Table of Contents
So I’m sure a lot of you have heard about “the situation”, and if not this article will explain everything. But this will also be my final say on this matter.
But before going into all that, I feel like I need to establish some context as to my contribution to the CRN’s development and eventual marketing.
The CRN Tuning Process
I think there are a few misconceptions behind what exactly my contributions are as a “tuner” for my collaboration IEMs. Some expect me to take over the entire engineering process, which is unrealistic given that an “outsider” like me would not be familiar with the unique internal processes each manufacturer may have.
The more accurate description would be that I’m serving a more consultative and advisory role rather than an engineering one.
That is to say, I’m not the one breaking into the shell and physically adjusting crossover values or swapping drivers. Rather, I provide direction to existing engineering teams using frequency response data and trust their judgement on what solutions work for each of my requests and what don’t.
Now this is not necessarily out of choice; the process would definitely be far more hands on if I were present in-person at the R&D lab. Alas, travel is restricted (for obvious reasons) and I myself cannot do any component swaps without the manufacturer’s actual parts list on hand. And so with such remote cooperations, delegating engineering tasks to the experts actually on-site would be the most optimal strategy.
(If it helps you visualise the process better, this isn’t much different from your standard product R&D in any company. The engineering team take cues from the design team, except this time I’ve taken over the design team in terms of tuning direction.)
From an “ELI5” perspective, the process does seem simple. “Just tell the manufacturer to hit <insert target here>”. But that really only scratches the surface especially in the situations where working with companies is remote.
The process effectively starts not with prototyping, but rather achieving parity (or at least, a good guesstimation) between measurement rigs at the manufacturer side and on my end. This is to minimise shipments between our two ends and ensure smoother communications when discussing tuning.
The biggest hurdle with KZ is that they had been using IEC60318-1 from the very beginning, whereas most of the industry (including my own database) take data with IEC60318-4 (“711”). Of course even coming to be aware of this discrepancy isn’t automatic; there was some back-and-forth and arguments on why our measurements don’t match up at all in the initial stages of discussion before the realisation finally set in.
After some time trying to convince the KZ engineers to start using the 711 coupler can we finally start the process of– no, not tuning yet; simply ascertaining the differences between our 711 couplers. Also additional issues such as software and smooth differences, scaling and whatnot, and all these take up far more time in the R&D process that most people would imagine.
KZ’s (left) and my (right) measurements of the ZSN Pro X.
And with variations as wide as these, a lot of guesstimation and experience is required to extrapolate comparisons between the two systems.
Still not a perfect comparison; we attempted to measure the same IEM on our different rigs (KZ sending one IEM they’ve measured to me and us comparing the data) but there’s not much more that we can do on this front and at the end it is good enough. Enough for us to exchange feedback through measurements, at the very least.
And only at this point can we finally begin the prototyping and tuning process. KZ did send over a few prototypes of varying setups; a modified DQ6 and ZEX just to name a couple. At some point in order to save on having to ship too many IEMs over, we just had to play “by graph” in a lot of instances. The philosophy for the CRN was simply:
Hit the desired frequency response first, then iron out non-FR kinks in the sequel.
Eventually after a bunch of misses and rejections on what exactly can be changed on some prototypes, some of them laughably imbalanced, we finally came across one with good potential.
With some slight modifications with reference to the measurements on KZ’s side (again, a ton of extrapolation), the above eventually was reworked to what we know now as the ZEX Pro (the pre-CRN). At this point we’ve exchanged a few failed prototypes already so the data between us was getting more and more comparable.
The prototype was sent over, I measured to confirm the frequency response, I greenlit the project, production went underway, and the rest is history.
On my end, the marketing was simply to tout the CRN as one of the cheaper ways to enjoy “my tuning”, an IEF-Neutral IEM with sub-focused bass and decidedly a radical departure from every other IEM that KZ had ever made. I made a video, punched out an article, and that was more-or-less my end of the bargain fulfilled.
(Marketing-wise, this is similar to all my other collabs.)
But now the community has discovered a problem.
Realistically, you’re only listening to the dynamic driver.
To touch on that a little more, every single driver is properly connected to the circuit and does play sound:
The problem here is that they are so dampened relative to the dynamic driver that they are insignificant to the overall frequency response of the IEM.
