Hidizs x NF Audio NF-3U
Michael Piskor 2018

Hidizs x NF Audio NF-3U Review

The Hidizs x NF Audio NF-3U is a collaboration between Hidizs and NF audio. This is a triple balanced armature design IEM priced at $499.

Disclaimer: The Hidizs x NF Audio NF-3U sent to us for the purposes of this review is a demo unit sample and does not have to be returned. Thank you to Hidizs for giving us this opportunity.

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Hidizs has sent me an interesting little IEM called the NF-3U, which is selling for $499 on the market as we speak.

This company is more well known for portable music players, so I was immensely excited to “hear” that they are producing IEM’s now in partnership with NF Audio. This is great news! A very musical inspired company that makes source music players now has a hand in headphones. This is a fantastic move for them as a company.

The Fit

For $499, the NF-3U (I will be referring to it as 3U from now on in this review) looks like a custom IEM but is actually universal. That means it fits “most” ears properly.

For me, the fit is not so good, but then again I have issues with this type of design all the time. They refuse to stay in place for me and feel like they are not snugly fitting.

They are also quite large and stick out a bit too much for my subjective tastes while I am wearing them. But, I digress. A small group of unlucky people like me just can’t use these types of IEM’s all the time unless they are smaller units. This 3U is on the larger size side, sadly.

The Driver Manufacturer

The 3U is…well…of course, a triple balanced armature driver. Oddly, a company named Knowles made the drivers, as fashioned and implemented by NFAudio (which is Hidizs) and then branded by Hidizs. That is a mouthful if you ask me. It really doesn’t matter who made them though, so long as they sell well enough and sound good.

Hidizs x NF Audio NF-3U

Build Quality

The 3U is made of medical grade curing resin, with red mahogany exteriors. Yes, it looks stunning and high, like a high tier CIEM. But, in feel, it is far less dense feeling than something like my Empire Ears Nemesis, which doesn’t even have woodcuts for plates.

Does that matter? Yes and no. I like a hefty and high end feel to my CIEM’s. This 3U feels a bit too light and thin to give me a high-end vibe. Considering it has woodcuts in it, I thought it would be significantly weightier.

The nozzle end is a nice cut of copper, although I don’t really understand why it is there. CIEM’s don’t use this and sound superior, I feel like this isn’t even remotely needed. It sure does look lovely though. Overall, the build is still very good in my book. I have no issues with it what so ever. It is sexy and striking at the same time with excellent quality materials top to bottom.

Hidizs x NF Audio NF-3U

The Cable

The 3U uses a fantastic looking braided 8core 6n single crystal copper wire, terminated in a 3.5mm adapter. I absolutely love this cable and how it looks and feels. We need more like this in the future. I hate black rubber sleeves. I need this type of a design for all my CIEM’s unless I can get fabric. Does it offer anything outside of visual appeal? Nah. Not really. It just looks fantastic and toting it around a bit, I got some questions and statements about how lovely it looks.

Hidizs x NF Audio NF-3U

Sound Impressions


The NF-3U responds down to 10hz, which I’d expect to offer much more bottom end without the need for boosting. On a flat EQ, this IEM is overly lacking in bass quantity but is audibly responsive to very low notes indeed. What is there, is just too thin to justify the lows I am experiencing on the track and that I know should be more dense and thickened feeling.

Clarity is not at all a problem. For $499 though, I feel like the Flare Audio PRO BT IEM from earlier in the year was still better than this, despite being a fair bit cheaper at $449USD and offering Bluetooth as well.

Quality aside, which is very good, but not top tier, the quantity is the issue for me. As well as responsiveness to EQ and how well bass can increase with more EQ. The 3U doesn’t perform well enough for me to justify the price. Meaning, the more I increase the bass boost, I should be feeling more bass without losing too much quality. At a staggering +9dB, I still feel it underwhelming in bass quantity and hardly changing from +5dB to +9dB. That means the IEM just isn’t responsive to bass boosting. So, if you are basshead, look elsewhere. If you are a purist, you’ll enjoy it a lot.


I am very impressed! The NF-3U is excellent with midrange response. In fact, I’d call it one of the better IEM’s I’ve heard in the price tier for vocal usage. With MSEB (a DSP for portable players) I am able to really push the midrange out and alter it significantly to my liking and that is a hell of a wonderful thing. Sadly, the bass end doesn’t perform the same, but the midrange is exceptionally responsive, indeed!

