Knowledge Zenith AS10

INTRODUCTION/DISCLAIMER:

The KZ AS10 is an in-ear monitor with five balanced armature drivers per side. KZ is the brand that started my Chi-Fi journey years ago with the ATE. Since then I have owned the KZ ED9, which I liked, and the ES4, which I disliked enough to return. I also own the C10 from KZ’s sister company, CCA, which is my go-to recommendation for a sub-$50 hybrid IEM.

The AS10 is the most expensive KZ model I have evaluated so far, retailing for $59.99 on Amazon at the time of this review. The AS10 was provided to me by Linsoul Audio in exchange for a fair and objective review.

SOURCES

I have used the KZ AS10 with the following sources:

Windows 10 PC > JDS Labs The Element > KZ AS10

Pixel 3 > Fiio BTR1K (Bluetooth Apt-X) > KZ AS10

Windows 10 PC > Fiio BTR1K (Bluetooth Apt-X) > KZ AS10

Pixel 3 > Apple USB-C to 3.5mm dongle > KZ AS10

I have tested these headphones with local FLAC and Spotify Premium.

PACKAGING AND ACCESSORIES

The KZ AS10 comes in a black rectangular cardboard box marked with the KZ logo on the front panel. Stickers on the bottom panel indicate the mic and color options as well as the contact information for the manufacturer.

The box has a flip cover which opens to the left, revealing a foam inlay containing the earpieces and a metal plaque. Behind this inlay are two translucent white plastic bags containing the AS10’s removable cable, 3 sets of KZ Starline eartips (S, M, L), a user manual, a QC pass chit, and a warranty card. The AS10 does not come with a carry bag or case.

BUILD QUALITY / DESIGN

The AS10 earpieces have piano black plastic housings with transparent faceplates. The housings are on the larger side with deep nozzles. The AS10’s KZ-branded circuit boards are visible behind the transparent faceplates. Although I love this look, there are many who do not. The model name, “Left/Right,” and “10 Balanced Armature” are printed in silver on the top face of the black plastic housing. “L/R” are also identified on the transparent faceplate above the cable connection.

Each earpiece has a tiny circular vent near the top of the inner face of the housing. The AS10 is an all-BA design, so driver flex is not a concern.

The nozzle does not have a traditional lip for securing eartips, and instead has 3 small protrusions along the edge of the nozzle. This worked just as well as a lip in my experience.

The AS10 has a copper-colored braided 2-pin cable with an L-shaped 3.5mm jack. The KZ logo is printed on the jack housing. The cable has pre-formed plastic ear-guides and “L/R” markings on the 2-pin housings. There is no chin-adjustment choker, and the Y-split is around halfway-down the cable length, roughly 2 feet from the bottom of the 2-pin connections. The cable is not as tangle-prone as the cable included with the CCA-C10, but is still problematic in this regard. Microphonics are minimal.

COMFORT / FIT / ISOLATION

The KZ AS10 is intended to be worn cable-up only. The wide housings and relatively deep insertion depth make the AS10 tolerable at best from a comfort perspective.

Noise isolation is above average relative to dynamic driver or hybrid designs, but not as good as the Tenhz T5, a sealed all-BA design.

The AS10 accepts a wide variety of eartips. The relatively deep insertion depth makes getting a good seal easy. I used the small silicone eartips from the Fiio F1 for my listening.

SOUND

The KZ AS10 has a warm, mildly-V shaped tuning.

The AS10 emphasizes mid-bass slam rather than sub-bass rumble. Sub-bass is present and well-extended but not visceral. Bass articulation is quick and precise. Bass texture is dry and clinical. The mid-bass hump bleeds into the lower mids, thickening deep and growled male vocals and causing distorted electric rhythm guitars to come off as boomy.

The lower mids are slightly recessed and a tad warm. Both male and female vocals are clear and full-bodied. The upper midrange could use a touch more presence. Both male and female vocals, while natural-sounding, come across a bit flat.

The treble, while smooth and inoffensive, has a plastic-sounding timbre. Resolution is adequate for the price, but the AS10 is lacking in sparkle.

Imaging and instrument separation are very good. Soundstage is slightly larger than average for the price point and compares well with more expensive IEMs.

MEASUREMENTS

My measurements were conducted with a Dayton iMM-6 microphone using a vinyl tubing coupler and a calibrated USB sound interface with a resonance point at 8k. The measurements are presented with 1/24th smoothing and without compensation. Measurements above 10k are not reliable.

AMPLIFICATION REQUIREMENTS AND SOURCE PAIRING

With a sensitivity of 105dB and an impedance of 14ohms, the AS10 can be easily driven to adequate listening volumes by a smartphone. I did not notice hiss with any of my sources.

COMPARISONS

KZ AS10 [$62] vs Simgot MT3 [$66]

The Simgot MT3 has slightly more prominent and extended sub-bass. The MT3 has slightly more textured bass. The AS10’s bass is better articulated, with more precise attack and decay. The MT3’s mid-bass hump rolls off earlier and does not bloat the lower midrange as much.

