KZ ZAX - Reviews
And daily the marmot greets
Pros: entertaining sound
punchy, tight bass
good detail reproduction
Cons: artificial
big V
metallic timbre
Rate: 7.9
Sound: 7.8

Slowly I am getting tired of reviewing KZ, or CCA-IEMs. Basically I can take any review of the last time (C12, ZSX, ZS10 Pro, C10 Pro ...) and adjust two or three little things. Done. Okay, this is perhaps a bit exaggerated, because if you take a closer look at the individual IEMs, you can see some small differences in sound, but these are more likely to be due to the different driver characteristics, because KZ has a house sound and they don't want to deviate from that. So they juggle with the number of drivers, as well as the combination of these and bring out again and again an (admittedly rarely bad) IEM, which is only a sidegrade, if at all, but still pulls the money out of the buyers' pockets every time.

A typical KZ. Silver plated 4-core cable, which only serves its purpose, with a selection of silicone tips. Only the faceplate changes on the chassis, otherwise it would be impossible to tell which of the abundant models it would be.

Isolation and wearing comfort is good, to very good, as with almost all models of the company, depending on the space available in the ear, which should not be too small.

8 drivers. I would never think of it if I didn't know. With the KZ house sound it is actually almost irrelevant whether I have 3, 5, or 8 drivers. If you like this sound, you will like ZAX and if not, ZAX won't change that.

The dynamic driver does its job quite well. I found the bass of the CCA C10 PRO to be a step in the right direction and the bass of the ZAX is in no way inferior. Compared to the ZSX, or ZS10 PRO, it is firmer and more responsive. The punch is fun and the depth is also a plus. For me the bass is the best thing about the ZAX.

The "V" is also part of the ZAX program and so the mids are reduced, especially in the lower range. In the upper range, however, they are quite pronounced, which brings voices to the fore and causes fatigue in my case. The mids are solid and especially with assorted music they have some nice details. But when it gets hectic, they break in a bit.

I think it is again a local (Europe, Asia etc.) discussion why the highs always have to have this subliminal aggressiveness with KZ. Personally, I'm slowly getting tired of it and long for more relaxation and real quality, instead of always simulating it with an artificial build-up. The trebles have this basic metallic character, which almost always resonates with KZ. You get used to it, but BA drivers can also do differently. The trebles provide a very good transparency and details, but the naturalness is a bit lost. In addition the sibilants are annoying and I can't attest the ZAX a fatigue-free audibility.

The stage is pleasantly large and the imaging is also quite good, as long as you look at the stereo image. However, it is also strongly concentrated on left | center | right. The spaces in between are occupied a bit more sparsely.

I would take a more customer-oriented approach to KZ, if they did not want to prove this every month in the form of a new IEM. It's good to fine-tune products, as well as to rework them and take into account the customer's wishes, but we are not test rabbits and I certainly won't pay 50€ again, just for a new faceplate and a slightly adapted sound. I will certainly not be able to change KZ's attitude towards this, but maybe I can sensitize the buyer not to have to buy every new model of the company, especially if you already own the models mentioned at the beginning. The KZ ZAX is a good IEM, without question and if you are new to the Knowledge Zenith world, you will find a cheap and competitive IEM here. All others should keep their feet still for 2 years, then you might get a real added value to the previous models.

KZ ZAX.jpg
KZ_CCA (ZAX).jpg

Rating in Letters
9.5 - 10
A: 9.0 - 9.4
B: 8.0 - 8.9
C: 7.0 - 7.9
D: 6.0 - 6.9
E: 5.0 - 5.9
F: 0.0 - 4.9
More reviews: CHI-FIEAR
Terminator 2!
Pros: Solid bass with good texture
Present mids not too recessed
Extended Treble with good detail
Wide soundstage
Good looking design
Cons: Underwhelming accessories
Cable could be better
Occasional bass dominance
KZ described their last multi-driver earphone, the ZSX, as the "Terminator of the hybrid line", so it was a surprise when the new ZAX was announced, although CCA had recently released their CA16 16 driver model, and often KZ and CCA release similar models in short order.

The ZAX is an 8 driver per channel hybrid design. Bass frequencies are handled by a 10mm dual magnet dynamic driver with a composite diaphragm. A total of seven balanced armatures cover the rest of the range: two 30019 units for the midrange, two 50024 dual BAs (four in total) for the mid/high region and one 30095 armature (placed within the nozzle) for the highest frequencies.

