【KZ ZA12】Hybrid 4BA+2DD IEM with Adjustable Switches

Introduction​

KZ doesn’t need any introduction, and nowadays they’re releasing tons of interesting IEMs that really made many change their mind with respect to the brand. Will the ZA12 be no exception?

Disclaimer: the KZ ZA12 were sent to me by KEEPHIFI so that I could write an honest review. This review represents my personal opinion on the set, it isn't promotional or paid content and I don’t get any revenue from the sales of this product.
At the time of the review, the KZ ZA12 were on sale for about $62 at KEEPHIFI.

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Technical Specifications​

• Driver Configuration → 2DD (10mm DD x1 + 8mm DD x1) + 4BA (30019 Balanced Armature x 2 + 31736 Composite Balanced Armature x 1)
• Impedance → 16.5 Ω
• Spec-sheet Frequency Response → 20Hz-20kHz
• Sensitivity → 96 dB/mW @1kHz
• Cable → 1.2m OFC cable with 0.78mm 2-PIN connectors
• Plugs → 4.4mm + 3.5mm modular plugs

Packaging​

The packaging of the KZ ZA12 is the same old and simple small box with a pic of the earphones on the front. It contains:

• The KZ ZA12
• One set of KZ starline tips (S, M, L sizes)
• The usual stock KZ cheap cable
• One pair of foam tips
• User manual

After the Zenith, Sonata and so on, which are shipped inside better-looking boxes and with better accessories organization, it seems like KZ went back to the roots in terms of packaging (unfortunately).

Design, Build Quality, Comfort and Isolation​

The design of the KZ ZA12 follows what KZ has been doing for a long time now, and in fact these look like the Symphony, the Sonata and similar products.
The build quality is pretty good, the isolation is good as well and they are comfortable as well as long as you don’t have very small ears.



This is the switch version as you can see from the previous photos, and here's a sum-up of the various positions:

Cable​

The same cheap cable all over again. KZ, c’mon, time to step up!

Sound​

GEAR USED FOR THE TEST

• DAC: Topping E30
• AMP: Topping L30, Fiio A3
• Mobile phones: Samsung Galaxy S7 Edge, Xiaomi Mi A3, Samsung Galaxy S23 Ultra
• Moondrop May’s DSP cable with PEQ=0
• Dongle: Apple Type-C dongle, Fosi DS2, Hidizs XO, Kiwi Ears Allegro Pro, Tanchjim Stargate 2, Dunu DTC480, Dunu DTC800, Truthear SHIO
• Portable DAPs: Snowsky Echo Mini, Benjie S8/AGPTEK M30B
• Bluetooth DACs: Snowsky Retro Nano, FiiO BTR11
• Bluetooth Adapters: KBEAR S1, KZ AZ10
• Other sources: Presonus AudioBox iONE, Elgato Wave XLR

Amplifier needed?
The KZ ZA12 don’t strictly need a desktop amplifier but they need more juice than your average IEM, so I would at least use a decent dongle.
If you follow the impedance adapter route (I will explain very soon, read below) then you’ll definitely need some power to drive these properly.

Let’s speak about the sound.
I will be speaking about the 1100 configuration (or UUDD if you prefer).
The ZA12 sound very technical, with very good micro detailing capabilities, good resolution, a wide stage that also have notable height for the price, pretty good imaging as well.
Where’s the issue? The overall out-of-the-box tonality, in my opinion.
The upper-mids and treble have some noticeable boost whereas the bass is kept very controlled and this results in a slightly shouty response that becomes thinner the more you increase the volume. In fact, I think this is perfect for those who want a low-volume set for music that has lots of sounds playing in the upper-midrange and treble regions, but if you’re someone who wants something to listen to music on the move, these can be risky since they can get fatiguing quite easily. The vocals sound very forward and I really loved listening to female vocals on these, except for the fact that they can become hot and fatiguing pretty fast. Male vocals, instead, could use a bit more depth and warmth as there isn’t a proper bass shelf to warm things up. The low-end doesn’t have that “wow” factor that I was expecting: the fast decay also doesn’t help at making kickdrums very punchy and incisive, and if you add this to the already bright nature of this set (and the perceivable BA timbre that comes up when increasing the volume) it’s not very easy to recommend this IEM to anyone out there, as only a specific range of users would make good use of this.
BUT… there is a BUT…
I have tried these with a 75ohm impedance adapter and well, these really become another thing. The low-end gets a lot of punch, depth, thickness, and this perfectly counterbalances the upper midrange and treble boost that also decrease a little bit. They still retaining a good sense of resolution and staging and even though they become a bit slower, the tonality is improved by a huge margin and it’s a pleasure to listen them at that point.

Are they something I would use considering my taste and preferences?
If using an impedance adapter wasn’t an issue on the move (and it is, in my case, since it’s not flexible and I don’t want that in my pocket) then these IEMs would be a very good set to keep in my backpack. However, it’s not a plug ‘n play set for me because they still have that thin character even in the bassiest setting, so I would not use it for my daily routine.

Some comparisons:​

KZ ZA12 (1100) vs Truthear HEXA
Straight to the point, the HEXA sound better out of the box: more controlled, slightly less detailed yet a lot more effortless and with a less “forced” resolution. The low-end is also fuller yet very balanced on the HEXA. The soundstage and the imaging are better on the KZ ZA12. With an impedance adapter, the ZA12 become a lot fuller, but they also sound much different than in their original state, with a more V-shaped response and this puts them in another bracket with respect to the HEXA, which instead maintain their controlled, tendentially neutral approach.

KZ ZA12 (1100) vs CCA Rhapsody
The KZ ZA12 are way faster, more technical, more resolving, they have a bigger stage and the imaging is better as well. The Rhapsody have a slightly better timbre overall thanks to the fuller low-end that makes them thicker than the ZA12 (which instead sound thinner and slightly more fatiguing on average). Both have some BA timbre going on unfortunately.
With a 75ohm impedance adapter, the Rhapsody are completely blown away in the low-end region as well, there’s no chance for real.

KZ ZA12 (1100) vs Simgot EM6L
The EM6L tuned much better than the ZA12, and the technical prowess is also slightly better (although not by a huge margin). The soundstage goes to the ZA12, whereas the imaging is mostly on par.
With an impedance adapter, the ZA12 blow the EM6L away out of the water in terms of low-end, even though they become more V-shaped and less “neutral” than the EM6L (not that the EM6L are really neutral, but they tend to sound more “audiophile-ish” with respect to the ZA12 with the impedance adapter).

Final Thoughts​

The KZ ZA12 weren’t able to blow my mind right out of the box, and this is probably because I was expecting much more from KZ, especially considering that I have really liked some of their latest releases (such as the Sonata, Zenith, CCA Trio and so on).
The sound is thin for the most part, with great technical ability yet with a bright tonality that is not properly counterbalanced by a healthy amount of low-end.

The impedance adapter really changed my mind, though, and I was able to enjoy the ZA12 like I’ve done very few times with a KZ IEM: the 75ohm adapter gave them a real life, with a super deep and punchy bass, a warm and slightly recessed midrange and a detailed, sparkling and vivid treble that creates a very dynamic sound counterbalancing the rich low-end.

I can’t give the ZA12 a super positive rating, because they aren’t something you pick from the box, connect to your phone and call it a day, but if you’re able to snag a cheap impedance adapter for a couple dollars, then the ZA12 get my instant recommendation as a super fun and competent set that can really rule its price range.
So I’ll put it this way: this set scores a solid 3.5/5 on my side, which is an average between a 3/5 (which would be my out-of-the-box vote) and a 4/5 (which would be the vote I’d give with the 75ohm impedance adapter).

KZ ZA12 Review: Tunable and Affordable​

KZ is a staple in the ChiFi (Chinese Hi-Fi) market. They’ve been releasing budget-friendly IEMs at a blistering rate. From among the salvo of fresh releases, a few interesting IEMs have stood out. Today we’re looking at one of them: an IEM towards the top-end of KZ’s repertoire, the ZA12. It boasts three (or four, depending on who you ask) balanced armature drivers and two dynamic drivers per side, for a total of 5 (or 6) drivers per side, all for under $70. Oh, and the ZA12 also packs four tuning switches per side. Is KZ’s new hybrid too good to be true? Let’s get into it.

