Disclaimer: The unit was sent by Tangzu as a part of a review tour, but all thoughts and opinions are my own.
I will be comparing the Nezha closely to Tangzu's own Zetian Wu Heyday, which is one of my personal favorite earphones to come out recently.
Build & Fit
The Nezha is significantly lighter than Heyday as it's a resin shell as compared to all metal. Size wise the Nezha is bigger as well. The Nezha looks more eye catching due to the red flakes (specially when the light hits them directly) as compared to Heyday which is really understated. When it comes to fit, even though the Nezha is a bit bigger, it sets better and snugger than the Heyday and that translated to better comfort in the long run. But both are comfortable to my ears. One thing to note though: The 2 pin on the Nezha is very tight, I wish it were a bit looser. Time will tell if it loosens up. The luxurious carry case and the cable that came with the Heyday was amazing, at any price range. And the same is the case for Nezha but it is now even more refined. The material on the carry case is now leather (mock leather I presume) and is textured. It is also a bit more streamlined as compared to the Heyday version. I would consider the Nezha case an improvement. But either way, neither can be fit in a pocket. They are transportable cases, meant to be put in bags.
The improvement carries to the cable as well. Both cables are gorgeous looking, but the Nezha plug is significantly smaller and less bulky, even though it retains the modularity.
The Nezha also comes with Tang Sancai Wide Bore & Balanced set of eartips (more in sound quality section).
Amp Needs
The Nezha is a BA+electret combination and it should be very sensitive, and it is. It is easy to drive. It is significantly easier to drive than Heyday which is a big (for portable uses) planar driver and needs more current. I use them both with my time tested E1DA 9038D and also the Fiio UTWS5 when outside. With Nezha i get loads of headroom, much more than I will ever need. With the Heyday I get loads of headroom on the 9038D but and also sufficient headroom with the UTWS5 unless the recording is quiet and, in that case, I need to max out.
So, in conclusion, no external amp is needed for the Nezha.
Sound Quality
As a reviewer, lots of earphones have come over the past to me. Some good, some bad, mostly "okay". I had really liked the Heyday, so much so I purchased a retail unit for myself. Up to that point, it remained one of the most resolving earphones I had heard, by a big margin. I really couldn't find much fault with it.
Honestly, I expected Nezha to be at most as good as Heyday for my personal taste. And I was a bit apprehensive about the electret driver, hoping it would be treble murder. Boy was I wrong. The moment I put it on, I was shocked to hear the smoothness in the treble, AND that excellent extension. It sounded open, un-restrained, extremely resolving as well. It out-resolved the Heyday by a big margin. A/B'ing the two, it sounded like the upper treble of Heyday was almost missing in comparison. I was shocked really. It was like going to 4k from 1080p. All of a sudden, the Heyday sounded a bit spicy in the upper midrange, slightly thin and simply put, a bit V shaped.
Nezha's sound is what you get if you take Heyday's sound, flatten it a bit and stretch it on both sides. The treble extension is very smooth and very high, devoid of sharp peaks. Upper treble extension is key to hearing ambiance of the recording and low-level details. And it shows. Then entire midrange is so natural and very resolving. The ear gain region is not overkill at all, which is not the case in most earphones. I have used the Nezha for hours each day- at home, while commuting as well. Just plug them in to the UTWS5 and it's a done deal. The included Tang Sancai tips are also of higher quality than the tips included with Heyday. With wide bore, that sound becomes lighter footed and becomes more analytical, shifting the focus on the treble, pushing the details in front. I preferred the Balanced tips, which simply makes the sound more balanced and makes the midrange sound "bigger" and more "open". The skin-compliant softer silicone is also more comfortable to wear in the long run.
But does it have "BA timbre"? What does it even mean? I have heard multiple BA sets before and yes, there is a "sound" to some of them. But that is only due to bad implementation. I have heard all BA sets like the BGVP DM8 which have minimal "BA timbre" because it was designed properly. Etymotic's BA driver is insane as well. The Nezha is also a BA earphone majorly. I kind of do hear it in the bass region, just slightly. The bass punch and extension are very good, simply put. But the bass presentation of a BA is different to that of a planar or DD. It is not a bad thing; it is just different. It is similar to the materials chosen for speaker drivers. Each material does impart a characteristic sound unless specifically engineered to do otherwise (and yes, it is done more often than not). I do hear the slight "BA timbre" in the bass of Nezha, but that takes away nothing from the resolution, speed and overall punch that it already provides. I would categorize it as neutral (yet very resolving) bass with a slight hint of that "BA timbre". Except the difference in presentation, Nezha's bass is similar to that of Heyday.
Conclusion
It is the best earphone I have heard it to this day and yes, it is not some hyperbole. I rarely rate something 5 stars on headfi, but this is an easy 5 stars for me. Tangzu knows how to tune stuff, excellent job by them.
