Knowledge Zenith Sonata

Introduction​

KZ has been changing something in the direction of their products lately, and the KZ Sonata follows this trend. It should be KZ’s flagship multi-BA set and in this review I am going to write down all my thoughts on them and how they compare with some similarly priced sets.

Disclaimer: the KZ Sonata were sent to me by KZ 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 Zenith were sold for about $159 at kztws.com.

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Technical Specifications​

• Driver Configuration → 14 x BA (per side)
• Impedance → 23 Ω
• Spec-sheet Frequency Response → 20Hz-40kHz
• Sensitivity → 108 dB
• Cable → 1.25m OFC cable with QDC 2-PIN connectors
• Plug Type → 3.5mm

Packaging​

The packaging of the KZ Sonata is another thing that follows their recent trend, being it one of the “newest” boxes. We finally see decent packaging from KZ as well, which is good news. The box contains:

• The KZ Sonata
• The detachable cable
• One set of starline silicone tips (S, M, L sizes)
• One set of foam tips (S, M, L sizes)
• One set of tips with a slightly larger bore than starline tips yet not really wide-bore
• Hard carrying case
• A small tool to move the switches
• User manual

Design, Build Quality, Comfort and Isolation​

The KZ Sonata look pretty good, they are well built and if anything one could only complain about these having QDC 2-PIN connectors instead of standard 2-PIN uncovered connectors.
The shells are comfortable yet a tad on the bigger side, so be careful if you have very small ears, and they are unvented, so the isolation is usually very good once the right tips are found. I have found better isolation on 3D-printed resin BA sets such as the AFUL MagicOne, but the Sonata still have very good noise isolation from external noises so I am not going to bother.

Cable​

The cable is not up to par with the expectations, especially if we consider the asking price for this model. There are tons of IEMs with great cables under 100$, let alone those that are priced above that price tag.
KZ should really do the jump and provide better stock cables, and I am not even talking about sound quality (this is another controversial topic from which I wanna keep the distances), it’s mostly about the perceived quality of the cable, the materials and so on.



KZ provided one of their “upgraded” cables in the package so that I could evaluate that as well, and even though that’s much better than the stock one, it’s still something for which you have to pay more money and it’s basically toe-to-toe with most 50-100$ IEMs’ stock cables (hence, they should include it as stock cable).

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
• Portable DAPs: Benjie S8/AGPTEK M30B
• Bluetooth Adapters: KBEAR S1, KZ AZ10
• Other sources: Presonus AudioBox iONE, Elgato Wave XLR

Amplifier needed?
An amplifier is not strictly needed for the Sonata, they are very efficient and are driven pretty well by most sources. I would suggest using a decent dongle DAC at least, since the Sonata are technically capable and a good source is always preferable.

Let’s speak about the sound.
I will refer to the 0000 configuration for this review, since the stock tuning is already very balanced and I’ve spent a lot of time using the Sonata with this switches’ configuration.

Straight from the beginning, the Sonata didn’t appear like “just another KZ release”. Instead, they surprised me with a very balanced signature and a cohesive, full sound, especially considering the number of drivers involved. It’s a set that, in its stock tuning, can tick all the boxes of a mature, good sounding mid-centric set. Yes, it might sound strange to you but this is really how the Sonata perform.
The low-end is not missing punch or impact, but it’s evident that it’s not meant to be visceral and rumbly like on some of their previous sets. The bass follows up with proper texturing and nice speed, adding some weight to the notes and giving the sound the dynamics it needs, but it never feels emphasized or out of place. I don’t really dig this kind of bass as it sometimes lacks some weight and depth and that’s where the switches come in handy.
The midrange is clear, resolving, with natural instrument reproduction, forward vocals and no timbrical issues. If anything, those who are used to deeper male vocals will find these a bit on the leaner side and since the midrange is very forward the soundstage depth feels a bit compressed thus leading to an improvable layering. Not something that dramatically changes what I think about the Sonata, but it’s something to point out.
The treble is another area in which KZ did a good job: the treble is detailed, not emphasized to the point that it sounds fatiguing yet not extremely rolled-off. It’s an approach that I like since I don’t want my ears to bleed with super sharp and annoying treble spikes but I don’t want a dark treble response as well. The Sonata sit in between, let’s say that KZ found the sweet spot.

