KZ ZEX

disclaimer:  The Zex was provided to me by a KZ representative for purposes of this review.  I have no financial interest in KZ or any of its subsidiaries or distributors.    To purchase the Zex or to learn more, see KZ’s official store.

 

Unboxing / Packaging:

If you’ve purchased a KZ earphone before, you’ll know the formula used for their packaging and will find no surprises here.  White slipcover with picture of earpieces on front, specs on reverse, and mic/color noted on side.   Inside we have the foam tray with the earpieces on top with the cable and tips hiding beneath.     The package contains 3 sets of silicone tips, the cable, and the  earpieces.  It is pretty sparse by current standards but we do have to remember that the ZEX also retails for less than $25 USD.

Build/Fit:

The Zex use a hybrid shell with a metal face plate and an polymer inner shell with raised bi-pin connectors.   Shape is the common teardrop with the nozzles just above the point and with a forward rake when positioned in the ear for fairly deep insertion.   The metal faceplates are stylized with a wave pattern at the front edge and the KZ logo on the main section and are well fitted to the inner shell.   The bi-pin connectors are cast into the inner shell so the faceplate does not require a cut-out to accommodate the connector.    I found comfort good for long wear but did have some issues finding a tip that sealed well.  It should be noted that the Zex like its CCA counterpart (NRA, I know different drivers, similar shells) use a smaller than average nozzle size and will make tip selection a bit more difficult.  I had some Spin-fits on hand that did the trick, but know that tip selection will be a bit tricky as normal sized tips may be too loose for the Zex nozzles.

 

Internals:

I guess with the recent market it shouldn’t come as any surprise that the internals of the Zex include an electrostatic driver.   What might be a surprise is the lack of 47 others drivers in the shell to go with it.   The Zex uses a 10mm dynamic driver for lows paired with the new electrostatic driver for highs.   KZ claims tighter tolerances and better driver matching for the electrostat when compared to balanced armatures with a lower overall distortion and better extension than an armature can deliver.    The drivers used in the Zex are both designed and built in house and the electret driver should not be confused with the Sonion electrostat that has become popular of-late as the Sonion part costs nearly as much as the finished Zex.     Nominal impedance is listed at 25Ω with a sensitivity of 103dB/mW which places the Zex in the easy to drive category and I had no trouble using a dongle, tablet, or low powered source with the Zex.  It does scale a little with more power, but the ceiling is low enough that high potency sources really offer little gain when considering the expense.

 

Cable:

The provided cable is silver plated copper in a clear housing and is two strands side-by-side from the jack up to the splitter and then a single strand to each earpiece above that.  The cable is heavy for its size and some microphonics result.    Starting at the south end we have a 90º 3.5mm single-ended jack in translucent clear housing with a good strain relief.  The splitter is simply a piece of clear tubing glued into place on the wire and as per KZ tradition is lower than I would have hoped with the splitter at roughly the half-way point of the cable.   At the northern end we have pre-formed hooks without memory wires  and hooded 0.75mm bi-pin connectors of the QDC rounded style.      Overall, its a functional cable and a very durable design so when considering the price its hard to complain too much.

 

Sound:

Bass:

Sub-bass is the star of the show with a pronounced emphasis centering around the 80Hz mark and then a gradual drop back above that point.   This gives the Zex plenty of rumble when called upon, but doesn’t over-power the rest of the signature or over-shadow it.  Speed here is only average so the sub-bass can feel a little monotone and not super well textured, but again at $22, we really shouldn’t expect tons of detail in the sub-bass.   Mid-bass although not quite as forward is a bit more dominant and here the driver speed is more evident as well.  Mid-bass has good slam but is a little loose at times and does bleed into the mids and add a warmth to the lower half of the signature.     Overall the lows are solid for a budget offering with good slam and rumble, but lack a bit of detail when compared to higher priced models.

Mids:

Lower mids are slightly recessed but have a nice weight to them and the mid-bass warmth helps with tonality of lower vocals.  Unfortunately a very rapid rise in the middle of the mid-range gives it an odd dichotomy between the lower non-accentuated voices and the higher ones that jump forward in the mix.   Depending on the track, either the lows sound a bit recessed or the higher end sounds a bit too forward.    I applauded KZ for not taking an existing model and simply adding the electret to the top end and calling it something new,  but in the mid-section it becomes obvious why some other models have opted to put a BA in to cover the territory between the dynamics low-end grunt, and the electret’s top end sparkle.   Mids here have good clarity and more detail than the lows, but are somewhat uneven in their presentation with strings having a particularly odd tonality at times.     Because of this tuning, the Zex is best saved for Rock, pop, and EDM where the mids play a lesser role.

