All That Shines Is Not Gold

Ratings

Pros

• Technical, analytical, transparent, clear and brilliant sound.
• 4 tuning switches.
• Comfort and low weight of the capsules.

Cons

• Driver Flex.
• KZ copy-paste design.
• Rigid cable.
• Minimal and repetitive accessories, with almost no added value.
• Low price/sound ratio.
• Soft bass, even in the 1100 position.
• First part of the mids with no physical or corporeal component.
• Upper mids high in amount of energy.
• Prone to sibilance and auditory fatigue.

Purchase Link

https://keephifi.com/es/products/kz-za12-hybrid-2ba-4dd-in-ear-earphones-hifi-earbuds-iem-headphones-for-gaming-noise-cancelling

Link to the Store

https://keephifi.com

Introduction

KZ needs no introduction. But, personally, it is a brand that I am grateful for that time when I bought their low-priced models as if they were knick-knacks, looking for the best sound that CHI-FI could offer at low cost. And for that KZ will always be respected by me. The umpteenth new model from the brand is called the ZA12, and the brand itself says that they are ‘the most powerful hybrid (dynamic + balanced armature) IEM KZ headphones to date’. Inside are 2DD+4BA for a richer and more delicate sound quality experience. The ZA12s use two dynamic drivers for deeper and more accurate bass. Advanced frequency division enhances sub-bass and bass clarity for a richer listening experience. As dynamic drivers, they use a 10mm superlinear unit and an 8mm high-performance unit. For the mid-high frequencies they use two BA 30019s, while for the ultra-high frequencies they use a composite BA 31736. The ZA12s are available in two versions: without tuning switches and with four tuning switches. With the switches, the bass can be boosted on the one hand and the mids and treble on the other. A perfect fusion of metal and resin has been used to manufacture the capsule for a refined and elegant look. The KZ ZA12 features an ergonomic exterior design, meticulously carved to ensure a comfortable and unobtrusive wearing experience. As a cable KZ uses a high purity silver plated conductor with classic 2Pin 0.75mm interface with 3.5mm SE termination. You can choose between a cable with or without microphone.
Let’s take a look at what this new KZ model has to offer.

Specifications

• Driver Type: 1DD superlinear 10mm + 1DD high performance 8mm + 2BA 30019 + 1BA composite 31736.
• Frequency Response: 20Hz-40kHz.
• Sensitivity: 103dB.
• Impedance: 45Ω.
• Jack Connector: 3.5mm gold-plated SE.
• Capsule Connection Type: 2Pin 0.75mm.
• Cable Conductor: high purity silver plated cable.
• Cable Length: 120cm ± 5cm.
• Starting Price: 65$.

Packaging

KZ makes no effort at all in the presentation of its models. The box is the same with a white background and dimensions 94x73x33mm. This time it features the large KZ logo in the upper left corner as a small difference. But the realistic photo of the model is still in the middle of the box, as well as the product description at the bottom of the box. The specifications and other brand information are on the back. This case slides vertically and shows the IEMS inside a plastic mould at the top and a box at the bottom. It is protected by a transparent plastic sheet that acts as a lid. Inside the box are the accessories, which are:

• The two KZ ZA12 capsules.
• One silver-plated cable, with 3.5mm SE connector and 2Pin 0.75mm connection interface.
• One pair of black foam tips.
• Three pairs of silicone tips type KZ, sizes small, medium and large.
• One metal pin to operate the switches.
• One instruction manual.

I still criticise the fact that the capsules are inside plastic moulds, instead of using foam moulds. I still find the cable too basic, even though it is silver plated. There is no carrying case, and no bag. This time there are 3 pairs of KZ tips, and I still like the detail of the metal pin and the foam tips.
But the level of the accessories and the presentation are too basic for a model with a price of 65$.
Another thing I don’t understand is that they use a cable with a 2Pin 0.75mm interface, when the most normal is 0.78mm, widely adopted by the majority.