The technical performance is good and they compete very well with sub-200$ earphones. The imaging is accurate for the most part, also thanks to the nice instrument separation, but the layering could be slightly better as said above. If anything I could say that the soundstage feels a bit on the smaller side also, probably due to the mid-centric signature. It isn’t bad by any means but if you’re looking for a very spacious stage then these are not the IEMs to get.

How do the switches affect the sound?
This is how it works:

• First switch ON → +1dB bass boost
• First and second switches ON → +2dB bass boost
• Third switch ON → -1dB in the upper treble region
• Third and fourth switches ON →-2dB in the upper treble region

I like the Sonata in their stock configuration (all switches OFF) but I like them even more if I turn the first switch ON only, even though this makes bass textures “softer” and a bit more blurred.
We finally get to try effective and useful switches with properly designed combinations between their operativity, which is something that many reviewers (including me) have been complaining with respect to how KZ was managing their tunable units.

Are they something I would use considering my taste and preferences?
Yes, and I am actually using them a lot.
Very good sound quality, versatile tuning, excellent isolation, good comfort. I mean, the boxes are fully ticked.
No DD bass, that’s for sure, and since I am a DD bass guy I will probably always take a single DD earphone over something like this because of my personal taste, but these have a pretty impactful bass so sometimes I don’t really miss my usual DD sets.

Sound​

KZ Sonata (UUDD) vs Celest Relentless

The Sonata sound more refined and more balanced than the Relentless, with a more forward midrange and less fatiguing treble. The Relentless win in terms of detail retrieval, even if this is achieved at the expense of a more fatiguing treble response, soundstage and imaging.
Isolation goes to the Sonata whereas build quality, comfort, cable and everything else go to the Relentless.
I like the Relentless more because of my personal preferences (also because of the DD bass), but the Sonata are a lot easier to recommend to most folks out there.

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KZ Sonata (DDDD) vs Juzear 81T Dragonfly

The Sonata are more versatile and balanced-sounding, whereas the 81T Dragonfly have better sub-bass extension and more information up top with better air and sparkle.
If we speak about bass, then the KZ Sonata can be punchier and perform better when reproducing male vocals, thanks to the more emphasized mid-bass that provides for warmer lower mids, whereas the Juzear 81T Dragonfly provide for better technical performance, a bigger soundstage, better detail retrieval and better female vocals.
In terms of sub-bass, the Sonata can be improved with the first switch but the sub-bass quality of the Juzeat 81T Dragonfly will still be better thanks to the superior control, better timbre and more viscerality when digging into the lowest registers.
Are the 81T Dragonfly worth the price jump? Probably not, and this is a big endorsement for the Sonata, but the 81T Dragonfly are superior indeed.
Except for isolation, everything else (build quality, cable, packaging and comfort) are better on the Juzear 81T.

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Final Thoughts​

KZ has been releasing some serious sets and the Sonata is no slouch. The 14BA (per side) units are very good and show the competition that KZ can actually make good IEMs. This set is also among the few sets with switches that was actually pleasant to play with, especially because the most important combinations are highlighted on the user manual and on Sonata’s official webpage (and the switches are finally usable in a smart way).
One thing that bothers me is the need of using 14 drivers when there are some competitors who can still do better with less of them, but it’s also true that the Sonata sound great and don’t really “lack” somewhere. They are not perfect and some improvements are needed, but it’s a very nice set and I think that complaining about the number of drivers would be redundant: if something sounds good, it sounds good.

Good job KZ!

