Introduction

If you’re reading this, you almost certainly fall into one of two camps. Either you’re deep into IEMs and want to know if the latest one from Crinacle is any good, or you’re totally new to the audio hobby and someone told you to just buy a CrinEar Reference so you’re doing a bit of research. Either way, you’ve come to the right place.

The Reference is a $349.99 IEM designed by the very popular Singaporean brand CrinEar. To quote their marketing spiel:

"The Reference is purpose-built for absolute neutrality, adhering to a population-averaged diffuse field response tilted down by -1dB/octave, with a couple added decibels of bass for perceptual neutrality (compensating for stereo speaker bass response and in real life bass physicality). All verified under ITU-T Type 4.3 conditions.

In other words, we have achieved it: The World's Flattest In-Ear Monitors."

I’ll leave it to other reviewers to nitpick through all of that. I’ll just give you my thoughts on what it means practically, how I find the CrinEar Reference to sound, and whether you should buy it.

Source(s) Used: Ferrum ERCO, Apple USB-C dongle, FiiO Q7

What in the Box?

The packaging of the CrinEar Reference is what I would call functional. If the unboxing experience is what feeds your retail therapy, the Reference will disappoint. What it doesn’t disappoint in is the accessory package. Inside the box you get:

• The CrinEar Reference shells - made fully out of aluminum with a little vented hole on the faceplate.
• 4 different sets of tips - one set of foam, one set of generic standard silicone tips, one set of short stem silicone, and one set of short, wide bore tips.
• A white taco-shaped faux leather zipper carrying case - I actually really like this case. It’s large enough so you aren’t cramming your IEMs in there. The faux leather does feel nice and there’s a slight padding to it so it’s squishy.
• A 2-pin braided silver cable with an interchangeable 3.5/4.4 mm termination - this is a fairly good cable and is on the thicker side. Maybe a bit stiff ergonomically.

Comfort wise, the Reference will depend if you like to deep fit your IEMs. I do. The shell is ergonomically designed to fit your ear, and in the inner face has a small sculpted part that juts out slightly. Many IEMs have a similar design, but I found that when deep fitting the Reference using the stock tips, that part specifically does press into my ear. It’s not wholly uncomfortable, but I do feel it after some time. 

Otherwise, the comfort is fine. Average for your typical IEM. The nozzle length is approximately 4 mm which may be why the Reference presses up closer to my ear when I deep fit it. The nozzle diameter is around 5.8 mm. Big, but not as large as the 6 mm that seems to be standard these days. There’s a decent heft to these IEMs, but it’s not awkwardly heavy.

For the technically curious, the CrinEar Reference uses two horizontally-opposed 10 mm dynamic drivers (DD) and three balanced armatures (BAs). Interestingly, CrinEar has opted to step away from the microplanar drivers they’ve been using in the Daybreak. As always though, driver configuration is secondary to sound quality. 

Sound - Objective

Here are frequency response measurements of the CrinEar Reference calibrated to Headphones.com’s new IEM Diffuse Field (DF) HRTF (see Listener’s review of the Reference for details). Preference bounds are depicted in the grey region. In extremely simplified terms, if the frequency response is within the bounds, it’s likely to sound balanced. And that means it’s most likely to be preferred by the average person - hence the name, preference bounds. That said, 1) You are not an average person; and 2) There’s no reason why you can’t enjoy multiple types of tunings. It’s a question of probability.

If these graphs look different from CrinEar’s official measurements at The Hangout, it’s because The Hangout uses a population average DF HRTF with a 10 dB downwards slope. That’s the target that CrinEar has tuned the References towards, though with a touch of bass elevation you can see.

For those who haven’t been following IEMs too closely in the past couple of years, IEMs that follow this population average DF HRTF, particularly in the mids, have been labeled as “new meta” by the community. And as a reminder, the 10 dB downslope comes from longstanding preference research showing that most people prefer more bass and less treble than pure DF. 

The interpretation is thus that if you manage to have a frequency response that matches this, you’ve created an IEM that is perceptually neutral (arguably flat) for the majority of people. This interpretation is subject to debate - hence Headphones.com’s own IEM DF HRTF that more accurately captures the B&K 5128’s canal transfer function - but that’s a discussion for another time.

