The Kilobuck IEM Shootout - What’s The Best IEM $1000 Can Buy?

Review written by Precogvision

I. Introduction 

Diminishing returns is one of the most real - and perhaps antagonizing - phenomena in the portable audio hobby. You’re going to have to drop the big bucks to squeeze out that last 5-10% in fidelity, and this certainly isn’t helped by the steady price creep we’ve seen in the last couple years. Flagships IEMs are regularly pushing upwards of $3000; heck, I’ve even seen some $6000 IEMs! I don’t know about you, but that is insane. 

So perhaps it shouldn’t be surprising that the sweet spot for price-to-performance, at least in this reviewer’s opinion, is much lower. In fact, it’s right at around $1000, a kilobuck, that diminishing returns start kicking in most to my ears. Yes, I’m sure one could make a case that it’s much lower; to be clear, this is my opinion only! So here are your competitors, the venerable kilobuck gatekeepers: 

• Campfire Andromeda 2020
• Hidition Viento-B
• Moondrop S8
• Sony IER-M9 

Again, I’m sure there’s a litany of other IEMs that one might consider worthy of the “kilobuck gatekeeper” title. These are just the IEMs that come up in discussion most often and that have established a reputation for themselves. And you know, the ones that I also happened to have on hand (hey, I’m just being honest). By the end of this shootout, hopefully you’ll be able to decide which one is for you; additionally, I’ll have something I can direct people to when I’m inevitably asked to compare these IEMs next. 

II. Source & Drivability

Listening was done off of a variety of sources including an iBasso DX160, A&K SP1000M, and iFi micro iDSD Black Label. I used lossless FLAC files and these IEM’s respective stock cables and tips (sans Spinfit CP145 with the Andro 2020). You shouldn’t have any trouble driving these IEMs; in particular, the Andro 2020 is quite sensitive. You might consider picking up something like the iFi IEMatch to kill any annoying hissing. But if you don’t want to drop the big bucks, the Apple USB-C dongle actually works exceptionally and lowers the noise floor more than any other source (minus the Black Label) that I used. 

III. The Tangibles 

Sony IER-M9: Normally, I’m not one to care about presentation too much because at the end of the day, let’s be honest: After I pry out my shiny toy, the packaging is going straight to my closet to collect dust. But Sony has outdone themselves here and, as such, I think praise is warranted. The IER-M9 includes a plethora of accessories from separate 3.5/4.4mm cables, a wide assortment of tips, and a carrying case. This is how you do an unboxing experience. The IER-M9 is very lightweight thanks to its magnesium housing and carbon fiber faceplates which add a touch of flair. Like most of Sony’s products, it inspires a sense of ruggedness and reliability. 

Campfire Andro 2020: The Andro 2020 arrives in Campfire’s signature candy-box-like packaging. Despite the much smaller packaging, you’re also going to get an endless assortment of goodies here: silicon/foam eartips, several mesh baggies, a CA branded pin, and a taco-shaped, zipper case. The Andro 2020 features Campfire’s angular design for their BA IEMs complete with emerald green anodization. If you regularly browse the forums, then you’re probably no stranger to pictures of well-used Andromedas; these IEMs will scratch over time. Fit is not an issue for me despite the more chiselled design, although your mileage might vary. 

Hidition Viento: Now the Hidition Viento. Getting one’s hands on the Hidition IEMs is notoriously difficult in the USA because the company is based out of South Korea and there is a massive language barrier. My own Viento-B was proxied by a good Discord friend (shoutout to KW405!), and although I believe it came with all the original accessories, what I received should not necessarily be considered representative. Something pretty cool is that Hidition includes an FR graph of your unit with verification of channel matching. I do find the shell of the Viento somewhat uncomfortable; the nozzle is extremely long in an effort to mimic the CIEM’s fit as closely as possible. 

Moondrop S8: If you’re a fan of anime, then you’ll be pleased to know that the S8 arrives in packaging that sports one of Moondrop’s (in)famous waifus. As the cheapest IEM in this shootout, the included accessories are somewhat more tame: a zipper case, an assortment of silicon tips, and an airline adapter. But with a highly aesthetically pleasing faceplate and stellar craftsmanship, the S8 makes up for it where it really counts. The build simply screams the essence of “moondrop” captured in an IEM. Fit on the S8 is exceptional too, although be aware that it’s not a vented IEM, so pressure may build-up over time. 