The ZAX comes packaged in a similar way to former premium KZ models in a grey box which opens like a book. The IEMs are nestled in a foam insert above a metal nameplate inscribed with the model number. Below this you will find the 2-pin silver plated copper cable, spare eartips and documentation.

The IEMs have a clear resin body and a zinc alloy faceplate which has five slot-shaped vents on its surface. My particular sample was finished in a matt black. It has a kind of "stealth" look, and is really cool. The words "ZAX - 16 units Hybrid Technology" are written on the side of the casing and there is a small pinhole vent on the inner surface. The nozzle is coloured gold and has a useful lip to secure the tips, and there is a silver mesh on the nozzle.

The cable has clear plastic QDC connectors and Y-split and a 90° angled 3.5mm plug. It is a silver-plated 4-core copper braided type and there is no chin slider.

The ZAX was tested initially using the supplied cable and pre-fitted tips and the fit was comfortable with good isolation. The source was an Xduoo X20 DAP and a period of 100 hours of burn in was carried out before evaluation.

First Impressions
The ZAX produced a big, bold and expansive sound with solid, well-textured bass, present mids and extended treble. Volume was adequate with no need for additional amplification. The soundstage was extensive in all three dimensions and the overall character resembled that of the ZS10 Pro but it was not as recessed in the mids and there was improved detail retrieval. After a short test I replaced the supplied cable with a silver plated balanced cable run from the 2.5mm output of my Xduoo X20. This resulted in improvements in all areas and the following observations were made with this configuration.

The bass was extended, firm and nicely textured with good resolution. It was mildly elevated in the sub bass, blending into the mid bass which was also somewhat north of neutral, slightly colouring the mids but producing an attractive "bloom". Decay was natural, allowing recorded ambience to be heard authentically.

The tonality of the bass section of the orchestra in the slow movement of Holst's "Moorside Suite" arranged for strings, was accurately reproduced. In the sensitive performance by the Northern Sinfonia under David Lloyd-Jones, the rich woody timbre of the basses formed a perfect support for the beautiful thoughtful melody in the upper strings.

The powerful tom-tom strikes and bass drum in the climax of "Private Investigations" by Dire Straits had impressive impact and decay. Set against the superb acoustic guitar solo and accompaniment, the effect was dramatic and powerful with dark silences in between.

The introduction to "Flame Nebula" from Kevin Kendle's "Light from Orion" displayed superb sub-bass extension and rumble, providing a solid foundation for the swirling synth figurations and special effects in this evocative piece of space music from one of England's best electronic artists.

The ZAX's mids were more present than expected and possessed excellent detail. The lower mids were slightly warm as a result of a little bass bleed and gradually became brighter towards the treble boundary. The timbre was very good for BAs, being just a tad brighter than neutral.

The clarity of the breath and lip sounds and edge harmonics on the flute in George Deuter's "Mirage" from the album of the same name, demonstrated the ZAX's excellent handling of micro-detail. Accompanied by gentle synthesiser and sparkling percussion effects, the whole piece came together very well.

The timbre of the cello in "Pygmalion" by Andreas Vollenweider from his latest album, "Quiet Places" was very natural with good transient attack on the leading edges and Vollenweider's trademark electric harp accompaniment complemented the solo instrument with its bright resonant tones, with the harp's decay and harmonics particularly well rendered.

"Adios" is a romantic ballad by Linda Ronstadt from the album "Cry like a rainstorm, howl like the Wind". Her clear voice and perfect diction came over very effectively on the ZAX, preserving the emotional message in the lyrics. The lead vocal was nicely balanced with the backing vocals and arrangement in a spacious acoustic.

The treble on the ZAX was surprisingly extended and generally free of disturbing peaks, given that the sole treble BA was placed within the nozzle. Detail retrieval was high and separation very good.

The bright sparkling riff behind the production of Richard Souther's "On the Third Day" from his album "Heirborne" was airy and open and supported by smooth synth patches and expressive solo voices. The clarity and attack in this superb recording was a joy to hear on the ZAX and was extremely entertaining. I ended up listening to the whole album, which is testament to the quality of the sound.

