In this review, I’m looking at the TANGZU Zetian Wu planar magnetic earphones. The Zetian Wu features 14.5mm, extremely low distortion and 4th-gen 3D-printed shells. It’s priced at $149.
Disclaimer: This sample was provided by Linsoul for an honest review. All observations and opinions here are my own based on my experience with the product.
The fact that I was a girl never damaged my ambitions to be a pope or an emperor.
Willa Cather
TANGZU Zetian Wu
Table of Contents
Specifications
- Driver: 14.5 mm Planar driver
- Distortion Rate: <1%
- Sensitivity: 100dB (1kHz)
- Channel Difference: 1dB (1kHz)
- Impedance: 16 ohm
- Frequency range: 20-20kHz
- Cable Material: 5N OFC 0.05 * 224 wire
- Interface: 0.78mm 2Pin Connector
- Price: $149


Package and Accessories
- Wu Zetian IEM
- Earphone case
- 5N OFC Cable
- 3 pairs of Silicon eartips (balanced)
- 3 pairs of Silicon eartips (vocal)


Design
Whether you like violet or not, you’d have to admit the Zetian Wu has a striking design. Inspired by the one and only female emperor in China’s history, the Zetian Wu’s shells are crafted using 4th generation DLP 3D printing technology.
The earphone’s shells are resin and are paired with CNC processed Aluminum faceplates. The faceplates have an engraved cloud pattern representing craftsmanship and traditional Chinese culture.

Zetian Wu’s shells are lightweight and have an ergonomic shape based on a large database of human ear shapes. As a result, they fit in my ears almost as if they were custom-made for me. Moreover, they have pretty good passive noise isolation too so you can enjoy your music without distractions.
In addition to the quality shells, Wu comes with a high-quality 5N oxygen-free copper cable. The cable components are all aluminium, including the chin slider. Zetian Wu’s cable handles beautifully: it’s supple, lightweight and doesn’t suffer from microphonics (cable noise).

Sound
Sources used for testing include the xDuoo Poke II, Cayin RU6 and Soundaware M2Pro.
The first thing to note is that this lady requires more driving power than your average IEM. Despite her low impedance (16Ω) and 100dB sensitivity, she likes a beefier source. Nothing extreme is necessary – a dongle DAC or DAP will do the trick.
The TANGZU Zetian Wu has a fairly linear sound signature. The mids and treble are fairly neutral but the bass is somewhat elevated. The end result is a mature but engaging sound that always maintains its composure.
This is a versatile IEM that works well across all music genres. She can provide thumping bass for hip-hop and electronic music and nuanced harmonics for classical works and everything in between.

Bass
In the typical 2022 style, the TANGZU Zetian Wu favours the sub-bass and puts less energy into the mid-bass. She can produce some thundering rumble when necessary but with the strict control for which planar magnetic drivers are known.
The mid-bass is less impactful but tight and quick. It’s closer to neutral and lighter in quantity. Accordingly, the mid-bass doesn’t intrude on the mids but lingering sub-bass notes do bleed a little, imbuing the lower bands with warmth.
Although it’s not offensive, I would have preferred slightly less sub-bass and more punch in the upper bass. However, one can’t deny that it’s a quality bass, even if the tonal balance isn’t ideal.
Midrange
Zetian Wu’s midrange is close to neutral in colour and forwardness. Depending on the music genre they become slightly recessed, especially in old skool hip-hop tracks where there are a lot of 808 sub-bass kicks.
What I really like about the mids is their natural note weight. Transients are fast but rounded enough to sound organic and lifelike. Vocals are articulate yet full-bodied. There’s enough richness in male voices and vitality in female singers to keep you engaged.
Even when she raises her voice, Zetian Wu maintains her composure. She doesn’t get shouty or nasally. Wu Zetian rules the midrange with effective governance allowing for optimum performance; at least in the absence of ebullient sub-bass.

Treble
Perhaps the most impressive of Zetian Wu’s attributes is her treble. Clear and detailed, the treble is remarkably smooth and coherent. It’s neutral in tone, with just a hint of warmth added for naturalness.
Zetian Wu’s treble may lack sparkle but it’s airy and crisp. The extension is excellent and the sheen of hi-hats and cymbals floats into the ether without truncation. You can turn up the Zetian Wu without fear of sibilance or sizzle. Her voice is clear and light but never sharp.
Soundstage and Technicalities
Speed is never really a concern with planar drivers and Zetian Wu is no exception. Note transients are fast but instruments and vocals are rounded enough to avoid sounding digital.
The soundstage has good proportions and is relatively large in both width and depth. Zetian Wu’s instrument separation is excellent. She takes advantage of the spherical soundstage to deliver optimal positioning and precise imaging. As a result, the overall resolution and level of detail are outstanding.
Comparisons

Raptgo Hook X
The Raptgo Hook X (review here) is more aggressive and bold in its presentation. It’s more V-shaped than the Zetian Wu which has a more even expression. It has more bass impact, especially in the mid-bass. Hook X has better mid-bass definition and cleaner leading edges.
The Raptgo has more vibrant and articulate vocals. In comparison, Zetian Wu’s vocals are softer but they’re also more forward in the mix – unless there’s significant sub-bass in the track which tends to dominate the mids on the Wu.
The Hook X’s treble is more vigorous. It’s more energetic and has sparkle compared to the Wu. The extra treble gives Hook X faster and sharper attacks on percussion hits. In addition, it widens the soundstage further. However, that extra energy can be fatiguing over time if you’re sensitive to such an upfront treble presentation.
So, the Raptgo is more dynamic and vivacious and has better clarity. Zetian Wu is more subdued and even. A safer approach compared to the boldness of the Hook X. But for around $100 less, the Zetian Wu is a stellar performer.

Letshuoer S12
The Letshuoer S12 (review here) follows a similar response on the graph above. But in reality, these 2 IEMs sound very different. S12’s sub-bass falls off slightly while the Zetian Wu’s just keeps climbing.
As a result of that (and its upper midrange tuning), S12’s bass is tighter. It has better definition and a more natural ratio of mid-bass punch and sub-bass thump. That’s not to say Wu’s bass is bad. Far from it. But I think with a little tweaking it could have been even better.
S12 has more lift in the upper midrange, giving kick drums more slam and giving pianos and acoustic guitars more clarity. In contrast, Zetian Wu’s tuning brings vocals and midrange instruments to the forefront, even if they’re not as articulate as they are on the S12.
As we see with the Raptgo Hook X, S12’s extra lift in the treble gives it more clarity and detail. This creates a vivid scene while the Zetian Wu is calmer and more organic. S12’s soundstage is a little wider but the Zetian Wu has better forward layering.
Both of these planar magnetic IEMs offer spectacular performance and value. Those who seek an energetic sound with some treble zing will prefer the S12. For the treble-sensitive folk and those who want something more laid back, the Zetian Wu is for you.

Verdict
I knew the planar age of IEMs was coming but I never expected it to happen so suddenly. Just like we saw with TWS earphones, every brand and its dog is jumping on the planar bandwagon. And why wouldn’t they? After all, these drivers sound incredible.
The TANGZU Zetian Wu is an outstanding IEM. It’s built well, comfortable and comes with a high-quality cable. But that aside, it’s one of the best-sounding IEMs in its price range, regardless of driver type. Accordingly, Zetian Wu gets my highest recommendation and earns a spot on my best IEMs list.
