, somewhat hollow. This is where the mids balance is lost. Even so, there is good clarity in this segment. Male voices sound natural, but far away, without too many nuances or too much joy.

From there, an increase in gain begins, reaching its high point at the higher mids limit. This is the peak of the V, the most emphasized range that defines the sound of the D4, dragging the mids towards the cold side, somewhat analytical and a bit hard. That’s what female voices sound like. In spite of everything I could say that the D4 keep the wheezings in the limit of what is allowed, controlling the excess to gain in clarity. And they do it, turning what could be their Achilles heel into their best virtue.




For the benefit of control the treble is softened in presence and enhanced a little more beyond to gain some air.


Scene, soundstage


The virtue of the D4 is its clarity; the sound is precise although almost more by omission than by separation, because I don’t find that the scene is very wide. Rather it is a well-focused sound, crisp, clean, but without going into much detail or nuance.





Rock Zircon


Rock Zircon are one of the classic kings of the cheap IEMs, which overcame the barrier of the typical V-headphones to offer more than bass. And hell, they did. In my opinion Zircon was the rival to beat and even now they still have something to say.

Especially on bass, this is where I wonder if the D4s with Bass-Mod are really V-IEMs, or just higher mids emphasized IEMs, with a good bass response. The Zircon are a bass cannon, there is almost nothing to do in this sense against them in this segment that I have in my possession. Of course, the basses in the Zircons are thick, wide, meddle in the mids and flood the sound. While the lows of the D4 remain deep, less present, thinner but not blended in the voices. The Zircon are warm and the D4 are cooler and this is totally valid for the mids too. The Zircons, coming from a bass mountain, don’t have the lower mids as far away as the D4s, but they have a more pronounced valley around 1kHz. This is where the Zircons climb back up to the other V-peak, but they don’t do it as much as the D4s. This has repercussions on the sound and hence the differences in the mids and voices.

The D4s have more presence at the top, starting with the higher mids. The sensation of brightness and air is greater in the D4 than in the Zircon. This gives you greater clarity, detail and precision in contrast to a certain darkness and duller sound in Zircons. Other parameters such as scene, image and recreation take advantage of this emphasis in the D4.

In terms of comfort the Zircons have a more peculiar adjustment, they move more inside the channel, which can even modify the sound. While the D4 remains static once fitted.





The MEMT X5 are a tough rival, basically because their profile fits better among my preferences, being more balanced and having more emphasis on the lower mids than the upper mids.

But the D4, with the bass-mod done, seem to beat the X5 on basses. In the sub-bass is the difference, the overall perception of this segment is deeper and more pleasant. The Low-End has more body in the D4, as well as more punch. The bass is clearly rotund and complete in comparison. And although the lows of the X5 were already good, I realize the quality of the D4 in this section.

In the mid zone I have a strange feeling with the X5, while my perception of the lower mids and medium mids in them is more complete, the presentation is not as clear and clean as in the D4. But the X5s do fill that gap that I notice in the D4s. This can be clearly noticed in the female voices, in the D4 they sound very clear, but fine and incomplete.

The perception is really due to the fact that the mids of the X5s go down in gain until they reach the treble, while in the D4s they sink at the beginning to end in peak in the higher mids. Here everyone will have their preferences and hence they choose one or another model accordingly. Personally I stay in this aspect with the X5, although this area has some darkness and veil. The ideal would be to add the clarity and definition of the D4, but perhaps it is too much to ask for IEMs of this price.

The treble is different, in the D4 the higher mids is emphasized, that makes the cymbals sound more complete and with more details. While in the X5 they sound thinner but brighter due to the small emphasis they have around 7-8kHz. It is also noticeable that the treble in the X5 sounds more isolated and is perceived with greater precision. On the other hand in the D4 this zone seems smoother and is somewhat more integrated in the mids.

As for other parameters such as separation, scene, image, detail, I do not see great differences between the two beyond the profile, being very on par and within what can be expected by the price.

As a negative note on the X5, the cable is really rigid and untamed and although it is thicker, I prefer the D4 cable.

Both are comfortable IEMs although their adjustment is different in each one.

The X5s are more sensitive than the D4s.


NiceHCK EP10


At first I expected the EP10 with more bass than the D4, but in reality it is not, once applied the bass-mod. So and using my hybrid tips in both, the D4 have more presence in sub-bass, as well as more depth. So these little D4s offer a great bass response, there’s no doubt about it.

In mids, things change in favor of EP10s, as they lack the feeling of sinking in the lower mids. I find the central range in the EP10 more complete, they generate more music, a fuller sound, with more nuances and details. Meanwhile, the D4 produces a rather focused, narrow, and somewhat dull midrange in comparison.

EP10s still have greater emphasis on the higher mids, and also on the lower trebles than D4s.

But the big difference between the two is the overall sound sensation: EP10s sound wider and have a larger scene and image. The musical recreation is also greater in the EP10, there is evidence of the narrower and more focused sound of the D4, on the more mature sound and higher overall quality of the EP10.

It is also true that EP10s cost almost twice as much as D4s. In this case the price does justify the quality improvement of one over the other.




Everyone who starts in the world of portable HiFi should listen to the D4 and from there climb up to more expensive models, which are not always better. These IEMs satisfy, as they say in my country, the three B’s “bueno, bonito y barato” (good, pretty and cheap). Do they offer the best sound? I’m sure they don’t, but in that price range they have a lot of battle and they’re a sure value.

His response in bass is remarkable and one of the best in his range qualitatively speaking as well as in depth. The sound is quite clear and well executed. Its profile is a cold shooting V. It suffers from certain deficiencies in mids, scene and image, but the price of the product must be made clear.

They’re comfortable, they’re small, they fit easily, the cable isn’t bad, they look durable, they have a good carrying case, and they have a microphone. What more can you ask for in price?