You can purchase the KZ ZA12 from Keep Hifi, here, for $65.

About My Preferences: This review is a subjective assessment and is therefore tinged by my personal preferences. While I try to mitigate this as much as possible during my review process, I’d be lying if I said my biases are completely erased. So for you, my readers, keep this in mind:

• My ideal sound signature would be one with competent sub-bass, a textured mid-bass, a slightly warm midrange, and an extended treble.
• I have mild treble sensitivity.

Testing equipment and standards can be found here.

The Big Picture​

Pros:

• Tunable sound signature
• Solid eartips variety
• Analytical midrange and treble
• Precise, punchy bass
• Appealing cable

Cons:

• Lacking in bass emphasis
• Very picky about sources
• Questionable material design
• Limited aftermarket cable compatibility
• No included case
• Misleading advertising

Tech Specs​

• Drivers: 10mm + 8mm DD, 2x 30019 BA + 1x 31736 BA
• Impedance: 45 Ohms
• Cable standard: 0.75mm recessed, 3.5mm terminated
• Cable wire: Silver-plated copper

Sound Signature​

Sonic Overview:​

The ZA12 is tunable and has way too many tuning combinations to cover in any intelligible way. I’ll be focusing on my favorite tuning, which is (1 ON | 2 ON | 3 OFF | 4 OFF).

The KZ ZA12 is a bright and analytical IEM. There’s no tuning you can switch to that will change that fundamental property. The ZA12 does, however, demonstrate a clear preference towards higher-powered sources. Average or weakly-powered sources will worsen lower register performance, making the ZA12 sound even brighter. Once set up correctly, one can begin to hear the ZA12’s gently-emphasized bass. The ZA12’s midrange is partially recessed in the lower mids and emphasized in its upper mids. The ZA12’s sound stage is wide with an above-average depth. With my preferred tuning selected, the ZA12 is surprisingly coherent, vastly outperforming many of KZ’s legacy products (in this respect).

Sonic Breakdown:​

Treble: Songs used: In One Ear, Midnight City, Outlands, Satisfy, Little One, Show Me How To Live (Live at the Quart Festival), Bittersweet Symphony

The ZA12’s treble is highly configurable, but in any given state, it remains well-toned, if not slightly stiff. My tuning of choice has the least treble emphasis, as I found the other tunings were brighter than necessary to bring out maximum detail retrieval. The ZA12’s upper register is precise and quick, in typical balanced-armature fashion. It is sibilance-free, making it well-suited to a wide variety of genres and mastering styles. It’s well extended too, giving music a strong sense of air and decent “sparkle”.

Regardless of driver count shenanigans, the ZA12 does seem to leverage its array of BAs to deliver a solid sound stage. It is wide, with solid depth and competes at the top of its segment in that respect. And while I do think that the ZA12’s treble will make a lot of listeners happy, my preferences would have KZ cool off the 8Khz range a little. I find that my most-resolving and widest-sound IEMs manage that segment of the sound signature more delicately (see: CTM Da Vinci X, Kiwi Ears Orchestra Lite).

Midrange: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Dreams, Too Close, Little Black Submarines, Bohemian Rhapsody, Cash Machine, Chasm

The ZA12’s midrange is recessed, but not veiled. This gives it a slightly-cool tone, somewhat deviating from “neutral”. This style of tuning is compatible with a plethora of genres, but will best-suite listeners who aren’t partial to warm or actually-neutral IEMs. According to KZ, the ZA12’s mids are generated from a combination of its two dynamic drivers and its balanced-armature array. This indicates the use of some type of cross-over, and thankfully the ZA12 sounds largely free from discontinuity or weird cohesion issues.

At five drivers per side, one would expect the ZA12 to be highly resolving, and they’d not be disappointed. In the sub-$70 range, the ZA12 competes with the very best, delivering large-scale detail retrieval, dense texturing, and midrange articulation. Flagpole Sitta’s guitars are crisp and discretely staged behind the vocals — which are themselves well-articulated. This track’s mastering is particularly dry and highlights the ZA12’s only real flaw — there is no combination of switches you can flip that add just a little more warmth to the midrange. As a results, tracks like this sound clean and detailed, but lack the last drop of weight needed to genuinely sound organic. Mid-centric hybrids have often struggled on this front, though some, such as the Rose QT-X, perform nicely.

Bass: Songs used: Moth, Gold Dust, In For The Kill (Skream Remix), War Pigs (Celldweller Remix)

For the first few hours, I really did not appreciate the ZA12’s bass. Even at its most emphasized tuning level, I found it lacking in strength. But, as I’ve adjusted to its sound signature and found more-compatible sources, I’ve found myself appreciating its tone and control more and more. The ZA12’s bass is gently lifted past its lower mids, peaking at around 100Hz. This gives its sub-bass a solid, well-weighted tactility while not adding unnecessary bloat to its punchy mid-bass. This tuning won’t satisfy bassheads, but I really don’t think that was the goal here.

Electronic genres, while not fully realized by this level of bass response, are still enjoyable to listen to. The ZA12’s mid-bass routintely lands solid, punchy impulses from Gold Dust’s filthy bass lines. Its sub-bass does a great job of filling out the track with a well-shaped rumbly sensation that clearly articulates the deepest elements of the track. War Pigs (Celldweller Remix) is a more technically-challenging track, though the ZA12 doesn’t struggle with it either. Traditional bass elements such as the track’s bass guitar are resolved cleanly and with solid shaping. The synthetic bass elements present during the drop are also well-textured and punchy, but again, a little less emphasized than I’d like for this genre.

Packaging / Unboxing​

KZ’s packaging is, as always, minimal and compact. There’s no flash or style, its all business. Whether this is a strategy to minimize cost or simply a preference for the brand’s designers, who knows. Either way, KZ demonstrates throughout all of their product choices that the only thing that matters to them is how their IEMs sound.

Build​

Construction Quality​

The ZA12’s shells are built from a mixture of plastic and metal. They look nice and feel solid in the hand. Underneath its transparent plastic shells lies a forest of wire and driver. KZ’s marketing material lists the ZA12 as having six drivers per side, for a total of 12 drivers. That’s a bit a misnomer, as KZ is counting a dual-diaphragm BA driver as two separate drivers. This isn’t how virtually every other manufacturer counts their drivers and is misleading at best, and a lie at worst. The true count, by industry standards, is 5 drivers per side for a total of 10 drivers. This is typical KZ behavior, and once again I strongly suggest that KZ resist the urge to embellish their products’ spec sheets like this.



On the back face of the shells you can find the ZA12’s tuning switches. They’re embedded in a plastic plate which sits in a cutout in the metal part of the shells. On the top face of the shells, you will find extruded 0.75mm sockets.

KZ’s material design has a history of premature failure and I was hoping that the ZA12 would represent a shift in their priorities. Unfortunately, that’s not the case. The ZA12’s nozzles are made out of a thin plastic. Some implementations of plastic nozzles are ok, but the ZA12’s is far too thin for comfort. Not only that, the ZA12’s debris filter appears to be made out of paper, or some wax-coated fiber. These types of filters are highly susceptible to deterioration from moisture exposure — a major problem for those who live in rainy or humid environments. Beyond that, thin plastic nozzles are highly likely to crack and crumble over time as they are exposed to humidity and heat-cycling.



KZ, to my frustration, has still not outgrown the 0.75mm recessed cable standard. Yes, it is technically standardized, but not well-adopted. The 0.78mm standard is far more common. Why has KZ refused to switch over? No idea. That said, I do generally like the ZA12’s included cable. It is a flat-braided silver-plated copper two-strand cable with a right-angled 3.5mm termination. The 3.5mm shell, Y-splitter, and 0.75mm pin shells are housed in plastic. There’s a decent amount of strain relief on the 3.5mm shell, but not much on the Y-splitter. The Y-splitter is not in that much danger of over-wear, but it would still be a nice if KZ added a dash of additional mechanical robustness.

Comfort​

Disclaimer: comfort is a highly individual metric — no two people will have the same experience.

The ZA12 is of average comfort. Its shells are sculpted with ergonomic intent, but there’s only so much you can do with this many drivers. I was able to get my work done without discomfort, though I took a 5 minute break every 60 minutes for the sake of my hearing health.

