In this review, I’m looking at the KZ x Crinacle CRN (ZEX Pro) IEM. Yes, the name is a bit confusing; especially since it has changed after its initial release. The CRN is a hybrid triple-driver IEM with 1DD + 1Magnetostatic + 1BA. It retails for $33.
Disclaimer: This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.
KZ x Crinacle CRN (ZEX Pro)
Specifications
Sensitivity: 104dB
Resistance: 25Ω
Frequency: 20hz-40khz
Driver: Electrostatic driver + Dynamic driver+Balanced armature
Plug: 3.5mm
Pin: 0.75mm
Packaging & Accessories
As is the standard for KZ IEMs, the CRN comes in a small white box. On the front of the box is an illustration of the IEMs and on the back is a list of specifications. Inside, you’ll find the KZ x Crinacle CRN, a detachable SPC cable and 3x pairs of silicone eartips.
Design
The shell design of the CRN has changed a bit from the original ZEX. This one has more curvature on the inner part of its transparent, smoky shell. Carved into the aluminium faceplates is a low-key KZ logo.
Once again we find the Type-C 2-pin connectors which have become the norm for the majority of big brand budget ChiFi IEMs. Another significant difference between this IEM and the ZEX is the size of the nozzle, which has been enlarged to better accommodate the additional BA driver.

Just like the ZEX, the CRN has very good build quality, especially for a budget IEM. In terms of comfort, I find these shells to fit my ears well and I can wear them for extended periods. Passive noise isolation is slightly above average.
Included with the earphones is the new and improved SPC flat cable. It has a right-angled plug with a 3.5mm termination. The 2-pin connector housings are sharply angled which I’m not a fan of but it doesn’t seem to bother most people. When it comes to handling, the cable behaves well; it’s fairly resistant to tangling and only has a small amount of microphonics.

Sound
Gear used for testing includes:
The KZ x Crinacle CRN (ZEX Pro) has a fairly neutral sound signature that aims for clarity and detail. It adds a bit of colour with its elevated sub-bass but is mostly neutral and with a significant lower treble lift. Coupled with a subdued upper bass, the CRN’s midrange is somewhat lean with a bright tilt.
Like all KZ IEMs, the CRN is easy to drive and doesn’t require any extra amplification. However, due to its brighter tone, it works better with a warmer source.

Bass
CRN’s bass favours the sub-bass which is elevated and produces a nice tidy rumble. Mid-bass notes are lighter in quantity but have good speed and definition. However, the mid-bass sometimes lacks weight and impact. The upper bass, in particular, is rather dry and lacks rhythm. The upside is a clean lower midrange that’s free from any bass bleed.
Kick drums have a clean leading edge but are a little too sharp at times. There’s not much texture to bass notes and decay is a little too fast but it’s tight and well-controlled.
Mids
The midrange is fairly neutral and uncoloured but has a slightly bright tone. Vocals are articulate and detailed, although they can be a little thin. There is some stridency and harshness in the upper mids which can be a little unforgiving on poorly recorded material.
Midrange clarity is good but the overall resolution is pretty ordinary, especially during complex passages. I find the CRN to be really good for string instruments; in Loreena McKennitt’s “Cymbeline – Live”, the vocals are a tad grating and sibilant. But the harp and other exotic stringed instruments sound exquisite and clear.
Treble
Okay, so if you know anything about frequency response graphs, you’ve already noticed the CRN’s 8kHz peak. This is where the brightness, definition and sizzle are generated. Any sibilance and stridency can be attributed mostly to this as well. It’s not an issue on a lot of tracks but it can be a problem on some recordings.
Detail retrieval is above average for a budget IEM. The treble is crisp and reasonably airy albeit with a slight metallic tinge. Treble extension is quite good but cymbals can get splashy.
Technicalities
The soundstage has average width and depth but surprisingly good height. Imaging is fairly precise on simple recordings but the stage gets quite congested during complex music. Despite having above-average detail retrieval, the overall resolution is somewhat disappointing.
Comparisons
KZ ZEX
The KZ ZEX is the predecessor to the CRN (ZEX Pro). It has a fuller, smoother sound signature with none of the edginess that the CRN brings to the table. ZEX has rolled-off sub-bass compared to the CRN which prioritizes the sub-bass and has a scooped out upper bass. This gives ZEX a punchier and warmer bass while the CRN’s bass has authoritative sub-bass and lighter mid-bass quantity.
ZEX’s midrange is thicker and more full-bodied. CRN mids are leaner and more detailed but not as musical. Where the ZEX has a subdued, smooth treble, the CRN’s treble is forward (to the point of stridency) and detailed. As a result, the ZEX treble sounds a bit dull and less detailed next to the CRN. The soundstage is slightly narrower on ZEX but it has a similar overall resolution. In comparison, the CRN has superior detail retrieval and a wider stage.
KZ DQ6
The KZ DQ6 is a triple-driver IEM with 3 dynamic drivers. Its sound signature lies somewhere between the ZEX and the CRN. The DQ6 has a similar sub-bass extension but a fuller mid-bass. As a result, it has a punchier, more rhythmic bass and some additional warmth in the lower midrange.
DQ6 has more vocal presence in order to counterbalance the extra weight in its upper bass region. Midrange notes are slightly thicker than on the CRN. Although DQ6’s treble is smoother overall, it can also show some stridency at high volumes.
Soundstage width is about the same on both but the DQ6 has slightly more depth, while the CRN has more height. In terms of detail retrieval, both IEMs are hard to differentiate.

Conclusion
The KZ x Crinacle CRN (ZEX Pro) marks another first for the KZ reptilian overlords. They were among the earliest to bring a 1DD + 1electret IEM to the budget arena but now they’ve gone and made an exotic tribrid budget earphone as well.
While it certainly has some shortcomings (namely stridency and resolution), people are sure to enjoy the tone, clarity and detail retrieval that this new breed of IEM delivers. It’s anyone’s guess what KZ will come up with next but you can bet I’ll be looking forward to it.