Review - Kiwi Ears Allegro

Review - KZ ZAX

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Also available on YouTube in Spanish: Acho Reviews YouTube 


I have to start this review by saying that the KZ ZAX have been sent to me free of charge by EE Audio, a seller on (I believe they are also on and maybe other European Amazon sites). The only request I have received from them is that I include the Amazon link to this product in my YouTube review. I have not been asked to write anything positive or negative, nor have any other requests been made, however, as always, I like to be transparent and point out that I have received this unit free of charge and do not need to return it.

I will aim to be as impartial as always in my review, but it is only fair that you are aware that this item has not cost me anything. Also, although the only request from EE Audio has been that I include the sale link in my YouTube review, I will also include it in my written reviews (both in Spanish and English) on the Acho Reviews blog.

The link to the product on is: EE Audio - KZ ZAX

I do not receive anything in exchange for any purchases that are made through that link, nor is the link associated with me in any way (I am not an Amazon affiliate etc.).

So, after all that, let’s get on with the important bit, the KZ ZAX.


The presentation of the ZAX is a bit of a break from the normal KZ presentations. Usually KZ IEMs appear in a simple white box, in this case they have opted for a black box with a lid that opens to the left.

Opening the box greets us with the IEMs located in a foam cut out, with Left and Right printed underneath. At the bottom of the foam piece there is a metal plaque with the KZ logo embossed on it, along with “KZ ZAX”, a phrase in chinese (that I have no idea what it says) and “16 Units Hybrid Technology Earphone” underneath.

On the inside of the flap that opened there is a phrase that I have noticed for the first time on KZ packaging and would be handy for a lot of people to remember: “Don’t forget, the original intention of using earphone is to enjoy music”. I am not sure if this has appeared on any other KZ packaging and I have missed it, but I do think it is the most sensible phrase I have read on chinese packaging lately.

Lifting the tab to remove foam insert holding the IEMs, underneath there is the typical warranty card and instruction booklet, the cable (white in my case, with a microphone) and two additional sizes of silicone tips. This is not a lot of content in a set of 70€ earphones (at the time of writing this) in comparison to others that I have reviewed recently by brands such as Hifiman or Urbanfun, but if the quality is good then I am not going to complain about case candy.

Build, aesthetics and comfort…

The shape of the ZAX is no different to so many other KZ models, nor is it radically different as far as aesthetics, except for the back plate. 

The body of the IEM is the usual tinted but transparent resin, allowing the insides to be seen. The connector is again the usual protruding (type C?) connector that KZ have been using for a long time now (well, a long time by KZ standards) and the nozzle seems to be the same as others that I have tried over the past year or so.

As I say, the only visible change is with the backplate which, instead of being a solid plate, has grooves in it with meshing underneath, giving it an open back look. 

I say open back “look” as the IEMs are nowhere near as open as the aesthetics would lead to believe, however, there is at least some kind of vent located underneath the plate as a slight blow through the mesh leads to hearing the driver flex, meaning that air is getting from the backplate to the drive (this is certainly not something I suggest anyone does, I just did it to see if it really did have any openness to it).

The included cable is the typical KZ cable and is identical to all other cables included with KZ products currently, with plastic connectors on each end. In my case the cable has an inline microphone and although it is not the best mic in the world, it is sufficient to have calls without the other person complaining. The cable is not the best but it is sufficient and does its job, there are far worse cables included with other products costing the same or more.

As far as comfort, well, it’s a KZ. If you have tried any of the KZ with this shape, such as the ZSN, ZSN Pro, ZSN X, ZS10 Pro etc. then you will know how they fit. In my case I find them comfortable enough for daily use, although they are not my favourite. If you have never tried a KZ in this shape, you can pick up a ZSN for less than 10€ and give them a try (and the ZSN is not a bad IEM for that price!).

As I have said, the build is no different to any other KZ and I haven’t had a KZ fail on me yet in the last two years or so. That doesn’t mean that they won’t break, it just means that with me personally, they have a good track record so far.


