KZ ZSA (Knowledge Zenith)

General Information


Brand: KZ Acoustics
Model: ZSA
Transducers: Dual Hybrid [1BA (30095) + 1DD (8mm)]
Frequency Response: 7hz - 40,000hz
Impedance: 18Ω
Sensitivity: 101db
Jack: 3.5mm
Cable connector: 2-pin 0.75mm
Cable length: 1.2m

Latest reviews

Pros: Cheap, flat yet not lifeless sound.
Cons: Looks weird and ear hook guide doesn't sit very well on the ear sometimes.

Being in this audio hobby is oftentimes a roller-coaster ride. One day you find aiming for a specific set of gear only to find another release being propped out of the blue. Knowledge Zenith however has a different way of doing the roller-coaster ride. 1 day they release a 10 driver IEM and then follow it up immediately with a little brother. What we have now to realview is their recent hybrid IEM, the KZ ZSA. Thanks to Linsoul/DDAudio for providing the review unit in exchange for an honest review. The KZ ZSA is currently priced at $19 and you can grab a pair from Linsoul/DDAudio which you can grab at their DDAudio/Linsoul Amazon site and their Aliexpress store as well, DDAudio/Linsoul AliExpress. The KZ ZSA sports a single BA driver coupled with a single dynamic driver. A Frequency Response of 7-40000Hz, 18Ohm Impedance, 101dB Sensitivity and metal housing which comes in 2 shades, grayscale and a red/black faceplate/shell combo. With a lot of other options out there on the $19 range, some even coming from KZ themselves, is the ZSA have anything significant to offer? Let’s dig in.

Packaging and Build Quality

Okay, nothing to see here really. Packaged in a semi-glossy white cardboard box with the ZSA outline silhouette and black fonts stating the brand and model of the IEMs inside it. This is already a standard among the entry-level KZ lineup and the ZSA is no exception. Opening the box itself reveals the ZSA immediately covered by a clear plastic sheet and the ZSA embedded on a black plastic mold, underneath this black mold is the stock cable, warranty cards, manual and 3 pairs of black stock KZ silicon eartips with the M size pre-installed on the ZSA. The cable used is a 1.2M round braid copper cable on a gold plated 3.5mm L-plug with strain relief both on the jack and the Y-split yet no cable cinch which would have been appreciated since the Y split sits lower than most cables I have tried. The cable is easy to store and easy to tangle as well even though it’s a braided cable and glad to have found that it isn’t microphonic as well when used on the go. The memory wire on the cable near the .75mm 2pin connection had a thin metal strip to aid in the memory wire conforming to your desired shape. The IEM housing itself is a 2-part faceplate/shell union and what we have now is the red/black colorway.

The faceplate has white printed “hybrid technology” on it and 3 horizontal vents with a metal mesh underneath and 3 installed allen screws which isn’t painted black, the shell is a matte red with L and R markings on each. I wasn’t a fan of these silhouette yet after sometime it wasn’t that bad except for the in-your-face “hybrid technology” on the faceplate. The included silicon tips that came with the ZSA is clearly a mismatch for it and it is highly recommended to get a 3rd party tip hence in this realview, the Final Audio Type E was used due to its perfect bore size that matches the ZSA nozzle nicely, at 1st it was weird not seeing a nozzle lip to aid with tip security however the Final Audio Type E didn’t come off when the IEM was removed for the duration of the realview, a metal mesh is also present on the nozzle which is good.


The 1st foray I had into the KZ lineup was the AS10 and that was a welcome sound which was easy on the ears, the ZSA showcased similar tonality after the “necessary” burn-in which this time around reached 150 hours. The ZSA gave out a relatively flat response which didn’t show aggressive emphasis on the lower and upper frequencies. Let me drop the ball this early, I prefer the ZSA over the AS10 in overall sound, the AS10 had slower decay on the bass which I wasn’t a fan on how the effect caused the overall sound to be warm however the other frequencies were similar between the 2. I used the Opus 1 and Xduoo x3ii churning out 16/44 FLACs on multiple tracks under the One More Light, Best of Olivia Ong, Fleetwood Mac Greatest Hits and Dead Mau albums.


DeadMau’s Cat Thruster track played a soft thumpy bass. I would have preferred a more full-bodied bass on this aspect but it is great that this still allows for a cleaner definition for the midrange tones. The sub bass plunges deep and sounds very easy on the ears even when used with more powerful sources. The ZSA’s low-end performance showcases a well-controlled bass that isn’t thin or too powerful. This can satisfy your regular need of low-end kick.