KZ Sonata

Introduction
I was invited to test the new 28 BA IEM from KZ. The Sonata is the company's latest flagship model, replacing the AS24 Pro at the top of the range. It is an all-BA design with 14 units per channel and retails for $150. Two versions are available, "Standard" and "Tuning". The Tuning version has four adjustable tuning switches. The model tested here is the tuning version.

Product purchase link:
https://www.kztws.com/products/kz-sonata

The Packaging
The packaging is far more substantial than any KZ IEM to date. A large rectangular black box with a printed sleeve which shows a large image of the IEM, below which some of the salient features are displayed. The KZ logo appears in the top left and there is branding on the sides as well. Removing the sleeve reveals a plain black box with a textured finish and a simple embossed KZ logo in the centre. The box has a hinged opening and inside, the IEMs are displayed in a cut-out. Below this is a grid holding the eartips. On the left in a plain grey box you will find the blue leatherette carrying case in which the two cables and the tuning switch are stored.

The contents comprise:
● KZ Sonata IEMs
● Flat QDC silver plated cable
● Braided 784 core blue/silver cable
● Three pairs black memory foam tips
● Three pairs black "Starline" silicone tips
● Leather zipped case
● Tuning lever
● Documentation

Build and Design
The earpieces are constructed of black resin and have a smooth glossy surface. They are somewhat bulky but they have to accommodate 14 drivers! The front of the shell has a clear section behind which is a decorative silver panel of triangle shapes. The name "Sonata" appears on the top edge in a script font along with a narrow horizontal grille. There is a small circular pinhole vent on the underside and the clear plastic 2-pin socket is mounted on the top surface. The four tuning switches are mounted on the rear of the shell and operate as below:

Switch 1 On: Bass increased by 1dB
Switch 1&2 On: Bass increased by 2dB
Switch 3 On: Ultra-high frequency reduced by 1 dB
Switch 3&4 On: Ultra-high frequency reduced by 2 dB

Internally, there are 14 balanced armatures per channel in the following configuration:

1 x 22955 BA (Low frequency)
2 x 29869 ( Mid-frequency)
1 x 30019 (Mid-high frequency)
5 x 31768* (Ultra-high frequency)
* dual BA array = 10 units

• Impedance: 22-50Ω
• Sensitivity: 110dB
• Frequency Response: 20Hz - 40KHz

A 4-way crossover network separates the various frequency bands. The 3D printed structure includes a series of sound tubes to channel the sound to the nozzle.

Two cables are included, the standard KZ silver-plated type with a 90° angled 3.5mm plug and a high quality silver/blue braided 8-core cable which features 48 strands per core (a total of 784 strands). It has a straight 3.5mm plug. I would have preferred a modular version of the high quality cable instead of having the two different cables, which would provide balanced operation.

Fit and Isolation
The Sonata comes with a set of medium foam tips pre-fitted. I prefer silicone tips and fitted the supplied medium Starlines. I did not obtain a good seal so changed to the large Starlines. Having decided on these I turned my attention to the cable. The supplied silver/blue cable was used and provided a well balanced profile with solid bass. Thus equipped, I obtained a very comfortable fit with excellent isolation. Although bulky, the earpieces remained stable and snug.

The principal source used for testing was a Hidizs AP80 Pro X in conjunction with a Penon OS133 USB-C dongle DAC. A Ruark R1 digital radio was also employed and a burn-in period of 100 hours was carried out before evaluation.

After some experimentation with the tuning switches, I settled on 1100. This enhanced the bass and brought it in good balance with the mids. Turning off switches 3 and 4 restored the upper frequencies and provided a superbly wide and spacious soundstage.

Sound Impressions
Tonality
As soon as I put the Sonata in my ears I was greeted by a huge, expansive soundstage and the midrange caught my attention with its excellent detail and expression. The treble was highly resolving yet smooth and clean, while the bass was nicely textured, deep and impactful. There was an overall feeling of refinement and maturity not often met with and the timbre throughout was natural and musical. Because of the remarkable transparency, the layering and separation was very impressive, with instrumental positioning accurate and imaging clear and precise. The overall profile was neutral with a somewhat forward midrange.