Treble

Lower treble starts out on the same plane as the upper-mids but drops back some as it moves up which keeps it from having too much push in the lower treble and results in a fairly polite tuning.  There are definitely some frequencies that get a little push forward with one around 5kHz and another around 8kHz that keep the Zex from feeling closed in but thankfully the upper peak drops back quickly so as to avoid the classic KZ ear-spike at 9kHz.   Snare rattle has a nice crisp edge with good definition to the body as well but cymbals lack a touch of energy that keeps them from being entirely realistic.    Air and sparkle is limited but this is obviously a tuning choice as the Zex is a bit more laid-back and easy-going as a result.

Soundstage / Imaging:

Stage is a bit wider than deep but fairly intimate in all dimensions so does not come across as disproportionate.  Seating the orchestra is a bit crowded partially due to stage size and partially due to average instrument separation.  There are not huge anomalies here, but it does feel a bit cramped and is better suited for genres with fewer voices.     Imaging is fairly good with movements easily tracked but absolute positions are a bit less well defined.   Layering is about average for the class and some compression does become evident as tracks get busier and faster.

 

Comparisons:

CCA NRA ($23)    These two are fraternal twins with similar shells and same drivers but don’t share exactly the same tuning.  The NRA comes across as a bit better detailed with better separation while the Zex is a bit richer and thicker and perhaps a bit more natural sounding (other than the odd-mids).     The separation gives the NRA a bit larger stage as well but at the expense of being a bit brighter and potentially a bit harsh.    Those looking for a more polite treble will prefer the Zex.      These two are more similar than not so differences are not huge, but if you are going to spend on one of them, the differences are large enough to make one or the other a better option depending on your preferences.

 CVJ Angel Wings ($28)     The Angel wings are slightly larger than the Zex with an all resin shell and a semi-custom shape that makes them a bit larger in the ear than the Zex.  Where size is an issue, the Zex may be an easier fit.  Internally, the Angel wings sport a single dynamic driver and a balanced armature so a similar arrangement to the Zex and a similar tuning.   Both have a big low end with recessed mids and then a bit of a treble rise.  The Zex has more treble than the Angel Wings but neither is particularly treble forward.   The Angel Wings need considerably more power than the Zex to sound their best so if using from a phone or dongle the Zex is a better option.   I have trouble recommending any <$30 earphone that needs $200 of other equipment to sound its best (Angel Wings).

KBear KB04 ($22)     The KB04 has been my recommendation in this price bracket for awhile now as its all metal construction gives it a build advantage on a lot of it competiton and its tuning is fairly safe with enough extension on the top end to have some air without being harsh.   Internally the KB04  is a dynamic driver / BA hybrid in a slightly larger shell than the Zex.   The Zex and KB04 have similar low ends with the KB04 having a bit less recess in the mids and more detail as a result.    Top end also favors the KB04 slightly as the Zex is a touch more laid back while the KB04 brings a little more air to the top end.

BLON BL03 ($26)    The Blon BL03 has hung around because of its tonality despite an odd cable angle and some fit issues.   That says a good bit.   The BL03 and Zex are tuned similarly with boosted lows, recessed mids, and polite trebles but the Blon once again wins for a more natural tonality.   Those who find the lower mids of the Blon too thin may well prefer the thicker richer presentation of the Zex.   From the mids up the Zex delivers a bit more detail as well while the Bl03 has a more organic sound.

Thoughts / Conclusion:

With every maker clamoring to introduce an electrostat into their line right now, I have to admit I figured the Zex was going to be a harshly tuned, treble heavy in-ear to show off their newest toy.  Thankfully it isn’t.   The tuning is more mature than I anticipated but is definitely still geared toward popular music with its bass push and lower treble/upper-mid emphasis.   While the electrostat is well tuned, I do think there is some odd behavior in the mids where at times the stat contributes to the mix and at others it is left to the dynamic driver.  This is no doubt something that will get worked out as the technology advances and is not a knock on the Zex as it still handles the electret driver better than many I’ve tried at considerably higher price points.   The Zex is at its best with popular music and works well from low powered sources so there is a lot of market out there for it.  If it goes on sale for black Friday,  it is worth considering as stocking stuffers for those on your list that listen to a lot of pop, rock, or edm.