Although the ZSA sounds rather flat overall, its midrange execution comes out alive and kicking. RUN D.M.C’s Peter Piper in 16/44 showcased clear and definite vocals even when the various instrumental tones kick in. It has great articulation on each vocal and instrument presence. The low-midrange performance is also clean and gives out a smooth transitional kick for the overall midrange sound. Upper midrange is delicate.


Nigel’s Stanford’s Cymatics in 16/44 Flac started smoothly on its low-end and midrange delivery yet when the upper frequencies kick on the 1:03 mark there is a soft treble bite without too much shrill which is further reinforced on the 2:04 mark. Note that the ZSA’s also emanates well the increase in both low and high volumes. It is best that this be properly driven with enough power which is should also be clean which doesn’t mean that this is hard to drive though. Trying the Sansa Clip+ on the ZSA is underwhelming.

Soundstage and Imaging

The ZSA faceplate features 3 grilled vents which should account for an affinity of an airy soundstage in relevance to IEMs however testing it out using Tom Jones’ To Love Somebody in 16/44 Flac gave out a spatially intimate width and has clear depth to it. Trying out the Beatles’ Hello, Goodbye still showcased an intimate soundstage with distinct imaging but also shows that the ZSA can also pan well with left to right instrument presence transition. The vents on this IEM don’t do a lot this time around.


Launched along with its famous siblings, the KZ ES-4 and the ED-16 which I am yet to try out gives the ZSA 1 distinct feature among its peers which its metal body and kind of weird silhouette. It is however comfortable to wear over long periods of time especially with your choice of ear tips. The ZSA comes with a good stock cable at best and along with its sturdy build and comfortable silhouette while still being able to give out a rather flat response with subtle focus on the lower midrange and a soft treble bite gives the ZSA a chance to be included in your entry level collection.
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Pros: great build quality, good cable, Lots of detail for the price point, shallower V with less aggressive treble than Zs6.
Cons: Shape and shallow fit make getting a good seal a problem for some, cable splitter and mic in odd location.
KZ is no stranger to most Chi-fi fans and 2018 has been a banner year so far for new releases. In this review, we examine the ZsA, a multi-driver hybrid in an aluminum shell. The ZsA was sent to me by Gearbest, in exchange for an honest review. I thank Gearbest for the opportunity to try new gear. Always a privilege.


KZs packaging remains pretty utilitarian. White cardboard slider over a cardboard rear box with a clear face. Plastic tray holding the buds with tips, cable and accessories hiding underneath it. Nothing fancy, but perfectly usable for its purpose and at least their packaging seems to make the trip across the ocean in one piece. Unlike some other brands I have received recently where the box looked a bit like it was delivered by Ace Ventura UPS man.


The ZsA continues the lineage started by the Zs6 of aluminum shelled IEMS and KZ seems to have learned from some of the comments regarding fit of the Zs6. The ZsA is roughly 2/3 the size of the Zs6 and all the corners have been rounded off leaving an almost teardrop shaped iem with the wider section toward the rear of the ear. My sample is bi-color with red body and black face plates. Anodizing is good throughout and color matching of the parts is good as well. The face plate has 3 vertical vents for the Dynamic while the inside of the shell is devoid of any venting. I like this arrangement as it prevents issues with movement blocking a vent and changing the signature. The nozzles do have a lip to prevent tip-slip too unlike some previous generations of Kz.


The cable deserves its own section as KZ has stepped up its game when it comes to cables on recent models. The Cable is brown with black fittings and braided nicely. Starting at the 3.5mm Jack the cable exits at a 90 degree angle with minimal strain relief and runs roughly ½ the length of the cable to the splitter. Again, the splitter has minimal strain reliefs and with the split being so far down the cable a chin slider is really needed. Unfortunately, no such thing is provided. I improvised with a dental braces rubber band which effectively moves the splitter up to more normal position. At the earpiece end are memory wires that are easily removed for those that don’t prefer them and .78mm bi-pin connectors. Overall, I’d love to see the split moved to the ¾ mark, a chin slider, and better strain reliefs on the next generation, but at least these are a marked step forward from earlier revisions.


The single button microphone works reasonably well but is positioned a bit too low on the cable so rubbing on a shirt during conversations while on the move introduces a bit of excess noise. I’m not a big fan of microphones on my cables as I don’t tend to use a phone as a DAP but for those who do this may be a consideration.


KZ has become known for the deep V signature with aggressive treble presentation and my expectation of the ZsA as a little brother to the Zs6 was that it would follow in its footsteps. I expected a stripped down version of the Zs6 sound with the single dynamic driver and single BA. In some respects the sound is still very much the big bass and big treble, but in others it shows KZ is maturing.