Here is the raw graph which is a different visualization of the same dataset.

If none of the above made any sense to you, don’t worry. Keep on reading to get a human translated version of that.

Sound - Subjective

Bass

When I listen for bass, I immediately listen for two things. The first, of course, is quantity. The Reference’s slight elevation in the subbass is very welcome. IEMs have unique advantages when it comes to bass response and I like it when IEMs have the quantity to show it off. The Reference’s bass is a hair above truly flat - a reassurance that the lowest octaves are there. However, because this is primarily a subbass elevation, the midbass can come off as a little left out sometimes. While my first instinct is to add about 1 dB here to smoothen the transition, there would almost certainly be some knock-on effects on the rest of the Reference’s sound. 

The second is perceived quality. Specifically, how does it feel? Is it soft and poofy? Tight and punchy? Weighty and impactful? That sort of thing. I’m happy to report that the Reference falls under the firm category. Notes land with measured confidence. It conveys bass presence and impact without being overbearing. The easiest example is a kick drum. You won’t always get the quick punchiness of the beaterhead or the big boominess of the drum, but there is a sense of finality in the subbass when the notes are buried. This is not a basshead’s bass response. It’s for those who prefer less boom and oomph in their bass, but can appreciate its almost academic presence in the mix. It won’t blow your mind, but meet it halfway and you’ll be quietly rewarded.

Mids

The Reference’s midrange is one of the best renditions of the “new meta” archetype. And by extension, among the best the IEM market has to offer. I find it incredibly well balanced in a way that clearly draws out the nuances and timbre of instruments. There’s fantastic clarity in, say, how the backing harmonies and melodies are distinguished from the lead vocals. Or how the texture of guitars and other stringed instruments resonates. Importantly, the Reference does this without “stretching” the upper mids in a way I’ve heard other “new meta” IEMs do. The midrange presence is a nice Goldilocks - not too forward, not too relaxed. Not too bodied, not too thin. 

The best way to describe it is that there’s little to no sense of masking. In a way, this makes the Reference a very revealing IEM. Not in the stereotypical “audiophile” fashion of having excessive treble to punish badly recorded music, but rather, the Reference guides accuracy in timbre. This is an IEM I would feel confident mixing audio on. It’s as if I’m forced to look at my music from a different perspective. Sometimes, this perspective can be eye-opening; I become aware of details I don’t typically notice otherwise. At other times, it’s just a subtle shift in tonal focus. Either way, it makes me look forward to the next track in my playlist to see if I can hear something I hadn’t before. 

Treble

The treble of the Reference tends towards the sparkly side. Leading edge transients of notes are crisp. Harshness and sibilance are not an issue for me. While this is not an airy IEM, it also doesn’t sound deadened in the upper treble. But if I were to be nitpicky, I would prefer if notes had a bit of a longer, more rounded decay. The shimmer of the hats and cymbals fade a little too abruptly and don’t quite have the space to breathe. 

I would also say that the Reference is not an entirely “treble-safe” IEM. It is well controlled, but it’s not shy about where it wants its treble to be. If you prefer dark sounding IEMs with muted treble, the Reference does not offer that. There is a minor peakiness that isn’t smoothed over, like a hint of scratchiness or sandiness that manifests on messy tracks. It’s not painful or annoying or anything like that, but I can’t predict how the treble response will be like in your ears or how you might perceive it. Upper treble measurements are merely an indication. 

Presentation

When it comes to the overall presentation, the Reference delivers perceptually in two standout qualities. The first is its staging experience. The horizontal soundstage is surprisingly large, diffusing out past the edges of my ears. While height is limited, stage depth is conveyed in a measured manner. The imaging of the Reference is precise and honest. It doesn’t impart its own character into the recording. It’s mechanical, but in a good way. 

The second is the sense of a black background. This is essentially another way to describe how little masking there is in the timbre of this IEM. It allows the Reference to feel resolving and detailed as layers of notes are built on top of an empty canvas. It’s not the same sort of perception of micro-detail you get from certain IEMs where you hear every little shimmer of the hats or quavering of the strings. To me, the Reference is more about ensuring every note in the mix is captured. 

