64 Audio – U6t Review

64 Audio U6t

Design & Build Quality


Personally, I really like the 64 Audio designs and I think their monitors look stylish and professional. The small U6t is no different in that regard. The U6t has a metal dark grey shell and it looks and feels soft. The U6t’s design is simple but the shiny black front plate which is showing the 64 Audio logo, simply works. On the inside of the earpieces you’ll only find the U6t name and the serial number.

The U6t’s build quality is also perfect. The U6t feels smooth and rounded and there are no sharp edges anywhere. The slightly longer nozzle has a tiny mesh grill on the inside and that’s always something we appreciate. The faceplate closing, the 2-pin connector and the apex module “opening” are also perfectly finished. The cable also looks nice with a shiny plastic sleeving and 64 audio logo on the connector and Y-split. The cable is completely tangle-free and it has a heat-shrink memory part to go over the ear and it for me works great. So this is as good as it gets. The U6t isn’t cheap, but in regards to design, comfort and build quality, you get a lot in return.

64 Audio states that while they looked at the U12t for sonic inspiration, the U18s influenced the new dark grey matte shell finish as well as its newly redesigned packaging and proprietary cable. The understated shell design and classic black faceplate reflect what you can expect from the new generation of 64 Audio’s audiophile products.

64 Audio U6t

Fit, Comfort and Isolation

The 64 Audio U6t is small to normal in size, but with its rounded edges and smooth finish, the units perfectly fit and disappear in my ears. The U6t universal shell design works super well for me and I can get a good fit all day long, without getting any discomfort from the unit. I do mostly tend to use the foam tips for extra comfort. Do note that the nozzles aren’t the shortest, so the U6t might stick a bit out of your ears, depending on their shape. I don’t feel they especially stick out and as I said, they perfectly fit my ear shape.

The over-ear cable design also works well for me and the cable is comfortable and light, so it doesn’t pull out the earpieces in any way. The 64 Audio U6t is not only about good looks, but it is very comfortable as well. Isolation-wise the U6t for me scores well and on par with a typical universal IEM. With the foam tips you get a bit more isolation obviously. According to 64 Audio, the m20 Apex module works best with a -20dB isolation. Using the mX and m15 filters results in -15dB isolation.

So we have a nice design, good comfort and a normal amount of isolation. But what does it sound like? Let’s find out!

64 Audio U6t

Sound Intro

I have mostly used the U6t in combination with the small sized foam tips and the impressions below are with these foam tips. In regards to sources I have used a multitude of DAPs and DAC/AMP dongles, such as the Earmen Sparrow, Luxury & Precision W2, Astell&Kern SP2000 and the new SP2000T.

This is what 64 Audio has to say about the U6t’s tuning:

U6t is a balanced natural sounding earphone, slightly set apart from our other UIEM models by offering a softer presentation of a mix. Beautiful upper-mid imaging, realistically presenting instruments like guitars and piano as well as breathing life into saturated mid-bass mixes, especially when vocal focused. Using the various included apex modules and ear-tips allows the listener to further customize the sound of the U6t based on the needs of the music.

64 Audio U6t

Sound general

First of all it’s important to mention that the U6t plays perfectly with all kinds of sources, and it’s dead silent at all times with a pitch black background. My favorite modules for the U6t are the m15 ones (gun metal grey like the IEM color) and the below impressions are based on that.

Sound stage wise the U6t scores well, but there is margin for improvement, so let’s call it moderate. This is especially the case when it comes to the sound stage width. The U6t extends better at the bottom than it does at the top, but you overall get a more intimate presentation. There’s nothing wrong with that actually, and many people prefer this kind of tuning. What I do like is the depth in the U6t, and that both for the bass and mids. Together with the lovely depth, you get good layering and that’s something I always love hearing.

Even though the U6t is more intimate, it in the mids does show a good amount of spaciousness and air, especially in the upper mid part. Separation-wise the U6t passes the bar, but also here there’s room for improvement. The overall level of resolution / detail retrieval and note extension is good but not as great as it is with 64’s more higher end models.

The U6t has a full bodied, heavier kind of presentation from top to bottom, but it never becomes too full or loaded. As such the U6t also has a slower kind of delivery and attack. The presentation is musically smooth, with a good hint of warmth. The sound is clean, but the U6t is darker than it is clear sounding.

The 64 Audio U6t is soft and pleasing on the ears. It has a very good level of musicality and it is very easy and inoffensive to listen to. There is a bass emphasis, but bass is not overpowering in any way. The lower mids are a bit more in the back while the upper mids and vocals have a more forward presentation. Actually, the vocals sound nicely spacious and natural and especially female vocals are super nice to listen to. The treble section is very soft, pleasing and it will never shock anyone. If you’re into treble extension and energy, you might find it a bit too soft for your taste.