Accessories​

Comparisons​

1: iVipQ Shanhai ($65)

The Shanhai is a 3x dynamic-driver IEM that targets a much more midrange-focused signature. It has as less-emphasized treble, warmer midrange, and slightly stronger mid-bass. The Shanhai’s sub-bass is similarly well-extended, though it lacks the emphasis you get from the ZA12. The ZA12’s hybrid driver configuration gives it an edge in transparency and treble-based detail retrieval, but at the cost of sounding less organic and less cohesive.

These are very different IEMs — from sound design to material choices to accessories, almost nothing is in common. The Shanhai features a thicker resin shell with metal nozzles. It uses the highly-standardized 0.78mm cable standard and includes a thick, robust 4.4mm cable in the box. The Shanhai also comes with a semi-hard carrying case that is spacious and functional, while the ZA12 comes with nothing. Again, these two IEMs target very different crowds and utilize very different tunings — but for those like me who want warmth and organic timbre, the Shanhai is the way to go. For those who don’t mind KZ’s material downsides, the more V-shaped and resolution-oriented ZA12 offers a good value.

Conclusion​

The ZA12 is a solid IEM, but I struggle with KZ as a company. Their reliance on deceptive driver-count claims and loyalty to an uncommon cable standard are an ongoing frustration of mine. KZ’s single-minded focus on driver count, and to a lesser degree sound quality, yields some impressive performance, but at the cost of long-term durability and reliability. Thankfully, the ZA12 is not a $500 IEM — it’s a $65 IEM. With that in mind, I think there’s a crowd that will still appreciate the ZA12 for what it is: a competent, interesting, and imperfect, earphone. For those with more-traditional expectations for warranties, build quality, and advertising ethics, you may want to look elsewhere.

Who This is For​

• Buyers on a budget who don’t mind compromised build materials
• Listeners who want an analytical, but not dry, sound signature
• Users who do not frequently change cables
• Listeners who enjoy tinkering with their IEMs

Who This isn’t For​

• Consumers who value material design or live outside of a cool, dry climate
• Those who use low-power sources
• Bass-heads or listeners with mainstream preferences.
• Buyers who value brand honesty and transparency

As always, happy listening!

Disclaimer: @KEEPHIFI provided me with a review unit. All thoughts and opinions are my own.

Introduction​

In the sea of confusing product naming of KZ IEMs, the ZA12 ($58 for standard, $65 for switch version) is another entry into their ZA* line, which consists mostly of higher driver count hybrids (usually 8 per side). As the name suggests, there are a total of 12 drivers used in the IEM, 6 per side (2DD + 4BA), making it the lowest driver count IEM in the ZA* lineup, exactly the same config as CCA Rhapsody.

That said, the ZA12 is quite a departure from what I normally expected from a KZ-style tuning, showing an exciting promise in the direction of the brand in my eyes. But will it give enough to justify its presence in the extremely competitive IEM market now? Let’s find out!

Packaging, Build & Specifications​

Driver configuration:

• 10mm dynamic driver
• 8mm dynamic driver
• 30019 balanced armature x1
• 31736 balanced armature x3

Impedance: 45Ω
Sensitivity: 103dB
Frequency response range: 20-40,000 Hz
Connector: 0.75mm
Cable material: SPC
Plug: 3.5mm

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To be honest, nothing’s really special about the packaging. It’s the standard fare from the hundreds of KZ IEM packaging, with 3 pairs of Starline eartips (S/M/L) and the foam eartips. The stock cable is the same SPC cable they always include from their cheapest to their most expensive cable. I would expect at least 50% of the buyers of KZ IEM will eventually replace the cable, which I also recommend.





The design is quite striking, bordering on gaudiness. I find it quite pretty, but the actual finish in my hands is quite rough. There is a major driver flex on both sides when I put the IEMs in, which is pretty disappointing, but it doesn’t really bother me when the music starts playing. I can say I’m quite disappointed at the build quality, but after listening to it, I think I might be able to forgive these issues.

Sound Impressions​

Sources: Snowsky Echo Mini, FiiO JM21, FiiO M23, FiiO K11 R2R, SMSL H300+D300 stack
Setup: stock cable, stock Starline L eartips
Music Sources: Youtube Music, Tidal, Lossless FLACs

The IEM has undergone a 24-hour burn-in at a medium volume prior to the review.

Impression from listening is a very subjective experience depending on individual ear shape, choice of eartips, music library, and personal preferences, so your experience may vary. I personally listen mostly to pop (J-pop especially), jazz, some rock, and very limited metal and EDM.

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I was pretty surprised at how modest the bass is with the ZA12, even with the bass set to the highest settings. The uppermid is also way more controlled, compared to the extremely V-shaped tuning in old KZs. I would describe ZA12 as neutral-bright with a slight midbass boost. All the tuning settings are generally within the same ballpark, with just 1-3dB difference.

The switches are pretty weird. Despite having 4 switches, it only has 9 different tuning combinations (theoretically 16). How so though?



The reason is that the even switches (2 and 4) overrides the state of the odd switch. So, the value of switch 2 or 4 are on, the states on switch 1 or 3 do not matter. The nine tuning combinations are:




My favourite tuning is the “bass +2, treble +0” setting, with which I will proceed with my review.



The bass is very tactile and snappy. There isn’t very obvious bleed into mids, and it can slam whenever the track demands it, especially if it is driven well. While it is not a basshead level impact, it does have enough texture and body to keep you engaged. There isn’t much resonance and trailing end to the bass notes, making it very clean and analytical, but in some tracks I may find myself wanting some more rumble and grunt in the subbass. Case in point, the downpitch-shifted guitar “bass line” in “Seven Nation Army” became pretty noticeably "guitar" than "bass", but I can still find the overall experience very enjoyable. Moving to “Through the Fire and Flames”, the quicker bass can really keep up with the inhumanly fast drums here, but indeed the rumble is still quite missing.

I have to say, ZA12 mids is one of the best I’ve ever heard from a KZ or CCA set. It’s generally neutral, with decent clarity and details. The positioning of the vocal is quite forward and the timbre is very natural. Both male and female vocals are equally well reproduced, with little to no sibilance, depending on the track. Listening to Vaundy’s “Kaiju no Hanauta”, the vocal stands out quite well with some syrupy quality to the timbre. Hoshimachi Suisei’s “XION” shows the limits of my sibilance tolerance and yet, I still enjoy the experience very much.

The treble in ZA12 is very quite energetic with a good amount of air and amazing resolution. It just stops short of being too bright to my ears, but I can understand if some people might find this too bright. I think, in terms of sheer resolution, it can keep up with IEMs from the 100-200 dollars range. That alone is pretty impressive to my ears. In Monkey Majik’s “Change”, the intermingling of the electric guitars/bass and the Yoshida Brothers’ shamisen are well separated here, with no sharpness in the notes.

Technicalities-wise, the standout is definitely the resolution. This is probably due to the very forward positioning of the sound, which unfortunately also restricted the soundstage slightly. The imaging is still decent though, and the layering is still excellent. Timbre is relatively natural and the coherence is surprisingly good.

Bass: tactile, snappy, fast, tight
Mids: neutral, detailed, vocal-forward
Treble: airy, resolving, no sharpness/sibilance
Technicalities: excellent resolution and layering, decent imaging, ok soundstage, good coherence, natural timbre

Power Requirement and Pairing Suggestions​

While it is quite easy to drive it decently, ZA12 scales pretty well when paired with a more powerful source. The 45Ω impedance allows it to tolerate more beefy amps, and warmer sources are preferred.

Select Comparisons​

Truthear Hexa ($90):
I think when Hexa came out, it was considered to be a technical bang-for-the-buck set, albeit with some issues with kinda plain tonality. I think ZA12 now replaces that position, with arguably better tonality. The mids and vocals are thicker in ZA12 and the resolution is quite a bit better. If anything, I would say the build quality is a better on the Hexa, but otherwise, I would prefer the ZA12 in terms of sound quality.




Tangzu Fudu Verse ($90):
Usually, I would move on to recommend Fudu for those who find Hexa to be a bit too plain. Fudu is a thicker, warmer version of Hexa, with similar technicalities. ZA12 is quite a bit more reserved in the bass, but overall resolution and layering is done better on the ZA12. Fudu became too laidback when compared head-to-head. I would go with ZA12 for a more critical listening, and Fudu for a more relaxed listening.