Construction and Design

The shape of the capsules of the KZ ZA12 is semi-custom. The outer face appears to be made of a metal alloy. But it has a large window on the inside which is filled with transparent resin pyramids. On the metal rim you can read the model name in a handwritten font. Underneath is the amount and type of drivers used, all in silver ink. The inner side is all transparent plastic. The rim is thick to house the 4 switches. The capsule connection interface is typical KZ, with the 2Pin 0.75mm connectors mounted on an overhanging oval. The inner face is smooth and rounded, not seeking a wavy shape beyond the edge, with no protrusions. The nozzles are integrated and made of the same material. They have two diameters, the initial diameter is 5.8mm and the crown is 6.4mm. The approximate length is 5mm. The nozzles are protected by a fine metal grid. You can see that inside the nozzle there is an integrated BA driver glued to the grille. There is a hole in the centre of the inner face, which coincides with the centre of one of the dynamic drivers. The construction of the capsule is classic, with a plastic inner face, whose greatest virtue is its level of transparency, allowing the drivers, cables and crossover to be seen. But, on this occasion, the design of the external face seems to me not very attractive, somewhat hackneyed and repetitive.
The cable is a classic two-stranded soldered cable with a silver-plated conductor. This is perhaps the most relevant thing about the cable. The rest is the typical 90-degree plug made of translucent white plastic. The splitter piece is a piece of transparent plastic. You can choose with remote control and microphone mounted on an elongated white plastic piece. The connectors are the classic angled connectors. All connectors are gold plated.
The cable is rigid and takes shape. KZ could improve in this aspect and make better cables.
I think that KZ is stuck in a repetitive design and construction, with accessories that don’t advance and don’t improve. It seems that they want to invest all the money in the interior, in the drivers, in their quantity, in the switches, in the filters. And that’s partly fine with me, but the little innovation in these aspects only deserves the same copy-paste that they use in their construction and design in my reviews on these aspects. Only the nozzles are longer to accommodate the BA driver inside.

Adjustment and Ergonomics

The capsule is medium to large, light, semi-custom shaped on the outside, but the inside is smooth and curved, with no protrusions on the rim. The slope of the mouthpieces is good. The length is superior, but the thickness prevents the insertion from being too deep, and can be medium for those with a wide ear canal. Depending on the tips and the morphology of the individual, the insertion will be merely shallow. The rim is thick due to the 4 switches. It allows for some rotation until it clicks into place. With the right tips the fit is quite good, with a remarkable fit and insulation.
The shape is still very classic, the orientation is more than acceptable and the slightly longer nozzle size may offer a more secure insertion. The ergonomics vary slightly, but remain within tried and tested and reliable parameters, uncontrived but efficient. KZ has opted for the safety of a design with no protrusions inside and this gives it a wider and more universal comfort index.
On the other hand, there is a negative effect when adjusting the ZA12: the classic Driver Flex appears too easily: with a minimum of inward pressure it becomes clearly perceptible.

Sound

Profile

KZ ZA12s are sold with several options, one without tuning switches and one with tuning switches. In my case I have the version with switches. These are 4 switches which, in theory, allow for 16 combinations. But the brand only highlights 5. The basic curve has all the switches in the 0 position and is the tuning that seems to be sold for the option without switches. Turning the first switch up increases the bass by 1dB. The two switches at 1 increase the bass by 2dB. Only the third switch to 1 increases the mid and high frequencies by 1dB, while raising switches 3 and 4 increases the mid and upper range by 2dB.
The base tuning is neutral with a clear bright tendency, with quite prominent high mids, while the sub-bass is in clear recession. Raising the first two switches corrects the net sub-bass recession, adding a greater naturalness to the ensemble and balancing a tuning that still has high upper mids. On the other hand, turning up switches three and four only increases that unevenness, increasing that bright, even metallic, sibilant and somewhat unpleasant tendency that KZ has not quite polished.
The review I’ve done is based on the 1100 setting with more bass, but also more balance.
On the other hand, it should be noted that the ZA12s, with 45Ω impedance, are IEMS that require a good amount of power to bring them in line with their competition, as far as output SPL is concerned.

