KZ “Knowledge Zenith” has come up with yet another budget offering, this time with a 10mm dynamic driver + 7 balanced armatures on each side for a total of 16 drivers in the KZ ZAX.

KZ is a Chinese IEM company founded in 2008 by musician Zen Li and ex Audio-Technica engineer Keith Yue. Located in Guangdong, China, it is the public brand of Shenzhen Yuanze Electronics. Starting from humble beginnings of selling their collection on Chinese popular e-commerce website Taobao, KZ has now gained a bit of a cult following from audiophiles around the world. They specialize in making great price performance earphones, aggressively attacking the under 100 USD price bracket. They have garnered a bit of a reputation for being one of the players leading the often memed driver count arms race, quickly churning out and releasing new IEM models with an ever increasing driver count number. 

Detractors say that driver count does not matter as much as people make it out to be, often comparing the driver count race to the blade count race of some popular shaving razor brands. Having previously owned both the KZ ED-9 and the KZ ZST, as well as having recently demoed the KZ ZST Pro, when the news of a fresh 1DD 7BA hybrid flagship was released by KZ, my interest was more than piqued and I laid down the cash. 

Honestly, I didn’t expect much from the ZAX. My delve into the KZ brand ended with the ZST, a decently performing, neon colour schemed 1DD 1BA hybrid which at the time was a worthy contender at around 18 USD. The ZAX comes in two colour schemes of blue/metallic and grey/black. I chose the latter as there was chatter online about the blue looking rather tacky and cheap.


2.Design & Ergonomics
3.Detailed Sound Review


Driver Type16 total drivers: 1x 10mm PEK spring diaphragm DD + 7 BA (2x 30019 + 4x 50024 + 1x 30095)
Frequency Response10-40000Hz
Cable1.2m, 4 strands of 25 wire cores, oxygen-free copper, silver-plated cable
2-pin connectors
Plug3.5mm L-plug

Design & Ergonomics

The resin shell build quality on the ZAX is very reminiscent of my old ZST’s, but with an added metallic faceplate. The faceplate has grooves cut into it and some sort of wire mesh beneath it. Leading up to the release date, there was rampant speculation on whether the ZAX were closed or open back. I attempted to find out by contacting various retailers on both Taobao and Aliexpress, but their customer support seemed clueless as to what open back meant at all. After three days of back and forth, one seller was able to confidently tell me that the ZAX was indeed open back, but until this day no other seller has been able to confirm this rather significant detail. 

The metallic nozzle is gold coloured and glued on with a nozzle lip – a very welcomed detail since many IEM manufacturers skimp out on a nozzle, causing eartips to slip off too easily. I’ve personally had to deal with unnecessarily lost eartips to such designs so this is a clear and easy point for KZ. 

The housing itself is passable, but with a matte black metallic faceplate, the design choice definitely helps elevate the brand image out of its teenage and fashion oriented affiliation with a more mature look. However, the cables, although already reported by many to be a significant improvement, felt very cheap and tacky, with the most ghetto in line mic I have ever seen. The stock cable is a silver-plated, high purity, oxygen-free copper with 4 strands of 25-core wires. The Y-splitter and plug are both made out of the same white translucent plastic, with a very “edgy” design. No chin slider to be found, which I personally don’t mind, but may be annoying to those who use them. 

KZ has chosen to go with the standard 0.78mm 2 pin connectors with the hidden connection design, which are very prone to failure according to online sources because they can easily be bent compared to ones which are flush with the IEM housing. The 2 pin connection is a standard angled plug, but instead of translucent plastic like the Y-splitter and 3.5mm plug, the connectors are made of clear plastic. This incoherence in design choice is probably borne out of cost control rather than purposeful decision, but again, doesn’t affect me too much. 

The eartips included are the standard Starline tips which come in three sizes. I’m not sure but I think these are slightly upgraded from the Starline tips for my ZST. They feel slightly softer than what I can remember, but the quality on these tips are still mediocre at best, getting uncomfortable and stiff after around 1 hour of for me. Even switching to the Sony tips proves problematic as the nozzle is longer than the standard earphone nozzle and the tips slide around on them.