IV. Tonality 

All frequency responses are measured off of the IEC-711 coupler. There is a resonance peak at roughly 8kHz and the coupler itself is certified up until 10kHz. As such, measurements after this resonance peak should not be considered entirely accurate. 

Campfire Andro 2020: The Andro 2020 follows a neutral-warm tuning. I’ve noted this before, but it has a “let’s just hang out and chill vibe” that’s incredibly inviting. Whereas many IEMs hitting the market these days are pursuing academic target curves - which tend to lean more “referency” - the Andro 2020 strikes a sweet spot: A more laidback tuning with broad listener appeal that doesn’t sacrifice engagement factor. The Andro 2020 has a very relaxed midrange tuning thanks to its gentle, 2kHz ear compensation and dipped upper-midrange from 3-4kHz. Contrasted to the thicker, more weighty lower-midrange from 200-500hZ, this does lend to slight tonal disconnect. Treble on the Andro 2020 has a slight mid-treble tilt with pleasing amounts of sparkle (although not to the extent of its predecessors) and excellent extension. Indeed, this might be one of the most well-extended IEMs that I’ve heard. 

Hidition Viento-B: While the Viento-B is foremost a reference tuned IEM, it’s basically what’d you get if you took the venerable Etymotic ER4XR and stacked on some more sub-bass and treble. Bass is tastefully boosted, curving out by 200hZ, nice and clean. The midrange of the Viento is quite lean throughout the lower-midrange and exhibits a strong tilt towards the upper-midrange frequencies. Perhaps too much of a tilt, in fact, and I frequently hear traces of sibilance. Treble on the Viento is strongly mid-treble emphasized with almost overbearing amounts of resonance - ring - to the way instruments decay. Unfortunately, as beautifully as the Viento-B graphs on paper, paper is not practice. I write true to what I hear: Notes are too thin for my preferences, too frequently sibilant. 

Moondrop S8: This is one of those academic target hitters I was talking about. But while the S8 adheres to the Harman target, there are small deviations here and there that I think make it just that much more pleasant to listen to. Bass is nigh-identical to the Viento-B with the sub-bass oriented curve. The midrange of the S8 is similarly lean in the lower-midrange, but kills some of the emphasis at 3-4kHz. What this results in, to my ears, is a balanced, leaner midrange that plays terrifically with female vocals. The S8 also eschews the Harman target’s notorious roll-off in the post-10kHz frequencies. I hear sufficient amounts of stick impact followed by an upward skew of sorts to the air frequencies; this is the entry-point for good treble extension to my ears.

Sony IER-M9: Ironically, if there’s any IEM on this list that harkens to sitting around the campfire, it’s the IER-M9. The IER-M9 is easily the warmest IEM in this shootout with its bass shelf sporting good amounts of both sub-bass and mid-bass. For whatever reason, it does sound slightly mid-bass leaning - with an emphasis on boom - to my ears despite what the graph might imply. Note weight is relatively thick moving throughout the midrange; consequently, this is the safest kilobuck IEM in terms of midrange tuning. Treble on the IER-M9 sports a lower-treble suckout followed by good amounts of mid-treble and excellent extension thanks to its BA supertweeter. So more closely, you’re going to hear a lot more crash, fizzle, and zing with the IER-M9 than you will the initial impact of percussive instruments. However, it is not fatiguing at all to my ears in this respect. 

V. Technical Performance  

Ah yes, here’s where things get real fun. Make no mistake that these are all very well-tuned IEMs. Still, you can have the most well-tuned IEM in the world, but it doesn’t mean much if you can’t imbue your IEM with the fickle, ever-elusive intangibles. This is a reference to characteristics of sound outside of measurable frequency response, or characteristics that we don’t know how to interpret from existing measurements yet. 

Imaging 

Unfortunately, the vast majority of IEMs do not have good imaging to my ears. I think it’s also important to lend some context to how I qualify imaging. Imaging, at least for me, is indicative of the extent to which an IEM is able to shape the “walls” of the room, or stage, around the listener. So by extension, soundstage is a derivative of imaging, and they are not distinct. Positional accuracy, likewise, is another subset of imaging that is commonly mixed-up. 