Bass

Even with the first switches in the high position, the ZA12s still seem neutral to me in the low end. This is because both the mids and treble stand out more in the overall mix. On the other hand, it’s a disciplined range, with a dry, fast punch, with very little aftertaste, with a marked technical edge. The bass drums have some colour, they don’t feel very deep and the level of darkness is low. Thus, the feeling of depth is quite neutral, as well as the volume and extension generated. These are not flat IEMS, but the amount of air moved is not enough to recreate a voluminous three-dimensional space. However, the technical ability is quite correct, the drums are sharp, with defined lines, executed in a fast way and with a fast decay. There is a slight sense of roughness and texture, something that contributes to show bass with a more realistic and natural connotation. However, the bass does not feel rubbery, nor does it feel too bouncy. On the other hand, it is possible to observe a certain level of punchiness in bass drums located between the sub-bass and mid-bass, generating an extra power and amount of energy.
In the very low-frequency pure tone test, the medium-low energy level in the sub bass of the ZA12s is noticeable even in the 1100 configuration. There is no physical character and a perceptible undulating behaviour is predominant, which is responsible for the aforementioned colouring. As we approach the mid-bass, the ZA12s seem to wake up and are able to show a bit more power and noticeability, but with a relatively neutral level of physicality.
It is in the dirty, complex and unfiltered bass test that the ZA12s’ neutral and technical bass ability is felt. Behaviour and control is good. Having a restrained energy level, complex lines are drawn in a quite correct way, without distortion and maintaining a vibration level within normality. On the negative side is the colour, tonality and timbre, which feels oriented towards the more audible, less physical, dark and sensory zone. As such, the reproduction of bass lines feels somewhat displaced, losing the grace of realism and naturalness. The result is a more than adequate technical level, but a coloured timbre and tonality that detracts from realism and naturalness.

Mids

The mid-range is relatively split, with the first half somewhat sunk and the second half clearly emancipated. In this way the string instruments are clearly ahead of the male voices, which are lean and with an eminently low physical and corporeal base. In this sense, the sibilance is more prominent than the fundamental of the voices. It is a tuning that elevates the nuances and details in front of the base. As such, the blend lacks warmth and the musicality is curtailed in favour of a somewhat contrived ornamental presentation in pursuit of a slightly metallic BA sheen that is not very appeasing for long listens.
I have used these IEMS a lot to watch series, where vocals are predominant, and I have experienced the sibilant character and idiosyncrasies of the KZ BA drivers on numerous occasions. I have even had to replace the ZA12s with a warmer model for some series, as these aspects cause me fatigue, regardless of the source.
The female vocals are closer to the listener, but even the handclaps feel over the top, taking centre stage in an unexpected way, with that vivid, crisp burst in the foreground. The result is a tuning that exalts details, nuances and harmonics above the fundamental base, projecting the trace of the voices and stretching them out more than necessary, in echoes and reverberations.
It is obvious that the sensation of clarity and transparency is patent, as well as that colder, analytical, even forced and somewhat synthetic touch, which shows a less musical and much more excited, spiky, exalted and splashy side. In this aspect, the technicalities exist, but they are shown in this somewhat forced, sought-after way, above all to mark the macro detail in a very evident foreground. So much so that the micro detail is overshadowed by the lack of depth in the media and by the overexposure of the overwhelming macro detail. And that’s a pity, because that lack of depth and the evidence of the macro detail wastes the good technical ability to discern the micro detail, at a fairly high level for its price.

Treble

The treble starts with a softened energy level, coming from an excited upper midrange. This tuning helps to control the amount of upper range exposure and favours a marked, crisp, sparkling and exalted character, but in a beneficial way. Without a doubt, the treble is highlighted and comes across as sharp, well extended, even airy, in pursuit of an obvious treble-head oriented character. Without overstepping the limits of overly penetrating listening, the treble is evident and prominent, standing in the foreground of the overall sound mix, but with a more beneficial and realistic, if also exalted, upper-range incidence than the clearly more forced upper mids.