Sub-Bass extension is good with the ZsA easily reaching down into the 40hz range before experiencing significant roll-off. Mid-bass is very forward but fairly well controlled. There is some mid-bass bleed into the mids which contributes to a warmer signature than found on the Zs6. That combined with more texture than expected in the mid-bass makes the signature different than previous generations of Kz and very similar to the ES4 in presentation. Make no mistake, bass is dominant so if that isn’t your pleasure, you may want to look elsewhere.


With the previous comments regarding bass-bleed, one would think the mids would be poor on the ZsA but while there is perceptible bleed and mids are certainly recessed when compared to the Bass and Treble, they have more texture and are better presented than previous generations. It seems KZ’s deep V has gotten quite a bit shallower on recent models especially the upper mids. While the lower mids feel recessed and male vocals can be slightly thin as a result, upper mids and lower treble are emphasized more and bring female and higher pitched vocals forward. I am perhaps the only person listening to these this critically, but the tuning puts viola as slightly recessed and violin as mildly forward and makes for odd listening on orchestral pieces.


As previously mentioned, the lower treble is emphasized and treble in the overall is forward of the mids as is typical of KZ’s house sound. The ZsA can be a bit aggressive and sibilance is still possible but not nearly as likely as it was on the Zs6 or Zs5v2. At the top end, treble extension is good, but not great which interferes some with reproduction of cymbals and the like. I also noticed the ZsA has a tendency to distort the treble as the volume increases and is best used at moderate listening levels. This is probably partially due to the sensitivity of the ZsA which is quite high so extra power is not needed or necessarily appreciated.

Soundstage is wider than deep and is only average for the class. Instrument separation is good but the ZsA can get overwhelmed by busy passages and gets muddy when this happens.


Overall the little brother of the Zs6 is very much just that. It doesn’t have the detail or the separation or the soundstage of its big brother, but it comes closer than one might expect with half the drivers, and it manages to do so with a more listener friendly tuning and better mids. I think for those that like a V signature, the ZsA is a steal at a price of <$20. For those who prefer a bit more mid-centric presentation the ES4 gets the nod. KZ is improving with every new generation and their latest round of products shows that. If you haven’t heard a KZ in awhile, you should, they’ve come a long way since the early days.
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Hi! I think that KZ almost nailed it with the ZSA. I like the shallower fit a lot more. It's comfier. But intimate vocals almost always sound sibilant. Vampire Weekend and Bjork are almost unlistenable. It's a shame because everything else about these earphones is either good or excellent. I actually prefer the mids on the ZSA over the ES4. The mids on the ES4 have a paper cup effect on the vocals.
Pros: Great build and fit
No sibilance/treble peaks
Clean bass with impact
Fun, smooth signature
Cons: Recessed mids
Quiet vocals
Lack of detail/clarity


It seems like Knowledge Zenith releases several earphones every few months, so it’s hard to keep track of which one is which, but there are a few that stand out. For me, the ones that stood out the most was the ZS6. This one had a design that was blatantly similar to a top tier IEM (The Andromeda) that was actually built well and priced under $50. The aluminum housing felt premium and solid as a rock, and the sound wow’d you in many areas, both technically and fun. It had a major drawback, at least for me and many others, and that was the treble on them was heavily emphasized and could become overbearing in certain tracks. Sibilance was another issue with them. There were ways to tone it down, either by using foams, small modifications, or with EQ, but you could never fully get rid of the treble peak.

Earlier this year, KZ announced a new metal shell IEM, called the ZSA, which piqued many people’s interest. The build of their previous metal housing was fantastic, so many people were hyped to see how this new IEM was going to sound, and the price was right, at under $30.


I was planning on getting this IEM to try out at some point, but Lillian from LinSoul Tech was kind and sent me a sample to review in exchange for my unbiased, honest review of this IEM. I did not receive any financial incentives or any other benefits from this review or the following links.

If you are interested in purchasing this after reading my review, please check out the following links for purchasing:




Packaging & Accessories:

The KZ ZSA comes in the standard small white KZ box. Packaged within it is the IEM with a brown braided cable with 2-pin connectors, and a set of star-silicone tips. This is the standard KZ suite of packaging.

What is new from some of the older KZ sets is the upgraded cable. The cable is better in usability and appearance then the former cable, however, it still has very poor memory wire and has some stickiness to it in use. Luckily, the memory wire is very easy to remove if desired.


Build & Isolation:

As mentioned in the introduction, the KZ ZSA continues where the ZS6 left off with an aluminum shell. It also retains the three slit vents on the front and the exposed fasteners. The overall shape has changed to a more curved triangular look while also reducing the form-factor so that it is a bit smaller than the ZS6 and ZS5 models.