Bass
Although possessing only a single 22955 driver for the low frequencies, the bass was well balanced with the rest of the range. It was well-textured, clean and resolving with the speed expected from a BA. There was some weight in the delivery which helped to fill out the lower octaves and the extension was good with the level slightly north of neutral.

"En route to Delta Pavonis" appears on the album "Thousand Star" by the spacemusic great Jonn Serrie. The track begins with sweeping synth patches evoking the vastness of space and are soon joined by a deep rumbling in the sub bass perhaps representing a powerful spacecraft engine. The Sonata reproduced this with precision, clarity and texture, as may be expected from a BA driver but there was also a good deal of weight which enhanced the presentation and was not dissimilar from that of a DD unit. Later in the track there is a section featuring space comms accompanied by a deep sub bass which once again impressed with its clarity and resolution. The level remained in perfect balance with the rest of the spectrum but never reached "basshead" levels. The tonality was a tad warmer than neutral with excellent detail.

In Mike Oldfield’s “Tubular World” from “The Songs of Distant Earth”, the bass reached down to the nether regions with excellent weight in the synth bass, the rhythmic integrity maintained well and the texture of the bass guitar nicely rendered. The synthesised low frequency percussion in this piece displayed excellent impact and remained clean and precise, being conveyed with depth and power and a real sense of weight with the delicate electronic effects remaining clear and distinct even during the most dynamic passages.

Classical music was also enhanced by the Sonata's excellent resolution. “The Swan of Tuonela” by Sibelius, performed by the Lahti Symphony Orchestra conducted by Osmo Vanska, was a perfect example.
The brooding atmosphere was captured very well with the menacing bass drum rolls at the beginning providing a satisfying rumble with a sense of foreboding, evoking distant thunder. Basses and cellos displayed excellent texture with bowing very well portrayed with the beautiful and haunting cor anglais solo clearly presented over the supporting orchestral backing.

Midrange
The midrange was a real highlight in the Sonata's performance. The twin 29869 BAs were very well tuned here, providing a wonderful open quality with high levels of detail, a natural timbre and pinpoint imaging which opened a clear window into the music. At the same time, layering and separation were as good as I have heard from an all-BA IEM with each element precisely placed within the image. The size of the staging was another high point, with the music presented in a huge space with incisiveness and delicacy. Vocals, in particular, benefited from this with the voices clearly delineated above their accompaniment and diction unusually well defined.

The character of Colin Blunstone’s voice in his classic single “Say you don’t Mind” was beautifully conveyed by the Sonata with lip and breath sounds clearly discernible and dynamic changes very evident. Set against a clever and imaginative string arrangement by Christopher Gunning, the balance between the vocals and the accompaniment was nigh-on perfect with the diction always precise, resulting in an entertaining and satisfying performance. The instrumental section was incisive and lively and the falsetto ending to the song was reproduced with excellent clarity.

Cello and piano are excellent indicators of midrange timbre and Reynaldo Hahn’s beautiful “A Chloris” is a perfect piece to display the midrange timbre of the Sonata. Written in 1913, it is a homage to Bach and has a real baroque feel. As the graceful melody dovetails with the bass line, the rich woody tones of Julian Lloyd Webber’s cello combined wonderfully with John Lenehan’s sensitive piano accompaniment. The Sonata's accurate reproduction of harmonics and unusually clear midrange allowed the character of the cello and the natural decay of the piano notes within a believable acoustic to be fully appreciated in this wonderfully concentrated performance and recording.