Soundstage, Separation

The scene is clearly frontal, with a good lateral feel that is evidenced by the macro detail. However, there is little sense of depth, although the horizontal impression is wide. The image is presented in a foreground whose distance between elements is shown in height and width, with few planes and very low separation between them. The perception of a dark background is limited by the fact that the background is close and the echo of micro detail and highlights cannot be muted in time to be felt clearly.
On the other hand, the sense of clarity and transparency is high, but this is a cold, more technical sound, focused on macro detail and harmonics, far removed from any musical softness. The character of the music is sharp, very splashy, penetrating, bringing out the sharp aspect of the musical notes. In this way the sound seems very resolute and defined, but it loses the essence of the notes, worrying too much about highlighting the minor aspects of the music, except for those whose fundamental coincides with the pinna gain or the treble.

Comparisons

Rose Star City 5 Pro

At first glance, I found the frequency response of the Rose Star City 5 Pro’s somewhat surprising with its upper midrange and treble peaks, as well as the somewhat flat bass response. It wasn’t the kind of graph I like to see. But that all changed when I listened to them, they turned out much better than I expected. This Rose model currently priced at $69 has a dynamic driver with a 10mm LCP diaphragm + 2BA. It has an impedance of 24Ω and a sensitivity of 104dB. Its capsules are made of metal and resin and its design is much more substantial than the repetitive KZ ZA12. Presentation is in the upper echelon of the range, with premium accessories: a round black leatherette case with snap closure, a two-strand textile-coated cable, a fully functional dongle. It even comes with two types of silicone tips, one more common and one more specialised. KZ seems extremely cheap in this respect. I just remember that the Rose only costs $4 more. KZ doesn’t come with any kind of carrying case, let alone a box. Its silver-plated cable has a hard case and an all-too-common angled connector. I want to emphasize that I am a fan of the KZ tips, but you can’t live from the memory, KZ must create something new in this aspect. The Rose Star City 5 Pro has a design and presentation above its price and will never be irritatingly laughable like the presentation of the KZ ZA12.
When it comes to ergonomics, the ZA12s are not bad and their low weight is a plus. Their capsules are larger and thicker but this does not penalise their comfort. The Rose’s design is more specialised, more streamlined, and allows for deeper insertion. Their smaller capsule, tuned towards the mouthpieces, hardly touches any part of my ears, the point of contact is only the silicone tips. If the comfort of the ZA12 is remarkable, that of the Rose is clearly outstanding.
The amount of power to equalise sound pressure levels is much higher in the ZA12s. The KZs need a powerful source to match the volume, and even then, there is difficulty in obtaining the fullness of sound that the Rose does.
In my opinion, the Star Citys have a balanced profile with a tendency towards clarity, due to their evident emphasis on the mid-highs and early highs. The bass rises subtly from neutrality, allowing itself to be felt with restrained power, thanks to its extension in both directions. The 1100 tuning of the ZA12s is neutral with a clear bright tendency, with quite prominent high-mids, although the sub-bass has recovered from the base tuning.
The first sensation you get when comparing the two models is the density and fullness of sound. The Rose has power, character, presence, body and soul. Their bass imposes much more than what the graph represents, compared to the KZ. The Rose manages to draw an almost reference bass in relation to what the KZ is able to deliver with 2DD. There is no vibration or unwanted colouration in the Rose’s bass, and this means that its translation to real music produces an optimal result in terms of performance. It is not the fastest bass, but it is not dry either, it has a subtle degree of elasticity to generate a certain volume that projects its importance and produces a more discernible, evocative and descriptive texture. The sonority of the lower notes is very successful, with a great level of darkness, naturalness and they are very nicely executed. The ZA12s are perhaps better in speed, and offer less decay and aftertaste, but they are not natural, but have a clear colouration, feel very soft and with little personality. The technical aspect is good, as well as their speed and dryness, but little else, you don’t feel the big bass that should come from two specialised dynamic drivers.
In the mid-range of the KZ, that sense of lack of body, physicality and warmth continues. The sound is lean, distant and light in the fundamental of the first half. It is enhanced in its nuances and macro details. It feels bright, sharp, vivid and splashy, but unmusical, without warmth, quite the opposite, it is cold and analytical but in a sad and dreary way. All in all, the sound isn’t bad, it’s very transparent, with lots of resolution and detail. But without soul. The initial midrange of the Rose doesn’t feel sunken and is more grounded than in the ZA12s. It’s still not quite full-bodied to my taste, but it is much more natural, realistic, full, dense and, above all, enjoyable and musical than on the KZs. And, despite all this, the level of clarity, transparency, separation is very good, all without the need of having 4BA’s, but only 2 tuned in a much more accurate and natural way. The mids of the Rose are much fuller, as the power and energy level is maintained from the base to the overtones, being much more expressive throughout the range. The ZA12s have a rising tuning that forgets the base, losing the fundamental body. But it is true that both models have a sound with a clear emphasis on the upper mids. While the Rose has a lower range that complements this higher energy level remarkably well, the ZA12s rely all their quality on technical skill, forgetting the natural musicality needed for the music. The result is a hollower midrange with little body or physical sensation that lacks the soul and passion that the Rose’s lack.
The ZA12’s treble is more powerful, crisp, sharp, even and extended than the Rose’s, it also has more air. But if the listener wants a slightly more controlled and perhaps even more natural treble, the Rose’s performance is very good. The Rose’s treble quality may be superior, while the ZA12s have more quantity and power.
The KZ scene is flatter while the Rose has more depth and volume. It has more separation between layers and good height. The distance between elements is also very good. There is a very good balance between clarity, transparency and body, generating a more vigorous, natural and realistic image, as well as immersive, volumetric and extensive. In the KZs, a lot of energy is needed to expand the scene, but it doesn’t become surrounding and is very flat up front, with very little bass extension. There is very good separation, but it is limited when it comes to recreating layers and its distance in depth feels congested, somewhat compressed on that axis. Thus, its image feels less than three-dimensional, while positioning is reduced to the horizontal axis.
What’s so great about the KZ over the Rose? Well, they use a 2Pin connection interface instead of the MMCX, which I dislike so much. But, even in that they are not perfect, because they still use the 0.75mm size with the classic KZ sleeve which makes it less compatible with the many cable models on the market.

