Just when you thought the KZ reptilian overlords had tired of feasting on human flesh, they’re back again. In this review, I’m looking at the new KZ ZEX IEM. The ZEX is a hybrid dual-driver earphone with one dynamic driver and one low-voltage electret driver. The KZ ZEX retails for $22.

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

KZ ZEX

Specifications

• Sensitivity: 103dB
• Resistance: 25Ω
• Frequency: 20hz-40khz
• Unit type: Electrostatic driver + Dynamic driver

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Packaging & Accessories

Nothing to see here folks: the ZEX comes in standard KZ packaging i.e. a small white box with an image of the IEM on the front and specifications on the back. Inside the box, we find the KZ ZEX, a detachable silver-plated copper cable and 3 pairs of (very small) silicone eartips. I really think they should increase the variety of eartips in the box because as many of us know, the sound isn’t good if you don’t get a good seal and fit.

Design

In terms of its design, the KZ ZEX adheres closely to other recent models such as the DQ6. It has aluminium faceplates with a smooth matte finish and resin shells. The thickness of the metal faceplates is significant, giving the ZEX some heft and a robust feel.

Just like the CCA NRA, the ZEX, unfortunately, has narrow nozzles. This imposes more of a challenge for tip-rolling as many standard eartips won’t fit properly. The nozzles have a protective mesh cover and a lip to hold eartips (with a smaller core) securely in place.

So is the ZEX comfortable? You bet it is. The shells fit naturally into my ears and I can wear them for long listening sessions. They don’t protrude out from the ears either so this is a good IEM for lying down with. Passive noise isolation is pretty average so I can hear my keyboard as I’m typing this. Of course, once the music starts you hear a lot less outside noise relative to how much you turn up the volume.

Cable

The silver-plated copper cable is the same one that comes with the CCA NRA. It’s a decent cable and in my opinion, better than the old KZ twisted cables. However, it does have the sharply-angled 2-pin connectors that I hate. So once again, I swapped out the cable for something more comfortable. There’s a microphone version cable available too and the quality of the mic is actually really good.

Sound

Gear used for testing includes:

• PC -> YLM B2
• PC -> Tempotec Sonata E44
• iBasso DX120

The KZ ZEX has a balanced and fairly mature tuning. There’s enough of a bass lift to make it fun though and the midrange is nice and full too. It’s a smooth sound with no harshness or sibilance. Detail retrieval is good, the tonal balance is on point and the level of clarity is respectable as well. When it comes to compatibility, ZEX is easy to drive and will work just fine straight from a smartphone, dongle DAC or entry-level DAP.

Bass

The bass is punchy and hits with sufficient impact while not being over the top. It’s not the fastest bass but has a medium-paced attack and decay which gives it a natural feeling of weight and density. There’s slightly more emphasis placed on the mid-bass that thumps with authority when called on.

But ZEX still has plenty of grunt in the sub-bass too, as is evidenced by Lorn’s “Drawn Out Like An Ache”. Here ZEX digs deep and the low synth bass notes have a pleasing but controlled rumble. It’s not a destructive bass by any means though and it doesn’t overshadow the midrange. It’s quite impressive overall, especially given the budget price of this IEM.

Mids

KZ ZEX has a natural and organic midrange with good warmth and spacing. The coherency is extremely good and one could easily believe this was a single dynamic driver at work. The dynamic and electret drivers work together in perfect harmony with no noticeable dips or inconsistencies.

The overall tone is convincing and although the clarity is only average, it doesn’t diminish the ZEX’s appeal. This is an IEM that sounds confident in its execution. It has a sureness that’s rare in this price range. While the midrange isn’t as forward or clear as the CCA NRA, it’s not recessed either. Vocals are articulate yet have lifelike body and fullness.

Treble

ZEX’s treble is both detailed and smooth at the same time. It doesn’t really sparkle but it’s crisp and forward enough to counterbalance the enthusiastic bass. Micro-detail retrieval could be better but what you get instead is a treble that’s free of harshness and sibilance.

Soundstage

The soundstage is somewhat intimate in regards to its size but has a nice roundness to it, meaning both width and depth are fairly even. Instrument separation is nothing special but the sound doesn’t feel cramped or congested. Imaging is still quite good though and although the sound isn’t ultra-clean, it’s still easy to pick out instrument positions in the perceived space.

Comparisons

CCA NRA ($23)

The CCA NRA was released just before the ZEX and has the same driver configuration. NRA sounds somewhat clearer and has better instrument separation whereas the ZEX sounds a little more organic. Both IEMs share similar bass levels but the NRA has slightly better note definition.

Vocals are more forward and have greater clarity on the NRA and the instrument separation is better compared to the ZEX. This is likely due to the NRA’s treble tuning which is just slightly more forward and clearer. It has a trickle-down effect, improving midrange clarity and definition. The NRA has a little more zing and sparkle compared to the smoother ZEX treble.

NRA’s soundstage is a little wider and larger with better spacing and separation between instruments. The differences aren’t extreme though and these two IEMs sound quite similar overall. If you’re averse to brightness or treble and love a smooth, laid back presentation then the KZ ZEX is the way to go. Conversely, if detail retrieval and clarity are characteristics you covet, the NRA is the one to choose.

KZ DQ6 ($27)

The KZ DQ6 is a triple-driver IEM with 3 dynamic drivers. DQ6 sounds more dynamic and contrasty versus the more linear ZEX. DQ6 has better sub-bass extension and less fullness in the upper bass and lower midrange. Midrange notes are slightly leaner and have better spacing than the ZEX.

DQ6’s treble is a bit more energetic and has more micro-details. Combined with the leaner lower mids, this gives it more clarity but at the same time, it’s a little edgier in the treble. I find the DQ6 to be slightly more engaging but the ZEX price makes it a compelling alternative.

BLON BL03 ($26)

Yes, we’re still comparing things to the BLON BL03 and that’s because it’s so good. The BL-03 is tuned closer in line with the Harman Target Response compared to the ZEX. Therefore, it has more bass presence, slightly recessed midrange and rolled-off treble.

BL03’s lower midrange is leaner than the ZEX, making the bass (especially the mid-bass) more prominent on the overall tonality. It also means that it still has good clarity and sufficient energy despite the rolled-off treble. Compared to the ZEX, BL03 sounds more engaging (to my ears) but ZEX has more detail retrieval and fuller vocals.

Conclusion

The KZ ZEX is another fantastic showcase for budget electret hybrid IEMs. It has a natural, earthy sound that many people are sure to love. It’s also a great IEM for people who want a full-bodied midrange, good detail retrieval and a non-fatiguing treble at the same time. I can’t wait to see more earphones with this new technology and am really curious to see how the electrets can perform in higher priced models.