CCA Rhapsody ($52):
This is probably the most direct comparison within KZ's own lineup. Personally, I find Rhapsody's bass too detached and loose, complete opposite to the ZA12, with better mids and more extended treble too. I pretty much prefer the ZA12 over Rhapsody for most tracks in my library.

Conclusion​

KZ ZA12 is one of the best releases from KZ in recent memory. Despite having some issues with the build quality, I think the sound quality can make up for it, especially at this price point. To be honest, I would rather KZ increase the price to somewhere around $90-100 and build it better (which they did pretty well with CCA HM20). So, with all that, I can’t give it higher than 4 stars, but I can still recommend this to those with very limited budget.

Beautiful Design, But Disappointing Sound​

The KZ ZA12 is a visually stunning IEM with a beautiful shell that immediately grabs attention. Internally it has a nice hybrid configuration of 2xDD and 4xBA’s. Priced in the mid-range of KZ’s offerings, it also comes with tuning switches that also promise customization for different sound preferences.

I had high hopes for the ZA12, as one of the first IEMs I reviewed this year and especially when I unboxed it and checked out the build quality of the shell. And since I am also a sucker for tweaking audio with tuning switches so this IEM seemed like it would be perfect but as you will see there are some aspects of the ZA12 that were just not for me.

But as always, I would encourage people to try various IEM’s and sound signatures and the ZA12 might still be the perfect you might like, so read on find out what you can expect.

But first lets get into that unboxing experience.

Unboxing Experience​

The unboxing experience for the KZ ZA12 is straightforward and functional, typical of KZ’s packaging style:

On the back of the box you the specifications:


Removing the box from the sleeve reveals the ZA12’s:

And they really are the star of the show with a gorgeous see through shell:

Taking all the contents out of the box:

• The ZA12 IEM shells
• A detachable cable with a standard 2-pin connector
• Three pairs of silicone eartips (S/M/L) and a pair of foam eartips
• A simple user manual.

The packaging does its job, but the focus here is clearly on the IEMs themselves, which look gorgeous with their translucent shells and intricate internal design.

Design, Build Quality, and Comfort​

The KZ ZA12 is a beautifully crafted IEM with a premium-looking shell that combines aesthetics with durability here are some videos showing it from different angles:

And here it is from another angle:

Tuning Switches​

I am a sucker for tweaking the sound of IEMs and do love to hear the differences tuning switches but I will describe the sound you can expect from these switches later in the review:

There is a sheet provided with details of how each switch affects the sound signature:


Basically the 2 on the right can tune the bass to different levels and the 2 of the left will tune the treble. The default sound signature is basically when all are up, so lowering them either lowers the bass or the lower treble depending on which pairs of tuning switches you lower. This would be amazing configuration if say the default sound signature was more ‘Harman’ as I might actually lower the bass slightly to my preference and possible also lower the treble but as you will see the default sound signature is very treble focused.

Shell design​

The design showcases a semi-transparent body, allowing a glimpse of the drivers inside:


I always think that a clear shell adds a sense of sophistication to the overall look where you can see the internals easily:

Comfort​

The ZA12 is extremely comfortable for extended listening sessions, with an ergonomic shape that fits well in my ears. The stock silicone eartips provide a decent seal, the extra provided foam tips work well but as with many IEMs, experimenting with aftermarket eartips can provide some subtle enhancements to the fit, sound isolation and sound signature.

The Nozzle is fairly large, but I think it should still be very comfortable for most people:


To get an idea of the size of the nozzle and shell, here is a short video comparison with Truthear Zero Red, Moondrop Chu II and the KBear KB02:

Cable​

The included detachable 2-pin cable is of decent quality in this price range, though it feels somewhat basic compared to the premium appearance of the IEMs.

Fortunately, the 2-pin connection allows for easy cable upgrades if you want to swap.

Sound Impressions​

While the ZA12 excels in design, its sound signature is a major letdown for me. The overall tuning is V-shaped but with extra treble emphasis that can make listening a little fatiguing over time but will initially sound pretty detailed. The tuning switches, which provide some customization options only slightly balance the overall sound signature, but for those interested I felt the UUDD worked the best for me but still not that balanced but these impressions below are with these UUDD configuration.

Bass​

The bass is good but not particularly noteworthy. It has decent extension into the sub-bass but lacks the impact and texture that would make it stand out. 2 of the tuning switches affect the bass making it sound more neutral but overall the bass mostly feels somewhat overshadowed.

Test Tracks:​

• “Billie Eilish – Bad Guy”: The bassline is present but lacks the punch and fullness that make the track engaging.
• “Hans Zimmer – Time”: The sub-bass rumble is decent but not as immersive as I would have liked.

Midrange​

The midrange is clear and detailed, with good vocal presence. However, it feels slightly recessed compared to the elevated treble, which can cause some imbalance in the overall sound.

Test Tracks:​

• “Adele – Someone Like You”: Vocals are clear but lack the warmth and body needed for a more emotional connection.
• “Fleetwood Mac – Landslide”: The acoustic instruments are rendered well, but they can sound slightly thin due to the treble emphasis.

Treble​

The treble is where the ZA12 falters the most. It is overly emphasized and can sound harsh, particularly on tracks with bright or sibilant elements. And the 2 tuning switches aimed at changing the treble only slightly decrease the treble, which in my opinion detracts from the listening experience. But this type of tuning can sound extremely detailed with some tracks, so might be an interesting option to have in an IEM collection to hear something you have not heard with other IEMs.

Test Tracks:​

• “Vivaldi – Four Seasons: Spring”: The violins sound overly sharp and fatiguing.
• “Daft Punk – Contact”: High-frequency details are present but overly aggressive.

Soundstage and Imaging​

The soundstage is average, with a moderate sense of width and depth. Imaging is decent, with clear instrument separation, but it’s not enough to compensate for the treble-heavy tuning.

Specifications and Measurements​

Measurements:​

Note: The following measurements were taken with my 711 clone coupler. They are available on my measurement database: here

Frequency Response​

The frequency response measurements show a significant treble peak, which aligns with my subjective impressions. The effect of the switches can be also seen in this comparison with the default UUUU configuration compared with the slightly more balanced UUDD configuration which was my favourite:

The bass and mids are reasonably well-balanced, but the treble peak dominates, making the overall sound signature fatiguing even with the treble reduced a little with the switches.

Distortion​

Distortion levels are low:


And as a percentage it is still very low showing a slight little increase in the treble:

Tuning Switches​

Here is a comparison of some of the tuning switches to give you an idea of how they affect the sound:

From the above graph you can see that it is best to keep the bass switches up and the treble ones down.

EQ Recommendation and some comparisons​

I do love various sound signatures and I believe everyone should own a few different IEM’s with different sound signatures, it is one of the great pleasures of current price of amazing IEMs that you can have at least one with a Harman tuning, a new Meta tuning, a V-Shaped tuning, a Midrange focused IEM and a Bass ‘monster’.

So I guess without EQ the question is do you want a treble focused IEM?

But I struggled to find some other IEM’s that I have reviewed that focused on the treble, here are a few:

But even these the ZA12 has the most treble with the best switches setting.
And then comparing with some recent popular IEMs you can see that ear gain region has way too much treble:

So, I think the major problem with the sound signature of the ZA12 is the ’tilt’ and one very simple way to EQ away this tilt would be with a Hiby device like the R1 that I recently reviewed with effectively has a ’tilt’ built into its MSEB EQ tool.
But using standard PEQ even just using 2 PEQ filters can effectively transform this IEM

This EQ is effectively continues the good work of the tuning switches by increasing the sub-bass a little more and decreasing the ear gain region of the treble to ‘harman’ levels:

Code:

Preamp: -5.1 dB
Filter 1: ON PK Fc 24 Hz Gain 5.1 dB Q 0.500
Filter 2: ON PK Fc 2400 Hz Gain -4.9 dB Q 0.900

With this EQ in place (and it really is just 2 very simple filters) you can have a very nice listening experience with a very nice looking and comfortable IEM.

Rating​

I have given the ZA12 a pragmatic rating of 3 stars, while I liked design, the comfort of the shell and the cable is decent for the price but its sound signature left me underwhelmed, especially given the tuning switches I was hoping I could tame that treble but unfortunately while the 2 treble switches help with the in balance of the sound it is still a very treble focused IEM. But with some simple EQ tweaks you can easily tame this “treble monster” and have gorgeous looking IEM that then sounds excellent.

