KZ (Knowledge Zenith) is a Chinese audio brand started in 2012, known for making budget-friendly in-ear monitors (IEMs). Their products often include features like hybrid drivers and detachable cables. KZ is popular with audiophiles looking for good sound at a low price, and they’ve released many well-received models like the
KZ ZSN PRO X,
KZ DQ6, and
KZ AS10 Pro.
KZ ZA12The KZ ZA12 is a powerful hybrid in-ear monitor that uses a mix of dynamic and balanced armature drivers. It features a 10mm super-linear dynamic driver and an 8mm high-performance dynamic driver for low and mid frequencies. For the highs and ultra-highs, it uses a set of balanced armature drivers: two 30019 units and one 31736, which is actually a dual BA unit in one shell. This means each earpiece has 5 drivers, not 6 as advertised.
The tuning version
The KZ ZA12 comes in two versions: a standard version with fixed factory tuning, and a tuning version that lets users adjust the sound to their liking.
The tuning version features four small switches that allow you to boost the bass, mids, or treble.
* Switch 1 boosts the bass by 1dB.
* Switches 1 and 2 together boost the bass by 2dB.
* Switch 3 increases mids and highs by 1dB.
* Switches 3 and 4 together boost mids and highs by 2dB.
You can mix and match switch settings to adjust the sound. For example, you can boost the bass by 1dB and the mids/highs by 2dB at the same time. Turning on all switches increases the overall frequency
response.
Cable and accessories
The KZ ZA12 uses a detachable cable system with 2-pin 0.75mm recessed connectors for a more secure fit and added durability. However, unlike the more common 0.78mm standard, this 0.75mm size limits compatibility with most aftermarket cables—especially if you're looking to go balanced. It's an odd choice by KZ that makes cable upgrades more difficult.
The included cable is 1.2 meters long, silver-plated, and features a simple two-strand twist design with a 3.5mm plug. It’s lightweight and has plastic connectors. While not the most durable, it resists tangling and has minimal cable noise. There’s also an option with an in-line mic and remote.
In the box, you get three pairs of KZ silicone ear tips, one pair of memory foam tips, and a metal tool for adjusting the tuning switches. However, the accessory set feels a bit lacking—some extra tips and a carrying pouch would have added more value. At $62, the overall package feels a bit underwhelming compared to today’s competition.
Non Audio stuff
The KZ ZA12 earphones feature a hybrid shell design made of two symmetrical parts—one metallic and one clear resin. The transparent section gives you a peek at the internal components, while the combination of materials adds a touch of elegance. The faceplates have a diamond-like texture that catches the light, along with a decorative KZ ZA12 logo in a handwritten style along the edge.
The ear-shells have a teardrop shape with a smooth, ergonomic inner surface and slightly extended nozzles. They’re very lightweight and offer a secure, comfortable fit, making them great for long listening sessions. Noise isolation is also quite good. Build quality is solid, with clean finishes and tight seams—no rough edges or visible gaps.
Efficiency stuff
The KZ ZA12 has an impedance of 45Ω and a sensitivity of 103dB. While it can be driven by basic portable devices, it does benefit from a bit more power to reach its full potential. For this review, I paired it with the Violectric Chronos and the Chord Mojo, both reliable single-ended sources.
Audio stuff
The dynamic drivers in the KZ ZA12 can produce a “driver flex” effect—a soft clicking sound when the earphones are pressed into the ears. However, this doesn’t impact sound quality or introduce distortion.
Out of the box, the KZ ZA12 offers a fairly balanced tuning. The bass isn’t overly boosted, the mids are well-present, and there’s a slight emphasis in the upper mids that extends into the treble without making the sound too bright.
Sub-bass extension is decent, but it rolls off a bit early and lacks the weight and impact needed for deep, thumping bass in modern genres. Turning on switch 1 slightly boosts the sub-bass, while using both switches 1 and 2 also adds more mid-bass.
With switch 1 activated, the bass sounds well-balanced and suitable for a wide range of music. The mid-bass is mildly emphasized, giving warmth and energy to modern tracks and rock, while still remaining accurate enough for classical music. Bass is clean, well-textured, and doesn’t bleed into the mids.
The KZ ZA12 delivers strong dynamics and impact when called for, but its real strengths lie in bass control and precision. For its price, the technical performance is impressive—the bass is fast, tight, and well-layered, offering clear definition. While it may not have the most weighty or physical texture, it never sounds thin or dull. In terms of tuning and bass performance, the ZA12 stands out as a clear winner in its class.
The mid-range is neutral and transparent, with a mostly balanced tuning and a slight upper-mid boost that adds energy and clarity without causing fatigue. Vocals and instruments are presented as they are in the recording, with minimal coloration. The ZA12 captures harmonic richness well and offers a natural timbre, avoiding the artificial or harsh quality sometimes found in balanced armature setups. Technically, the mids are impressive—detailed, well-shaped, and articulate, without sounding overly sharp or analytical.
The treble of the KZ ZA12 is bright and lively, with lots of sparkle and clarity. It’s well-resolved without being too sharp or harsh. Most listeners will appreciate the added detail and definition, though some might find the treble a bit tiring over long listening sessions.
While you can’t reduce the treble using the switches, boosting the bass can help balance the overall sound. The treble textures aren’t thin or dry, and the tone doesn’t sound metallic or artificial. Although it doesn’t reinvent the wheel, the KZ ZA12 offers a surprisingly detailed and clear treble for its price.
The soundstage feels mostly flat and wide from left to right but is open enough to avoid feeling crowded. Imaging and instrument positioning are average but good enough to keep complex music clear and well-defined.
Conclusion
The tuning version of the KZ ZA12 offers great sound that easily rivals other IEMs in its price range. I would recommend skipping the stock version since it has weak bass and no way to adjust the sound. For just $4 more, the tuning version is an easy choice.
The KZ ZA12 is lightweight and comfortable with solid build quality, but the overall package feels less competitive, and the included cable is a big downside. Still, it’s the only earphone in this price range with tuning switches, making it a much more versatile option that’s worth considering.
-------------------------------------------------------------------------------
The review sample was kindly provided free of charge in exchange for an honest review. I don't use affiliate links. The price of the KZ ZA12 tuning version is $62 and you can buy it from KeepHiFi .
Disclaimer: For various Google indexing reasons, most parts of this review have been processed with an automatic paragraph rewriting tool. However it reads exactly the same as the original content that is available in my website.
