The Best In-ear Headphones in 2021- An IEM Headphone Buying Guide

The Best In-ear Headphones in 2021- An IEM Headphone Buying Guide

15 minute read

It's that time of year again where, you, the reader, will ostensibly be searching for what is the best in-ear headphones or in-ear monitors (IEMs) that you can put on your wish list for a given budget. If you're looking for other headphone types, check out our headphone buying guide for 2021

I opted not to write a buyer's guide last year because I'd only heard ~70 IEMs or so at that point in time. But it's been a packed year for me and that number now sits at over 200, so I get the feeling it's about time that I penned down my thoughts in a formal buyer's guide. This is me sifting through the rift-raft so that you don't have to waste your time hearing all the mediocre, horrible IEMs I hear. All you have to do is read on to find out which ones made the cut - at least to my ears, of course!


For those who are wondering about how I selected these IEMs, the overarching metric for my decisions came down to pure sound quality. It's a lot more difficult taking into account other variables like quality control (outside of my control), fit and comfort (100% subjective to the end user), or build and accessories. If it's not here, there's definitely also a possibility that I just haven't heard it! 

If you're looking for more information on how to pick out gear, what to listen for and how to build a system, check out our 2021 Buyer's Guide where we will cover all of that information and more. 


BLON BL-03: The infamous "giant killer" IEM that wasn't nearly one, but that is a pretty sweet value even today. The BL-03 has a warmer, mid-bassy tuning, a pleasant midrange, and a largely smooth treble response sans a small bump at 5kHz. It's one of those IEMs that is very hard to hate on first listen and mostly makes its mark by virtue of good tonality (a rarity in this price bracket). Easy recommendation, especially because you can find these on sale. Listeners seeking a similar IEM with slightly worse extension and technicalities - but far better build, fit and accessories - might also check out the Tripowin x HBB Mele.

Buy the BLON BL-03 

Tanchjim Tanya: With the venerable Sony MH755 on its last legs in terms of availability, the Tanya has risen to the plate as the new V-shaped IEM to buy. But while the Tanya sports a healthy bass shelf, it balances this with a more forward pinna compensation and a smoother, darker treble response. It's clearly not as technical as the Sony MH755 in A/B, but I would argue that the Tanya takes the cake when it comes to ease-of-listening. Stack on a comfortable bullet form factor and a set of nifty accessories, and you have one of the most solid IEMs that $20 can buy today. 

Buy the Tanchjim Tanya

Moondrop SSR: If you're looking for a more technical set and don't mind some "shout" to your sound, then you might find favor with Moondrop's SSR. The dynamic driver in the SSR attacks and decays fast, and in tandem with the thin, upper-midrange oriented response, lends the SSR to a clean, sharp presentation. Imaging is also immediately impressive with good amounts of pseudo-space between instruments, perhaps partially aided by a slightly hollowness to the mid-treble. I would even go so far as to argue the SSR surpasses Moondrop's own Aria in the technical department; of course, you trade the Aria's decidedly better tonality for this edge. The SSP fixes some of the SSR's shout by virtue of more bass; however, I'm not sure if I would say it's necessarily better than the SSR - that's more a matter of preference. 

Buy the Moondrop SSR

Moondrop Aria: The Aria, KXXS, KXXX, or the Starfield, it doesn’t matter. Once you’ve heard one of them, you’ve more or less heard them all. The Aria’s just the cheapest, latest instance of Moondrop undercutting themselves again. And who are we to complain? The Aria follows a tuning that’s not dissimilar to Harman, but it takes on more warmth and is generally a whole lot easier-on-the-ears. It’s not the most resolving IEM in its price bracket (it’s actually slower in the transients and doesn’t layer as well as its younger brother, the SSR). However, timbre is oh-so-pleasing and natural. Stack on a 13kHz peak in the treble which lends to a pleasant haziness, and the Aria's certainly not lacking in that icky, musical buzzword. This is one of my favorite sub-$100 IEMs, one I can just pop-in and enjoy for hours on end.

Buy the Moondrop Aria


Etymotic ER2XR: The ER2XR continues to be a shoo-in for one of the best bang-for-your-bucks IEMs on the market, especially considering you can regularly find it for much lower than its stated MSRP. It follows Etymotic’s interpretation of the classic Diffuse Field tuning. And if you’re asking me, it’s better. The overall sound here is a reference-oriented one with a touch of “oomph” down-low. Bass is lacking texture, but is quite clean with adequate slam. Some might find the ER2XR’s midrange slightly upper-midrange forward; however, I’ve never found it shouty. It has good technicalities too, probably the best I’ve heard under $200. The ER2XR’s biggest weaknesses would be its darker treble response and narrow imaging. Oh, and the fit. The nasty, nasty fit that you’d better hope you can live with for a price-to-performance ratio so good that it’s almost unfair.