Conclusion​

The KZ ZA12 is a beautifully designed IEM with a lot of potential, but its overly treble-heavy sound signature makes it difficult to recommend without some EQ adjustments. While the tuning switches and multi-driver setup are appealing features, they ultimately fail to deliver a balanced and enjoyable listening experience.
If you are someone who enjoys a bright sound signature or doesn’t mind some EQ tweaking, the ZA12 is still worth considering. However, for those seeking a more balanced or bass-forward sound, there are better options in this price range.

KZ ZA12's build quality is excellent, sporting a gorgeous bling faceplate, alas as usual (at this price point) the included accessories are best avoided. Comprised of BA's + 2 DD's, the hybrid's crossover renders tracks very fast, hence there's no lag in dynamic cohesion, akin to that of a single DD.

Micro detailing really stands out, which perceptibly increases your sense of engagement and immersion.
Having an extra DD, what's instantly noticeable is there's no bass boom whatsoever. Plus the obligatory metallic sheen, associated with KZ tuning has now been totally circumvented. If I'd blind tested the ZA12 I wouldn't have guessed they were KZ.

The shells appear a tad more premium, smaller graphics lettering looks far more refined than previous sets, which were emblazoned with huge tacky logos. Their fit is fairly snug albeit rather large sized. Driver flex is initially an issue with this set, which ameliorates once you get used to them.



Bass
In comparison with previous KZ iterations the Hydro & Rhapsody, the ZA12 balances out the bass. Hence bass boom is no longer present. They're a set not for bass-heads, as now bass doesn't step all over or bleed into the mids. Texture of the bass sounds authentic, alas it's quantity could be elevated in the mix & sub-bass definitely needs to be boosted via EQ!

Mids
The midrange frequencies are no longer recessed as was the case with Hydro & Rhapsody, & the veil has now been lifted, as the mids join in the mix, elevating the dynamic fidelity and non metallic tonality. The improved authentic timbre is amazing for all genres, male and female voices, excelling when listening to electronica & complex binaural soundscapes.

Treble
Resolution is absolutely superb! There's no longer present, the shackles present of a V-shaped signature, as there was in the case of the Hydro & Rhapsody. The highs now have a good extension, with zero transient peaks or harshness. Micro detail rendering is excellent; & there's a good sense of "air" which helps to convey that "live" gig experience I crave!


Soundstage & image:
Soundstage width, height and depth is fairly average, alas the ZA12 manages to render the directionality of the sounds particularly well. Imaging/separation of instruments even in busy tracks is very impressive. They do have an addictive quality, due to the prowess of their technicalities. Acoustic instruments especially in Jazz & Classical really shines on this set!



Conclusion:

The ZA12 were touted as the Rhapsody Pro & they fulfil this tag & then some, elevated beyond any KZ set I added in 2024, so Kudos goes out to the tuners. Alas with KZ releases there's invariably a caveat to be taken into account.
Driver flex is in this set is unfortunate but not necessarily a deal-breaker. Over time the awareness of this issue appears to reduce somewhat. It's frustrating because in this price range, there is honestly very little to dislike about this set.

Hopefully in the next iteration they'll include rear ventilation holes for the DD's? If they also increased the bass quantity a tad & boosted the sub-bass bigtime, then KZ could easily have a winner on their hands!!

They're a set I always return to in my rota, as their larger shell size reproduces the sense of a speaker cabinet system. In that sense they pair up well when critical listening, in contrast to recently acquired full-sized cans. They certainly pique my interest regarding the flagship KZ Sonata, which I'll audition for sure at Canjam London this year!!

This is a first for me… reviewing a KZ IEM. Interesting. This company has come a long, long way. After all of the controversy they’ve been involved in over the years, it seems like they just keep going with horse blinders on, racing to this finish line that they can never cross. Constantly releasing new sets every week with marginal improvements, hoping something sticks. Well, I think the ZA12 deserves some spotlight time here. It's a good set. Especially considering the price. After boycotting KZ for years, I finally decided to buy a pair from them a few weeks back, the Castor Bass edition which is also a pretty good set that sounds fun and bassy but with that, comes coherency issues and a slightly glare-prone upper mid-range and thin lower mid-range. Still, they're $18 USD... It's hard for me to complain and nitpick a pair of IEMs so heap, relatively speaking of course.

Recently, coincidently, I was offered a review unit of KZ's newest hybrid offering, the ZA12 by the fine people over at @KEEPHIFI - a very special thanks to them for offering a unit for review! They've been nothing but kind, cordial, understanding, and patient. I was very upfront with Vivian from the beginning with my way of reviewing. No script nor any specific points from the manufacturer or retailer were given to me. I was simply asked to share my thoughts on the set so I have to shout Vivian and the rest of the team over at KEEPHIFI out for that.

I’ll note that I have the tunable version and I’ve been listening with the UUDD configuration, aka, more bass. II should also note that I’m listening to the first initial release of this IEM, as KZ is known for its retunes.

If you’d like to pick up a pair for yourself, I highly recommend working with KEEPHIFI on the purchase. They also have an Amazon store for US residents for quick shipping!

https://www.amazon.com/sp?ie=UTF8&seller=A1C56YBYGER9K1&asin=B0CRHDNPF8&ref_=dp_merchant_link&isAmazonFulfilled=1

Their international storefront is here;

https://keephifi.com/?srsltid=AfmBOopwy3rXNeoJ_GTX08KlSuLe1rnhkQlWCG32Fo-jl6qQswijSLK2

Technical Specifications - Price - $58.00 - $65.00 (Tuning and non-tuning version/with mic or no mic)
• Model: KZ-ZA12
• Frequency Range: 20Hz–40kHz
• Impedance: 45Ω
• Sensitivity: 103dB
• Plug Type: 3.5mm
• Cable Type: Silver-plated
• Cable Length: 120±5cm
• Pin Type: 0.75mm

Sources
- Apple Music Streaming Hi-Res Lossless when available -> SMSL MDA1 RAW -> SMSL SH-9 or Schiit Midgard
- iPhone 16 Pro Max wired or BT -> FiiO BTR17 (No PEQ)
- iPhone 16 Pro Max wired -> Fosi DS2

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I’m not going to post my playlist as I didn’t find myself using my usual playlist with this set. As some of you already know, my preferences lean heavily toward the bass-biased side. This set is not tuned for the bass aficionados. But that doesn’t mean it’s not enjoyable… I found myself enjoying a lot of acoustic tracks with female vocals being front and center. The likes of Indigo De Souza, Mim Jensen, Sweet Pill (Their unraveled album sounds great with this set), Ethel Cain, Superfan, Kylie V, Skullcrusher, Le Ren & more were some of the artists that stood out to me. I also did a bit of source rolling and the ZA12 sounded good on most of my devices but I focused more so on my BTR17 and the Schiit Midgard this time around. Both provided a slightly warm and mid-range/vocal-centric sound that are both enjoyable in their own ways. I should also note that I listened with a lower volume than usual, and for good reason. The ZA12 is, as I said, a brighter leaning set meaning for my HRTF anything above mid-volume does exhibit some excess glare and overly forward treble elements, like cymbals for example. Certain female vocals also can get a bit hot if you’re not paying attention to your volume level. I’m going to try and explain the balance this set is going for using some specific music references from this point forward, rather than breaking the sound down by its individual elements (bass, mids, treble). This isn’t my idea so I can’t take any credit. I’ve seen a few others use this technique to great effect and I’d like to give it a shot myself so, here it goes.

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Viking Funeral by Lacuna has a spacious sound to it, especially that intro. It’s not the busiest of songs in terms of layering, most of my library isn’t, and I think that’s where this set excels. The vocals have a slight distortion to them but they still come off as clear, crisp, and mostly natural. Detail retail on all of the individual instruments is quite high, the bass guitar cuts through the mix nicely, providing a driving force in the song that adds some cohesion, bringing it all together. The Electric guitar riffs towards the middle of the song also come off as perfectly placed in the mix and never come off as harsh. Then there’s the violin that comes in… it sounds far back in the stage adding to the sound stage effect this set presents. To my HRTF it’s both deeper and wider than average. Where it falls apart somewhat happens during big cymbal crashes. They’re overly crunchy and too forward compared to the rest of the mix, taking away from their resolution. The bass is on the lighter side, the bass kicks are audible, but not forward enough to balance out the bold cymbals. Overall, I’d say it’s an enjoyable listen just as long as you don’t crank the volume too far to the right.


