KZ ZSX Earphone Review – Terminated?

KZ ZSX featured

Hot on the heels of their successful ZS10 Pro model, Knowledge Zenith has released a new model dubbed “Terminator”, which we are reviewing today. Meet the KZ ZSX, a 6-driver (5BA+1DD) earphone from the Chinese manufacturing giant.

History (and prior KZ releases) has taught us those big driver counts do not guarantee a superior sound. In many cases, it merely becomes marketing material on top of a very average sonic performance. Will the Terminator take over the world or will it be banished back into the future?

This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

KZ ZSX Review

  • Value for money
  • Detachable cable
  • Build quality
  • Clarity and detail

  • Still rockin’ the brown KZ cable

Package and Accessories

The theme with KZ packaging for ages now is ‘If you’ve seen one, you’ve seen them all’. ZSX comes in the usual KZ box, complete with the plaque of honour, the legacy brown cable and 3 pairs of Starline silicone eartips. Who woulda’ thunk it?

ZSX what's in the box

Build Quality and Design

KZ seems to have latched onto a common theme for their shell designs of late too, “When you’re onto a good thing, stick with it.” So, once again, we see a slight variation of what seems to be the new universal KZ shells. We get an aluminium faceplate with a transparent acrylic shell.

The faceplate has a futuristic look with a series of V-shaped ridges and pointed triangular shape. “12 Hybrid” is printed on the face, reminding us that this budget IEM has a high driver count (even though there are only 6 drivers per side).

It would seem that there are 3 popular colour choices in humanity’s future and those are the available choices for your colour of ZSX shell, which include black, cyan and purple.

ZSX faceplates
Comfort and Noise Isolation

For my large ears, the ZSX is a good match but it may be awkward for those with smaller ears. It’s bigger than the ZS10 Pro and protrudes out from the ears more. The nozzles reach deeper which could be good or bad, depending on your ears and preferred eartips. Personally, I can wear these all day no worries at all.

Noise isolation is pretty good and these are suitable for noisy environments and public transport. Noise leak is fairly minimal too, so you needn’t worry about that.

ZSX view of internals including dynamic driver

Finally, after all this time…Nah, just kidding! It’s the same old KZ brown cable with the stupid Y-split position (halfway down the cable). It has angled, transparent connector housings, a rubber Y-split with no chin slider and a right-angled 3.5mm plug. The quality of the cable is quite good but it will tangle very easily so be prepared to spend a minute sorting it out every time you take the earphones out of your pocket.

Included 2-pin copper cable


Gear used for testing includes the FiiO M5 and Shanling M5s as portable sources. As usual, on the desktop, I used my little friend, the FiiO K3 and fed it FLAC files from MusicBee on my Windows 10 PC. The ZSX is very easy to drive and is perfectly happy being plugged straight into a smartphone but I never leave the house without packin’ a DAP and so that’s what I was using as my source.

The ZSX has an energetic and upfront presentation. Boosted bass, engaging mids and lively treble are descriptions that come to mind. It performs above and beyond what I normally expect for a sub $100 IEM. Clarity? Got it. Tone? Got it. Instrument separation – you’d better believe it.

KZ ZSX frequency response graph

The ZSX bass is like quicksand. When you first step in it feels normal. Then before you know it you’re tapping your feet and up to your neck in it. I’m sure even the Avengers’ Mr Fantastic would be impressed by the reach of the ZSX’s low end.

A reasonably fast attack gives the mid-bass some snappiness and texture but the long decay is where the weight and authority come from. Despite its abundant girth, the bass doesn’t feel sluggish and maintains a good pace.


ZSX has a fairly neutral midrange until it starts to rise in the upper mids. Naturally, it gets some warmth from the bass but the lower midrange is mostly uncoloured and fairly lean. There is a boost in the upper mids that adds a little brightness and attack to guitars and percussion.

Male vocals are a touch dry and could use a little extra warmth to sound more natural but female vocals are crisp and vibrant. The leanness of the midrange notes makes for a detailed presentation and good vocal articulation.


For me, it’s the treble that has improved the most when compared to the ZS10 Pro. There’s no sign of the usual KZ steely treble timbre. It no longer sounds like someone swinging a hammer in the kitchen sink. However, it does sometimes creep forward, like those people that try to sneak in front of you when you’re standing in line at the 7-Eleven cashier.

Overall it’s a crisp and detailed treble with good tone and good extension. It’s not sibilant or harsh and the 10kHz peak adds air and clarity into the mix. This is the kind of treble that KZ should be doing more often.


The ZSX creates an average stage with more width than depth. The vocals are positioned toward the back of the stage while instruments are placed closer to the front. There isn’t much in the way of layering but because of the above-average instrument separation, the stage feels fairly spacious. Imaging and positional cues are solid for something in this price range.

Top side of shells


KZ ZS10 Pro

ZSX vs ZS10 Pro

The ZS10 Pro (review here) has one less balanced armature driver per side, making it 1DD+4BA. Its shells are slightly smaller and may offer a more comfortable fit for people with petite ears. In terms of sound, the ZS10 Pro very closely resembles the ZSX, almost as if it was a non-identical twin. There are, however, enough differences, in my opinion, to substantiate the existence of both.

The ZSX’s bass sounds a bit tighter to my ears, the ZS10 Pro bass is ever so slightly thicker. It might be simply due to the ZSX’s superior treble extension or difference in the shape of the housing. Throughout the midrange, both earphones are hard to pick apart but the resolution and instrument separation of the ZSX is better.

