KZ ZAX Review: A Pleasant Surprise

Pros: Soundstage, Crowd-pleasing timbre, Fit, Improved Treble

Cons: Overpowering bass, Cable, Bass resolution, Recessed Lower Mids

Driver Setup: 1DD + 7BA

Price: US$60


Disclaimer: This review set is a demo set graciously lent to me by Daniel at Oardio when I reached out to ask if I could try the ZAX out. This review is written of my own accord and all thoughts are my own. The ZAX is available for purchase from Oardio through their website should you find yourself interested in a pair.

Accessories and Build Quality (Score: 7/10)

Build Quality is an improvement, albeit a subtle one. Aesthetics is also improved a little, and while the KZ ZAX comes in another Blue/Silver colourway, I very much prefer the all-black one. It still preserves the look of KZ IEMs, but I really dig the black matte aluminium faceplate and the understated vented design. As can be seen from the meshes, the ZAX is quite vented and isolates noticeably poorer than your typical KZ IEM so take note if you were considering using this as a musician.

The included cable is a small step up from the ones included on their lower-end models. KZ states that the cable is made from silver-plated, high purity, oxygen-free copper with 4 strands of 25-core wires. However, the build of the cable is similar to the infamous brown one and is prone to tangle. However, it seems to hold up well and aren’t too fragile.

Fit (Score: 8/10)

I must say I was pleasantly surprised with the fit. It has improved curves that sit more snugly in the aural cavities than other KZ IEMs I’ve tried such as the EDX and ZS10 Pro. I had no issues using these while moving around and didn’t need to constantly adjust them.

Sound (Score: 8.0/10)

Frequency Response Graph of the ZAX

Sources Used

  • Hiby R5
  • Lotoo Paw S1

Albums and Tracks tested with

  • Gryffin – Gravity
  • Ragtime Broadway Musical
  • BORNS – Dopamine
  • Spinners – Essentials
  • Queen Great Pretender
  • Itzhak Perlman Carmen Fantasy
  • Taylor Swift – All Too Well
  • Martin Frost – Mozart’s Clarinet Concerto in A

Bass (Score: 7.5/10)

What’s a KZ earphone without its bass, right? Staying true to their house sound, or some may call it “speciality”, the ZAX’s bass response is full of oomph and takes centerstage whenever the song calls for it. There is a decent nice sub-bass extension on the ZAX and less of the mid-bass bloat that plagues many KZ IEMs. I really enjoyed the resolution of the sub-bass listening to Spinners’ “Cupid/I’ve Loved You for a Long Time“. However, I would say that the Achilles heel of the bass is that the speed and resolution of the midbass can still be improved. The snare drums on the Spinners’ album seemed to be lacking in punch and attack. Personally, the quantity of bass is still too much, and the bassline is a little too forward at times, though some may appreciate this tuning better.

Mids (Score: 8/10)

Mids have a much better timbre in the ZAX as compared to the typical KZ house sound. They are still a little recessed and laid back as expected of the V-shape sound signature. I would have wished that the ZAX cut back a bit on the bass to give the lower mids and male vocals a little more room to shine.

Listening to female vocals on Taylor Swift tracks, they avoid sounding sibilant or overly bright. It is a little more laid back and remains authoritative but doesn’t come across as overly aggressive.

Treble (Score: 8.5/10)

On Itzhak Perlman’s performance of Carmen Fantasy, highs were quite present but remained stable and never out of control. Instruments on the lower treble like violins and upper woodwinds had very nice air and timbre to them. The upwards extension of the treble gave a very nice sense of space. Detail retrieval and layering impressed me, and I could only wish I could say the same for the bass.


The ZAX has a very pleasing tuning and timbre. However, the slow and overpowering bass is the only thing I can really fault it for, especially for its price point. It has enjoyable imaging and soundstage, probably owing to its vented design. This certainly has its place in the KZ lineup, and that is saying a lot given their far-from-consistent track record.


Quite recently, I said the ZS10 Pro was the best KZ I had heard to date and had the best bang for the buck. The ZAX potentially shakes things up, giving more for a small increase in price tag. It has proven itself to be a very relevant update. Small improvements like the better fit, cable and aesthetics also go a long way.

There are still many things I find hard to love and can be improved upon. However, I cannot deny that the ZAX has managed to pleasantly surprise me and I managed to enjoy numerous genres on these earphones.

Overall Grade: B


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