64 Audio U6t

All-in-all, the 64 Audio U6t has a very easy to like tuning and it plays well with all kinds of music and sources. It’s the kind of IEM that lets you enjoy your favorite songs without the technical side becoming too involved. It’s more about musicality in this monitor than it is about technical excellence. But that being said, the U6t still comes with a decent technical level. I really like listening to the U6t when I just want to enjoy my music without having to really focus on listening to it. The U6t is not he technically strongest IEM but it will have you foot tapping and head shaking in no-time. I also find it excellent for watching movies with.

Sound m20 & mX

The m20 module increases the bass amplitude some more but it’s not so that the U6t becomes a dark and overpowering bass monster. Bass still is well separated and it doesn’t run into the (lower) mids. I don’t really agree with some other impressions which say the m20 module makes the mids more relaxed, I actually find them to have more focus and energy, especially in the upper mids. I don’t find there to be a big impact on the tereble section to be honest.

The mX module is more neutral in regards to bass presence and presentation. Bass here is flatter / lighter and it also impacts the mids, which here have a bit less fulness and body. For me the mX module also has the best speed, attack and clarity. Because of the lighter bass and mid-body, you can more easily hear the 2-4k peak. It makes the vocals sound more clear and energetic and more to the front.

For me the choice for the m15 module is easy as it delivers the most balanced sounding U6t. You get a good mix of body, bass and vocal energy and all that with a musical presentation, being soft, easy and pleasing to the ears.

64 Audio U6t


The comparison part was done with the m15 module installed and with the SP2000T as source. The monitors we chose for the comparison are the the 64 Audio U18s, the FIR Audio VxV and the MMR Gae Bolg. Unfortunately the 64 Audio Duo was reviewed by an other writer of the team, so I can’t include it in the comparisons at this stage.

I really wanted to include the U18s flagship universal IEM from 64 Audio in this comparison, simply because the U18s (priced at $2,999) is incredibly good. When I say the U6t can be better when it comes to detail retrieval, extension and basically the complete technical side, the U18s is what I have in mind. The U18s without doubt is one of the best universal IEMs in my collection. I absolutely love its technical performance but the beauty here is that the U18s has the perfect balance. The mix of musicality, technical strength, energy, body and bass impact is exemplary. If you’re familiar with the U18s and you listen to the U6t, you can easily and clearly hear they’re family and what 64 Audio is capable of when price is no issue. The U6t really is the little brother here but that’s ok. If you’re used to the top level sound of the U18s, the U6t will probably come over as a bit simple. But at the same time it’s still musical and pleasing to the ear.

The MMR Gae Bolg ($1,199) is the little brother of the Balmung we reviewed just last week. The GB is a 5-driver IEM and it has the exact same price tag. The U6t is a little bit smaller in size compared to the Gae Bolg, and the design style is also completely different. Comfort-wise the U6t is the clear winner for me. Sound-wise the GB sounds more spacious and open, but the lower mids are somewhat more at the back. I do find the clarity of the MMR to be better as well as the PRaT. The U6t sounds mellower but the bass is better defined. For me the GB sounds more energetic on top. These are 2 very differently tuned IEM, making them complementary in any collection.

The FIR Audio VxV ($999) and U6t are very much alike in both build quality, design as well as sound. The VxV also present a full bodied sound, with a smooth delivery and good bass presence. The clarity level is comparable though I feel the FIR is a little bit faster. The U6t for me is better in depth and layering, while the VxV has more top end energy. In regards to sound stage and intimacy, both of these units are very similar. The vocals of the U6t are a bit softer, where they in the FIR are a bit sharper tuned. So very comparable IEMs with a similar tuning, and that shouldn’t be a big surprise.

64 Audio U6t


In regards to build quality, design and accessories, the 64 Audio U6t universal IEM is very impressive to say the least. In regards to its tuning, the U6t will impress you if you like a more intimate presentation with excellent vocals, combined with a higher than normal bass presence and a good amount of all-round body and easygoing treble.

The 64 audio U6t is musical and with its smoothness and naturalness it is easy on the ears and a pleasure to listen to, no matter what source you’re using it with and what music you’re playing on it.

Compared to it’s biggest brother, it’s less balanced, clear and less technically strong, but in its price range, the U6t without doubt is a strong contender, especially if enjoying your music is a top priority for you.

This – next to the U18s – was one of the first official 64 audio IEM reviews I do myself and I’m clearly a fan of the 64 house sound. I hope to be doing many more 64 Audio reviews in the future. If you’re looking for a universal IEM situated on the lower side of the high end market and with the sound characteristics as described in this review, the U6t without doubt is one to put on your short list and listen to.

64 Audio U6t

Page 1: 64 audio, U6t, Specs, Box & accessories & Cable

Page 2: Design & Build Quality, Fit & Comfort & Isolation, Sound, Comparisons, Conclusion


Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.

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