KZ CRN ZEX Review (3) – Pointless Drama

Note: this earphone was first released as KZ ZEX, later as KZ x CRN ZEX. They are all the same earphone.

I have no direct experience with KZ products. Most of all, as my 15 readers know very well, I’m never enticed about overhyped products in general. If something, hype works towards distancing me from something, not the other way around.

That being said, I’ve recently been sent a pair of privately owned KZ CRN with a request for an extra assessment in light of the known (and let me add: quite pointless) drama emerged on social platforms a few weeks ago, which I won’t bother you with the cloying details of here.

KZ CRN (a.k.a. KZ ZEX Pro) are still available for purchase on multiple Ali Express shops for prices around 30-35€

Here’re my findings.

At-a-glance Card

Full Device Card

Test setup

Sony NW-A55 mrWalkman / Questyle M12 / E1DA 9038D – stock white silicon tips – lossless 16-24/44.1-192 FLAC tracks.

Signature analysis

One can guess that KZ CRN presentation may have been originally intended as a U shape, although the design intention was evidently missed due to a bad job done someplace, revealing itself most of all on the treble segment.

With that said, and within the limitations and the issues I will say more about in a bit, the ensamble – once corrected – comes accross as not tonally bad at all, and this should definitely be underlined.

The timbre is what mainly “reveals” the product’s (corrupted) multidriver nature. Long story short, one can clearly hear timbre incoeherence between bass and mids+trebles, and most of all a major timbre mixup all over the highmids and presence trebles.

A suspect about the origin of the latter issue is the crossover setup being completely screwed, and instead of separating BA / MEST drivers’ frequency scopes it lets them overlap for a large area. In more vulgar words it’s as if I’m hearing “both” a BA and EMST timbre… aka as “a mess”.

Again mine is a guess. I don’t know what’s precisely going on inside KZ CRN really (and/or inside the specific sample I received, of course). What I do hear is that their tonal levels are more than decently calibrated accross the most part of the spectrum, while such good job is depleted by some evident cause screwing the overall experience. Such effect is totally obvious. I wonder how could developers/tuners approve a product like this, which type of customer did they think this would be liked by? Whatever…

Bass is fully extended and strongly elevated – sub bass more than mid bass. The (inexpensive) driver itself proves unable to deliver big wonders on the tech side so apart from a nice volume, and not overly sloppy transients, we are left orphans of organic note weight and most of all texture.

Mids are surely the best part of KZ CRN’s presentation. Quite organic, well rendered, organically calibrated. Nice. On the low side they suffer some timbre incoherence with the midbass but not an excessive one. No sibilance on the upper hand. Really commendable vocals for such a low price.

Trebles is where the main disaster happens. There’s first of all a major flaw at 8 Khz where a sharp peak keeps polluting the entire tonality, delivering unnatural metallic notes. As is, they are just unaudible to me, period. Technically, this can be aposteriori greatly mitigated by a sharp EQ intervention: a narrow negative bell by at least 5 / 6dB, or even a band stop filter if you wish, centered on exactly 8khz will bring me back into audible territory.

In addition to this, presence trebles are dramatically rolled off shortly above the aforementioned peak, from approximately 9-10Khz on. Again, a “substantial” high-shelf filter helps recupe the situation into a much better result.

As I already mentioned above, this situation on the trebles region makes me suspect a screwup at the crossover level, with the MEST on one hand inappropriately overlapping the BA, thereby potentially generating or exhalting the 8K issue, and on the other hand being excessively tamed thereby resulting “audible enough” to contribute with its timbre (also in negative, where mixed with the BA’s one), yet not enough to deliver enough air up above.

Hence the surgical intervention of a high-shelf above 9 / 9.5K, to bump the MEST up, but only above a certain frequency range, thereby adding air back without (overly) exciting the aforementioned BA/MEST interference.

While we’re talking corrections, a slight taming on midbass might also help making them a bit faster. You won’t get better texture from the driver there though.