The Unanswered Question" is a modern orchestral piece by Charles Ives. In the beautiful interpretation by the New York Philharmonic under Leonard Bernstein, the serene and yet slightly unsettling orchestral backdrop was punctuated by incisive woodwind tone clusters which cut through the atmosphere in a very dramatic fashion. The trumpet solo hovered in the air and possessed good definition and space and the clean treble delivery and separation of the ZAX conveyed the composer's message admirably.

Isao Tomita's "Electronic Realisations" of well-known classical works always cover the whole frequency gamut and display a powerful dynamic range. "The Old Castle" from Mussorgsky's "Pictures at an Exhibition" is no exception. From the beginning there was a wealth of information, especially in the treble, and the ZAX made the most of this with copious detail on offer with impressive separation and clarity. The 30095 BA has certainly been well-tuned here and there was good extension with little or no harshness, despite the bright nature of the recording.

The ZAX's staging was very impressive, being expansive in all dimensions. Imaging and separation were precise and movement was very well handled.

The various elements in "Elsewhere" by Vangelis from the "Direct" album occupied every square inch of the soundstage, which resembled a vast dome with the solo voice located high in the image and electronic sounds dancing around in complex patterns. The excellent portrayal of the reverberation and ambience added to the effect. Climaxes were effective with an impressive dynamic range.

Mark Dwane's brand of electronic music is based on MIDI guitar synthesisers and is always recorded in audiophile quality. "I remember you from Tomorrow", from his latest album, "Future Tense" features incisive electric guitar and smooth sax solos floating over the top of broad synth washes presented in a wide, spacious manner. The ZAX produced an exciting and satisfying rendition which displayed all the atmosphere of the piece and retained its character perfectly.

The orchestral transcription of Debussy's "The Engulfed Cathedral" received a brilliant reading from the LPO under Nicholas Braithwaite in a superb Lyrita recording. On the ZAX, the orchestra was laid out in a most convincing manner with all the orchestral sections occupying their correct positions in the image, both in width and depth. The sense of distance in the brass and percussion relative to the string sections was particularly notable.

With the ZAX, KZ have managed to retain the best qualities of earlier hybrid models while improving their shortcomings. It takes the bass of the ZS7, the fun factor of the ZS10 Pro and the balanced character of the ZSX, and adds to these improved treble extension, a more expansive soundstage and superior midrange timbre. Compared to CCA's recent CA16, it is much brighter and clearly has the hybrid sound, whereas the CA16 almost sounds like a single DD with its warmer tonality, excellent timbre and superior driver integration.

The ZAX has an engaging V signature which is less recessed in the mids than the ZS10 Pro and is highly entertaining to listen to while having good technicalities and timbre. Definitely KZ's best hybrid so far: It's Terminator 2: Judgement Day!

I find them even more comfortable than the ZS10 Pro although they are similar in size. The rounded edges make a difference. Good job getting 8 drivers in that shell!
Thanks Nimweth. Yeah, crazy how they can fit these BAs in so well. I wish the BA5 wasn't so heavy and bulgy.
Yes. The KZ BA10 is even bulkier but I love it.
Pros: Really good detail retrieval. Easy to drive
Cons: Not the most musical, a bit "polite"
Another day, another IEM release from KZ. After focusing for a bit on their great sounding but technically limited TWS IEMs, they've returned to putting out a set every week.

First impression is, well, it's a KZ IEM so it's Starline tips and a cable in the box. Lately they've tended towards using a silver plated one rather than the old copper coloured one we all know and... tolerate. It still tangles like the old one did but it looks nicer and better built.

A point of note here is that unusually I can't get a good seal with the included Starlines, normally the mediums fit perfectly but they leak the bass and the big ones hurt my ears. I used Tin foamies to burn in and I've just received some Misodiko S450s that have been pressed into service. Literally the only tips that fit that I had to hand. Definitely they open up the sound compared to the foamies and bring out detail which isn't there.

Plugging the ZAX straight into my LG V40 yielded enough power to drive them amply - unusually I didn't feel the need to crank them anywhere near full volume. They drive ok with my ES100 and my GeekOut 450, my Fiio X5 iii and Echobox Explorer both reveal a little hiss. Not a deal breaker, and compared to a DD IEM it's nice to have true plug and play.

