Crinacle (In-Ear Fidelity) is a professional IEM reviewer based in Singapore. He has measured thousands of headphones and also ranked them. He has collaborated with KZ (Knowledge Zenith) to tune the ZEX PRO, which sold for a couple of months before releasing a re-packaged version called KZ x Crinacle CRN. The both are essentially the same product and same tuning with different packaging. I bought my unit from a reseller in Shopee for about S$32, while the KZ official shop is selling for S$46.
8 Mar 2022 update: KZ has hit a reputational issue among the audiophile community, and that is their multi-driver IEMs are not working in totality, as they produce sound level that are too low to add to the overall sound signature. Crinacle has also distanced himself from the product and has stopped endorsing it. This “scandal” has no impact to the final intended sound balance, but it basically means that some of the drivers are redundant or perhaps only for show. This issue has no impact to the article as Music Photo Life reviews audio products based on features and user experience, without regard on the technology behind it.
The ZEX Pro / KZ x Crinacle CRN is a triple-driver IEM – one Balanced Armature for high frequency, one 6.8mm electret magnetostatic unit, and a 10mm dual magnetic circuit dynamic driver.
The faceplate is made of aviation-grade zinc alloy with laser radium engraving matched with medical-grade skin-friendly resin shell. The shell shape is utilises data from thousands of ear models and it appears my ear shape fits within the average, as I find the earbuds to be very comfortable, snug, and easy to wear.
The stock cable is silver-plated with options of mic or without mic. I chose the mic version so that I can use it for calls.
The Reason I’m Interested In The CRN Earphones
It’s time I share with you about interpreting the headphones frequency response graph. It is something that I never mentioned in any of my audio reviews, because I want to keep my reviews easy-to-understand for readers. In fact, one cannot simply base the sound quality from graphs, and if you want to know why, go read this detailed article written by Crinacle on how to read headphone measurements.
Based on the above FR graph, the KZ x Crinacle CRN is tuned with a flat midrange, slightly elevated bass, and a natural treble roll-off in line with the Karman curve, a reference tuning standard. There appears to be a peak at 8kHz. As Crinacle puts it, “use it as a litmus test to see if you’re one who’d enjoy such a signature”.
Audio Quality
To me, this is how I would describe the CRN earphones:
- The bass is meaty but not bloated. I can hear the timbre of the bass lines as well as the bass notes. I find it musical to listen to the performance of bass instruments on the CRN. 7.8/10
- The midrange offers sufficient details and tonality, which remains clear thanks to the disciplined bass keeping within the lower frequency range and not invading. 7.8/10
- The treble lacks transparency that makes earphones like Sennheiser IE 300 sound outstanding. Depending on the recording, the vocals might sound a little screechy due to the bump at 8kHz. 7/10
Do note that the above curve represents how loud the frequency sounds during the sine-wave sweeping test. Besides the loudness of bass, midrange and treble, the tonality and the sound staging are probably even more important to characterize the headphones.
While the bass lacks the exciting punch and kick, and the treble does not offer much sparkle, the earphones are enjoyable thanks to the sound staging, delivering spatial depth that keeps instruments tidy.
I took out 2 polarising earphones just to make my point.
Comparing Sennheiser IE 300
The Sennheiser IE 300 is V-shaped tuned with powerful bass performance and an impressively detailed treble. But compared to CRN, the IE 300 bass is too muddy, the midrange details are suppressed. I very much enjoy instrument genres without heavy bass so that the recording does not sound imbalanced. From the below graph, it only reflects how bright the IE 300 sounds, but you couldn’t tell whether the bass sounds bloated or whether the midrange sounds empty or whether the treble is too bright to be listenable. My view is that the IE 300 is stellar in the treble presentation and the bass is fun to listen to, but critical listening below the treble would be not as satisfying.
Comparing Shure AONIC 5
Next, the Shure AONIC 5 (with warm filter, my preferred choice) has an overall warm tonality that melts in your ears. There is no bite or hurtful peaks. The AONIC IEM retail package comes with dozens of ear tips from silicone to foam to triple-flange, each of them will achieve a different frequency balance. One thing is for sure: the sound staging is cosy yet the instrumental layering is clean. I really enjoy listening on the AONIC 5 with the volume turned up. Comparatively, the CRN is staged a little wider, more space, less compact. I prefer listening to Daft Punk of AONIC 5 as it is less pushy and full of depth. The CRN does very well with jazz and fusion with really fast musical lines which it can keep up.
Conclusion: FR Graphs Mean Something But Not Everything
This would probably be the only review article that I will use frequency graphs to explain and compare earphones, because I want to show that the graphs do not tell the full story, and I don’t want readers to compare and then wonder why the actual earphones don’t really represent what they see.
But since this review is all about referencing Crinacle’s outstanding work in measurement graphs, I have to share how you can spend the least money to get a reference IEM like the KZ x Crinacle CRN, listen to it, and stare at the graph he created, and understand certain strengths and flaws of headphones. From the graphs, it would be clear as day to conclude which headphones are bass-heavy, or treble-bright. But it would require an audition to decide whether the heavy bass is cloudy or the treble is sweet, whether the stereo imaging is wide or narrow, and whether they are comfortable to wear.