Let’s talk about the IER-M9 and the Andro 2020. Both are IEMs that I would consider to be truly holographic, the oft-misused word that is qualified by image incision. To this end, these IEMs have a quality with which instruments “float” on the soundstage; I suspect that this is in part due to their excellent upper-harmonic extension. But when it comes to actual image diffusal, or soundstage size, I find the Andro 2020 to take a notable lead. It has the advantage of a 3-4kHz dip in the upper-midrange. This imparts a sense of center image distinction - soundstage depth - with which the IER-M9 lacks to my ears. For a sense of layering, or space between instruments, the Andro 2020 also seats itself in best-in-class territory. When it comes to sheer accuracy, however, the IER-M9 is more sound and sports extremely well-defined positional cues. 

On the other hand, the S8 and Viento-B are a whole lot more average in the imaging department. Neither of them has the aforementioned incision to their imaging to qualify mention of the “holographic” buzzword. Where these IEMs excel most, then, is in their positional accuracy and layering chops. Of course, this is not to say that these IEMs exhibit copious amounts of pseudo-air between delinations, but rather that instruments, again, have segmented “pockets” on the stage. 

Dynamics 

Some context is warranted here again, I think. Dynamics are largely a reference to the intangibles of transient attack, or what some might call the leading edge of a note. The Andro 2020, S8, and Viento-B exhibit the snappy transient attack that is distinctive of most BA IEMs. By contrast, the IER-M9 seems more mellow on this front. Furthermore, on Aimer’s “Hakuchuumu” for example, there is a distinct lack of intensity to the dynamic swings at 1:03, 2:45, and 3:50. These shifts should be slamming you. 

Of course, this ties into macrodynamics and microdynamics which are really quite different. These terms are indicative of how an IEM scales the decibel peaks and valleys that are present in a given recording. Macrodynamics are dynamic swings on a grander scale: quiet-to-loud transitions and build-ups. Think of riding a roller-coaster. You want to move quickly, but you also want to hit all those build-ups, peaks, and free-falls, or the fun is lost. Microdynamics, as the name might suggest, are shifts on a more intimate level: vocal inflections, the nuance of a piano key being hit, the amplitude of a cymbal hit. 

As I alluded to above, macrodynamics is not the IER-M9’s strong suit; it has a tendency to scale these swings somewhere in the middle to my ears. I think these are also both weak fronts of the Andro 2020. Even off of a source like the iFi iDSD Black Label (in an effort to kill noise floor which I’d wager goes hand-in-hand with microdynamics), transient attack seemed to take on something of an upwards compression, particularly in the midrange. As a whole, at least to my ears, I would not consider any of these IEMs to be particularly exceptional on the macrodynamic front. Perhaps it might be surprising to note that the Viento-B has the best microdynamic contrast to my ears. 

Timbre

Within the context of IEMs and their technical performance, timbre is most closely a reference to the pattern of decay. This is especially relevant when talking about BA (balanced armature) IEMs because BAs have a tendency to decay on the quicker side - at least faster than their dynamic driver counterparts - lending to egregious transient overlap. This phenomenon, and the weightlessness that ensues, is often dubbed “BA timbre” or “grain”.

To this end, the Viento-B is decidedly the “dirtiest” of its brethren and sports good amounts of grain. But with some caveats, I don’t think this is necessarily a bad thing. Grain goes hand-in-hand with note texture; I would argue that said texture flies very nicely alongside the leaner lower-midrange, lending to the aforementioned micro-contrast. I do, however, find this quality unnatural when it comes to songs that token the upper-midrange more closely. Generally, I am looking for a smoother timbre in these instances. 

The Andro 2020 and S8 sport cleaner decay; they mostly suffer on the front of note weightlessness or what some might refer to as plasticky-ness. This is most apparent within the context of their bass responses. Neither slams particularly hard nor is adequate decay present. So, yeah: You might want to look elsewhere if you’re going to be listening to a lot of EDM. The Viento-B falls into this same category for the most part, although I want to say it’s a tad tighter, more defined to the way it slams.

But the real shocker: The IER-M9 might just be the cleanest BA IEM that I have heard. Decay is just, well, clean, so much so that I could see a less familiar listener mistaking the IER-M9 for a DD IEM. The bass on the IER-M9 is equally commendable, and this is coming from someone who holds that the vast majority of BA bass responses are mediocre. There’s a slight bloat due to the mid-bass emphasis; however, the IER-M9 is leagues ahead of these other IEMs - and most BA IEMs I’ve heard - in this department. 