KZ seems to release new models every week and a search of KZ earphones will bring back dozens of models to choose from. Some of these are as cheap as 7€ and others, such as the ZAX, are ten times that price. While these would all be considered budget IEMs, the ZAX certainly aims to the higher end of their line up, it could even be classed as their “flagship” model. Therefore, we should expect a decent result from these IEMs.

In the bass category, there is plenty of extension down into the sub bass rumble area but it is not overly boosted. The bass is enough to feel the lowest of notes on tracks like “No Mercy” by Gustavo Santaolalla or “Bury a Friend” by Billie Eilish, but it doesn’t overpower everything like in certain other KZ models.

Kick drums and bass lines are held nicely together, not feeling loose and offering a very realistic timbre in the lower regions. Songs that have double bass to fill up their low end may feel a little overly present on occasions but electric bass guitars fit in quite nicely. In the case of electronic music, the bass has a decent rumble but without losing control and definition, keeping the “hit” intact, such as with songs like “Shot Me Down” by David Guetta.

In the lower mids, there isn’t really bass bleed as such, it is more of a ramp down from the bass that continues up to somewhere in the center of the mids, where it starts to ramp up again. 

The V shape in the mids, between the low and higher end of the mids, is not overly pronounced but it can sometimes leave certain voices feeling lacking in the foundation of them. The ramp up to the presence area (around 3k) is steeper than the drop down from the lows, this does help with presence to some degree but voices that are over bass heavy backing tracks will sometimes seem a little overshadowed.

Vocal tracks that have plenty in the lower registries of vocals but don’t have any overpowering bass instruments are presented very nicely, such as “These Bones” by The Fairfield Four. I think the mids suffer more when vocals are backed by electronic music, when this is heavy on bass.

Up in the higher frequencies, there is little presence of sibilance on tracks that are more propense to it, such as “Code Cool” by Patricia Barber. It is not unbearable sibilance but does get a little harsh on occasions. 

As we get higher, there isn’t really a noticeable drop off in the treble until it is past the 14k mark, which allows the ZAX to present plenty of air and openness, which is something that is appreciated. I certainly don’t find myself wanting for more treble but I also don’t find it overly bright except for that slight peak in sibilance, which I would rather tame down a little.

In the detail and definition category, I would say that these are the most detailed KZ IEMs I have heard so far. They are not miles better than the ZS10 Pro, my reference for detail as far as KZ, but they are noticeably better. They also don’t exhibit as much of the metallic ring that the ZS10 Pro does, something which is appreciated.

They are also one of the widest soundstages I have heard in an IEM, certainly the widest from KZ, and the placement of images is very well defined. I was listening to “Bubbles” by Yoshi Horikawa and both the soundstage and imaging was way superior to the ZS10 Pro, in fact, it felt superior to almost all budget IEMs I have reviewed so far.


Until now, my favourite KZ offering was the ZS10 Pro, an IEM that takes well to EQ (and needs a little to sound it’s best) and has great detail for a sub 50€ IEM. The ZAX is a step up from the ZS10 Pro and, while it could still do with a little tweaking in the EQ department, has replaced the latter as my preferred KZ.

Admittedly I haven’t tried all KZ offerings (I don’t think I have even seen photos of all KZ offerings) and there are models such as the ZSX that I have not heard, therefore I cannot say that the ZAX is the best KZ to date. I will, however, say that the ZAX is the best KZ offering I have heard personally so far.

It is over the 50€ price that I limit the “ultra budget” category to on the blog, which means it cannot replace the Tin T2 Plus as my favourite under 50€ IEM, but I am sure that in the near future we will see prices dropping slightly on the ZAX and it may even fall into that category. With this I am not saying that it is superior to the T2 Plus but it does offer certain things that the T2 Plus doesn’t, such as the spaciousness. I would have to do a lot of side by side listening to come out with a preference from the two but the ZAX would certainly rank high on the list!

At the current standings, it competes with the YBF-ISS014 and I feel that the ZAX is a better deal in the sound department than the YBF.

As I said, I received this unit for free so it wouldn’t really be fair for me to say if it is worth its price but I have purchased plenty of other IEMs at similar prices that I feel are inferior to this model. I am liking what I hear from the ZAX.

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