Buy the Etymotic ER2XR

Moondrop Kato: If you're looking for the next step-up from the Moondrop KXXS, one of my favorite single DDs of all-time, then you'll want to take a look at the Kato. The Kato is a marginal improvement over the KXXS in the technical department all-round (for resolution, imaging, bass slam, etc.) while maintaining the general tonality of its predecessor. It also smooths out the 13kHz peak of the KXXS for a less hazy treble response. Weaknesses? Well, I'd say the Kato mostly draws the short end of the stick when it comes to dynamics. It's a little soft to the way it articulates quiet-to-loud swings, particularly in comparison with its contemporary, the Tanchjim Hana 2021. 

Buy the Moondrop Kato

Tanchjim Hana 2021: Speaking of which, the Hana 2021 took me by surprise as suffice it to say I was not a fan of the original Hana. The Hana 2021 adds back in some sub-bass and tames the upper-midrange, bringing this much closer to Harman with some extra warmth. But the Hana 2021's standouts would lie in 1) its timbre and 2) its imaging chops. The Hana 2021's pattern of decay is almost spot-on, even making an established DD IEM like the Moondrop KXXS come off as etched in A/B comparison. To the point of the latter, imaging is also slightly out-of-head, boasting staging that defies the Hana 2021's price point and its single-DD nature. 

Buy the Tanchjim Hana 2021


7Hz Timeless: The new kid on the chopping block, the 7Hz Timeless is the world's first competent planar IEM that clocks in at a relatively manageable price of $220 no less. Sheer clarity is the name of the game here, thanks in part to 1) the Timeless' speedy, initial attack and decay and 2) quite a lot of upper-midrange presence and a strong peak at 7.5kHz in the treble. So no, the Timeless does not sport the best tonality overall and I also find the imaging on this IEM to sit somewhere within the realm of average. But for listeners seeking that classic planar advantage? You'd be hard-pressed to look elsewhere, especially at a price point this compelling. As far as I'm concerned, this is likely the most technical IEM I've heard for $220. 

Buy the 7Hz Timeless

Moondrop Blessing 2 Dusk: How could this IEM not make the list? Improving upon the already great (albeit in my opinion, far from perfect) Blessing 2, the Dusk is a re-tuned Blessing 2 with IEM reviewer Crinacle at the helm. It adds in a juicy sub-bass lift and follows a neutral tonality onwards, minus the treble which could definitely use some more extension and has something of a mid-treble recession. Listeners looking for a leaner, slightly more technical sound might be better suited with the original Blessing 2. But the Dusk is still no slouch in the technical department, and either way, this is the $300 benchmark IEM for good reason. 

Buy the Moondrop Blessing 2 Dusk

Buy the regular Moondrop Blessing 2


Moondrop S8: The S8 is foremost a technical performer, sporting sharp resolution and pinpoint precise imaging. This IEM's other standout would be its treble response; while not the smoothest, it's definitely some of the most extended treble you'll find at this price point (eclipsing even the venerable Thieaudio Monarch and Clairvoyance). I'd stay away if you're after a warmer, more "musical" listen, but the fact that Moondrop themselves have put the successor to the S8 on the back burner because "we can't improve upon the S8 right now" (I'm paraphrasing) should speak wonders to this IEM's sonic prowess. Did I mention how pretty those shells look too? 

Buy the Moondrop S8

Moondrop Variations: And yet another Moondrop IEM to make the list. You must think I'm a Moondrop shill. Well, I sort of am, but they're really just that solid, and I'd consider this Moondrop's interpretation of a more "fun" set, and a general upgrade to the Blessing 2 / Blessing 2: Dusk IEMs. The Variations mostly picks up where the Dusk left off, sporting a similar tonality but with better bass texture, less intangible grit to the midrange, and a smoother, more extended treble response. Yes, the EST treble in the Variations is actually pretty darn good despite my usual disdain for the EST drivers. I'd still stay away if you want a "richer" presentation, particularly when it comes to the lower-midrange frequencies, but the Variations is definitely one of my favorite IEMs for its price point - perhaps rivaled only by the Dunu SA6. 

Buy the Moondrop Variations

Dunu SA6: The SA6 has been affectionately referred to by reviewers as both a "baby 64A U12t" and a "baby qdc Anole VX". But like most things, I'd say it falls somewhere in-between. Tonally, it's definitely more reminiscent of the Anole VX, especially with that dip at around 5-6kHz which kills sibilance and takes the edge off of the lower-treble. Intangibly, though, I find it's more reminiscent of the U12t. The SA6 has above-average BA bass and a slightly "wet" characteristic to the way its transients are articulated, thus circumventing some of that maligned BA timbre characteristic. The SA6's biggest weaknesses would be its treble extension and imaging performance; however, this is still an extremely solid set that really makes no glaring mistakes and that'll appeal to listeners after a more relaxed, easy-going listen. 

Buy the Dunu TopSound Studio SA6

Thieaudio Monarch MKII: The successor to the much hyped original Monarch - which I actually wasn't a very big fan of, hence why it's not on this list. But the Monarch MKII deserves a spot on this list and then some. The midrange detail on this IEM is nothing short of excellent, some of the best I've heard in the IEM game bar none. Imaging is also a great step up from the original Monarch with the pinpoint precise channel distinction I felt that the original was sorely lacking. Of course, the Monarch MKII is far from perfect. It's got too much upper-midrange so some might find it overly forward (I certainly do on my weeb tracks) and lower-treble around 5kHz, thus lending to a hint of metallic-ness in the treble. The bass on this IEM is also pretty weak for a kilobuck contender. But if you're after a forward, high-clarity presentation, you'd be hard-pressed to find better at this price. 