It’s in the treble where the ZSX spreads its wings and rises above the ZS10 Pro. It dips a bit more at 6-7kHz which makes it less edgy and steers further away from sibilance. After the mid-treble peak that both IEMs share, the ZS10 Pro falls off more sharply. This gives the ZSX an edge when it comes to treble extension and air. Additionally, it counterbalances the bass more making the overall tonality just a little more balanced.

I bet those of you who have the ZS10 Pro are wondering if you need to get the ZSX. In my opinion, you don’t – although I think the ZSX is better, it’s almost a sidegrade more than an upgrade and depending on personal preference you may even like the ZS10 Pro more. If, however, you were to ask me which earphone is the better one, I would tell you it’s the ZSX.

Tin Hifi T2

ZSX vs Tin T2

Clash of the budget titans going on right here. The T2 (review here) dual dynamic driver is known as the sub $100 linear king and (deservedly) has a lot of diehard fans. It has such a nice tonal balance with good bass extension and detailed sound.

It definitely has less bass quantity than the ZSX, with a near-flat response from 20Hz all the way to the lower treble. Despite having less bass quantity, the T2 sounds full-bodied and warm when you have a proper fit and seal.

Vocals and midrange instruments are forward on the T2 and sit in line with the bass and treble, a rarity in the budget arena. Vocals sound warmer and more emotional on the T2 and more articulated on the ZSX. The boosted upper midrange and lower treble of the ZSX gives it a brighter tonality.

ZSX has increased lower and middle treble making it brighter and more detailed. But listening to them side by side the T2 sounds more natural and smoother. So, if you love bass plus a clean sound and micro details, the ZSX would be the one to get and if you want a very natural and musical tone, the T2 is still the one to beat in the budget segment.

ZSX with cable attached


So there it is. The KZ ZSX Terminator does indeed terminate the competition in terms of price to performance. It has powerful, controlled bass, clean, articulate mids, a sparkly, detailed treble and costs less than $50. You’d better believe this IEM is here to take souls and there’s very little to stand in its way. Our best IEMs list just got a new addition, of that you can be sure. If you already have a ZS10 Pro then you have some thinking to do. If you don’t have one then you should jump on the ZSX today.

You can check the latest prices on the ZSX here:

ZSX on Amazon
ZSX on AliExpress

  • Driver: 5BA+1DD
  • Impedance: 24ohm
  • Sensitivity: 111dB
  • Frequency Response: 7Hz-40kHz
  • Length:125cm
  • Plug Type: 3.5mm Plug

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3 years ago

Which iems are the best for runnijg/ jogging? It has to stay put really well.

Gung Bhisma
Gung Bhisma
3 years ago

Thanks for the review Crabbos. Who is the best KZ ZSX or Soundmagic E11c?

4 years ago

I got these as an upgrade for my kz zsr, I also got the trn v 90 at the same time and have been testing them all back and forth. At first I loved these but after time I keep going back to my zsr with eq tweaks as a more fun listen. They def have the most detail but there’s something about the treble ?. In some ways the less detailed v90 sound better as well. I may hold off for when amazon has the newest KBEAR items. Any comparisons to the v90?

4 years ago

I have an as10 and would like to know if it is worth upgrading to zsx. I listen to music (flac) only by cell phone.

S M Janarthanan
S M Janarthanan
4 years ago

Excellent review. I have one of these and your review just confirmed my experience. To the Dot…. I have tried many iEMs in the Mid-Fi category. I must say these ZSXs give them a run for their money. The one IEM I prefer to listen to over these are the Andromedas. Probably the Meze Rai Pentas…. but there’s no match for P/P ratio of the ZSXs….Not even worth thinking about…. You can’t go wrong with these…..

4 years ago

Hi Crabbos,
I’m confused between kz zsx,as10 and zs10 pro. I am concerned with the clarity and sound seperation, mids and lows, more compared to the higher bass. Which one’s offer a smooth and wide sound stage? Which one would you recommend?

Evandro Cesar
Evandro Cesar
4 years ago

Thanks for the review! Great work!
I bought the KZ ZSX, very good, but I confess that I expected stronger bass. Would you have an item with the same quality as ZSX (or higher) but more powerful bass? And that does not cost so expensive?
Forgive my lousy english by google translator.

Evandro Cesar
Evandro Cesar
4 years ago
Reply to  Evandro Cesar


4 years ago

Hello Crabbos good morning.
I would like to know if I can use some of your information from this review and join with other reviews to make a total summary in a YouTube video. Obviously I will give you the credits so they can visit your page and get to know your work.
I do it nonprofit, just with the idea of helping my Spanish speaking friends, since there isn’t much information in Spanish regarding audiophilia, I hope you can give me that permission. Thank you very much and keep up the successes, I also look forward to the review of the Shouer Tape.

4 years ago

Zsx is a dlc for zs10 pros

Cthullu Follower
Cthullu Follower
4 years ago

Hi Crabbos! just passing by and this review showed up. I think I found my next IEM. Thank you for this very informative review! Can you help recommend best alternative cable for this?

4 years ago

Thanks for the review Crabbos. I’m in the market for 2 new earphones. I’m currently stuck between getting the kz zsx, and the yinyoo V2. My other option is the kz zsn pro. What two would advise I get from these?

4 years ago

Thanks for another fine review, Crabbos, especially the comparison to the 10Pro and calling the ZSX a (better) sidegrade, rather than an upgrade. You saved me some pennies, the next beer is on me.

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