IEMs, Reviews, Uncategorized

REVIEW: 64 Audio Shootout – Nio. Trió. Fourté. Noir

REVIEW: 64 Audio Shootout – Nio. Trió. Fourté. Noir

Analysis and verdict

Having spent several intense weeks listening, understanding and appreciating their relative strengths and shortcomings, it’s fair to say all four of 64 Audio’s high-end hybrids are impressive in their own right. While the scope of this review doesn’t seek to compare them to other IEMs from 64 Audio (and other IEMs in general), I believe the regard with which each of these IEMs is held in the market is justified. 

I’ve summarized my personal feelings about each IEM below, taking into account everything discussed so far, but also factoring in the most important factor you won’t find in any measurements: personal preferences. Reviewing IEMs can be a very clinical process that bears little resemblance to listening to an IEM on its own merit, with your favourite music, for enjoyment rather than analysis. Keep this in mind as you read my verdicts, and know that in most cases, how you hear these IEMs will be very personal to you too.


Nio has a relaxed, easy-listening tonality that’s suited to wide range of genres. It may not win any technical awards compared to its older and more mature siblings, but is, on its own, very technically capable. It also has the ‘latest and greatest’ when it comes to 64 Audio tech, including switchable Apex modules (that genuinely alter its sound profile), LID and Tia, and has more physical drivers than Trió and Fourté combined. 

Nio is the most versatile of the bunch as well, and depending on your preferences, could fill the role of two separate IEMs in your collection. With the default M15 module, Nio has a powerful, elevated bass that gives music a warmer undertone, with fuller notes and a more relaxed treble. Detail and clarity does take a small hit, however, as does stage size and imaging, and Nio can feel a touch congested when the music gets particularly complex or busy. 

With the mX module Nio is more linear, with bass still playing a role but taking a back seat to the mids and treble. There’s less rumble, and less slam too, but the mids are opened up as a result, with more nimble notes and a more sparkle in the treble. Detail is improved, but not significantly enough to challenge the other IEMs in this regard. The stage does get bigger though, and separation more apparent, and while it’s relatively faster sounding than M15, Nio mX is still a fairly relaxed and very polite sounding IEM. 

For me personally, what Nio lacks in technical prowess it makes up for with its smooth, lush tonality. Nio’s warm and richly-textured sound is ideal for female singers, folk, indie and acoustic music. It also does well with vocal jazz, bass-rich electronica and EDM, but might be less suited to faster, aggressive music, or more complex, dynamic classical pieces, with which it might sound too relaxed for some. 


Trió is an enigmatic IEM, and often seems to get lost in the crowd when discussing the virtues of 64 Audio’s high-end IEMs. I’m not quite sure why that is, because Trió is an exceptionally accomplished performer. It may not have the technical mastery of the Fourté or Noir, but it’s not far off, and for some, its combination of energy and dynamism might actually be preferable to the Fourté’s unapologetically precise tuning or Noir’s thicker, more adventurous tonality. 

Where Nio goes for a softer touch, Trió hardens the edges, speeds up the tempo, and delivers your music with gusto. Bass is prodigiously elevated, favouring sub bass rumble over midbass bloom, and while mids remain fairly neutral, they’re very clear and detailed, if a little dry. Treble can be spiky, yes, but on the whole it’s smooth and well extended, rewarding well-recorded music with plenty of sparkle and air. 

Trió ticks more boxes than it doesn’t for me. Stage is wide with decent depth, though not quite holographic, instrument and vocal separation are both above average, and imaging is always on point. Speed and dynamics are within touching distance of Fourté (which is to say, extreme), as are detail and overall clarity. What Trió lacks, perhaps, is that last bit of refinement. For all its boldness, Trió can sometimes overstep the mark, especially with brighter recordings, or where cymbal splashes and high-register vocals are less than perfectly mastered. 

If you’re into EDM or fast-paced music in general, Trió is custom made for you. As a recovering basshead, Trió completely satisfies. It also handles more complex music with aplomb, including classical music, along with acoustic recordings and anything instrumental in general. At the other end of the scale, Trió will just as easily satisfy treble heads, especially if you have a penchant for treble zing. I consider Trió an excellent all-rounder, in particular if you’re after dynamic excitement from your music. 