Buy the Thieaudio Monarch MKII


Campfire Andromeda 2020: My first love in kilobuck IEMs. The Andromeda 2020 has a warm, south of neutral sound signature. Its pinna compensation and upper-midrange are also more relaxed and contrast to a well-extended treble response, resulting in what I'd affectionally deem a "musical" presentation done correctly. Where the Andromeda 2020 really makes its mark, though, is its imaging chops. Staging breaks the head-stage with a strong sense of space between individual instrument lines and the Andromeda 2020 actually has some minor center image diffusion. While the Andromeda 2020 definitely has its flaws (mainly in its lackluster dynamics and bass response), it's the IEM I recommend to listeners who are after a musical - dare I say magical - sound to kick-back and relax with. 

Buy the Campfire Audio Andromeda 2020

Symphonium Helios: If the Andromeda 2020 is an IEM for more low-key listeners, then the Helios is an IEM for listeners who like their IEM to demand attention. The Helios has a more segmented, clean presentation with a slight upper-midrange emphasis and a class-leading (probably better than class-leading if I'm being perfectly honest!) treble response. Now, it's not the best tonality overall (personally I find it somewhat too disjoint due to a 200Hz recession), but the Helios has almost zero weaknesses in the technical department: sharp leading edges to notes, some actual micro-contrast, and incisive, slightly out-of-head imaging. If you can get around the chonky fit, it is my humble opinion that the Helios is the best sounding kilobuck IEM overall on the market.

Buy the Symphonium Audio Helios


Unique Melody MEST: One of last year's hottest IEMs, the MEST made its mark with its holographic imaging and excellent technicalities. Any tracks that play with staging on the MEST are a real treat to hear, and it also has a DD to back-up where something like the Campfire Andromeda falls short. On the other hand, where the MEST draws the short end of the stick is its coherency. The attack of the midrange does not match the bass very closely, the bass itself is still milquetoast for a DD, and the MEST's treble has some noticeable compression issues in the attack, likely not helped by an emphasis at 5-6kHz. Nonetheless, the MEST definitely has the technical chops to play with the big boys, and it's not lacking what I affectionately deem "special sauce" by a long shot. 

Buy the Unique Melody MEST


64 Audio U12t: It had to make the guide of course. The IEM that is, in my opinion, the world's best IEM, my favorite IEM. The U12t really makes almost zero mistakes thanks to its slightly warm, yet clean tonality with a touch of spice up top in the treble. And it's no technical slouch either, from its superb BA bass, impactful center imaging, and authoritative macro-dynamics. Listeners seeking a more exciting sound - particularly in the upper-midrange - might be suited elsewhere, but you can't go wrong with the U12t. It's the first IEM I'd recommend to anyone with money to spend and who doesn't know what they want. 

Buy the 64 Audio U12t In-Ear Monitor Headphones

Elysian Annihilator: Looking for an IEM that'll have you at the edge of your seat every time you hear it? Then the Annihilator should be the first IEM on your list. The Annihilator's standout is its treble response; as far as I'm concerned, it's still the one and only true implementation of the Sonion ESTs with almost linear extension and the lightning quick tactility that true electrostatics like the Shure KSE1200 deliver. The general dynamics and transients on the Annihilator are also nothing short of extraordinary. It articulates dynamic swings quick and with superb macro-contrast, only falling short in the micro-contrast department wherein it has some compression to its individual instrument lines. But no matter - give it up for one of the select few IEMs to blow me away. 

Buy the Elysian Annihilator

Empire Ears Odin: Whereas most of Empire Ears' IEMs are distinctive for being V-shaped bass cannons, the Odin eschews this trend, falling more along the lines of neutral with sub-bass boost. Moving onwards, it sports a pronounced emphasis to the pinna compensation and upper-midrange whilst not straying into unwanted thinness, lending to strong center imaging and a present, crystal-clear midrange. The Odin's sure to impress on first listen in this regard, even if some might find it toeing the line. The treble of the Odin is also remarkably controlled if not a little soft in attack (which does benefit coherency at least). My main gripe with the Odin would lie in its macro-dynamics which veer toward unwanted loudness; however, there can be no doubt that the Odin is an IEM that comfortably rests at the top.

Buy the Empire Ears Odin 

Sony IER-Z1R: I'm not as hot on this legendary IEM these days, but I definitely like getting my ears on it once in a while. Why? Simply because it does things no other IEMs can do from its effortless, cathedral-like imaging and its category-defining bass and treble responses. The bass response of the IER-Z1R is absolutely unrelenting if not a tad compressed, and the treble has a beautiful sense of impact and trailing reverb. You're not going to want this IEM if you prioritize your midrange, though. It has a recession at roughly 2kHz which lends vocals to some grittiness and generally doesn't sound too correct. Still, even four years later, there's nothing quite like the IER-Z1R on the market. Better hope your ears can fit those chonker shells if this is your sound!

Buy the Sony IER-Z1R

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