64 Audio U4s Review

64 Audio U4s

In this article we review the 64 Audio U4s universal IEM. It is selling for $1,099 USD.


Disclaimer: 64 Audio kindly supplied the U4s for this article. We are in no way related to 64 Audio.

64 Audio

64 Audio has been around the audio scene for over twelve years already. They began their journey as 1964 Ears but have renamed themselves to 64 Audio in the meantime.

The company was founded by Vitaliy Belonozkho and during the process of the company’s success many brothers of the Belonozkho family have joined Vitaliy. Although it has to be noted, that some of them also have left the brand in order to realize their own visions.

Since their creation 64 Audio has kept pushing the envelope with new technologies. They introduced their tia drivers, which are openly radiating balanced armature drivers. Aside from that, they also introduced LID (Linear Impedance Design) and Apex. LID basically sets an almost linear impedance curve throughout the entire frequency range, while Apex helps mitigate ear-fatigue with a viscoelastic open-cell foam to control the rate at which air can pass through the vent. This is an open module that eliminates pneumatic pressure that builds up in an otherwise closed room.

64 Audio U4s

64 Audio’s main focus clientele-wise however is not necessarily audiophile based. They work with many renowned artists, such as Alanis Morissette, Beyonce, John Mayer, Nathan East, Black Eyed Peas or Bon Jovi. Just to name a few.

Their product range goes from the A2e dual drivers up to the whopping 18 driver A18t and A18s.

One thing that sets 64 Audio apart from the competition, is their all tube-less IEMs. They were the first to ever launch an IEM that did not use a single tube in it. This specific IEM has been sitting at the top of their lineup ever since its introduction – of course you know I am speaking about the all mighty Tia Fourté! An IEM that still holds up to its competition, even though it has been launched almost eight years ago. How time flies.


The 64 Audio U4s is 64 Audio’s latest universal In Ear Monitor and the keen eye might have spotted already, that it is the universal version of their A4s Custom IEM.

The U4s is 64 Audio’s fifth (out of nine) hybrid IEM, that uses a dynamic low end driver and three balanced armatures for low mids, high mids and treble. The treble is done by 64’s fantastic tia drivers.

Unless you lived under a rock for the past seven years or you have just stepped into this hobby, you should know, that the tia drivers are fully open balanced armatures. This means, that the membrane of the driver is completely exposed and able to deliver a more natural sound with better extension.

The U4s of course also packs 64 Audio’s other proprietary technologies. It comes equipped with Apex modules that limit listening fatigue. Think of Apex as sort of a secondary eardrum that’s sitting outside of your ear. Many, especially custom, In Ears build up pneumatic pressure when your ear-canal gets sealed. With Apex you form a pressure relieve and don’t stress your human eardrum as much.

64 Audio U4s

64 Audio also flattened the impedance curve by implementing LID (Linear Impedance Design). Thus making sure, that the U4s will sound its best, no matter what you hook it up to. This is a big bonus especially for touring artists and professional musicians where the gear often has different output impedances. LID makes sure, that the drivers won’t be affected by an impedance swing.

The U4s is available through 64 Audio’s website, or one of their global dealers for $1,099 USD.

The review continues on the second page. Jump to Page 2 for more!

Page 1: 64 Audio, U4s

Page 2: Package, Build Quality, Sound

Page 3: Comparisons, Verdict

4.2/5 - (112 votes)

Been into music and sound since he was a little brat, but spent his profession in a more binary field making things do what they were supposed to do. Ultimately just another dude on the internet with an opinion, into which you shouldn't put too much thought.

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