KZ ZEX Review (1) – Patchwork
Pros — Good build and accessory pack
– Comfortable
– Mostly inoffensive tuning
– Magnetostatic treble sounds interesting (at low volumes)
Cons — Boomy, texture-less bass
– Lack of sub-bass rumble at the extreme end
– Scooped lower-mids, male vocals sound muffled
– Treble sounds harsh when listening to higher volumes
– Imaging/staging/resolution are average at best
– Compressed dynamics
In this Article
INTRODUCTION
KZ is perhaps the most popular chi-fi manufacturer and in terms of sheer number of models available I think they got everyone beat. I did not keep up with their hectic release schedule for the better part of the year, but the KZ ZEX did catch my attention. Why, you ask? The EST (Electrostatic) buzzword, of course.
Most IEMs in the budget range go for a single-dynamic or a balanced-armature hybrid setup, so the ZEX is a refreshing change of pace. Let’s see if the sound quality is as good as it’s supposed to be.
Note: the ratings given will be subjective to the price tier. KZ sent me the ZEX for evaluation.
Sources used: Hidizs AP80 Pro
Price, while reviewed: $25. Can be bought from KZ’s Official Website.
PHYSICAL THINGS AND USABILITY
PACKAGING AND ACCESSORIES
The packaging is no-frills but has all the necessities. You get 3 pairs of Starline tips (white) and a 2-core SPC wire. The cable itself is rather nice, especially given the price and how some manufacturers cut corners here. I wish there was a carrying case, but I am nitpicking here.
4/5
BUILD QUALITY
The KZ ZEX have plastic shells (including the nozzles) with a metal backplate. The finish is good with no visible seam between the plastic shell and the metal backplate. At the bottom of each earpiece you’ll find the 2-pin port (protruted ones, sadly). There are no vents which is surprising given the existence of a dynamic driver inside. A pretty generic build overall but it’s well-executed.
4/5.
COMFORT, ISOLATION, AND FIT
Due to their lightweight nature and lack of vents, the KZ ZEX are very comfortable to wear and they isolate well. There is some pressure build-up but it only occurs occasionally. Not bad for a vent-less shell design.
4/5
SOURCE AND EARTIPS
The ZEX is very easy to drive and shouldn’t need any special source to sound its best. For the review I primarily used the Hidizs AP80 Pro. As for tips, I used the stock tips and they worked well.
DRIVER SETUP
KZ ZEX is a dual-driver hybrid, with a 10mm dynamic driver in charge of the lows and mids, and a 6.8mm “electrostatic” driver in charge of the highs. In reality, the electrostatic driver is a magnetostatic one and operates similarly to the principle of electret mics (just reverse-engineered). Despite the misleading marketing, the driver combination is quite rare in the budget realm and warrants a closer look.
TONALITY AND TECHNICALITIES
The KZ ZEX has a V-shaped signature with the mid-bass bloom dominating the sound signature.
I usually start my sound section with the bass and then I go upward, but this time I’ll change things around a bit. The treble will be the highlight here for me because the KZ ZEX has a quite interesting treble response. In moderate listening volumes (around 70dB or so) the treble has a nice attack and sounds crisp without being overbearing or fatiguing. However, as you push the volume up, the treble becomes even more peaky ~5KHz and loses its composure.
I believe that this particular electret/magnetostatic driver is not suited for high SPL listening. So perhaps this is something to take note of when auditioning the ZEX. As for the midrange – it is not well-tuned. I am not a fan of the scooped out male vocals. Moreover, the upper-mids sound suppressed in high-pitched vocals, resulting in a boxy vocal reproduction.
The bass response, meanwhile, is mostly mid-bass focused and sub-bass rumble is not prominent. Bass lacks texture and has slow decay so bass notes can smear into each other. The emphasis on the upper-bass is a bit too much (rising from 700Hz almost) and this masks lower-level detail.
Speaking of detail, the ZEX isn’t particularly resolving even for the price. Dynamics sound compressed due to aforementioned upper-bass boost. Soundstage is below-average whereas imaging is basically left and right. Not much to write home about here.
Bass: 3/5
Midrange: 2/5
Treble: 3.5/5
Staging: 2.5/5
Imaging and Separation: 2.5/5
Dynamics and Speed: 2/5
KZ ZEX FREQUENCY RESPONSE GRAPH
SELECT COMPARISONS
vs BLON BL-03
The BLON BL-03 have been one of the few hype-trains that did not get derailed. It’s been a couple of years now that the BL-03 has remained the de-facto budget IEM recommendation.
In terms of overall build, comfort, accessories – the KZ ZEX are superior to the BL-03. The BLONs require a cable and tip change as the stock ones are horrible. When it comes to sound though, these IEMs go for different direction.
BLONs go for a slightly V-shaped tuning with warm mids and slightly rolled-off treble. The KZ ZEX on the other hand goes for a more pronounced treble response. In terms of midrange tuning and timbre, the BL-03 trounce the ZEX. I do think the ZEX has more sparkle in their treble. BL-03 bass is also more textured and doesn’t sound as smeared as ZEX.
Staging is middling on both whereas imaging is better on the BL-03. BL-03 also sounds more dynamic and less compressed than the ZEX. So apart from the treble, the ZEX is not really an upgrade over the BLON in most factors. Rather the opposite is often true.
CONCLUDING REMARKS
The most interesting part about the KZ ZEX are their driver configuration and their treble response (in moderate listening levels).
Sadly, the midrange tuning isn’t up to the mark with overly recessed male vocals, and the bass is just slow and texture-less. The treble itself can get grainy once the volume is pushed up, so the ZEX have caveats all around.
The KZ ZEX falls victim to poor tuning decisions in the bass and mids despite having a fairly novel driver configuration. I hope KZ goes back to the drawing board and fixes the tuning issues in the upcoming model. For now, I cannot recommend the KZ ZEX.
MY VERDICT
2.5/5
Interesting driver configuration let down by questionable tuning decisions.
DISCLAIMER
Get it from KZ Official Store
Our generic standard disclaimer.
PHOTOGRAPHY
You find an INDEX of our most relevant technical articles HERE.