Upon my request, KZ has also provided their own analysis of the crossovers on the CRN, which confirms that the magnetostat and BA are playing but at insignificant volumes relative to the dynamic driver:
It pains me to say that due to my limited involvement in the engineering side of the CRN’s R&D as well as not having the foresight to break apart a CRN and check its crossovers, I was not aware of this issue until it came to light.
The VK4 Debacle
Upon the reveal of these facts, I’ve observed an increase in accusations that the ZEX Pro/CRN was simply a reskin of the original VK4 given that the magnetostatic and BA drivers are duds.
I think one statement clears the whole thing up right away:
QKZ is not affiliated with KZ.
KZ themselves have branded QKZ as unauthorised copycats.
The CRN utilises a driver from Earbridge that consists of a magnetostatic tweeter stacked onto full-range DD.
This driver is basically an all-in-one solution and the components are largely inseparable.
The original QKZ VK4 on the other hand uses a single dynamic driver only.
I will not deny tuning similarities; after all I held the OG VK4 to very high regard and it hit my IEF Neutral target almost perfectly, so it would only make sense that another IEM tuned to “IEF Neutral” would also measure similarly.
However, it would be impossible that the CRN is using the same dynamic driver as the OG VK4 given that QKZ and KZ are wholly separate entities more-or-less at war with one another; and more importantly, the CRN using a AIO driver setup that comes with the magnetostatic tweeter attached to the DD by default.
The CRN is not related to the VK4 in any way other than tuning. Plain and simple.
The Bigger Picture
This isn’t a problem exclusive to the CRN; rather this is a KZ-wide problem that the CRN (and thus myself) got caught up in.
Jeffrey Fries and Delta Fyre have tested the crossovers of multiple KZ IEMs between them (NRA, ZEX, ZEX Pro/CRN, CA16 Pro, CA24, ZES, DQ6, DQ6S) and it seems more or less confirmed that these KZ IEMs don’t make full use of their driver selection. The issue varies from having poorly thought-out crossovers to drivers being completely blocked by glue.
All-in-all it seems like this is just driving up the costs and subsequent prices of KZ IEMs at no tangible benefit (from a frequency response standpoint at the very least), and may be a rather convenient explanation as to why groups of KZ IEMs seem to measure (and sound) largely the same despite having different stated driver counts.
Speaking of driver count…
First, I’ll have to make one thing very, very clear.
Drivers were never part of my marketing of the CRN. While there was of course acknowledgement of it being a tribrid (still factual even when some drivers are inaudible), I promoted the CRN almost entirely on the merits of its tuning and price point.
Repeating again: I promoted the CRN almost entirely on the merits of its tuning and price point, and not its drivers.
But still, I know I’m not totally blameless.
I acknowledge that my branding and endorsement can almost be seen as a “mark of excellence” for many, and issues like these only serve to disappoint the ones who have put faith in my work. It was my responsibility to ensure that issues like this should not happen especially with my name riding on it, and on this front I have failed.
Yes, in hindsight I should have checked the frequency response breakdown of each driver on my own or asked KZ to provide their data. I placed too much trust in the process and assumed the best, and so my negligence has resulted in my involvement in this matter.
And so to all who had purchased a CRN for the purpose of wanting a “tribrid”, I deeply apologise for my contribution to this half-truth and will take this hard lesson to heart, in the event of any future collaborative endeavours of a similar vein.
Effectively immediately I will be distancing myself from the CRN/ZEX Pro and stopping all discussion of future cooperation with KZ until further notice. I have taken down their links on my website and removed any recent mention of them on my social media (Discord banners, promo pictures etc.). The promotional video and article will have to remain up to prove the points that I had made in the section above.
I’d like to do more but here’s where I remind people that I am not KZ and I’m effectively powerless in terms of enacting hard changes. To put it in perspective, I do not even have the right to pull the CRN out of the market, nevermind process refunds.
A quick side-note: I do not get paid per CRN sold. KZ paid up a single sum for consultative services and the right to use my name on the CRN, and that’s where my monetary gains start and end for the CRN.
I hope I’ve addressed most of your concerns related to this situation and have clarified my culpability in the matter. I can only speak for matters related to the CRN at this point in time. All that’s left to do is to wait for a statement from KZ themselves for everything else.