The natural timbre of the Sonata's midrange was further displayed in "O fim das coisas" by Brazilian violinist Marcus Viana. A prolific artist, he has an impressive number of albums to his name across various genres. This piece appears on his album "Trilhas e Temas" (Tracks and Themes) on which his trademark violin solos are supported by a lush electronic accompaniment. The piece opens with a romantic string arrangement, after which a synth guitar voice states the theme supported by bass and synthesised strings. The lead voice was clearly projected above the backing and as Viana's violin combined with the lead melody the two voices produced a romantic and wistful effect which was beautifully portrayed by the Sonata with the natural timbre of the violin showcasing the soloist and highlighting the emotion of the music.

Treble
With an arsenal of 10 31736 BAs singing in unison, the Sonata's treble displayed an unusually delicate and airy quality with superb resolution, precise transient attack and an authentic timbre. Nothing escaped its attention with the finest details clearly discernible and an attractive shimmer in the tonality. This high level of technical ability was matched by an attractive musicality, a combination not often met with.

"White Winds” is the third album by the maestro of the electric harp, Andreas Vollenweider. “The Glass Hall” features a wealth of crystalline percussion sounds
which spread across the stage. Through the Sonata, these were amazingly precise and clear and reproduced with astonishing realism. After this, there is a woodwind solo before the harp enters, supported by percussion and wordless female vocals. Transient attack and dynamic range were also evident in the more dynamic concluding section with every tiny subtle detail captured during this complex and intricate production with the whole blending together in a most satisfying and musical way.

The Sonata managed to create a realistic picture of a classical orchestra, where the superb treble response was clearly demonstrated. In Charles Ives’s “The Unanswered Question” performed by the New York Philharmonic under Leonard Bernstein, the different timbres of the instruments were authentically presented with a clean and sprightly quality and thrilling immediacy. The strange effect of the haunting trumpet solo over the serene and hushed string background was portrayed beautifully, punctuated by staccato parts for brass. The contrast between the tonal string parts and the atonal woodwind was particularly well handled, with the aggressive woodwind tone clusters cutting through the peaceful orchestration in a striking and incisive fashion. This created a wonderful sense of atmosphere and an otherworldly feeling with a disturbing emotional effect.

Percussion certainly benefited from the Sonata's clean and detailed character, with the delicate metallic timbre of the cymbal work and subtle brush sounds in Jacques Loussier’s “Air on a G string” being wonderfully true to life. This beautifully remastered 1960 Decca recording, in a three-dimensional acoustic with double bass and piano, was a joy to hear. The high frequencies had an airy quality which contrasted well with the incisive piano runs in which each note was precisely detailed and defined and even in the most dynamic passages accompanied by the double bass, the percussion was still clearly audible.

Soundstage
The Sonata's soundstage was really something special and perhaps its stand-out feature. An expansive stage in all three dimensions displayed precise imaging, excellent separation and realistic layering with a natural perspective and depth. Positioning of instruments within an orchestra were authentically presented giving a believable picture of a live performance.

Anatoly Liadov’s “Enchanted Lake” in a very natural recording with the Philharmonic Symphony Orchestra of London conducted by Charles Gerhardt showed what the Sonata was capable of. Bass trombones and horns floated at an attractive distance with excellent timbre and harp and horns appeared on each side of the orchestra in their natural positions. Closing your eyes, you could imagine yourself in the concert hall with the orchestra spread out before you. The recorded ambience on this piece came over very well, with a believable hall acoustic and the stereo imaging was very precise. The front to back perspective on this piece was particularly well portrayed.

The holographic soundstage in “Enchanted Forest” from Jeff Clarkson’s electronic album “Peace and Quiet” produced a remarkable sense of space and movement with a variety of electronic sounds and percussion accompanying the synth strings and woodwind leads. The superb sound quality of the recording combined with the spacious and detailed arrangement created a magical atmosphere which the Sonata conveyed perfectly.

The Sonata's superb stereo imaging and layering came to the fore in Bert Kaempfert's "A Swinging Safari". In this recording reminiscent of the stereo demonstration tracks of the 1970s, each element was defined in its own space while gelling together as a unit. The lead melody is taken by woodwind, set against a lively rhythm section featuring double bass and bass guitar. Their contrasting timbres were nicely differentiated by the Sonata while the percussion was particularly clear with bass drum being impactful and brush work easily discernible, resulting in a really entertaining performance. The lively trumpet solos added interest and were accurately positioned within the wide stereo image.