So straight off the bat, it's to REM for soundstage - vocals are in the right place on "Shiny Happy People", with none of the weirdness of Michael Stipe having swallowed Cate Pierson that can afflict a poorly resolved centre soundstage. My width and depth perception isn't that great - I can identify a poor soundstage but not so much an excellent one. This isn't a poor soundstage. Further listening to "DARE" by Gorillaz shows even a relatively complex mix to resolve nicely, instrument separation is very good, although perhaps not up to the level of the Tin T2.

Bass goes deeper than a stoned philosopher, easily reproducing the low notes of anything I found to throw at it, be it "Love Me or Hate Me" by Lady Sovereign or "Bad Guy" by Billie Eilish. The intro to "There She Goes" by Babyshambles reveals a nice consistency to the bass levels, fluctuations with the plucking of every note but none of the huge differences between notes that ruins the Blon BL-03 until you get the tip selection "just so".

Sadly, it's not all good news for the bass frequencies. Firstly if you're a basshead I think you would probably need to up the EQ to get the level to something acceptable, and secondly " 'merican" by Descendents reveals a recession of where upper bass meets lower mids. There's no bleed, but some of the notes in the fast bassline are MIA. Saying that, the ZAX has no problem keeping up with the bassline which is a positive.

Staying on the Descendents I feel that the midrange is just a little bit "polite" for punk rock. The aggression that you get with the Tin T2 Plus and especially with the NiceHCK N3 (NOT a great IEM - but superlative with Punk music) just isn't there. It's weird to be levelling this criticism at KZ after using the words "steely" and "timbre" together so many times.
The level of detail these things throw up though is absolutely mind-boggling. Amanda Palmer's vocal on "Coin-Operated Boy" is so detailed you can hear the spit rolling around in her mouth as she forms the words. Pretty much every track I listened to with these turned up whole layers of detail I've never heard before. Not in an IEM, nor even in my Hifiman HE400i. Acoustic guitars have good timbre to them, and a piece such as Beethoven's 5th doesn't throw up anything obviously wrong, timbre-wise though my instrument is guitar so I'm more attuned to how guitars sound. Which is, in the main, pretty good.
Vocals however are a mixed bag. Male voices sound good whether a deep baritone like Johnny Cash or a tenor like Matt Bellamy. Perhaps not best in class (I prefer the T2 Plus) but an improvement on the CCA C12 which in itself was fine. Female vocals, less so. A powerful female vocal is fine but Tanya Donnelly sounds just a bit "TOO" fragile on her cover of "Moon River". It's not the worst for female vocals but these aren't £20 IEMs

Treble is really detailed with good extension as far as my 40 year old, listen to music too loud, tinnitusy ears can decipher. My hearing needs a very definite sweet spot as far as treble is concerned. Too little and I can't hear hi-hats, too much and I want, without exaggeration, to tear the skin off my face. These get right into the sweet spot, and listening to a sibilant recording like anything by the Libertines provides just enough sibilance to make it sound correct without being enough to be unpleasant.

So, who is this for? It's a fantastically detailed IEM and if you want to hear what is on a recording this has to be one of the best IEMs around for the money. But, it's not just about listening to the recording and listening to the gear. This hobby is (or should be) about the MUSIC. And sadly that's where it falls ever so slightly short. It lacks the emotion of something raw sounding like the NiceHCK N3 or LZ A6 Mini, but also doesn't sound as sweet and musical as the Tin T2 or T2 Plus, leave alone everybody's favourite one trick pony the Blon BL03.

In summary, it's a very good, easy to drive IEM that will bring out details in recordings that you may never have heard before without being too unforgiving of a poor recording. Yet it's also not going to be my first choice when I just want to kick back, earphones in, and enjoy the music.
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KZ ZAX and CCA C10 PRO: a tale of slight, but vital adjustments!
Pros: C10 Pro: Nice Air and Sound for the Price. A jewel in the new KZ Line-up.
ZAX: Inoffensive Sound; softens harsh recordings/genres.
Cons: ZAX: Lackluster sound; CCA C10 Pro sounds better
Hey everyone! Welcome back to the Neighborhood. It’s Your Friendly Neighborhood Reviewer with InToit Reviews. Today we’re taking a look at two earphones, the CCA C10 Pro and the KZ ZAX, which share many similarities, yet ultimately, in the end, are very different. The moral of the story is that slight adjustments can make all the difference.