I would consider at this point legitimate to wonder wether one should invest competence and resources on doing what the manufacturer wasn’t able or willing to do, and “fix” an unhearable 30€ product into a decent one, or just bin it. The answer is very personal I guess.

Technicalities

If EQ-corrected KZ CRN’s tonality can be called “good” not the same can be reported about their technicalities. I presume there’s not much to dig to understand why here: little money pay for short blankets, compromises do apply.

Soundstage is nicely extended, but one-dimensional. KZ CRN almost totally lacks space depth.

Instrument separation and layering are not bad, yet imaging is close to tragic: whenever more than 2 or 3 instruments are playing together macro dynamics fail quite rapidly and spatial positioning goes down the drain with it. There’s no fix.

Physicals

One very surprising aspect of KZ CRN is the incredibly ergonomic fit. They are seriously comfortable, wish many of my other much better sound quality (and higher priced) drivers were half of this.

Passive isolation is also not so bad. Can’t say much about the cable, it looks pretty solid in terms of construction.

Specifications (declared)

Comparisons

Senfer DT6

An historical low cost (< 30€) tribrid designed around 1 DD ,1 BA and 1 Piezo driver.
Out of the box DT6 is tonally warm, with a significant midbass presence, very good low mids and trebles and tamed highmids. As is, it’s not bad at all. An optional EQ correction pushing the highmids up, adding +2dB to the entire treble line, and (for my taste at least) lowering the midbass by -2dB makes DT6 presentation close to spectacular when put in perspective to their negligible price.

Comparing DT6 vs KZ CRN “after the corrections”, KZ CRN delivers more neutrality and clarity, yet much less “substance” (note body & texture) behind that, while DT6 sounds warmer, more musical, more engaging. Timbre incoerence on DT6 is less than KZ CRN. Technicalities are monumentally better on DT6, unlike KZ CRN, offering near-holographic soundstage and very good imaging and separation.
DT6’s fit may be an issue though, and a serious one for some.

Final E1000

To me (and I reiterate that) the absolute best and therefore sole rational choice below 30€, E1000 carry a single DD driver, and masterful tuning which makes them extremely enjoyable already out of the box.
A perfectionist might want to apply some finetuning EQ to raise the too timid sub-bass (< 80/90hz), and help up the highmids and trebles with a modest bump up from 1.5/2K on, to my taste just that. Such EQ finetuning is even “more optional” than in DT6 case.

Comparing eq-corrected KZ CRN vs E1000, and taking timbre coherence off the table for obvious reasons (easy win for E1000 of course), E1000 first of all comes off better for stage drawing, and most of all imaging; detail retrieval is a give&take (much better E1000 down low, somewhat better CRN on mids/highmids). Timbre is clearer and tonality more neutral on KZ CRN, but their underlying note aridity is bad; I do prefer E1000’s warmish coloration on top of much more organic, credible notes accross the spectrum.

I find E1000’s bullet shape comfortable but that is subject to wide personal variations. E1000 has a fixed cable and this might irritate the senses of some phobic – I will never understand them frankly, not on a 30€ device really.

Considerations & conclusions

Simply put, and without needless sugarcoating, KZ CRN are a flawed project.

Out of the box they are close to unaudible to me. Well ok, you know, I’m an exacting (read: nasty) reviewer. Let’s tame this into saying they must be clearly addressed to very undemanding customers. Whatever.

Applying some aposteriori EQ the situation can be made dramatically less tragic. In a sense, this makes my general opinion even worse about this: even within all the logical limitations connected to the inexpensive parts which need to be involved on such a low cost finished product, the problem is clearly not in the hardware per se, but exclusively in the competence – its lack thereof really – of the people involved in the development and/or at least the final approval of this specific model. It’s been my first experience with a KZ product. I hope my second will be better, or I guess I’ll hardly find the time for a third.

With all that said, once severely corrected KZ CRN are more than audible, actually quite nice really – especially on the tonality side, while more limited on the technicalities front.

Disclaimer

A deep thank you to Simone Fil for the loan, and our always so rich opinion exchange on audio topics.

Our generic standard disclaimer.