Dog Song by Sweet Pill is a song that really stood out to me during my time with the ZA12. This song is a bit of a cheat code for IEMs, the entire album this song comes off of, Unraveled, is mastered so beautifully that I fell in love during my first listen. It’s perfectly warm tilted without losing ANY of the details. Drum kicks are wonderfully bouncy and deep. The vocals sound so life-like and resolute, if I close my eyes it feels like I’m in the room with the band and I’m front and center about 15 feet away. Nothing steps out of place here, and I’d say this is a huge highlight for this set. It’s almost like this song was mastered and produced for a set of IEMs with this tuning, mid-centric. It’s dynamic, crystal clear, powerful, and honestly, very good. I’m failing to find a fault in this song on the ZA12.


Only Got Myself by Mim Jensen is another great song this set excels with. This song is again mastered a touch warmer which helps the ZA12 not come off as harsh in any part of the recording, mostly. The imagining stands out to me in this song. A little bit before the 2:00 minute mark, this rim shot comes in that plays in the lower left of the stereo image and it’s almost uncanny. Remember when I said the ZA12 doesn’t come off as harsh in any part of the recording, mostly? Well, towards the middle part of the song prior to the tempo change, the vocals hit a bit of a crescendo, and even with mid-volume, a touch of glare sneaks in on those really high notes. Otherwise, around the 5-minute mark when those big drum kicks come in, they come across as big and bold with the guitar solo following close behind. It’s mostly in the right channel and bleeding in a touch into the left channel, but then the rhythm guitar is keeping pace in the center channel, and man, all the elements of the song come together so well in the ending seconds.


Younger & Dumber by Indigo De Souza is a beautiful song. I sat back and just listened to it first, then went back and started writing. Indigo’s voice is wonderfully textured, all of the little details like lip smacks and breaths in can be felt through the recording, The same goes for the sliding fingers on the acoustic guitar strings. A little easter egg I think I can hear happens right around 1:25 where someone is either resetting their instrument or shuffling around in the background and I can, almost literally, hear it behind Indigo singing. I think this song really highlights the stage magic this set is capable of. Where it’s not as impressive is the bass performance. I’ve heard this song with other sets and towards the ending portion of the song, those big drum kicks are meant to really match the vocals in power but they just don’t with the ZA12 and that does lead to a lack of dynamics hindering the overall replay of the song. I’d like a little more here, or maybe a better balance between the bass and the upper-mids. I think that would really help the song come together in a more cohesive way but also add some extra power to the overall replay.


The entire album Lush by Snail Mail is one of my favorite Indie/Alternative Rock records of recent memory and it’s the perfect album to test the ZA12 a bit when it comes to keeping the elements in check. My findings are to keep it really simple to not sound redundant. The vocals sound great, timbre and tonality sound life-like and beautifully textured. The bad, however, comes in the way of the overly cooked cymbals. When those huge crashes come in the mix, I am missing so much info not only in the cymbals but also in the rest of the mix because the part of the treble handling those harmonics completely overpowers the rest of the mix, especially the bass. It gets completely lost in the shuffle on songs like Pristine. Speaking Terms, the very next track then resets your listening experience back to positive. The intro sounds incredibly clear and coherent with the cymbals being mixed a lot lower in this song compared to Pristine. Heat Wave, track 4, is most likely the most well-known song off this album and it doesn’t disappoint. Consonants on this song can be a touch harsh on a lot of IEMs, the ZA12 mostly keeps it together here, respectively, but it might almost be the fact that I’m listening on a lower volume setting than usual. Something that’s usual is the volume of that guitar that comes in about a minute into the song. It sounds distinctly louder than the rest of the mix, which is very peculiar. Around the course (1:45 seconds) a touch of glare is present when those vocals start creeping up in volume, a small adjustment of the volume wheel helps mitigate it, though. Overall, it’s mostly positive. I actually haven’t listened to this album in quite some time, I had forgotten how good it was… The ZA12 gave it to me well, for the most part.


In terms of my Rap/Hip-Hop/Dance/Electronic part of my library… mmmm nope. Unfortunately, the Sub-bass is just non-existent in this set. It is so buried in the mix that to my ears it’s barely audible. It’s there, I can definitely hear and somewhat feel the rumble, but to truly get the full effect, I’d have to raise the volume to an uncomfortable level and I’m just not going to do that, I’d like to keep my hearing bit longer, thank you very much. It’s a shame because the DD handling the bass is obviously capable. The mid-bass is tight and impactful when called on, so I know that if they just leaned into the bass a little bit more and brought down the upper mids just a touch KZ would have a market disrupter on their hands.

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TLDR; The ZA12 is a pair of IEMs I FULLY did not expect to enjoy in the slightest. A resident of the gated cul-de-sac known as Bass Head Town would never touch this set with a 10-foot pole after glancing at that graph. 15 dB of ear gain?! Only 5-6 dB of mid-bass lift?!?!? SUB-BASS ROLLOFF?!?!?!?

No. Hell no, in fact.

But that would be neglecting my inner treble lover and female vocal aficionado. Indeed it would have been. This set is a treblehead budget IEM of choice in the under $100 segment. The clear, crisp, wide, and engaging treble section of this tuning is truly enjoyable in every sense of the word if you can get around the lack of bass in most cases. Mid-bass is punchy and provides a decent little kick when called on, but it’s not what this set is going for. Put down your Kendrick Lamar playlist and pick up your ballads and acoustic playlist because for $65 if you get the tunable version, this set is a treat for the ears… just as long as you keep the volume on medium. Shockingly, I thoroughly enjoyed the ZA12. They're not perfect by any means, but they've subverted my expectations entirely.

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No, I didn't take any pics for this review, I know it's out of the norm, but I saw some absolutely stellar pics taken by @mikaik down below and I thought, he has done a better job than I ever could, so I decided to skip.

Not to mention, I think the design is a bit... uninspiring. It's clean but certainly not very memorable.

I'd like to again thank @KEEPHIFI for the review opportunity! This was a surprising listening experience, to say the least, and It never would have happened without their support so, many thanks!

Thanks for reading, have an awesome day

This is a free sample I have received from @KEEPHIFI for which I am of course grateful. The opinions expressed here are, however, mine and reflect the way I hear this IEM.

What is ZA12?

It's a hybrid with 2xDynamic Driver and 4xBalanced armatures. What appears to be distinguishing it from the rest is the placement of one of the BAs directly in the nozzle, so that no sound tube is needed.


The packaging is what I came to expect from KZ, simple paper box. Cable, IEM, tips, that’s it.



The shells are very nicely built, with a combination of mirror-polished metal and a resin insert bearing a crystal-like aspect. They look very classy to me and the quality of the manufacturing is a clear step up from KZ ZS10 Pro and Pro 2.



The shells have the part facing the ear flat (no sculpted part to fit into the concha). The size leans towards big, (see comparison with other KZ sets I own). It was easy enough for me to find a good fit, even though the angle of the nozzle is not exactly right for me. The nozzles are short and stubby. You can easily see the BA in the nozzle, this is a first for me.

IEMs like Fatfreq Deuce, VE Ext are a perfect fit for my ears, just for reference.


The cable is decent, soft and thin with practically no microphonics. The kind of cable you’d want when commuting, for example. I quite like this cable, even though it does have a tendency to tangle up. It’s easy to untangle though and it does not feel fragile. It is the same one from ZS10 Pro and ZS Pro10 2.

There is audible driver flex when inserting them. Not much, but it’s present (it's tips dependent, of course, the better the seal, the more flex)
.

Sound

Bass is lean, almost flat with low amount of rumble and a nice warmth added to it. While the subbass is nothing to right home about, being very shy, it’s not necessarily a bad thing, as it gives them a rather neutral sound. There is, however, a very good, clean and fast midbass. It lacks a bit of texture, but it’s definitely the co-star of the show, along with the treble. It’s also a good counterbalance for those hyper enthusiastic highs. Without this anchor, even my insatiable appetite for cymbals would not have been enough to keep me interested. But the midbass does its job admirably.

