KZ ZST Review - Criminally Good For $20

[jiyeon]

 

The KZ ZST is an off-the-shelf 'in-ear monitor' with a modest pricetag of just $20 from Amazon. This low entry cost is affordable and easy to invest in for the average consumer, so I thought I would pick these earphones up after seeing multiple reviews praising these as one of the most affordable pieces of hi-fi to come out of China, with the visuals and features to match and blend in with the big guns. I bought the colored purple & blue version and later found out that there may be a deviation between the black carbon fiber shelled KZ ZST and the colorful version of the KZ ZST, the difference of which is merely a bump in low-end and a sprinkle of more high-end. I don't think they're terribly different and so I'll be writing my review on the perspective of the colorful version of these earphones. I've had these for about a week, and sank in around 10 hours, whether it was at my desk at home, or out and about on commutes or at work.

 

The KZ ZST earphones feature a dual-driver setup, specifically a single Dual Dynamic accompanied by a single Balanced Armature. They also feature a dual-pin removable cable which terminates into a right-angle L-plugged 3.5mm headphone jack. Coming from my daily drivers the FiiO FH5, the move down to a dual-driver setup had my expectations somewhat low, but I still anticipated what kind of sound quality and signature the KZ ZST would produce.

 

 

The design of the KZ ZST are quite nice, with their colorful faceplate along with the signage of the 'ZST' moniker. The shell is also shaped ergonomically to universally fit ears of all shapes and sizes, which is a plug as this creates a nice seal for most people. The design is vastly different from other $20 earphones found on the market, I love that KZ has gone above and beyond to make the ZST look premium and stylish.

While it is a plastic construction, the plastics are fairly solid and are actually transparent to display the internal workings of these earphones, such as the big dynamic driver up front with the balanced armature next to it.

 

 

The cable is also fairly good, but nothing stellar. It is a dual-pin detachable cable that is fairly thin and unbraided, so it's prone to tangling which is a shame. The terminators at the middle and end of the cable are also made of this odd rubbery plastic which doesn't scream quality to me. I feel as if the cable is where KZ had to cut corners and it shows in how crudely-constructed the cable is.

On the flip side, the addition of the hooks at the end of the cable where the earphones connect is great, it has this memory construction which contours to your ear once you have put these on, and they are awesome. I can forgive the flaws of the KZ ZST for this subtle touch of flair and care as this is one thing about the KZ ZST that I did not expect would be done right, especially for this price point.

 

 

 

Highs:

The highs are exceptionally bright to the point where is very noticeable sibilance and hiss. While the highs in something like female vocals are nicely pronounced, the sibilance is there and it hinders the listening experience. The sibilance does not take away from the whole thing though, as songs like Ariana Grande's 'God is a woman' still manage to keep the bright and colorful vocals in check whilst not kneecapping the other frequency ranges. I might be beating a dead horse, but the highs are piercingly bright for me, and I usually prefer bubbly and colorful highs.

 

Mids:

The mids are the KZ ZST's kryptonite. The mids are not as pronounced as the lows or highs, and are quite quiet and shy in comparison to both, creating a very V-shaped sound signature. When listening to something like Twice's 'Knock Knock', the mids in the instrumental sound very far back as the highs and lows grunt their way forward in the composition. The mids are also not particularly well-separated either, instrumentals tend to sound very close and claustrophobic, even though highs and lows sound airy and wide.

Drake's 'One Dance' is also another example of this, the instrumentals while noticeable and distinguishable, the soundstage just isn't there.

 

Lows:

The lows are where the KZ ZST shines along with the highs. The lows are nicely pronounced and punchy. Eminem's 'Til I Collapse' makes the most of the KZ ZST's awesome lows. The 1-1-2 drums are deep and punchy while still not muddling the mids and highs. Childish Gambino's 'This Is America' is another great example of the lows of these earphones. The rumbling low tone throughout the song is greatly pronounced and doesn't interefere with the other frequencies which is exactly how lows should be done.

 

 

I will now listen to some songs using the KZ ZST. I have these directly hooked up to my PC which is using a Sound Blaster Audigy Fx card, however there is no additional EQ tweaks enabled, as I want to listen to music with these with as stock of an experience as possible. Similarly to my other reviews, I will be listening to music using the 320kbps audio quality from Spotify as I feel this is a good representaion of the average consumer who would be likely to stream music using something like Apple Music or Spotify. I'm going to comment on particular sections as a whole instead of commenting on particular parts of the song like I do for full album reviews.

 

Song 1 - BTS (방탄소년단) - Mic Drop (Hip-Hop K-pop)

• Intro: The bass is outrageously pronounced and punchy here. The synth while having a dirty sound, is super clear and pronounced. The intro is a real head-banger thanks to the awesome punchy lows produced here. The bass is also not overly warm or muddy here which is excellent for the listening experience.
• Verse 1: This is where the mids get to play around a bit, and it's a modest and subtle detailing from the mids here. The highs and mids in the vocals are clear and nicely-detailed, with the bass still hitting hard and contributing to the composition well as it does not interfere or muddle the other frequencies. Overall so far, there is an awesome blend of bass from the lows and the enhanced detailing from the combined strength of the mids and highs.
• Pre-Chorus: The highs and mids are utilized well here, the vocals are clear and detailed, with the intrsumentals also sounding clear albeit a bit bright.
• Chorus: The lows are definitely the contributing factor here. They create so much punch and deepness to the song. The vocals and instrumentals are also nicely-staged and clear, but the lows stand out a lot.
• Verse 2: Similarly to the first verse, the lows stand back a bit which allows the mids and highs to develop. The dual driver setup is used well here in both verses.
• Bridge: I can't speak enough about the level of excellence the lows have, not just in this song, but in general. The single dynamic driver is awesome at low-end reproduction and since it's separated from the balanced armature, manages to just go nuts without muddling anything else up. It stands on its own legs.