So, let’s get InToit!

Disclaimer: Per usual, Linsoul has provided the products to me, but they have not tried to influence my review otherwise, and all views, comments, and opinions are my own.

CCA C10 Pro:

So, let’s begin by discussing what these two IEMs have in common. CCA is a sub-brand of KZ, so these two earphones share a manufacturer. They’re also both hybrid IEMs consisting of a variety of balanced armatures and dynamic low-end driver. The ZAX tops out a 7 BAs and 1 DD, while the C10 Pro consists of 4 balanced armatures and 1 DD. More specifically, the low-end in each earphone is handled by a 10mm dual-magnetic, large, dynamic driver.

Other aspects of build quality are also very similar. The shells are composed of a plastic cavities and metal, alloy faceplates. The ZAX metal faceplate is comprised of Zinc Alloy, while the C10 Pro’s faceplate is composed of Aluminum. Both IEMs wear comfortably in my ear, but the ZAX’s corners are more rounded, and much, less sharp compared to the C10 Pro’s angular, somewhat pointy, edges. While the boundaries of neither earphone touch my ears, the sharp edges of the CCA may be uncomfortable for those who have more unique shaped ears whose outer ear may encroach more upon the metal faceplate.

Both earphones also sport KZ’s new, clear-style cables; which are softer to the touch and a general joy to use after years of terrible KZ cables. Each IEM initiates in a QDC connection, has an in-line microphone, and terminates in a right-angled unbalanced connection. However; the ZAX’s y-split and termination take a very traditional KZ shape, while the CCA’s cable’s y-split is more unique, and it ends in a conventionally rounded, right-angled termination instead. One thing to note, about this variance in termination, is that the CCA cable may fit more universally into 3.5 mm socket on phone or tablet cases, as I have had some fit issues with the shallow, angular termination of KZ cables in the past.

With regard to their global frequency responses, again, both earphones appear somewhat similar- at least on paper. In fact, after initial sound impressions, I could barely tell these two apart! However, after short, critical, listening sessions with each, it became very apparent that each set has its strengths and its weaknesses, and they, most likely, will appeal to different audiophiles.

(ZAX FR pictured on top; C10 Pro FR pictured on bottom)

Although slightly more detailed, the ZAX is also the more subdued of the pair. It is limited with regard to transients and decay. It is dark in the traditional sense, meaning that it lacks treble extension. Top-end intensity, brilliance, and sparkle is also simply lacking, which is surprising, as, given its moniker, as the “ZAX.” I expected the ZAX to be somewhat of a follow-up to the ZSX, which is a fairly intense experience- to say the least! Instead, the ZAX is somewhat lifeless in comparison. However; like the ZSX, the stage of the ZAX is pretty average, at best, and fairly restricted in its presentation for the most part. But unlike the ZSX, I find layering, distinctiveness, and separation inadequate for an earphone in this price-range. The ZAX is somewhat claustrophobic, lacking in air, cohesiveness, dimensionality, and generally cluttered on busier tracks.

The tone of the ZAX is mildly warm, but also on the drier and duller side of things. Timbre is subtly artificial, and largely, overly smoothed-over. Its bass is somewhat sloppy, and bleeds into the lower mid-range as it swells. Yet somehow, I still found the bass to be missing a certain amount of presence, even when it was acoustically elevated on a number of tracks. I’m not saying that the bass level lacks representation, the bass is simply just “lifeless,” I guess. And, when I think about it, it brings to mind the image of a flopping fish, out of the water, on a muddy river bank.

Additionally, the character of the mids are somewhat recessed, particularly in the lower mid-range, and they often lack sufficient energy to engage their listener. Of particular note, the lower mids simply drops out too much for me on these for me to derive any kind of enjoyment from listening to the ZAX.

I tried experimenting with tips for the ZAX, and while SpinFit CP100s were my preference, for this set, they far from save it. The included KZ Starline tips are a nice inclusion in the package here, as the are some of KZ’s nicer tips, but I ultimately found that they further darkened the sound, limited the treble, and contributed to the already lifeless, bloated bass.