In terms of perceived dynamics, the Reference is strong at demonstrating the gradation of notes as they rise in a crescendo. But it does arguably feel flat at the peak. With big sounding notes and soaring passages, the Reference remains more even-keeled. Of course, this is inherently tied to the little overall bass elevation this IEM has, and one may argue the accentuation of such characteristics is a form of colour that the Reference was not built for. Fair enough.

Comparisons

The Reference is, of course, the latest in the line of the “new meta” IEMs that all provide (whether intentionally or not) a frequency response that’s close to the population average in the midrange. As such, there are a lot of IEMs to compare it to.

CrinEar Daybreak

The first and most obvious comparison point is CrinEar’s previous effort for this style of tuning: the $170 CrinEar Daybreak. Even today, it remains one of the closest renditions of a neutral, reference-tuned midrange we have in the IEM market. This is one of the first IEMs I recommend those new to the hobby try so they can understand what IEMs are truly capable of. 

That said, the Daybreak does have a character of its own. There is an intentional U-shaped bass and treble emphasis to make music livelier. Interestingly, I find it creates a bit of a W-shaped imaging experience where notes are quite centered or hovering right at the ears, with a small hole in between. To be clear: it’s not a 3-blob image of left/right/center. There is good nuance in those clusters. 

But a quirk of the Daybreak that I wasn’t the biggest fan of was its relatively strong sense of the upper mids. At times, it makes vocals and certain instruments like the acoustic guitars feel isolated from the rest of the track. For lack of a better word, it’s a bit too “ear gain-y”. This is actually a complaint I have with a few of these “new meta” IEMs, so the Daybreak isn’t the only one. And to its credit, it’s a lot less obvious than others that I’ve heard. 

As such, I prefer the Reference. The whole midrange balance is softened just by a fraction, but that fraction is doing a lot. Instruments play on a much more even field than the spotlighted vocals of the Daybreak. The larger soundstage and more precise imaging are the cherry on top.

That said, I would still recommend the CrinEar Daybreak for someone’s first IEM outside of the budget category. At $170, it offers greater price-to-performance than the $350 Reference. The extra subbass and upper treble extension add a fun factor that the Reference doesn’t have. I find it slightly more comfortable as well. And for all my tiny little nitpickings vs. the Daybreak, they are honestly very close. Having them both in front of me side-by-side, I’d lean 55-45 for the Reference. 

The Reference is not the Daybreak 2.0. But it’s also not the Daybreak Pro Max. 

MoonDrop x Crinacle DUSK (DSP)

The DUSK was Crinacle’s last big IEM before he launched CrinEar. It was one of the first of these “new meta” IEMs, and to this day it remains one of my favorite IEMs under $1,000. That said, at $400 it isn’t quite as competitive in today’s market, especially considering the Daybreak was literally built to be the DUSK but without the DSP cable and at less than half the price.

So it goes without saying that the Daybreak and DUSK are extremely close in sound quality. Both have a U-shaped sound signature with a subbass and upper treble emphasis, except the DUSK goes a small step further. The Daybreak’s subbass feels tighter while the DUSK’s feels weightier. Part of this is due to the DUSK also having more upper treble airiness.

However, I do prefer the DUSK by a slim margin. Once again, it's that upper mids that’s pulled back a fraction. Compared to the Reference however, the DUSK comes off as warmer because of its larger bass elevation. On the other end of the spectrum, the upper treble of the DUSK is fairly elevated so there is more of a wispiness to the treble notes. This elevation helps give the DUSK that balance in note definition that wasn’t necessary on the Reference.

For those looking to buy, there’s unfortunately not much justification for the DUSK. It’s still a very enjoyable IEM for me, but the Reference is cheaper by $50, comes with a full metal shell, and doesn’t need the USB-C DSP cable. And if you do want the DUSK-like sound, the Daybreak is right there. Maybe you can consider the DUSK if you can find it for around $200 somehow.

