Once plugged in, the Hidizs X NF-Audio NF3U unveils its true colours. Like the shell, this IEM offers an excellent resolution and a very high amount of detail, especially in the highs. There is a clear emphasis on the higher end of the spectrum, so if you’re a bass-head this are not for you. Precision is the key word here, every song seems more define, more polished thanks to thes nearly-overwhelming highs.
It may look like the other frequencies are lacking, but they’re not. Bass is good and can go as low as you want even if there isn’t the usual boost in the mid-bass section. If not for the treble, this would be a flat-sounding IEM since neither the bass nor the mids were boosted. On the other hand, once you cross the 6kHz limit, you can really feel where NF-Audio put their heart at. It’s always at the limit of sibilant and, with a specific DAP, it can easily slide from precise to tiring.
For me, the NF-3U shares a lot of traits with the latest Etymotic, with a lot more bass of course. If you need an IEM dedicated to discriminate listening and love to have the ability to discern every detail, this could be it. Extra point for the crossover, every layer is perfectly audible even with super complex songs.
After a few days of listening, you get fully accustomed with the terrific highs. Thanks to them, the soundstage is wide and accurate and I’m loving this 8kHz bump combined with a distortion-free sound. It’s still a closed-back IEM, don’t expect an open-back headphone presentation, but among all the recent earphones I tried, it’s clearly a league above.
Highs : deadly precise. I could not fault them whatsoever, be it Jazz, Electro, Rock or simply Pop. On the last album of Justice – Women World Wide, it could become tiring once you crank up the volume due to the abuse of limiter and heavy distortion. However, this can also be strongly addictive once you tasted it, even compared to higher end gear. It’s both the best point and the drawback of the Hidizs X NF-3U, but if you can live with it you’ll be one happy guy/girl.
Mediums : flat and clean. I didn’t say much of them previously because… there is not much to say. Voices are steady and never seems out of the place, if you’re a jazz lover don’t worry the NF-3U does an excellent job. The mids are not amazing by any means, so don’t buy this IEM for their mids as they mostly support the highs and lows, but it’d be unfair to discredit the engineer’s work. Try it on Part VII from Prequel and you’ll hear what I mean.
Lows : deep and thick. At first, I found the NF-3U bass-lacking but that was mostly due to the extensive abuse of highs. Once you have digested the information in your brain, you can begin to feel the lows. It’s a tight and fast bass, each drum precisely cut once it’s played and as for the highs, they won’t please everyone. Personally, I find them great and if you love Electro music you experiment something close to planar, my favourite type of sound.
Sensitivity / Hiss / Association
The Hidizs x NF-Audio NF-3U are fairly easy to drive, and good sensibility and low impedance even allow them to work with a smartphone. I used the iBasso DX150 90% of the time and it was a nice combination. The best match was with the A&Ultima SP1000 but it’s a bit of overkill, on a more simple setup the Hiby R6 was a good call.
If you want to try some Sabre or FPGA DAC with the NF-3U, you’re up to one of the most chirurgical experiences of your life, the more you turn up the volume the more you could get some hiss. It’s prone to sibilance but as I said, in 90% of situations, it stops just before. That’s if you listen at moderate volume of course.
A balanced cable adds an extra layer of separation and precision but I don’t find it necessary unless you really want to go the extra mile.
The Hidizs X NF-Audio NF-3U is a great IEM, even if they will not suit everyone. It’s one of the most precise earphones you could get, for sure in this price range. The highs are astonishing and if you own a Focal Utopia or a Sennheiser HD800, this could be your everyday IEM.
For the others, you may want to try it first, like coriander you will either love it or hate it. Craftsmanship is excellent, as comfort, and I had a really pleasant time through most of my listening. The shell is a major step-up from my old CIEM and if I would have to choose from comfort only, this would become my daily drive. Tame it with a good DAP and you’ll be rewarded.