84 Audio Nio Earphones

Sometimes I find the extent of miniaturisation in consumer technology startling. For example, lots of home theatre projectors use DLP technology, which means the picture is generated by a “Digital Micromirror Device”. A full HD DMD incorporates more than two million physical mirrors – each with a hinge on one edge, each of which can tilt under the influence of a signal by ten to twelve degrees – on a chip less than half an inch in size.

Or another example would be the 64 Audio Nio earphones. They aren’t unusually large, but each of the left and right earbuds has nine drivers, one 9mm dynamic woofer and eight balanced armature drivers.

Plus a crossover network.

What does all this add up to in terms of performance?

64 Audio Nio Earphones


  • The 64 Audio Nio earphones are wired earphones packing nine drivers in each earbud, eight balanced armature and one 9mm dynamic bass
  • They feature machined aluminium bodies, with blue natural abalone faceplates
  • Six of the BA drivers are for midrange, one for high-mid frequencies, and one for high frequencies alone
  • High frequency driver employs “tia” tubeless design (the tube is the section emitting the sound from the balanced armature “box”), designed to reduce resonances
  • 10 to 20,000 hertz rated frequency response
  • 105dB/mW rated sensitivity
  • 4-way passive crossover network, designed for linear impedance
  • Three sets of “apex” plugs which provide different isolation from external sounds, and also tailor bass performance.
  • Three sizes of silicone ear tips, three sizes of memory foam air tips
  • 4 grams each (disconnected, with mid-sized memory foam tip)
  • Removable 1.2 metre cable; 3.5mm single ended plug at source end, seemingly proprietary two prong connectors at earphone end
  • Hard carry case included
  • The 64 Audio Nio earphones provide a penetrating look into whatever music that you’re enjoying, for enormous detail and with an excellent bass performance.
  • Price: $2899
  • Available at fine high fidelity retail outlets, and direct from distributor's retail division here
64 Audio Nio Earphones

    More about the 64 Audio Nio IEMs

    We simply must talk about something I haven’t come across before. Each earbud had a hole on the outside, with a plug in it. There were two other sets of plugs in the box. These were labelled “apex”. There was very little documentation provided with these earphones, nor for that matter was there much on the website. But I eventually managed to puzzle out what all that was about.

    Each earphone has a hole behind the 9mm dynamic bass driver. The apex plugs – “apex” stands for Air Pressure eXchange – fit into those holes and provide three different levels of both acoustic isolation and bass driver loading. Each plug is a small, seemingly aluminium cylinder with two O-rings for sealing. Each sports two port slots on the section which sits above the body of the IEMs. Inside there is apparently a different degree of damping materials affecting the transmission of sound between each earphone and the outside world. That affects both the amount of outside sound that they permit to pass through to your ears, and also the bass power provided by the dynamic driver. The pre-installed ones are M15 models, which stands for 15 decibels of outside-noise reduction. The others in the box were MX, for 10dB of isolation, and M20 for 20dB. They are colour-coded: black for MX, grey/aluminium for M15, and near-white for M20.

    Or, to use 64 Audio’s description, this plug system is a “pneumatically interactive vent that relieves pressure and reduces ear fatigue.”

    64 Audio Nio Earphones apex plugs

    64 Audio notes that the high-frequency balanced armature driver uses a “tubeless” design. Most BA drivers are little boxes with a tube that emits the sound. In these ones, the tweeters presumably dispense with the tube. I’m guessing that this has advantages in time alignment, but 64 Audio says that this design “eliminates resonance providing optimal clarity”.

    I must also note the 90-degree 3.5mm plug provided on the cable. This 3.5mm plug is a substantial gold-plated thing of a kind I’ve never before seen. It’s impressive. But no 6.35mm adaptor is included.

    What is included is an 86mm-diameter case for the earphones.

    The mounting tube for the earbuds was a little unusual in that it was just a straight tube with no lip for locating the tips. That made it easier to switch tips, which encourages experimentation. But I found the silicon tips, with their give, could all too easily be pushed back down the tube far enough for the hard material of the tube itself to press up against the inner surface of my ear canals. The memory foam tips were longer and didn’t have this problem.

    64 Audio Nio Earphones

    Listening with the 64 Audio Nio IEMs

    I should also note that I used mid-sized memory foam tips throughout my listening. This provided good comfort, an excellent acoustic seal.

    Reporting listening impressions with the 64 Audio Nio IEMs presented some unusual difficulties. Specifically, the three sets of tuning plugs resulted in noticeably different sound profiles. These primarily affected the delivery of bass … the deeper the bass, the more the effect.