Male vocals are more prominent on the AS10. The MT3’s lower midrange does not exhibit the boominess that can be heard on the AS10. The MT3 has a livelier but more aggressive upper midrange, which makes vocals sound more exciting at the cost of sibilance. The timbre of the MT3 is thinner than the AS10’s. Distorted electric guitars can be too bright on the MT3.

The MT3’s lower treble rolls off earlier than the AS10’s, but is harsher, splashier, and grainier. The MT3 has more air and sparkle. The AS10 has more realistic transients.

The AS10 has better instrument separation, a larger soundstage, and more precise imaging. The MT3 is slightly harder to drive. The MT3 is more comfortable thanks to its smaller housing. The MT3 comes with a wider variety of eartips, a nicer cable, and a mesh carry bag.

CLOSING WORDS

The AS10 errs on the side of caution, presenting a safe tuning that is unlikely to offend. Build quality and technicalities are very good for the price point.

It's early KZ, not really good in any way.
Sibilant as hell.
Sounds off.

This review was made possible by LINSOL AUDIO.
https://www.linsoul.com/product-page/KZ-AS10-Earphone
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Intro
When Knowledge Zenith announced their first pure BA driver in-ear release, this made many Chi-Fi hearts beat faster. After all, a pure BA driver configuration can only be found in much more expensive models and KZ quickly made it clear that the AS10 as well as the BA10 will be available for less than 80 €. In comparison to the numerous hybrid models of KZ these are however also clearly more expensive.

Whether KZ really lived up to the high expectations will be shown in the test. It is especially exciting how the AS10 perform in the low bass range!


Handling
The AS10 uses the design of the ES4 and ZS10, which also use a transparent housing with a visible PCB.

Because the sound openings are very large, it is not advisable to use the largest foam/silicone tips, as this could cause pain when wearing them.
I also don't know what makes KZ so vehemently rely on their wire reinforcement in their cables, which impairs the wearing comfort somewhat.
Apparently we get new cables from the ZSN, which have preformed earhooks with rubber tube reinforcement.

The insulation is very good in both directions, and since there are no dynamic drivers, there is no need for the possible plop effect when inserting, which can be caused by negative pressure in the ear if there are no ventilation holes or are covered.

After almost 3 years KZ has also decided to change its packaging. This package doesn't have any more content (cable, 3 pairs of silicone tips, headphones), but it looks better.


Sound
Now it's time to get down to business. Basically the AS10s are very balanced IEMs with accentuated good resolution mid-range, airy, detailed treble and appealing bass.

This doesn't come from a dynamic driver, like the previous hybrid models, but a BA driver (woofer) takes care of the low frequencies and that surprisingly well with some compromises.
What is quickly noticeable is the lack of pressure and the rapid drop in the sub range. The bass is partly very dry and sterile, but fast and precise, because the inertia of the dynamic drivers doesn't matter. That's a bit of a matter of taste. However, the midrange bass is really good and to the point. It also provides the AS10 with a warm sound without being overly accentuated, even if it slips into the midrange.
As accurate as the bass plays here in quality and quantity, I lack a bit of sub-bass, which is especially noticeable with electro.

The mids are really great, also because they come out better than many other KZ models. The lower mids are warm, due to the more dominant midbass and with a good body. The higher mids, however, are very clear and detailed, but also emphasized, which in rare cases can lead to unpleasant peaks if it favors the music. But you have to turn it up a lot until it hurts.
In general the AS10 are very loud and can be driven easily. In comparison to many other in-ears I need less volume of the end device to achieve the same result.
The stage of the AS10 isn't one of the biggest, but it isn't too intimate either. I would describe it as pleasant and very spacious. The separation works perfectly and is also due to the good tuning of the individual BAs.

The highs crown the very good overall impression, even if they are not particularly remarkable in comparison to earlier models, which does not make them worse. They are airy, bright and radiate some brilliance. They don't tend to unpleasant peaks and also treat the sibilants very relaxed. This is where it must have been applied in music production in order to get it out in an exhausting way. I would wish that they would play a little further and roll-off a little later. In and of itself, however, KZ has the best heights to offer.


Outro
KZ can meet your expectations, even if, as so often, there is still room for improvement. For example in the sub bass range, or an even finer tuning of the drivers, stage size and height extension. But at some point this can no longer be achieved in terms of price, even if the AS10 with its price tag also has higher class competition, so that it certainly doesn't stand alone with its quality. While KZ was often able to outperform the competition in the price class around 20 €, it is no longer so easy in the higher price segment.

Nevertheless KZ doesn't miss out even in the higher class and delivered a remarkable in-ear, which belongs to the most interesting models of the company in terms of sound, but also technically.
I'm curious about the BA10, which is also equipped with 5 BAs and possibly makes the small flaws of the AS10 forgotten.