IEMs, Reviews, Uncategorized

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

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

Sound impressions

  • Source: HiBy R8 DAP (low gain, Turbo on).
  • Cable: PW Audio No. 10 8-wire 4.4mm.
  • Tips: JVC Spiral Dot.
  • Source files: lossless FLAC and DSD, local files only (no streaming).
  • Apex modules: Nio was tested using the default M15 and mX modules only.

All four 64 Audio hybrids have outstanding bass quality. In my opinion dynamic drivers are best suited for producing an optimal bass response, creating more analogue sounding and more tactile bass than the faster but generally less dynamic (pun intended) BA drivers. Bass – especially sub bass – should be felt as well as heard, and that’s where dynamic drivers have an advantage over other driver designs. No matter how good a BA driver is at producing clean, textured bass, it can rarely deliver realistic rumble with lifelike decay and timbre.   


Nio’s bass is really a story of two (M15 and mX) Apex modules (these are the ones I used for testing and the ones most people will likely switch between). With M15, Nio’s bass is a good few decibels louder than the other three IEMs, is well extended into the sub bass, but has more of a midbass emphasis. Nio’s bass has a rounder edge to it, so when drums hit they feel slightly cushioned. It has a good amount of texture and detail too, and a slower decay that gives it a very analogue feel. Talking relatively, Nio can sometimes be more bloom than boom, in light of the way the bass notes linger a little longer than perhaps they should.  

Switch to the mX module, however, and the picture is flipped on its head. Now Nio has perceptibly (and measurably) less bass than all three IEMs, though that’s not to say its bass completely drops off a cliff. Sub bass is impacted the most, but is still present, as is midbass, and retains a good amount of texture and detail. All the bloom is gone, and while there can still be some rumble if it’s in the track, it’s fairly muted. Since bass levels are now lower relative to both midrange and treble, mX shifts the focus of the sound very much onto the mids (more on this below). 


Trió has similarly elevated bass to Nio (M15), but is centred more on sub bass than midbass, which slopes down steadily to the lower midrange with no perceptible midbass bump. I hear Trió’s bass as more impactful than Nio, with a slightly more defined edge and more visceral punch. Rumble is deeper and more extended, while texture and detail are more or less on par, which is to say very good. Trió’s bass is also perceptibly faster, with a wicked dynamic slam that comes alive with both real and electronic drums, upping the energy compared to the more laid-back and softer Nio.


Where both Nio and Trió have generously boosted low ends, Fourté is far more restrained in its bass bump. Closer to Trió in its sub bass emphasis, Fourté’s bass slopes down rapidly almost as soon as the rumble is done, to a fairly neutral level more in line with the midrange and below its elevated upper registers. Fourté’s bass serves as a foundation for the music rather than being the star of the show, but make no mistake, where there’s slam in the track, slam is what you’ll hear. Coupled with its internal acoustic chambers, Fourté’s bass tends to appear from nowhere and ‘fills the room’ with its presence. It’s also faster, cleaner, more detailed, more textured and better nuanced than Trió, giving real shape and dimension to drums and bass instruments and creating a better sense of space, though it may not have quite the same impact as its younger sibling.


Bass is one of the biggest tuning changes in Noir from the Fourté. Instead of sloping down from the sub bass, Noir’s bass remains fairly elevated through the lower midbass and then gently slopes downwards right though the upper bass and lower midrange until a sudden dip at 1kHz. This gives Noir a much warmer, thicker sound that, on the whole, maintains detail and texture but is not quite as nimble as Fourté. Despite its perceptibly thicker tone, Noir’s bass mostly avoids bleeding into the mids, but still presents with a slightly softer edge than the laser-like Fourté. Also, unlike Fourté, Noir’s bass doesn’t take a back seat in the mix, and is more reminiscent of both Nio and Trió with its bolder attack.    

Track notes 

Mary Fahl’s Raging Child, the opening track from her rare 2001 EP, Lenses of Contact, delivers a powerful electronic drum medley at the 1:00 mark that is fairly well textured and quite resolving with Nio (M15) – picking up some distortion in the left channel at 1:10 that’s in the recording itself – but is also slightly bloomy and rounded. Switching modules to mX, the drums lose almost all the forcefulness, replaced by a more nuanced and textured rendition with the spotlight shifting to the vocals and supporting instruments.

Trió’s bass, by comparison, presents the same drums with a deeper tone, less midbass bloom and more subterranean sub bass rumble, while the drums appear from nowhere and ‘float in the air’ with Fourté, giving the sound a real sense of space, as if played back in a real room with real speakers, with exceptional texture and detail. Noir, on the other hand, is less like Fourté and more Trió (in depth) and Nio (in roundness). I could tell there was more sub bass energy here, but mixed in with a dollop of midbass that made the drums ever so slightly bloomy, and not quite as detailed and spatially defined as Fourté.

Ingrid Michaelson’s The Way I Am from the 2006 LP Girls and Boys is an excellent test for bleed, and while none of the IEMs came close to bleeding over Ingrid’s silky vocals, Nio’s bloom and Noir’s thickness made the bass more dominant in the mix than was the case with Trió or Fourté, while Nio mX hardly registered any bass at all relative to the mids. Fourté was again the fastest and most detailed, followed closely by Trió and Noir, while Nio was slower, softer but still full of nuance. 

Massive Attack’s Angel from 1998’s Mezzanine is a litmus test for bass texture, quantity and thickness. The bassline that fades in from the start quickly establishes itself as the foundation for the track, and can tell you a lot about the bass response of an IEM. Nio M15 had the thickest presentation, with its elevated midbass, followed closely by Noir, with its similarly thick but more nuanced and less bloomy delivery. Both Trió and Fourté had less drone and more texture and rumble, their bass response leaning more to the sub bass than mid and upper bass. Coming in dead last was Nio mX, which effectively cancelled out the drone altogether.

James Blake’s Limit to Your Love from his eponymous 2011 album, is a torture test for deep, strobe-like sub bass with midbass fullness thrown in for good measure (I always turn down the volume a few notches before playing this segment, which starts at 0:55 and repeats again later in the track). Interestingly the Noir gave the most visceral performance, its combination of sub bass depth and midbass fullness combining to highlight every warble of the eerie electronic effect. Nio M15 was likewise thick but less rumbly, while Trió and Fourté left little midbass meat on the bones while shaking the driver with sub bass, revealing the underlying texture a little better too. Nio mX tried but failed to move much air at all.