Detailed Sound Analysis

Each housing contains eight driver units and four different models of drivers. One 10mm dynamic driver (DD) takes care of lows, two 30019 balanced armature (BA) drivers for mids, four 50024 BA for a wider spectrum and a single 30095 BA tweeter for highs, which is located in the nozzle. Although the 30019 BA are not from Knowles, they definitely chose the same serial number which can be confusing or misinterpreted as such. 

All of the below sound impressions were made using a DAC AMP combo FiiO BTR5 on low gain. I felt that the KZ ZAX did benefit from amping, slightly tightening the overall sound of the earphones. However, those without an amp should be just fine driving them directly out of a computer or phone. 

Overall, the ZAX is a decent sounding earphone for its price bracket. The tonality is slightly warm, with a decent soundstage and a maturity which was unexpected from a brand which historically seemed to have been aimed at a younger customer with rather pronounced V-shaped tuning. The ZAX, although still clearly V-shaped with boosted lows and highs, display a much welcomed refined sound signature, aligning itself with KZ’s future aims of breaking into higher price brackets as well as wanting to attract a more serious clientele. 

Bass response from the ZAX is slightly boosted, with decently good bass extension into sub bass with almost no bass bleed. Bass texture is very good, showing restraint in volume which was rather unexpected, yet still being punchy and responsive. Bass performance does have trouble keeping up with very fast tracks, starting to blur during speedy drums. However, the differentiation between sub bass and mid bass is clear and distinct. 

The mids take a backseat to the lows and highs, coming across very clean, cool, neutral and almost dry. Like most of its Chinese brethren, the mids of the ZAX has a clear tuning preference of female vocals over male vocals. While female vocals are colourful and slightly more lush, male vocals tend to be a touch harsher and chalky. One thing to note is that there are no sibilance issues in this frequency range. 

The treble is elevated, airy and smooth with good extension. It has just a sprinkle of sparkle to give the ZAX a much needed impression of soundstage. Imaging and instrument separation is very decent for an IEM in this price bracket. Lower treble may be a little subdued, giving priority to smoothness over analytical detail. Upper treble may be just a tad too hot for certain people more accustomed to a darker sound signature, but to me they were tuned just within the sibilance line. 

There is surprisingly little disconnect between the DD and BA drivers, the ZAX is able to deliver one congruent sound spectrum. The soundstage is slightly wider than normal, with the mids and highs opening up the width a bit more than the low frequencies. 

The open back mesh grills seem to be for aesthetics only, with no evidence from any sources saying the ZAX is open back. There are however air vents on the front of the IEMs which seem to be helping with soundstage. The V-shaped sound signature definitely lends itself to electronic, hip hop and pop music genres which have pronounced bass.


To conclude, the KZ ZAX is a very good earphone at 60 dollars. Is it worth upgrading from their almost bloated and very confusing line up of predecessors? Probably not. The 8 drivers only marginally bump up the ZAX’s performance from its 5 or 6 driver cousins. However, as a flagship hybrid, its only aim is to be the best performing hybrid IEM out of the entire brand’s line up, and it might just have succeeded. 

Sure, you’re not paying for the cable, or the box, or the eartips, but what you do pay for, the IEMiem itself, has no faults. There is always the option to slap on some Spinfits and grab an aftermarket cable if you choose to, maybe even get a Pelican case if you’re a high roller, but the core product is fine. 

Regardless, if you are a beginner looking to upgrade into this price range, or you’re a veteran looking for a cheap “beater” to use haphazardly, these are dead solid for its price as a conservatively V-shaped 8 driver hybrid earphone. I’ve found myself reaching for these time and time again in the four weeks I’ve had them, over my BGVP DMG and Kinera H3. If KZ wants to get into the big boy’s club, this is a good first step.