In contrast, although it measures similarly, the CCA C10 Pro appears to be precisely elevated in its frequency response in just all-the-right places. While this set also suffers somewhat from limited, lower mid-range presence as well with certain music, I found it acoustically more tolerable to my ear than in the ZAX. In comparison, the upper mid-range is sufficiently forward, and peripheral details are excellent. Imaging capabilities are beyond average for the price-point- both with regard to imaging placement and instrument distinctiveness. Layer is also above average. I particularly enjoyed the C10 Pro’s layered presentation on Hailee Steinfeld’s “Hell Nos and Headphones.” The soundstage has a lot of depth to it, and even more width. Especially with regard to its peripherals.

Vocals isolate fairly well, and provider a good center image that is decently large in comparison the rest of the mix. They are neither too far forward, nor to far recessed- for both female and male vocalists.

The CCA C10 Pro might not be class leading with regard to details and resolution, and there is some mild treble glare, but they were right up there with the best of them, especially amongst KZ’s that I have tested to date. They are more detailed, and have greater resolution compared to the KZ ZS10 Pro, but are less detailed than a ZSX. Having said that, the CCA C10 Pro is less fatiguing, compared to the ZSX, has a more expansive soundstage, and is generally more pleasing in its presentation; which is more pleasant to listen to across a wider variety of music.

Unlike the ZAX, which appears disparate and somewhat unbalanced to my ears, cohesion is a strength for the CCA C10 Pro. Overall timbre is warm, but there is also pretty decent treble extension here. The treble presentation on the CCA C10 Pro possesses as a certain amount of air to it, which adds to its uniqueness in this price-range and enhances its enjoyability. Transients and decay are also excellent for the price-range. The CCA C10 Pro seems to delicately whisper in your ears on certain tracks. Nevertheless, I should note that the treble was a bit thin with stock tips, but this was easily rectified by switching to either KZ Starline or Final Type E Tips; the later of which I preferred best for this set.

The bass has a good amount of warmth to it, without ever really being overdone. Most of the time, the bass level is appropriate in its presentation, but it also can have surprising amount of extension to it, when it needs it, as its dig relatively deep at times as well. Yet, there is more mid-bass emphasis here than sub-bass, which is generally not my preference, but because of this, dynamics are punchy, impactful, and resolve relatively quickly.

In summary, the CCA C10 Pro is a great all-around earphone with good extension at both ends. It is smooth, bassy when it needs to be, and is restrained and tightens up when additional low-end is unwarranted. Its strengths lie it its open, airy, and articulate character. In contrast, the ZAX lacks treble extension and cohesion, is stuffy, and it blooms in an unpleasing manner. To my ear the more expensive KZ ZAX at $60 dollars is boring and lifeless, while the less expensive CCA C10 Pro at $41 is engaging and expressive. While I’m sure there is more going on here, I am left astounded, exclaiming in amazement; “What a difference slight bumps in the frequency response can make!”- at least in this case.

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KZ Is Back
Pros: balanced tuning, great technical performance for the price
Cons: cable is better than previous KZ cables but still not great, bass articulation not class leading, paltry accessory selection

The KZ ZAX is a hybrid in-ear monitor (IEM) with a 10mm PEK spring diaphragm dynamic driver (DD) and seven balanced armatures (BAs) on each side. KZ is one of the biggest names in ChiFi, and I thought highly of the ZSX “Terminator,” KZ’s last major wired hybrid IEM release. However, following the release of the ZSX, KZ’s previously frenetic release schedule slowed to trickle, and what new products they did announce fell mostly into the total wireless stereo (TWS) category. The release of the ZAX comes as a surprise and relief to those that feared KZ had, in fact, “terminated” their hybrid endeavors.

The KZ ZAX was provided to me for review by Linsoul Audio and retails for $60. This is appreciably more expensive than the ZSX, which retailed at the lower end of the $40–50 price bracket at release. Other KZ and KZ-affiliated IEMs I’ve heard include the KZ ZSX, CCA C10, Tripowin TP10, KZ AS10, KZ ATE, and KZ ED9.


The KZ ZAX comes in a small rectangular black box with a lid that opens to the left. The box is unmarked apart from the KZ logo printed on the front of the lid. Stickers on the left face of the box indicate the selected mic and color options, as well as KZ’s contact information in Chinese and English. The ZSX comes with a detachable .75mm 2-pin cable, three pairs of KZ Starline-type black silicone eartips (S, M, L), a user manual, a QC pass chit, and a warranty card. The ZSX does not include a carry bag or case.