Comparisons
KZ AST (12BA)
The AST is a former flagship model and features 12 BAs per channel. The BAs are the "s" type "black" and are arranged in the following configuration:

Bass: 1 x 22955s
Midrange: 1 x 29869s
Mid/High frequency: 2 x 30017s
High frequency: 6 x 50024s (matrix)
High frequency: 1 x 30019s
Ultra high frequency: 1 x 30095s

The AST is smooth, warm and well-balanced and the integration of the 12 drivers is very good. The bass is firm and solid, being just a little softer and warmer than that of the Sonata, with a more emphasised mid bass. Midrange is less forward than the Sonata and just a bit recessed, but is easy-going and smooth. The treble is not as extended, but still displays a good amount of detail. The overall presentation is gentler and very amenable and there is no listening fatigue, but it loses out to the newer model in terms of resolution. The staging is well done but not as expansive, and falls short in terms of layering and separation. However it is very relaxing to listen to. The two models are very different in their presentation.

KZ AS24 Pro (12BA)
Also a former flagship model, the AS24 Pro is another 12 BA per channel design. Internally the BA driver complement comprises:

1 x 22955 BA for the bass frequencies
2 x 29869 BAs for the midrange
4 x 31736 dual BAs for mid/high area
1 x 30019 BA for the ultra high region

The AS24 Pro impresses with deep solid bass, a detailed and open midrange and very clean, bright treble. Its profile is brighter and somewhat more "V-shaped" than the Sonata, with the midrange just below the level of the bass and treble. The bass, which is slightly stronger than the Sonata, is also a little warmer due to a mid bass lift but it is not as detailed or textured. Sub bass is well defined and mid bass is on a higher level, whereas the Sonata's mid bass is more laid back allowing the sub bass to come through and resulting in a cleaner midrange. The midrange is slightly recessed but still very articulate, but the more forward mids of the Sonata impress more with their resolution and detail. With its 10 drivers, the Sonata has a smoother and more extended treble than the AS24 Pro whose treble is brighter and not quite as airy or detailed. In terms of soundstage, the AS24 Pro is very capable but set against the outstanding staging of the Sonata, there is only one winner here.

Conclusion
Although released quite soon after the AS24 Pro, the Sonata is its worthy successor as the flagship model in the KZ range. Attractively presented with a good selection of accessories, it continues the advance in tuning we have seen recently from the company. The tuning switches are very effective and produce a range of different sound profiles which should suit many listeners.

Possessing a superb expansive stage, high resolution and well balanced and refined profile, it is a real step up in quality and elevates the KZ brand to a higher tier. It shows what can be achieved with multi-BA designs when correctly implemented.

There really is very little to criticise here. Although the earpieces are attractively designed and well constructed, perhaps they could have been made of metal, and bass lovers may find the Sonata a little disappointing even with the bassiest switch setting. However, overall the Sonata's delivery joins technical excellence with a musicality and refinement which encourages further listening. I consider this to be the finest model I have heard so far from KZ and is a serious contender in its price range.

KZ Sonata Review​

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KZ Sonata Review​

Intro​

Today I have with me the KZ Sonata ($149), from KZ Audio. The Sonata is actually an all-balanced armature earphone. Well, there’s more to that, actually, the Sonata has 14 balanced armature drivers per side. Yes, you read that right, that’s “14” balanced armature drivers. The second I found out about the Sonata I was beyond thrilled to hear them, so naturally I am also pretty excited to explain my thoughts about them. I have reviewed a mountain of KZ/CCA earphones in the past and I can say with complete assurance that the Sonata is without question KZ’s most ambitious earphone to date. Did I mention it has 14 BA’s per side? That’s, cray-cray. Ya know, usually I write my intros prior to even having the earphones in hand, it’s something I enjoy doing in anticipation of receiving the product. That said, I didn’t even know I was receiving the Sonata at all. In fact, I didn’t know the Sonata even existed. Not until I opened the very nice packaging and saw that KZ once again “upped the ante”. Marketed as the perfect earphone for the novice as well as seasoned musicians. It has tuning switches, upgraded cable, better tips, better case. However, I’ll cover that later. The point is, the Sonata was a big surprise for me.

