KZ ZES Review: Yet Another Bassy KZ

  • Clean textured lows
  • Good clarity in the midrange
  • Well extended highs

  • Instances of bass bleed
  • Lower treble peaks

Knowledge Zenith, or simply KZ, doesn't really neejd an introduction at this point. They are, by now, pretty much well-known by long-term audiophiles and newbies alike. With the past few years, KZ has been continuously launching a ton of IEMs. The ZES is the third IEM from KZ to be equipped with what they call an "electrostatic" driver, with their ZEX and ZEX Pro being the first and second one respectively. The ZES currently retails for 32 USD, and was provided to me for free by KZ in exchange for this review.

Driver units: 12 mm dynamic + 6.8 mm electrostatic
Impedance: 32 ohms
Sensitivity: 113 dB
Frequency response range: 20 Hz - 40 kHz

Poco X3 paired with Cayin RU6, FiiO KA3, Tempotec Sonata E35 and Zishan U1

Test tracks:
Africano - Earth Wind and Fire
Dark Necessities - Red Hot Chili Peppers
Gurenge - Lisa
The Chain - Fleetwood Mac
Monsters - All Time Low
Ours - Taylor Swift
Stay - Mayday Parade
Snuff - Slipknot
Yesterday Once More - Carpenters
So Slow - Freestyle
Aurora Sunrise - Franco
Attention - Pentatonix
Blue Bird - Ikimono-gakari
You're Still The One - Shania Twain
Anyone Who Knows What Love Is(Will Understand) - Irma Thomas
Salamin - Slapshock
AOV - Slipknot
Hey Jude - The Beatles
The Way You Make Me Feel - Michael Jackson
...and a lot more.

Unboxing and Accessories:
The ZES comes in a small, white sleeved box that is what KZ commonly uses in their budget lineup. Upon removing the sleeve and the top lid, you will see the earphones inserted in a molded plastic film. Right below it is another, smaller box that contains the cable, instruction manual, small and large white starline eartips with the medium already attached to the earphones.
The shells are mostly made of metal with green plastic accents. The faceplate has this design that is very similar to the ZSN and ZSN Pro. The top portion of the shell has a translucent window where you can see the dynamic and electrostatic drivers. At the rear side there is a single vent hole. The nozzles are also made of metal and has a fine mesh filter and a lip for the eartips to hold on to.
The cable is a braided 8-core silver plated copper. The cable itself is soft and light but the bulky plug gives it a little more weight. Slight microphonics can also be heard. The angled 0.75 mm 2 pin connectors are made of plastic, while the splitter and the 3.5 mm gold plated plug are made of metal.
Now let's get to the sound.

The lows are dominant and drops with authority. Subbass has an average depth alongside a decay that should be more than enough for many. Midbass has great texture. It is partially more forward than the subbass with a slightly above average weight.

Overall, the lows of the ZES surprised me in two ways. First, even though the lows have huge impact and can sometimes feel out of control, it has surprisingly good texture. Second, it has minimal impact to the mids compared to KZ's previous models.

The mids are slightly recessed, as expected from KZ. Male and female vocals are linear in position with great clarity and articulation, also slightly leans on the thin side but stays within comfortable levels. Instruments have adequate note weight and reproduced with good transparency.

Overall, the mids of the ZES are colored to some extent but still feels natural. Even though it is a bit thin, lower mids never felt lacking in substance and there was not a hint of aggressiveness or shoutiness in the upper mids.

The highs are forward and vibrant sounding. Treble reach is very good with a decay that is slightly above average. Instruments are sparkly but cymbals can sound too splashy and aggressive that may induce fatigue especially for treble sensitive people.

Overall, the highs are right up there with the lows. Cymbals tend to sound shouty at times but sibilance was very minimal even on notoriously sibilant tracks which, for KZ, is a very notable improvement.

Soundstage and Imaging:
The stage is sufficient in size. The height and the width are just about equal in space. The clarity in the imaging is great, better than most KZs in any price range. Instruments have adequate space and air between them and have good layering. Congestion can be perceived every now and then especially in genres like metal.

KZ ZES (1 DD + 1 electrostatic, 32 USD) vs. BLON BL-07 (1 DD, 45 USD)
Lows on the ZES are bigger sounding. BL-07 has deeper subbass but the ZES has stronger rumble and marginally longer decay. BL-07's midbass is more boomy and packs a heavier punch, but it also bleeds to the mids more than the ZES. Mids on the ZES are slightly thinner while it's almost neutral in terms of position and weight with the BL-07. Clarity in the mids is just about equal. Highs are more forward, has more presence, and has better reach with the ZES. Decay is longer in the ZES as well, but the highs of the BL-07 are more comfortable for extended periods of listening. With the soundstage, ZES has a bit more expansion in the width, while the BL-07 has more expansion in the height by just a tiny margin. Imaging is definitely clearer in the ZES, as well as better instrument separation.

KZ has been steadily improving over the years in both build and sound quality. What used to feel flimsy, now feels more solid, what felt too overwhelming and ear piercing, now feels under control to some degree. The ZES is one of the better options from KZ in my opinion, while still equipped with KZ's house sound; the V-shaped signature. KZ was able to show incremental improvements, but at this point, their sound signature really feels dragging and very redundant.


  1. You have to experiment with eartips I use 2$ KZ clear "terrible" eartips with these ZES sounds open and I can't get enough of listening to these. I have bunch of 300-800$ earbuds from Fiio 7hz Campfire. These ones make me want to listen to music for hours and loud. never tire and detail is all there. QC is terrible on ZES line I have a pair that went dead. barring that I feel this is magic for me.

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