I chose to use this set with SpinFit C145 tips which work very well for me on this IEM. The small size is very comfortable to wear and does provide good isolation. Because it does have open vents, isolation isn’t dead silent. You can still hear through it but it’s average to above average overall.

While the smaller size does help with comfort and fit with smaller ears, it may make it feel loose sometimes. This may become a bigger problem with larger ears.


Sound Quality:

The ZSA has a definite V-Shaped sound signature like pretty much all KZ products do, where the bass and upper-mids/treble regions are elevated and the mids are recessed. This type of sound signature provides a lot of fun and wow, and I find it good for certain genres like hip hop, EDM, and other dancier music genres. It also works well for movies and games. This isn’t my standard daily signature but I do find it fun to listen to every once in a while depending on my mood.

For the review, I swapped out the stock cable with my own 2-pin braided cable featuring a 2.5mm balanced connector. I used three different sources to listen with: The Onkyo DP-S1 Digital Audio Player, the Radsone ES100 bluetooth portable amplifier, and my desktop Topping DX7 using an iFi IEMatch with a Norne Audio 4-pin XLR to female 2.5mm adapter. All units were using the balanced connections.

For music choices, I listened to a broad variety of music genres from rock to jazz to hip hop to edm to country, folk and post-rock/soundtrack music. Artists in my playlists include Real Estate, Norah Jones, Daft Punk, Cigarettes after Sex, Chvrches, The Beatles, Vince Guaraldi, Radiohead, Chris Stapleton, Krysta Nicks, Jason Isbell, Allison Krauss, Hans Zimmer, Corrine Bailey Rae and many others.


BassThe bass on these is elevated as expected. They have good impact while lacking depth and texture. They can be boomy sometimes and bleed over to the lower mids, which isn’t too unexpected due to the recessed mids. That said, the bass is fun and most of the time, it sounds about right. At the price it’s being sold at, I find it better than expected. Many IEMs in this price range will have overly boomy mid/upper bass which gets in the way of details. This IEM doesn’t do that often.

Mids – They are recessed. That said, the sound is slightly warm, and vocals sound good albeit a little distant sometimes. What I do like about this model vs the ZS5 and ZS6 is that the upper mids have been toned down a bit. This helps prevent the sibilance I was hearing in those prior models and really prevents that harshness and piercing upper mids/lower treble as well. The smoother sound is welcomed in this case.

Treble – As mentioned in previous section, the treble is also toned down. It is much easier to listen, though you do lose a bit of detail and energy compared to the ZS5/ZS6 models. Cymbals don’t have the same crash you’d expect, for example. You lose a bit of the glitter in the sound.

Soundstage - The soundstage is average on these. You never feel like the any instrument is beyond your head. Imaging is also average as well.

KZ ZSA - FR RAW.jpgKZ ZSA - THD.jpgKZ ZSA - Waterfall.jpg


I am used to listening to more neutral-bright leaning headphones that priced many times above these, and even my past experience with KZ have been on their upper tier. It’s a bit tougher to re-adjust my standards to listen to these, but just remembering that these are $25-30 IEMs, it is impressive what they can do. They lack details and clarity that IEMs priced $10-15 above them have, but compared to many budget IEMs, these do sound pleasant.

I found them enjoyable and, in some ways, more likely to be used than a ZS6, which cost nearly double it. The ZS6 beats these in many areas such as bass impact, stage width, clarity, details, and imaging, but I found the ZSA better at vocals, due to its more accurate timbre, lack of sibilance and upper mids/treble spikes.

In the end, I think these have their flaws, but they are also priced accordingly and may even exceed other competitors in its budget class.

KZ ZSA vs AS10.jpg



Thanks for the great review, B9Scrambler! I was wondering if you've had the chance to test the ES4's? And, if you have, how would you compare them to the ZSA's?

I recently got both and have been testing them side-by-side for several days and, at least in comparison, I find the sound of the ZSA's very underwhelming in terms of clarity, bass, treble (it's more sibilant), recessed-mids and the soundscape sounds so compressed to my ears... in other words, in very way but fit and conform, the ZSA's seem to my ears to be very much inferior. Moreover, if I take them separate from the ES4's, i.e. as if these were the only pair I had got and weren't comparing them, still I find the sound doesn't satisfy my ears and I would prefer returning them and getting others. (Which is all a shame, because in terms of comfort and aesthetics, these are my favourite of all!)

Anyway, after reading your review I'm wondering if it's just that I received a lemon pair of ZSA's that doesn't measure at all to the mark I'm seeing reviews out there.

Thanks again for the great work!