A lot to live up to… ​

Now, the Sonata comes hot on the heels of one of my personal favorite earphones above $100 in the KZ AS24 Pro (AS24 Pro Review), and let’s not forget the KZ AS24 (AS24 Review). Without question the Sonata has a lot to live up to as the AS24 Pro is a true testament to KZ’s ingenuity and willingness to push the boundaries of what is possible inside of a small housing. Well, the housing is actually quite large for an in-ear monitor. However, the fact that KZ squeezed two more BA’s inside of that housing is pretty awesome. I’d also state with complete assurance that another one of KZ/CCA’s best iems to date is the CCA Hydro (Hydro Review). Have you heard that set? Friends, it’s an absolutely wonderful sounding hybrid iem and I couldn’t sing its praises enough. So, between the likes of the KZ AS24, AS24 Pro, and the Hydro, I really feel strongly that the Sonata has a lot to live up to and should likely be an upgrade to them all.

Good position​

I’m not going to push this intro too far, keep it short, less word babble. However, I do need to speak on a few things. First, the price of $149 is a hotly contested price point. No doubt about that. However, one thing that the $149 price point is missing is… all BA iems. You don’t see them all that often. Well, you don’t see non-KZ all-BA iems very often under $150. It’s sort-of a rarity which places the Sonata in a unique position against the current crop of contenders. We see a ton of single dynamic driver earphones, hybrid earphones too. Yet there are only a handful of all-BA iems in this price point. Whether that’s single BA sets, or multi-BA sets. KZ has been one of the few brands willing to bring-to-market all balanced armature earphones at a cheaper price. I think a lot has to do with the fact that they source their own drivers, create it all in their own factories and cut out all of the middlemen. Something that I don’t think many people know. With that in mind, I feel the Sonata is in a very good position as far as competition is concerned. Also, with that said, I think I’m ready to get into this review. The KZ Sonata…

Non-Affiliated Purchasing Links:​

–KZ-audio
–Amazon

Disclaimer:​

I received the KZ Sonata from KZ Audio as a review sample and in exchange I will conduct a full review and feature at Mobileaudiophile.com. I have not received any payment or any other form of compensation for this review. This set is a review sample iem. KZ Audio has not requested to pre-read any review and doesn’t have any control over “what” or “when” anything gets published to mobileaudiophile.com. All thoughts within this review are my own, though please take note that I will always have my own biases. This is impossible to get around. I try to be as objective as my subjective self can be, but this is an opinion piece folks. Thank you to KZ Audio, and thanks for reading.

Gear used for testing​

–Ifi Go Blu

–EPZ TP50

–EPZ TP35

–Aful SnowyNight

–Shanling H0

–Fiio Q15

–iBasso DX240 with Amp8 MK2

–Shanling M6 Ultra

Packaging / Accessories​

Unboxing ​

Well, the KZ Sonata came to my home in a much larger box than I usually see from KZ. The 1st thing you’ll notice is the giant picture of the Sonata adoring the black sleeve cover. On the back of the sleeve is some specs, a couple frequency graphs, and some stats as well. Nothing out of the ordinary. Take off the sleeve and you’ll get an almost blank black box besides a small KZ logo in the middle. Obviously made very well and not some cheapo box being used. Open the lid and the Sonata are sitting to the right/top within foam cut-outs. Below the earphones you’ll see the assortment of eartips in a nicely packaged tray. To the left is a larger box which houses the carrying case. Take out the carrying case, open it up and you’ll see two different cables (I’ll explain later) as well as a dip-switch tool. All things considered; the unboxing is nice. Certainly, better than we are used to seeing from KZ and very nice at the $149 price point.

