64 Audio U6t Review

64 Audio are finally offering up their most popular custom IEM in universal form. The U6t has a smooth and balanced sound that makes it a superb everyday earphone for the majority of people.

Fit and Comfort

64 Audio have used the same universal shape for the U6t as their other models (U12t / tia Trio etc…) and this is a tried and tested design. Offering up smooth edges with a good length nozzle for a secure fit and great comfort. Once you settle on the right size tips for your ear canals, they fit securely with the new included cable being more ergonomic and comfortable.

The U6t fit comfortably in your ears. They are also extremely comfortable for long listening sessions. The new cable is softer and has pre-moulded earhooks which, in my opinion are always more comfortable than stiff memory wire. 64 Audio provide plenty of eartips with the U6t. So try them all to find which suits you best!

Compatibility

Whilst the U6t is easy to drive, and has 64 Audio’s LID technology meaning there won’t be drastic sound signature changes between sources. However, an IEM of this quality still deserves a good source. Lossless tracks and the use of an external DAC/Amp with a mobile phone, or a dedicated DAP would definitely be my preferred choice of source.

Apex modules and tia drivers

64 Audio have a few interesting technologies they employ in their lineup. the U6t uses their apex technology that relives inner ear pressure whilst also allowing a certain amount of noise through. In turn this also tunes the sound slightly. The U6t comes with the m20, m15 and mX modules, which offer -20dB/-15dB and -10dB of noise reduction respectively. The more isolation results in more lower bass response and a warmer sound signature too. Along this logic, you get minor variations in soundstaging too. The more open being the more open sounding. Personally I do find the apex modules reduce listening fatigue and 64 Audio IEM’s are always perfect for long listening sessions.

The U6t also includes a single tia high driver. This high frequency driver is an open-top BA driver which is tube-less too and sits in the nozzle. This provides an increase in air and space in the treble region along with a more realistic treble presentation. Quite a while ago I listened to the original U6 against the new A6t. The tia driver definitely delivers a smoother and more realistic treble response than a typical BA with tube and damper design.

Sound

(M15 module as installed out of the box)

Bass:

The U6t have a nice and full low end that is exceptionally well tuned for a BA model with six drivers. There is enough warmth to add pleasant body to the sound and enough punch to be engaging. But it’s always composed and controlled, there is never excess bass, or unwanted bloat. Bass guitars are articulate. Kick drums hit with impact and have excellent body to back them up. They are not in your face. They also don’t try and impress with overblown bass, instead focussing on making the low end sound accurate and realistic with a little hint of warmth to ease those long listening sessions.

If you want a little more low end than the m15 module, the m20 offers up even more body. This in turn tricks your brain into thinking there is less treble. I.e this module is one for those who prefer a warmer and thicker sound. On the opposite end, the mX module leans out the low end. Making the U6t sound like a more typical reference tuned device. Allowing the mids and highs to cut through a little better with a tighter and slightly less thick bass response.

Midrange:

The midrange is superb on the U6t. It nails the natural yet not analytical presentation, being detailed and nuanced without being clinical. Vocals have an intimate quality without being up-front and central. There is such a pleasant balance overall that nothing sounds out of place or forced. More aggressive tracks have good bite, yet softer tracks have a sweetness that is intoxicating. Heavily distorted or acoustic, it doesn’t matter to the U6t, they can do it all with ease. Something lacking in many earphones. Both male and female vocals sound excellent, with maybe a slight nod to female vocals having the upper hand. The transition from upper mids to lower treble is handled superbly. They are not pushed to sibilance yet there is no discernible dip robbing them of energy and presence.

Regardless of the module used, the midrange is always very well presented. However it does sound warmer with the m20 and slightly thinner with the mX. So take your pick! For most the m15 is probably going to be just right.

Treble:

The treble is airy and well extended. It is also very well balanced in the mix, with the right amount of attack and energy without sounding bright or harsh. The tia driver provides exceptional treble response. One that sounds tonally accurate without nasty peaks or dips. You never lose track of the treble, it simply never gets lost in the mix. Snares are snappy and cymbals crash with authority. Yet, I never find them to be edgy or uncomfortable. 64 Audio are experts of pulling off the correct balance in the treble, and they are not lacking detail at any point either.

If you want well presented treble that isn’t harsh or fatiguing I highly suggest testing one of the 64 Audio models. These are utterly fatigue free. Should you wish for a little more bite, toning down the bass helps the mids and highs cut through a bit better (mX module).

Soundstaging and Genres

The U6t have a wider than average soundstage, but it’s not huge as these are still based on a pro-audio model. They are very accurate with their placement of instruments within the soundstage and everything is very well separated. I.e never sounding congested during complex tracks.

These are a superb all-rounder to be fair. They might not have the bass quantity many EDM listeners might crave, but they lend their hand to most genres. These have a slightly smooth presentation. Meaning they might lack a little energy for some. But on the other hand they are super easy to listen for long sessions.

Apex Modules

With the U6t you almost get 3 different signatures in one IEM. Whilst the core sound presentation will be similar between the three there are distinctive differences which allow you to fine tune them to your preference. The apex modules mainly affect the bass region. But an increase here will lead to a perceived lowering of the treble/midrange so take this in to account.

Using the most closed module (m20) you get quite a thick, warm and laid back sound. One that has good body and warmth overall but still with the signature tia driver an airy top end.

Using the m15 you get slightly less bass. Which in turn leads to a more balanced but still slightly smooth sound that is a great compromise and likely the sound that most users will prefer. It is well balanced but not lacking in punch and body.

The mX module will give you a more analytical presentation. More akin to a studio monitor sound that might be lacking a little body for some listeners. But it is the one that will sound the cleanest in the mid-range and treble due to less body overall.

It is down to each listener as to which module they will prefer, but the overall signature refinement and balance is present over all modules.

64 Audio U6t vs A6t

Should you go for the custom version? In short, not really. The custom version is for those who are using these professionally or who want increased comfort. The universal is much more accessible for the average user and it retains resale value should you want to change in the future. The U6t gives you 98% of the sound of the A6t. The custom version has a tiny bit better instrument separation and the seal means you get a bit fuller low end, but the difference is subtle and not in the extremes.

Who are they for?

• People wanting a high quality everyday earphone
• Those looking for a balanced but not clinical sound
• Lovers of a natural sound that it tonally accurate
• Conclusion

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