64 Audio U6t
The U6t from 64 Audio aren’t new here. They were reviewed and eventually let go in the hunt for a single dynamic driver. With the hunt over, it is now time to revisit a dearly missed old friend.
Where a single dynamic driver (DD) makes sense in the pursuit of coherency and timbre — multiple balanced armatures (BAs) make sense as transducers of choice for something being so close to one’s ear canals. With that said, the closest multiple BAs get from replicating a dynamic drivers’ coherency and timbre, the better.
The object — Oozing understated class, the U6t are likely the sharpest-dressed IEMs of all 64 Audio’s lineup.
Small, light and comfortable, the U6t come with a no-nonsense newly upgraded 3.5 premium cable; three apex modules allowing to customise the isolation/tuning; a tip holder wheel — ever had an ear tip rolling and tumbling under barely accessible furniture? — and round leatherette case. The downsides? A scratch-prone epoxy faceplate and there’s no bundled mesh pocket.
Fit & Comfort — 64 Audio’s nozzles are on the thin and average-length side. To most, and certainly here, this means a high likelihood of comfort. The three types of bundled tips (Foam, Silicon and SpinFit) in S, M and L only strengthen the likelihood of getting a nice, comfortable, fit.
Worthy of note is the stock cable’s angled 2-Pin connectors ending up in an ergonomic curve of hard plastic which can be an issue for some ear shapes as it (slightly) was the case here.
64 Audio’s air pressure exchange (apex) modules essentially alleviates listening fatigue as the modules vent air pressure from what would otherwise be a sealed ear canal. Apex modules have different levels of isolation which breaks down as follow: M20 module (-20dB), M15 module (-15dB) and MX module (-10dB). The less isolation, the less pressure, the less impact different tips have, the more comfort, but also the more soundstage, detail and texture.
Tips used: SpinFit CP145
Sound — The U6t, with either the MX or M15 modules, are an organic, effortless and musical listen. With no hint of BA timbre, they are utterly enjoyable for short or long sessions alike.
The amount of lows will very much depend on the apex module in use. The default M15 module will offer plenty of both sub- and mid- bass while the MX module will highlight mid- rather than sub-bass.
Albeit more than adequate with the M15 module for an engaging listen, the MX module will highlight the U6t’s true capabilities in terms of mids, highs, soundstage and overall detail and texture.
All-in-all, regardless of the module used, the U6t stand out for their natural, organic, musicality and tone.
Conclusion — The U6t are an amazing organic and effortlessly musical listen which is difficult to get tired of. In spite of their admittedly hefty “entry-level” price in 64 Audio’s lineup, they are recommended without hesitation as a blind buy for anyone who’s looking for an IEM to enjoy their music library without any reservation.
Files / Sources used: CD-quality FLAC bought from Qobuz & Tidal HiFi streaming / Sony NW-WM1AM2 (Direct Source: On), Cayin RU6 (NOS) and Astell & Kern SR25 MKII (Low Latency Slow)
Compared to Softears’ Twilight — While equally coherent, natural and lifelike, the U6ts are warmer and more intimate than the Twilight.
Overall, the Twilight are clearer than the U6t. Moving from the M15 to the MX module on the U6t gets them closer to the Twilight but it will be at the expense of the U6t’s sub-bass.
In terms of quantity, the Twilight’s sub-bass sits in-between the U6t’s M15 and MX modules. In terms of quality, the Twilight have the unmistakable physicality and timbre of a single DD IEM compared to the U6t which have an excellent low-end for an all-BA IEM.
The Twilight’s mids are more up-front and you’ll get more grit out of them than the U6t’s although the MX module will get them closer to the Twilight.
Highs feel a tad sparklier on the U6t, especially with the MX module, yet never get too hot. Paired with a bright source, the Twilight could be too much for some.
The Twilight have more detail and a bigger soundstage than the U6t with both the MX and M15 modules.
The U6t, however, can feel like they have more natural transients and texture.