If you want a very forward sound, you can get it with proper EQ. If not, the stock flat EQ sound is still what I’d consider forward in vocal presentation. As for quality and purity, again, I am impressed.

At the $500 level, this is right on point with what I’d expect. I’ve only heard some customs in the tier that sounded more realistic and dense feeling. And that is the problem with this IEM, density factor, which I’ll detail in a bit. For now, midrange purity is very good and if you are into female vocals, you will absolutely love this IEM.

Hidizs x NF Audio NF-3U

Upper Mids and Treble

The NF-3U has some brightness issues with the upper midrange that I find to be unnatural sounding and a bit overblown. Thankfully, not sibilant at all. Nasalness is also not the problem. It is just an odd contrast between the very musical feeling midrange below it. All be it, treble that can get a little bright at times.

What I do enjoy is the tonality factor, which, for the most part, can be sweet and exaggerated. I don’t think it is always a purist type of tonality up top. When the track calls for it, it is extremely neutral feeling, but not dry.

This is interesting because I consider the new Shozy Hibiki2 to be dry up top and more prone to harsh impact. But, this 3U to be the more tamed of the two. However, on tracks that are blatantly terribly recorded, the 3U really showcases that more than most of my other sub $500 IEM’s. And that is a great thing if you are a purist. If not, and you are like me who gravitate for subjective musicality factor, then it is a bit of an annoyance.

Quality considered is very good all the way up to the treble end, but as mentioned…density factor is my issue, similarly to that midrange thinness.


Typically, the more expensive products get, the more a realistic tonality and density factor comes into play. Low-end Dynamic drivers often sound very thin by comparison to a Planar. In this case, the 3U is outshined significantly by cheaper IEM’s I have. I do not enjoy a $500 IEM that feels on the moderate side of the spectrum in regard to feeling full, weighted and dense all around.

Does that mean it is thin sounding? No. It is what I’d consider moderate in that regard. It is just for $500 this tonality and density factor feels overly thin for the price. I am not fond of it. I have some $99 and under IEM’s that feel more realistically dense and weighted, especially in the treble and bass areas.

Hidizs x NF Audio NF-3U


The NF-3U does a very nice job at imaging, but I don’t consider it as coherently formed as I would wish it to be. Again, cheaper sets like the newer Hibiki 2 trump the 3U in this category of a realistically formed sound when it comes to space.

However, the 3U trumps that Hibiki in how realistic vocals feel. The artist itself feels more realistic here than on the Hibiki 2. But, the staging size, air, and space in-between feels more realistically coherent on the Hibiki 2 overall. This is extremely easy to spot with big band and slow jazz vocal tracks, where the 3U outperforms in clarity and realism in the midrange. However, switching to the Hibiki 2 showcases more air and space, more breathing room.

For $499, I expect better than this in terms of air factor from left to right. Stage depth is excellent. Which lends credibility to the realistic vocal performances in the 3U vs audibly inferior depth of field in many other sub-$500 IEM’s. The Flare Audio PRO still remains the best overall that I’ve ever reviewed for this in a standard IEM design and it was still cheaper than this 3U.

So, there are plenty of factors to consider. If you like stage depth and midrange realism, this is a great option. If not, and you want more of a general, all-purpose IEM with excellent imaging, there are other sets that outperform this.

Hidizs x NF Audio NF-3U

Our Verdict

For $499, this is NF-3U that isn’t really a CIEM. It looks like one, behaves like one but isn’t one at all. The build is very pretty and it will turn heads. The tonality and density factor of the IEM falls a bit short for me, I expected more of a heft to the sound signature. Especially so on the treble end. The low end isn’t very responsive at all to alteration but is plenty clean for the price.

As it stands, this is a fantastic vocalist IEM with a strong pension for very slow and relaxing jazz standards. If you like that genre, this is one of the better IEM’s out there for you. If you can get over the moderate density factor, that is. They did a good job overall. Outside of that heft factor, nothing is really objectively lacking. For the price, fidelity is on par with what I’d expect a $499 IEM to offer.

Hidizs x NF Audio NF-3U Specifications

  • Shell Material Red Sandalwood Faceplate
  • Cable Material  Eight Core 6N Single Crystal Copper And Silver
  • No. of Drivers Three Knowles Armatures
  • Frequency Response 10-22000Hz
  • Sensitivity 105dB@1kHz
  • Impedance 25 ohms
  • Detachable Cable Design  Yes (0.78 2pin)
  • Plug 3.5 mm plug jack
  • Cable Length 1.2 m
  • Sound Insulation 25dB

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