    It was instructive to do a just a tiny bit of listening with none of the plugs installed. In other words, the dynamic drivers’ rears were exposed to the atmosphere. In that state, the bass was diminished by a huge amount compared to listening with the plugs – any of them! – installed.

    Initially switching the plugs was kind of hard. The fit was tight, but after a bit of switching, the dual O-rings around each plug loosened up a little and made it easy to swap. The small vents in the sections of the plugs which protrude from the body of the earphones make convenient fingernail holds.

    64 Audio Nio Earphones

    Using Billie Eilish’s new, ironically-named album, Happier Than Ever showed the effect clearly. In essence, the MX (I’m guessing that the X equals 10, as per Roman numerals) provided the strongest bass performance, the (pre-installed) M15 offered a little less and the M20 the least of all. But the M20 offered the greatest acoustic isolation from the outside world, the MX the least and the M15 somewhere in-between.

    In all cases the bass was simply excellent. I found myself preferring the MX for the greater bass delivery. This was most apparent in the lower octaves.

    In addition to the bass, the 64 Audio Nio earphones lean towards a noticeable emphasis on the upper midrange and lower treble. For example, the rich upper harmonics in Laura Marling’s voice on Once I Was An Eagle were on full display, along with the occasional sibilance. It was loaded with detail and revealed aspects of her signing that I hadn’t heard before, but I found the tone a little out of the mainstream in presentation.

    With the Schubert String Quintet performed by the Alban Berg Quartet, that upper midrange/low treble prominence again asserted itself. And again, it revealed a huge amount of detail. For those seeking a deep analytical look into music, you’ll find these earphones an ideal instrument. Despite that emphasis, rather than the violins becoming screechy or steely, they were actually somewhat sweeter than usual.  The two cellos were just a little down in the mix. The strong bass seemed to be most prominent in the deepest octave.

    64 Audio Nio Earphones

    And as for that octave, it was a delight to hear the bass pedal delivered on the Michael Murray rendition of Bach’s Passacaglia and Fugue in C minor on Telarc. It was there, and there in full. As the climax approached and the banks of pipes were unleashed in long, sustained, overlapping musical strains, these earphones kept the whole thing together in an unusually orderly way. I could follow the rapid right-hand arpeggios throughout. These earphones let me hear into what was going on in an unusually penetrating way.

    Finally, back to Billie Eilish, this time her hit album When We All Fall Asleep, Where Do We Go? And, yes, there it was: impressively powerful and extended bass. The mid-frequency lift was kind to Eilish’s voice, and tended to do things like bring slightly forward the claps in “bad guy”.

    64 Audio Nio Earphones


    The nominal six-ohm load of the 64 Audio Nio IEMs was by far the lowest of any earphones I’ve reviewed. Plenty of headphone amplifiers proclaim themselves suitable for loads from 16 ohms up to whatever. Six is low.

    Yet the various devices I used to drive these earphones all seemed comfortable driving the earphone to high levels. That includes an iPhone 8 with an Apple Lightning to analogue audio dongle.

    You’d think that with a four-way design and nine drivers in each bud, the impedance curve presented by these earphones might be … complicated. But one of the features of the 64 Audio Nio earphones is their “Linear Impedance Design”, which the packaging describes as “a proprietary circuit correcting non-linear impedance for a consistent sound signature.” It looks like 64 Audio pulled that off. Here’s the curve, shown as the affect that the impedance has on the signal voltage delivered from a high output impedance (466-ohm) source:

    64 Audio Nio Earphones impedance curve

    That might look like a wide variation, but at its most extreme it’s less than 2.5dB. You’d probably hear that difference if you use it with, say, a Denon or Marantz home theatre receiver since they have that kind of output impedance. But with a typical quality headphone amplifier the variation will be two orders of magnitude less. You'll note also that differences in loading made virtually no difference to the curves.


    To my ears, the 64 Audio Nio IEMs give a somewhat idiosyncratic view into the music. Absolutely everything is there, including bass that is amongst the best I’ve ever experienced from IEMs. But the balance in the upper midrange, lower treble is kind of different from the norm, giving a strong presence and vibrant immediacy, but without quite the natural flow I prefer.

    Yet as I write, I hear revealed something new in some Robben Ford music of which I’d never previously been aware (in “Sweet Sixteen” from Discovering the Blues – the fader on the mixer is turned up on an instrument, revealing some live amp noise).

    So, no pronouncements on high from me for these earphones. They are obviously well-engineered, and let the listener tune them to some degree with the tuning plugs. I’d strongly recommend anyone looking for IEMs in the pricing ballpark of the 64 Audio Nio IEMs give them a listen.

    64 audioIn-ear earphones