Fourté is the best sounding IEM, and possibly headphone, I’ve ever heard – most of the time. With the wrong music, or the wrong source pairing, or tips that don’t quite seal, or a cable that’s too bright, it wouldn’t be the best at anything. That’s the thing with Fourté; like any great Diva, give it exactly what it wants, play to its strengths, and you’ll get the most immersive, expansive, transcendent aural experience imaginable. But if something’s not quite right, it’ll let you know, sometimes painfully.

Fourté is unquestionably the best technical performer of the bunch. It has the widest, deepest and most three-dimensional holographic stage I’ve heard with any IEM, with a pitch-black background, outstanding vocal and instrument separation, pinpoint imaging, laser-like speed, and a unique ability to resolve every miniscule detail in a recoding. More impressive is how effortlessly it manages to do all of this and still sound musical. Yes, Fourté can be used to chop your music into neat little building blocks, but to my ears it’s not inherently analytical. 

Where Fourté stumbles, for some, is in its balance and overall tonality. It has a brighter leaning for sure, and while bass can be big and bombastic when called for, it more often than not isn’t. This is not a basshead IEM by any stretch, and despite its bass quality, I personally wouldn’t accept any less bass quantity than this in my collection. Its restraint, combined with an overall airiness in the mids, means Fourté can lack some gravitas when compared to the other, fuller sounding hybrids, but when I’m not comparing, it almost always sounds on point. 

What Fourté lacks in weight it makes up for with finesse. While it comes off as brighter than Trió, for example, it’s also more refined. As someone who’s very sensitive to harsh treble, Fourté has the most delightfully smooth treble I’ve heard. It’s something I honestly feared leading up to my first listen, but those fears were quickly allayed. Yes, I’ve heard the unnerving power of its treble – a harmonica too closely micced in a Cowboy Junkies recording quickly brought me to attention – but, when everything is just right, as it generally is, you’ll get no nasty surprises here, no temper tantrums, just gloriously beautiful music. 


Noir is a very interesting IEM, one that I consider an experimental attempt at creating a fuller, warmer Fourté without sacrificing any of its world-class technicalities. On the whole, the experiment works. For those that think Trió is already that IEM, I couldn’t disagree more. Noir is actually more Nio than Trió, with a thicker tonality and more rounded edges compared to Trió’s sharper, punchier sound. But it’s also far less Fourté than the same DNA and driver configuration might suggest. Even their graphs are virtually identical, barring one or two deviations here and there, but there’s no mistaking Noir’s significant departure from the Fourté blueprint. 

Technically, Noir and Fourté are cut from the same cloth. The stage, while not quite as wide or holographic, is still immense, imaging and separation are both excellent, it’s fast and dynamic, and can dig almost as deep into the details as its older sibling. Where it differs completely is tonality. Where Fourté is airy and unflinchingly clear, Noir adds a layer of midbass extension that warms up the sound right through to the upper mids. Where Fourté leans its W-shaped tuning to the right, Noir leans it left. 

Listening to Noir and Fourté side-by-side is quite disconcerting. Depending on your preferences, it’ll leave you feeling one or the other lacks something, whereas giving each IEM an extended listen on its own irons out most of the ‘flaws’ your brain is convinced it’s hearing. Listening to Noir right after Fourté, for example, left me missing some of Fourté’s clarity, even though I know Noir isn’t veiled. Switching the other way, I missed some of Noir’s weight and denser notation. 

Despite the name, Noir isn’t a dark IEM. It is a warm IEM, but balanced by a brighter – sometimes surprisingly brighter – treble. It’s also more detailed and more fleet-footed than a warm, thicker-sounding IEM has any right to be, like a bodybuilder dancing ballet. There wasn’t a song I heard on Noir that didn’t sound controlled, cohesive and musical. From faster-paced EDM to slower acoustic and singer-songwriter tracks, both name and female, I enjoyed them all with Noir. Does it hit the highs, so to speak, of Fourté. No, not for me, but it’s also less prone to throwing a hissy and poking your eye out with a poor recording. Which ultimately makes Noir an easier recommendation for some, especially for those that want the very best with the least amount of fuss.