The KZ ZAX follows the now-familiar design archetype typical of the last couple of years of KZ-affiliated IEMs, with a metal faceplate and a semi-transparent inner acrylic body. The metal faceplates are vented, though as I will discuss later the function these vents serve is mysterious to me. The housing has a teardrop-shaped cross-section. The ZAX’s inner acrylic body is less overtly ergonomic than the ZSX, omitting the latter’s bulbous protrusion on the top half of the housing. The nozzle is swept forward from the bottom corner. “ZAX — 16 Units Hybrid Technology” is written on the top face of the acrylic body just below the faceplate seam. The nozzles are metal, with a small lip for securing eartips. Each earpiece has two small circular vents on the inner face of the housing. I did not notice any driver flex with the TRN memory foam eartips I used for this review.

The four-strand 4N oxygen-free copper silver-plated cable is a huge improvement over the KZ norm. It has little-to-no microphonics and is much less tangle-prone than other KZ stock cables. The cable has a clear rubber jack and Y-split hardware and clear plastic housings for the 2-pin connections. There strain-relief above the 3.5mm jack and at all junctures of the Y-split. The 3.5mm jack is L-shaped. The 2-pin connectors use the KZ “type-C” recessed connector and have indented markings to indicate left and right. These markings are difficult to distinguish in dim lighting. The cable has pre-formed ear-guides without memory wire. The KZ logo is embossed on the 3.5mm jack housing. There is no chin-adjustment choker, at least on the mic’d cable that I received.


The KZ ZAX is intended to be worn cable-up only. The earpieces have a moderate insertion depth and were comfortable for me. The housings protrude moderately above the surface of the ear. Secureness of fit is average and the earpieces need periodic readjustment. I suspect this is due to the nozzle angle not being ideal for my ears. Despite the vents on the faceplates, there is negligible sound leakage and isolation is above average.

KZ ZAX.jpg

My measurements were conducted with a Dayton iMM-6 microphone using a vinyl tubing coupler and a calibrated USB sound interface. The headphones are driven using my Element, which has an output impedance of no more than 1 ohm. The measurements use a compensation file derived from relating my raw measurements to published measurements from Crinacle and Antdroid. The indicated SPL readings are not accurate. The measurements are presented with 1/24th smoothing. There is a resonant peak at 8k. Measurements above 10k are not reliable.

I do want to take a moment to congratulate KZ for their consistently excellent channel matching at all price points. I have a review forthcoming of several IEMs with retail prices orders of magnitude above the KZ ZAX with horrifically bad channel matching. This is completely unacceptable and unfortunately quite common.

A Note on the Vents:
KZ ZAX Vents Comparison.jpg

The faceplate vents, while real and not cosmetic, do not seem to serve a sonic purpose. There is a tiny amount of sound leakage from the vents, but covering the vents with one’s fingers or tape does not appreciably change the ZAX’s frequency response. Covering the vents may have some effect on soundstage, but it is difficult to say for certain. Although putting pressure on the faceplates while listening has a definite effect on the sound produced by the ZAX, this does not vary based on the degree to which the vents are covered, rather, it depends on how hard and far one pushes the earpieces into the ear canal. This may in fact result from the two circular vents on the inner face on the housing being covered with deeper insertion.


The KZ ZAX has a more balanced sound signature than what I expect from KZ IEMs. The ZAX is U-shaped rather than V-shaped. It has a more aggressive bass response than can be defended as “neutral,” but the bass is less elevated than most other IEMs I have reviewed. In addition, the upper midrange and lower treble are restrained by Chi-Fi standards.

The bass tuning exhibits an elevated sub-bass shelf falls in a linear fashion before receding into the lower midrange. Sub-bass extension is excellent but I would have preferred the bass shelf recede slightly earlier, as there is a fair amount of mid-bass bleed that creates congestion in the midrange. The bass response is meaty and textured, with fast attack, but prioritizes note weight over agility. Notes have organic decay but the DD strains to keep up with faster musical passages. The ZAX lacks the sense of effortless speed that characterizes the bass performance of higher-end DDs. The overall bass resolution is very good, however.