Conclusion

I have a lot to thank KZ for in my beginnings in this hobby, as it was exciting to see each new ChiFi model from this brand and try them out without spending a lot of money. But after several years and a lot of experience, the brand itself should remember that more is not always better and that you don’t need so many drivers to sound good. On the other hand, KZ is losing the battle with its own philosophy. It offers practically the same packaging, the same accessories, a similar type of design to each other. I don’t think it’s enough that the added value is the sound, the number of drivers, the number of switches or the number of tuning options. The competition offers much better accessories, better cables and clearly better sound for the same price. That’s where KZ loses its advantage – getting the best sound for the lowest price. With this new ZA12 model, it is relegated to a second or third division in this range and I would never recommend it as there are plenty of better, even cheaper options ahead.
What do the KZ ZA12s have to offer? A brilliant sound, 4 tuning switches that allow the sound to be even brighter, hollower and more unbalanced. KZ say that the ZA12s are the strongest KZ hybrids. For me they are very soft, from the bass to the upper mids. From there, the energy is almost overwhelmed. It corrects itself in the treble surprisingly, although they are still quite vigorous. The sound relies almost entirely on technique, macro detail, resolution, brilliance, harmonics, echoes, nuances, and forgets the musicality, the soul, the base and the passion. The sound becomes cold, hollow and dull. I think KZ knows how to do it better.

Sources Used During the Analysis

• Tempotec V3.
• iFi GO bar Kensei.
• EPZ TP50.
• Burson Audio Playmate 2.