Prisma Lumen

The start of 2026 welcomed an IEM that a couple reviewers have claimed to be the best IEM they’ve heard. That is the Prisma Lumen. It costs $1,400 and measures strikingly close to the CrinEar reference. So, is it worth over a thousand dollars more? 

Obviously no. Not if you’re going for price-to-performance. A kilobuck IEM will never beat a <$500 set thanks to diminishing returns. But if you’re someone considering the Lumen, you probably aren’t worried about diminishing returns are you? So here’s my take on it. Full disclaimer: I’ve only heard the Lumen in impressions rather than having it for a review. 

I prefer the Reference. But unlike the Daybreak and DUSK where it was a bit of splitting hairs and me leaning towards the Reference, I can see an argument for the Lumen. The Lumen has a meatier, richer mid-bass and lower mids presence. It’s actually very nice down there. However, the subbass impact is lacking in comparison while the treble response is overly safe for me. Simply put, the Lumen had little bite in the music. 

The midrange of the Lumen, like the Reference, is skillfully tuned though. It’s hard to say if I’d put it on par with the Reference given that I haven’t had a chance to hear them side-by-side, but if you prioritize a rich, bodied midrange while still wanting a reference-neutral sort of sound, the Lumen is the answer. For $1,400. 

While we’re on the topic of the Lumen, I do highly recommend you watch Resolve’s review on the Prisma Lumen at The Headphone Show if you’re considering it as he shows with personalized data why some IEMs may measure great on paper but don't always play nicely with a wide variety of ears.

Softears Volume S

The $320 Softears Volume S was the champion of yesteryear with most reviewers singing praises. Personally, I thought it was a quite well tuned IEM with a coherent tonal balance that I enjoyed, but some parts of its sonic character didn't quite live up to the overall vision. Maybe it had to do with a wimpy subbass despite a reasonably punchy and weighty midbass. Maybe it’s the awkward combination of an overly safe low- and mid-treble response coupled with a pesky upper treble peak. Either way, I see the Volume S as a competent IEM in its price range, but not one that particularly excites me. 

And so, the Reference remains my preferred option between the two. The Reference is simply better across the board. Its midrange is more refined. Though it has less bass quantity, the sense of quality is better. Treble is cleaner and more cohesive without being substantially brighter. While you save $30 with the Volume S, I would buy a replacement cable to rid myself of the cable noise in its stock fabric cable. The Reference is practically a no-brainer here. 

NiceHCK Rockies

The $500 NiceHCK Rockies is an interesting IEM. It’s one of the few unabashedly bright-neutral IEMs out there while still having a substantial bass presence. The Rockies is unique in that its brightness comes from a full-spectrum treble elevation that isn’t painfully sharp or peaky for me in any one area. It’s just bright.

Here, we’re starting to do a bit of apples-to-oranges when it comes to comparisons. You buy the Rockies if you love treble. Buy the Reference if you don’t. All the other little details and nuances are secondary to your preference in tonality and you get to save $150 with the Reference.

Should You Buy It?

Yes. The CrinEar Reference is a very good IEM. It consistently handles any track I throw at it. I hate to use fanciful language like “culmination of everything we’ve learned” or “a milestone achievement”, but to an extent, I do think that applies to the Reference. If the goal is a neutral-reference signature to the population average DF HRTF, the Reference is a small but meaningful improvement upon the Daybreak and most other IEMs that came before it. 

Note the qualifier in there. For an audio brand, creating an IEM to population average DF HRTF is a great way of getting sales. The more likely its sound fits someone, the more likely they will enjoy it, and the more likely it will get recommended. That’s just business 101. It’s a smart approach and as the Reference demonstrates, has very clear benefits. But remember: you and I are individuals, not a statistical average. 

And so if your ears are like mine, the Reference still isn’t perfect. The fit is a potential concern and the treble isn’t quite how I like it. I might also prefer a hint more midbass. But with a uniquely crafted midrange and an excellent overall sonic presentation, this IEM is worthy of praise. At $350, I do think the Reference is very appropriately priced, but not a game changer like the Daybreak. I wouldn’t recommend it as a first-timer’s IEM, but if you’ve decided to commit to the hobby, the Reference is absolutely an IEM that should be near the top of your upgrade list.