The midrange has a cool tonality. There is enough presence to lend vibrancy to female vocals and bite to electric guitars, but not so much that either of these things sound harsh or overwrought. Though male vocal intelligibility is very good, there is a nagging sense that male vocals and drums lack body. The intelligibility of female vocals is equally good, and there are no issues with sibilance. Female vocals have slightly more color than male vocals. Male and female vocals roughly level with each other. There is a hint of BA plasticity but not as much as one would expect given the price point.

The treble response is smooth and extended, with ample air. Detail retrieval is good but avoiding harshness is more of a priority. The lower treble is restrained and fans of older or cheaper KZ offerings may find themselves wishing for a more sparkly presentation. Transient delivery is realistic and avoids being overly splashy. Soundstage width and depth are in line with my expectations for a hybrid IEM at this price point. Imaging is very good and instrument separation is mostly exceptional, held back only by some lower midrange congestion on bass-heavy tracks. The ZAX is easy to drive with a variety of source devices.


ZAX vs ZSX.jpg

Note: the 7k valley on the ZSX measurement is an artifact of my earlier measurement setup
The ZAX is recognizable as an evolution of its predecessor with some marked improvements. The wooly bass of the ZSX is more distinct and resolving on the ZAX. The ZAX’s upper midrange is more restrained and even-sounding, avoiding the sibilance that sometimes accompanied female vocals on the ZSX. The ZAX’s treble presentation is also slightly smoother.

KZ ZAX vs TinHiFi T2 Plus
ZAX vs T2 Plus.jpg

These two IEMs are extremely competitive and choosing between them requires distinct trade-offs. The KZ ZAX has a slightly smoother yet more detailed treble presentation than the TinHiFi T2 Plus. The T2 Plus has better overall bass articulation and less congestion in the lower midrange. Neither IEM is “bad” with respect to their bass or treble presentation but each has a different strength.


The KZ ZAX meaningfully improves over the ZSX and is competitive with the other heavy hitter at the $60 price point. If you are beginning your IEM journey, there’s never been a better time to start (shipping delays excepted).

The KZ ZAX can be purchased at the link below:

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Crap, I just bought the CCA CA16 a short time ago, and this looks to be much better. Jeeze, this hobby...
And CCA CA16 are very weird.
KZ zax are very better. Better DD, better tuning, better build

I don't understand the ca16
The gentleman of the Z lineup
Pros: Comfort, style, pleasant and fun sounding KZ signature with some refinement.
Cons: cable is newer silver but still meh, minimal accessories, back plate is dull not shiny like in post but looks simple and good.

Build is simple and decent... because its a KZ similar to the ZSN pro, the ZS10 and Most CCA earphones The accessories are stereotypical KZ the silver cable is standard now that once was the upgrade cable, starline tips still here in package. I think the white tips from the CA16 would have looked good on the ZAX but who is not going to remedy the tp problem right off the bat. Comfort is usually good with KZ/CCA and the ZAX is no different even when laying down it was good.

I'm not one to dive into the complexities of multi driver IEMs and the differences in the tuning between BA and DD hybrids but that said the ZAX follows KZ tuning formula but with some subtle differences at first listen I thought its basically the ZSX with more bass control, coming from the CCA C10 pro , Bass almost seemed like a all BA IEM with added SubBass thump. More listening was needed. So A and B testing on and off with the CA16 to see if there was a difference, Ill point out the CA16 is a safe tried and true IEM nothing spectacular about it but that doesn't make it bad, I think the ZAX has a bit more energy in the MIds and faster Bass with more control over the Bass and Treble IMO.
Bass is rapid the Sub-Bass has a good amount of energy and dissipates quick leaving the mids warm but clean. Mid-Bass has good speed details and is punchy.

Mids are forward very much in front of the Bass yet have a wonderful Warm quality to them. vocals are front and center giving them somewhat of a 3D feeling and a little unnatural but stereo sound I admit is different but not unwanted or too odd

Highs has a fair amount of sparkle but far from that typical KZ extension we are used too, no pain or sibilant tones here, I find this nice. The Treble has clarity and details as well.

Soundstage is clean with above average width and imaging is very good. I honstely can see these used in games no problem.

The ZAX is a more refined KZ maybe a baby step forward from the ZSX but still its a forward step none the less. Its a fun and competent IEM and its sure to make most KZ fans open their wallets once again for the latest offering, The KZ ZAX is decent in build, comfort and sound so I can see this being popular.


How is isolation? What type of environments would you think the ZAX would isolate well at?