It’s not clear to me if it is the mids that are depressed or simply the treble that is way too energetic. Unfortunately, female voices quickly become strident and tiring as I increase the volume. So if you’re looking for something that renders female voices with warmth and emotion, look elsewhere. Female voices are ok for the most part, except for those that go higher, which can be piercing. Male voices perform better, and are a tad closer to the center stage. As expected, less chances of becoming strident.
I would have liked more grit in the guitars attack, but this is so hard to do right.

Treble is the main attraction here. It’s upfront, it’s loud and it’s unapologetically energetic. Maybe it’s not unexpected with that BA directly in the nozzle, a bit a la 64 Audio. No energy is lost via sound tubes, the treble hits you right in the head, until your head starts ringing. Not for the treble sensitive ones. If you happen to like rock/metal, you’re in for a treat. In my experience, these genres benefit the most, because of the amount of cymbals used. They sound detailed, crisp and quite airy. A bit like Dita Project-M, if you want.




The stage is average, with enough instrument separation. The soundstage extends sideways, but not that much vertically. I find it quite ok for a budget set.

Overall, they have good presence, and the timbre is ok. They could sound a bit fuller, but it could also be an effect of the dominating treble.

Selection of songs

Christoph Mae - Pays des Merveilles. It works very well, the song is rendered in a very lively manner, I had problems sitting down and not dancing. Dynamics are very good,

Halestorm - Raise Your Horns. This is tough one. Is my supreme test for sibilance and female voice. There is some sibilance, but not dramatic. Lizzy’s voice is, unfortunately, a bit strident.

Dua Lipa - You got Me In Love Again. Enthusiastic rendition, nice extension of the bass with the treble ever so slightly strident. The voice is very close to the center. These things are quite detailed, you can hear well that huskiness in Dua Lipa’s voice. Once again, very dynamic, very lively. This set has the enthusiasm of a puppy.

Mark Knopfler - Boom, Like That. Sounded almost perfect. Mark’s soothing voice works very well here, things are calm, controlled. The bass has some breathing room and shows what it is capable of. Highly recommended.

Concierto de Aranjuez - Thibaut Garcia this is my favourite interpretation of it, less guitar machismo, more interplay with the orchestra. Here the treble does the job admirably. Very detailed, every breath he takes is there, the attack is great and the notes ring with enough body. Quite a surprise, really.



They are quite power hungry. With the SE cable I’ve reached volume of 90 on the Activo P1. For reference, my usual levels lingers around 50.


With a balanced cable there is more power available to them, they sound more spacious, the sound stage is a bit larger. (Tested with Eletech Eclipse).

I have tested them with a balanced cable with a variety of sources. They do benefit form the extra power, that is clear, there is more tactility to the bass, rather pleasant. The soundstage is extended and the imbalance is less obvious. There is not much rumble, they remain rather close to neutral.
Cayin RU7 and LP W4 are both good pairings. Sources that are overly analytical, like the FiiO dongles are less preferred, but the margin is small.



Comparisons

One unexpected comparison is the Dita Project-M. Although not being one of the über expensive offerings from Dita, it remains almost 8 times more expensive than the KA12.

P-M is a one DD + one BA hybrid, that has very nice treble, nice mids and one of the best mid-bass in sub 1k territory.
Unsurprisingly, Project-M wins across the board. But, there is something to be learned here. I wanted to make KA12 more similar to P-M, so I did a quick graph of both and I got this.





EQ tip: By lowering that rather large hump extending from 3K-6K, the KA12 becomes less prone to being strident, and a lot more enjoyable.

KZ ZS10 Pro
The finishing on the KA12 is much better, without any sharp edges. Sonically, the ZS10 Pro has more subbass, and dramatically capped treble. It is more balanced, but because it is so safe, some might consider it boring. The treble while being less in your face, is less detailed. I prefer KA12 to ZS10 Pro.

KZ ZS10 Pro 2
The most balanced of the bunch, but also the most difficult to find a good fit. Better finishing than ZS10 Pro but a bit worse than KA12. You can already see the direction they took, with extra bits of polished metal, no sharp edges, etc.
Sound wise, even though the most balanced, they are somehow less pleasant than KA12. There’s more rumble than KA12 but less mid-bass. The mids are rather uneventful, with a tinge of metallic timbre. The treble is more detailed than ZS10 Pro, but less than KA12. KA12 wins this one as well.


Size comparison with KZ ZS10 Pro and KZ ZS10 Pro 2


The BA in the nozzle

Conclusions

This is a bright set, so if you are sensitive to treble, it is probably not for you. However, if you are a treble head, this is a very fun one. I did not think such detailed and tonally adequate treble is possible in a budget set.
They are an ultra-specialist set, working best for rock/metal (hence the title). At low volume they can be quite enjoyable, but if you crank it up you need to carefully choose the tips.

K-bear is on a killing spree, and in the best way!
I put them on, and....i really think these guys CAN distrupt the market. While the KB02 was a nice first step, the ZA-12 feel like a big step up!



Touch - Daft Punk
WHat can i say, one of my most enojoyable renditions and i'm a guy with a trifecta and the Anni23, so it's not like i get easily impressed. These little guys make me hopeful that in the future we might get TOTL price down to less than a quarter of what it is now.
A delicious bass, maybe a tad less impactful than the KB02, but everything else is really well made.

School's Out - Wig Wam
Big sound big impact big fun! that's how i'd describe the feeling i get. The male voice is well defined, and of course the bass underlines the notes. Good impact good extension and good FR means you get a complete expereicne when listening to them. I was suprised because i think separation and note weight are some of the most important features.

Call me Maybe (10 kings vs ollie green remix)
Lovely female voice, good bass base, maybe a little less detail on the highs that feel a bit less defined.


TL;DR

Another great IEM at amazingly low prices, another hard-to-pass IEM. The segment of cheap but great sounding IEMS keeps growing and it's wonderful news for us all audiophiles, even more so for those who are sick of the "MORE COST=BETTER SOUND" predatory approach of many companies that feeds on buyer's remorse.
The two DDs gives a nice impact to the bass, the mids are defined and the vocals are never drowned. In itself it's a solid IEM that gives you a proper frequency response and decent technicalities. Factoring in the price, it is another easy reccomend for both neophites of the audio world and for those who want a pair of IEM on the go that won't break bank but will pleasantly accompany you in your day.

A sincere thanks to https://keephifi.com, that provided the review sample! they shipped the unit very fast!

KZ ZA12

Let's get started. Firstly, I'd like to thank @KEEPHIFI for sending me this set for review. I am so very appreciative for the opportunity, as I was definitely interested in listening to these IEMs. As the owner of several KZ, and as a fan of the older KZ ZS12 Pro X, I was interested in how this stacked up against that one and some other hybrids. So yes, this is a 4 BA + 2 DD hybrid, so sporting one extra DD than the ZS12 and 2 less BA's. Now you'd think the dual dynamic drivers would give you head pounding bass, especially tuned by KZ, but you'd be wrong. More on that later. The shell is reminiscent of one of my favorite budget IEMs, the CCA Trio, also made by KZ, with a sparkly faceplate. It's a comfortable fit, but driver flex is present. Again. more on that later. Ok now, so buckle your seatbelts and prepare for a 100% unbiased impression with heartfelt observations and thoughts. Now on to the fun stuff.



This unboxing experience is pretty much the same as every other KZ unboxing experience, which is it's almost non-existent. Tiny white box with black lettering, proclaiming KZ's strongest hybrid sound solution. Not sure how accurate that statement is, but we'll go over that later. Inside you get the IEMs, a set of those KZ Starline tips that are useless to my ears, Tuning switch tool and one of those thin throw in cables that KZ has included with every IEM that's not called the Hydro or Zenith. All of it are toss outs. I tip rolled to DUNU S&S tips, which I found to be perfect for this IEM, and a Tripowin Altea monocrystalline copper cable. The shells are hard plastic and metal, are medium sized, with average sized nozzles, and a sparkly patterned faceplate with ZA12 branding. I got very good comfort from these shells, and could wear them very easily for hours on end without issues or discomfort. It's sold in a standard stock tuning option, or the unit I was sent, which is the tunable unit with 4 tuning switches. So now that we have those pleasantries out of the way, let's move on to the sound? That's what you're all here for anyways!! It's time to get it on!!...but first, let me share with all of you some information about the IEMs themselves. Internals, specs, and a graph? Fun times indeed!



