64 Audio U6t Universal IEM – Review

64 Audio U6t Universal IEM

64 Audio has made one of their most beloved custom IEMs a universal model with the U6t. Running for $1,299, it sits in the middle of their luxury price range. Each IEM that comes out of 64 Audio has a lot of pressure on it to perform well, with many seeing the company as a gold standard in the audiophile world. Having tried the U18s, U12t, U18 Tzar, and Tia Trio, I was completely blown away by all of them. However, most of those are around twice the price of the U6t, so I wasn’t quite sure what to expect from it. Still, my hopes remained high.

Click Here to watch my video review of the 64 Audio U6t!

64 Audio U6t Universal IEM Accessories

What’s in the Box

  • U6t Universal In-Ear Monitors
  • 64 Audio Premium Leather Case
  • TrueFidelity Eartips (S,M,L)
  • Silicone Eartips (S,M,L)
  • SpinFit Eartips (S,M,L)
  • Black Premium Cable
  • m20 apex Modules
  • m15 apex Modules
  • Round Sticker

64 Audio U6t

Look and Feel

These have the same shape and design of most 64 Audio IEMs, with rounded edge and fairly low profile. The U6t have a more low-key look than some of their other models, though the clear backing with the shining 64 logo beneath it makes these feel very luxurious nonetheless. Their fit is very comfortable as they barely touch your ears. How they manage to feel so firm without anchoring themselves in at many points, I’m not sure. But I never worried about these falling out, despite not feeling them grip my ears as strongly as I do other IEMs. 

64 Audio U6t Universal In-ear Monitors


The U6t uses 6 balanced armature drivers: two low, two mid, one hi-mid, and one of 64 Audio’s signature Tia Drivers for the high. The Tia driver is a tubeless driver that is meant to “reduce resonance for a transparent and lifelike sound signature.” The included Air Pressure Exchange (Apex) modules are meant to help minimize listener fatigue by offering us -15dB or -20dB. 

These have a frequency response of 10Hz – 20kHz and an impedance of 10 Ohms


You’ll have trouble finding an IEM that can compete with the soundstage of basically anything from 64 Audio. The U6t certainly did not disappoint with its soaring width and expansive depth. Sounds ares separated to the point you’ll have thoughts like “since when did this song have all these backing vocals?” and “where were all these guitar layers last time I listened to this?” The U6t is a true-to-life, hyperrealistic listening experience, sure to impress even the most pessimistic ears (and I know many of you reading this have them). Listening to Kelsey Lu’s cover of 10CC’s “I’m No In Love,” the song is given a new intensity and theatrical energy. Its mix is already very wide and holographic, but the U6t takes it to new heights and widths. 


The U6t have a full-bodied, maximum depth low end. They keep a pretty tight grip on their bass response to stop it from creating any bleed or mud, but make sure it’s never overly-contained. These have a very satisfying bass response, enough boost to insight a cinematic feel, but with such an expert handling it never feels overbearing or unnecessary. Their low end strikes a good overall balance between live/in person and up close/intimate. Listening to Kelela’s “Gomenasai,” the U6t handles the booming, percussive track gracefully, giving enough impact and boom to create some light vibrations and physicality without overpowering the mix whatsoever. It’s the kind of clean bass response that makes you want to keep pumping the volume, even when you know you probably shouldn’t. 


The first thing I noticed about the mid range on these is how well the high-mid is handled. It’s clearly cut a bit, creating a softened, smooth, warmed up edge to the U6t’s sound. However, as I’ve come to learn through using numerous of 64 Audio’s IEMs, they manage to modulate the sound without making it obvious. On most IEMs, a cut like this to the high mid would make me feel like I was being given a sonically reimagined version of each song I played. On the U6t, however, it just feels like I’m getting a heightened reality, the song conveyed with newfound clarity and no distracting, overt adjustments. The low mids are pushed forward, increasing warmth and body while keeping a relatively neutral character, but they stay contained enough as to not overshadow the more delicate high mid. Listening to Weyes Blood’s “Wild Time,” the vocals and keys feel like they’re given a smooth, comfortable presence, while the bass, drums, and guitars create a velvety underbelly. 


Perhaps my gushing is getting old by this part of the review, but you’re going to have to listen to a bit more because it’s about to reach its peak. The U6t’s high end, to me, feels like the perfect high end. These are a bright IEM, but the high end feels light, delicate, and impossibly purified. There’s not a hint of harshness from the high in these, no matter the song it seems. Listening to the silky vocals on Sabrina Claudio’s “Natural,” the U6t adds a thin layer of satisfying crunch to the performance. It feels like the the vocal is at a great middle point between crisp and warm, its brightness fluid and never stepping outside the range of pleasurable extension. The U6t has one of those rare high ends that could please almost anyone’s taste, as it seems to give the best of both worlds in terms of brightness attenuation and extenuation. 

64 Audio U6t IEM

Apex Modules

Light Grey Modules (-20dB): Slightly less shine, warmer mids, tighter bass.

Black Modules (-10dB): More shine, more high mid, extra tight/less booming bass.

Dark Grey Modules (-15dB), most neutral highs, most balanced mids, strongest bass.

I used the -15dB for most of this review


For casual listening, the U6t are an IEM that will breath new life into your favorite songs and make you fall back in love with them all over again. For live applications, this is about as balanced and honest of a sound as you can get in this price range. The immersive, engulfing quality these have is something truly special. These come shockingly close in quality to some of 64 Audio’s highest priced models for a fraction of the cost, and for those who have been eyeing their IEMs for a while but waiting for the right deal to jump on, the U6t may be your opportunity to pull the trigger.

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You can purchase 64 Audio’s U6t IEMs at Audio46

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Luke is an audio engineer, music producer, and sound designer. He focuses much of his work on ethereal, atmospheric music and soundscapes.