VI. The Subjective

As if something like audio could get any more subjective, right? Nonetheless, I’ve done my best to keep subjective preference out of the way thus far. So now, to be blunt: I don’t actually like the IER-M9 or the Viento-B very much. I can already hear the cries of outrage, and trust me, you’re not alone. Many close audio buddies have likewise opined me crazy; all the more so considering these are the de-facto IEM recommendations in the circles I regularly hang in. But hear me out. 

First, the IER-M9. It sounded really good when I first heard it, like “straight to the top of my tier list” good. It sounded pretty good the second time I heard it. Then I spent an entire week with it, and my enjoyment was diminished to “it’s the IER-M9”. You see, the thing about the IER-M9 is that it’s just so safe. From tuning to intangibles, it’s unmistakably the most well-rounded, best kilobuck IEM that money can buy. But it’s also the most boring by a long shot. Boring to the point of which I found myself scrutinizing it, trying to find any and every reason to dislike it (and you read about that here). Funny how things play out like that, right? So good it’s frustrating. 

On the other hand, my issues with the Viento-B are most likely the product of fit. The Viento’s elongated stem is intended to mimic the custom’s deep insert, inherently favoring listeners blessed with “blackhole” ears. Much to my chagrin, I do not have said ears, and the end result, again, is an overly bright and sibilant presentation. Oh yeah, if you want to buy the CIEM version, well, good luck: Better hope you speak Korean or have a proxy; you’re also going to be paying a premium. 

Now, back to the Andro 2020 and the S8. They’re not perfect, not by a long shot. But looking past their decidedly poor dynamics and weightless notes, they really do sound like they have that special sauce. Special sauce, mind you, that’s probably not attributable to much more than this reviewer’s subjective preferences. Is it the Andro 2020’s stellar imaging aided by its 3-4kHz upper-midrange recession; the way it sieves through the chorus of Taeyeon’s “Fine” and presents the vocal overdubs with that slight shimmer and oh-so-much air between them? The way the S8 foils so neatly to the Andro 2020’s dipped upper-midrange? Or god forbid, the waifu art skewing my assessment? I don’t know. I just really like what these IEMs do, and I can’t get them out of my ears. 

Perhaps this is a testament, then, to the nature of diminishing returns. When you’re deciding amongst IEMs that many would already consider to be top-performers, listener preference becomes all the more paramount. 

VII. The Verdict

If you’ve made it this far and are completely lost, then this section is also for you. In the interest of keeping this simple, here’s the TL;DR: 

• Tragically, much to my personal ire, the IER-M9 remains the best IEM for a kilobuck on paper. It runs circles around these other IEMs in the bass and timbre departments. So can’t decide? This is the IEM I’d take a look at.  
• Looking for the best bang-for-your-buck and listening to a lot of female vocals? Or just looking for weeb tuning? Then you’re going to want the S8.  
• Those who enjoy a slightly warm, north-of-neutral tuning and want the most holographic imaging will gravitate towards the Andro 2020. It’s the IEM you hand, by default, to someone who has no idea what good sound is because you want to knock their socks off.  
• Avoid buying the Viento-B unless you’ve won the genetic lottery and have chad blackhole ears. That, or make sure you’re buying the CIEM version.

Ultimately, for my plethora jibes and tongue-in-cheek, make no mistake that these are IEMs that I have massive appreciation for. It’s natural to assume that something more expensive is inherently better. But unfortunately, while there may indeed exist a correlation, this is simply not true. IEM prices have soared to the point of which kilobuck IEMs have been relegated to the “mid-fi” bracket. That’s a shame, really it is, because I’d take the likes of the IER-M9 or the Andro 2020 over a lot of the multi kilobuck stuff that I’ve heard. And while none of these kilobuck IEMs are quite top-tier IEMs, I could see many listeners happily dying upon any of these hills. 

VIII. Reference Tracks

• Aimer - Hakuchuumu
• David Nail - Let It Rain
• Dreamcatcher - Silent Night
• Girls’ Generation - Galaxy Supernova
• Illenium - Broken Ones
• Joe Nichols - Sunny and 75
• Keith Urban - Defying Gravity (2009)
• Sabai - Million Days
• Sawano Hiroyuki - Best of Vocal Works Remastered (2020)
• Steve Jablonsky - Arrival To Earth
• Taeyeon - My Voice (2017)
• Tiffany - I Just Wanna Dance

-Precogvision

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