THE SPECS :

KZ ZA12 :

TECHNICAL INFORMATION :


Frequency Response graph provided courtesy of KZ & KeepHiFi

PRICE : $65.00

Available for purchase at this location.

The Gear :

What did I use for my listening sessions for my review??

So the gear used for this review revolved around my Cayin N3 Ultra (Classic Tube mode, Sharp roll off filter, M gain, untethered), Sony NW-A25 (untethered), FiiO JM21 + iBasso DC Elite, and the Hiby R3 II + iBasso Nunchaku (Tube mode, NOS filter, High gain). So the IEMs were privided a swath of very high performance, high quality sources to render this review.



Music used for the review and all my reviews in general?

Ezra Collective - Dance, No One's Watching
Robert Glasper - Canvas
Alfa Mist - Antiphon
Mareike Wiening - Reveal
Avishai Cohen - Brightlight
Bob Marley & the Wailers - Survival
Rob Van Bavel & Joris Teppe - Dutch Connection
Kaisa's Machine - Taking Shape
Junior Kelly, Bounty Killer, and Capleton - The Good, The Bad, and the Blazin'
Dominik Eulberg - Avichrom
Abysmal Dawn - Phylogenesis
Megadeth - Rust in Peace
Drive By Jehu - Self Titled
Cognizance - Phantazein
Crownshift - Crownshift
In Aphelion - Reaperdawn
Cradle of Filth - Nymphetamine
Shuffled Classic Rock, Reggae, and 80's Pop Music playlist

SOUND IMPRESSIONS :

Dynamics : 3
Resolution : 4
Details : 4.5
Instrument separation : 4
Imaging : 4
Low End Impact : 2
Sibilance : 3 (Sibilance is occasional)
Soundstage : 2.5

Overall score : 3.5/5

BASS/MIDRANGE/TREBLE :

The KZ ZA12 is an interesting new entry hybrid by KZ. The aforementioned KZ ZS12 Pro X is cheaper, yet has a metal shell, 6 drivers per side, and was given quite the marketing push. The ZA12 has less drivers, is a hybrid shell (mostly plastic), and is more expensive, and was not given any marketing push at all. The technical aspects of this IEM are through the roof. On sheer technicalities alone, this IEM punches way above it's price point, and lives in the same neighborhood as some IEMs that cost $200.00. The resolution and separation are both some of the sharpest and best that KZ has to offer, or any maker of IEMs in the $50-$200 range. This became apparent while listening to one of my test albums for timbre and resolution (both bass incisiveness & midrange resolution), spatial cues, and soundstage, Rob Van Bavel & Joris Teppe - Dutch Connection. While the stage is average at best, and more intimate that wide and deep, the imaging, instrument separation, and spatial cues are excellent. Instruments placement is above average, and note resolution and incisiveness in the bass frequencies is razor sharp. You can hear every strum, pull, and pluck of the bass strings very clearly and without any haze. This extends to the lower midrange as well. Now, for this being dual DD, the impact is lacking. While you get a very linear approach to bass, where the emphasis is on the clarity and snap, punch lacks energy, and rumble is almost non-existent. This is the definition of bass you can hear but not necessarily feel (except for the resolute snap of the bass strings).

Midrange weight is on the thinner side, with a high degree of resolution, much like the bass. There is very little natural warmth in the midrange, with almost no bleed from the bass. Tonality is crisp, resolute, and there's really good resonance and reverb in the notes. The midrange is also clean as a whistle, and clear. There is no mud. Technicalities are focus and spit out like a champ. Details are delivered with precision. When I fed the ZA12 vacuum tubes, they responded well in the midrange, providing much needed warmth and synergizing well with the stock resonances and tone. Gave it just a bit more weight to the timbre, and reigned in the sometimes hot upper mids. To boil it down...the ZA12's midrange is a technical marvel!

The treble is divisive. On one hand, it's shimmery, airy, and has lots of extension, with crispness, but at the same time, it can exhibit BA timbre, crispiness, and sibilance. Once again, like with the bass and midrange, incisiveness is king, but sometimes, it can be too much. I was able to tame it to some degree by using sharp roll off filters, and tube modes, and warmer sources. This worked to varying degrees, and for jazz, instrumental rock, and nu urban, the tuning made for a wonderous listen, and allowed you to pick up all the overtones and details present in the music. For vocals, some guitars, and cymbals and percussion, it tended to walk the edge, but you were never met with any smear, and glare was limited to BA timbre. So precise note delivery and precision clarity.



CONCLUSION :

Whereas the ZS12 Pro X has a linear but impactful bass with a relatively warm midrange, with a fuller soundstage, the Pro X falls short on the end of sheer technicalities, air, and imaging. The ZA12 is less colored, more accurate, and more technical. While the bass fun factor is dialed back, when you play Megadeth - Rust In Peace, or Abysmal Dawn's Phylogenesis, or even Robert Glasper - Canvas, the bass is so resolute and incisive, you'd swear you can hear the foot taps of the double bass drums, or the sniffles and slides of the bass player. The ZS12 Pro X doesn't have that ability to present details in that fine way. Neither does the CCA Hydro, CCA Trio, or the KZ Libra X. Detail retrieval, instrument separation, and imaging are superior to the Kefine Klean or the Sound Rhyme SP01. What it's lacking ultimately is warmth, bass impact and rumble, and maybe just a bit of upper mids roll off to reign in the hotness. The antidote to this is feed it vacuum tubes, and EQ the mid bass. Still, at the end of the day, the KZ ZA12 is satisfying listen to those who are looking for accurate, balanced, technically sharp and precise music delivery that does not skimp for details and crispness, clarity and cleanliness. SSo if you want to experience a technically superior IEM on a budget, then you cannot go wrong picking up the ZA12. Just remember the caveats, and fire up the vacuum tubes, and you should be alright?

RECOMMENDATION LEVEL : BUDGET TECHNICAL BOSS - HIGH 7/10.

Thank you so much for reading and remember to be water with your audio luv! When you do...AUDITORY ZEN UNLOCKED!

Well, the shortest review, sadly.
That is my first IEM (out of 150+) that clearly displayed audio imperfections right out of the box.

I got my copy from KeepHiFi directly (a pre-order of an early January with the "discount of the day", ca. $46.5 paid).

Really nice shells in all the aspects - arguably, nicer than that of Sonata, KZ's true flagman. Surprisingly, the shells of ZA12 are not of the same mold (that I thought would be the case for cost savings), but slightly smaller, so the fit is very nice to my ears evolved to accomodate larger KZ shells


Yet, it is the sound that really matters.

For the sound, first, the right unit of my copy has featured an apparent driver flex that was not the case with the left unit (and I can live with some flex), yet also the tonality mismatch became apparent with the right "flexed" unit being more brazen and prone to sibilance and distortions at higher volumes, clearly observed when I tried to "burn" ZA12 for few hours while closely monitoring the process.

I do not have Hydro and ZS12 Pro X to compare.

Compared to Rhapsody that I never was any fond of due it's overabundant to me midbass and not prominent treble, a properly functional ZA12 is likely notably better, yet not that I can fully tell with my unit.

The measured DC impedance of ZA12 was varied from 118 to 183 Ohm for different switch positions - really high, far from a nominally stated single value of 45 Ohm (seemingly ignoring the switches). I understand about 1 kHz vs. DC - yet, ZA12 has the highest difference that I have ever encountered for the records. Interestingly, the sound volume of ZA12 was quite comparable to 40-Ohm Sonata (Sonara sound is incomparably better in all dimensions, if you wonder, no any surprise).

Is ZA12 a special KZ experiment done exclusively for KeepHiFi (?) - with an odd impedance and limited QC (or my unit is a sad anomaly).

Well, I got ZA12, as something not yet reviewed, while it seems the higher forces are clearly telling me that I should stop with my unnecessary gear acquisition and do something better for humanity. I will leave it here at this sober note...

P. S. KeepHifi representative first "liked" my review, then withdrew their response. I am curious of any further actions on their part, while not requesting anything from them - well, it is ChiFi, loosing $46 is kind of what I would expect for better or worth...