Song 2 - John Travolta - Greased Lightnin' (70's Pop)

• Intro: The intro to Greased Lightnin' is farily simple and is honestly more a show of the soundstage than anything else. The small stings are nicely pronounced after the small whispery yet clear dialogues.
• Verse 1: The mids are surprisngly nice here, the instrumentals such as the tamborine and the piano are clear and sharp, with Travolta's vocals also warm and husky. This is one of those times where the $20 price tag is shocking for how good the sound reproduction from the KZ ZST can be depending on the situation of the composition.
• Chorus: The chorus is beautifully presented using the KZ ZST. The vocals are well-separated from the subvocals and the piano medley. I love that I can also distinguish the light saxophone mid-way through the chorus too. Everything is nicely detailed and clear.
• Verse 2: Similarly to the first verse, this part is also nicely-presented thanks to how the KZ ZST are tuned. The subvocals are nice and clear too and also well-separated from Travolta's main vocal as well as the instrumentals.
• Bridge: So the bridge being mainly an instrumental solo, there is a lot of emphasis on instrumentation separation and clear detailing. The KZ ZST do this perfectly. The saxophones, pianos, drums, everything is greatly blended together to create an awesome instrumental bridge.

 

 

I really did not expect much buying into the KZ ZST for a mere $20. I expected at most tinny highs and overly muddy highs. But what I got after some time with these is detailed and clear albeit a bit bright highs, decent mids, and amazing lows. I was definitely caught off guard with these.

 

The design of these is great as well, they fit right into a modern in-ear monitor design with the universal, ergonomic fit. The addition of the removable cable is also a bonus, and at the $20 price tag as well, which allows for easy replacement of cables should the one that came with the KZ ZST breaks, but even then, the cable would probably come out to be almost half the price of the buds themselves which is mind-blogging to contextualise.

 

 

So overall, these are great earphones for the everyday person, there is minor sibilance and the mids aren't very pronounced with that V-shaped sound signature, but the overall aesthetics, fit, and the sound quality of these earphones more than make up for it. Couple this with 320kbps audio such as Spotify streaming, and you've got yourself some capable earphones to take around wherever you go.

[kokakolia]

Yeah... I wonder how these compare to more recent KZ models. I remember getting banned from the KZ forum on head-fi because I was furious about the amount of hype these earphones were getting. I annoyed everyone with the Marshall Mode. I still think these are better than most KZs for around $40. But everyone on the KZ forum only cared about "detail", at the cost of listening fatigue and poor balance. The KZ ZST was definetely the most hyped... over 600+ pages.  You see, I bought:

 

- ATE (actually didn't mind these, but the mids were weak)

- ZS5 V2 (these things ignited my rage: all treble and bass, no mids. The sibilance was overbearing)

- KZ ED7 (Loved those, they sounded just right without screaming sibilance and booming bass)

- KZ ED9 (absolute garbage like the ZS5 V2)

 

Fortunately, KZ redeemed itself (to me) with the ES4. Sonically, it's not the most impressive. But it's warm with punchy bass and no sibilance. It's a bargain in my book. I just can't find a way to keep them from popping out of my ear holes. 

 

The KZ ZSA is a similar story, but unfortunately there's sibilance to ruin the picture. 

 

I'm sure that KZ has released half a dozen pretty decent IEMs since. But I'm tired of gambling my fortune on these cheap little earbuds.  Just find one pair and stick to them. 

 

 

 

 

[jiyeon]

4 hours ago, kokakolia said:

But everyone on the KZ forum only cared about "detail", at the cost of listening fatigue and poor balance. The KZ ZST was definetely the most hyped... over 600+ pages.

The ZST's sibilance was piercing, and I'm sensitive to highs so it became apparent real quick after using these that I wouldn't last 10 minutes using these.

 

4 hours ago, kokakolia said:

I'm sure that KZ has released half a dozen pretty decent IEMs since. But I'm tired of gambling my fortune on these cheap little earbuds.  Just find one pair and stick to them. 

I've read my fair share of KZ earphones reviews and I'm on the boat that I won't buy another pair of KZ stuff. Scared I'll go down the same loophole as others who will buy half a dozen KZ IEMs and only end up like one pair of them.

 

Fortunately got my Tin HiFi T2 and FiiO FH5 IEMs so I don't have to worry about finding the perfect KZ IEMs for my ears.

[kokakolia]

@sowonThe Tin T2 is basically the reason people dropped the KZ bandwagon. They're just a little more expensive but lack most of the glaring flaws of the KZ lineup (sibilance, weak mids and boomy bass). 

 

I personally use the KEF M100 as my daily buds. They're perfectly smooth and neutral. The KEF M100 is largely ignored due to their $275 MSRP. But a store in Canada called Visions has been selling them for less than $100 for years. And nobody cares because every IEM ever released has to be compared to the Tin T2 (which is completely stupid IMHO). And since the KEF M100 is an older model, it won't happen.