Eartips​

So, KZ added in a total of seven pairs of eartips. They provide four pairs (S, M, L, L) of slow-rise foam eartips which are of high enough quality. I don’t usually use foamies unless I absolutely have to, but these are quite nice. The next type of tips are three pairs (S, M, L) of KZ’s highly enjoyed KZ Starline tips. I actually really do enjoy using Starline tips when they are needed. However, I feel for my own comfort and sound enjoyment I went instead with KBear 07 eartips. If any of you have read any of my reviews, then you know that the good ole’ KBear 07 tips fit me like a glove, and I love what they generally do for the sound with any set of earphones. They are just a little bit more robust at the flange then the Starlines which seals better in my ears. You may be entirely different. Also, the 07’s seem to add just a touch more punchiness to the low-end while opening up the upper mids to a degree. Just more of an edge to the sound, more crispness. Of course, I do feel that each one of you should check out every tip you have in your arsenal to get the sound closest to your preferences.

Carrying Case​

One thing we aren’t used to seeing is an actual carrying case with KZ models. So, the Sonata comes with a very nice faux leather zipper case which is of good size and very nice looking too. It comes in a deep blue color which contrasts nicely the silver zipper. It’s a nice case folks. Plenty large enough to house the Sonata earphones, the cable, some eartips, and maybe a small dongle dac. Great for throwing into a bag and not having to worry about anything becoming damaged. It’s a nice case and not one I would have expected to see with the Sonata.

Cables​

KZ provides not just one, but two cables with the KZ Sonata. That’s right, one is the regular KZ QDC style SPC cable that we see so often with their products. The next cable is KZ’s own upgrade cable. The upgrade cable is a 784 core fairly fat cable which can be purchased separately by the way. It is a mostly white/silver cable with blue accents making it a very attractive cable for the Sonata. Both cables come in 3.5 single ended terminations, both are QDC style 2-pin, and both are silver plated copper cables. I’m fairly positive about that last sentence. So, both cables are very useful. The regular KZ white opaque cable which we see with every KZ set actually has a microphone and a switch on it to control different things while listening. However, one thing I rarely hear anything about is that the KZ “mic” cable actually records the human voice pretty darn well. I don’t want to go crazy about this, but my voice comes through fairly naturally. Just an added little tidbit which I don’t think ever gets spoken of. I suppose I only ever get the “non-mic” versions and so I usually don’t get the opportunity to check out the mic quality.

What did I use? ​

Having said all of that, I actually went with an entirely different cable for my listening. Folks, I went through a multitude of cables trying to find the perfect pairing in a budget form. Basically, I didn’t want to spend 8 thousand dollars finding a good cable match. What I came up with is one of the best cable discoveries I’ve had in a while. I used the Nicehck IcyMoon cable in the 4.4 balanced variant. Friends, I spend way too much time going through different cables, trying to find suitable pairings. I’m telling you that the Nicehck IcyMoon is truly a perfect cable for the Sonata. If I’m being honest, the IcyMoon works wonderfully for many sets. However, the pairing was too good to not speak of in this review. For a cheaper cable ($22-28) it’s as pliable as can be, non-microphonic, very fat, dope looking, and is simply a nice feeling cable. Now, for any 3.5 single ended listening I did use the KZ upgrade cable. Still, if you want to find a nice non-expensive cable which will upgrade your listening experience, the IcyMoon is a good place to start.

Build / Design / Internals / Fit ​

Build Quality ​

So, the actual build of the Sonata is very much reminiscent of previous KZ/CCA models. The Sonata uses the large sized housing from KZ’s mild lineups, which is pretty obvious considering the staggering number of drivers they somehow crammed inside of the shells. Made entirely by way of DLP-3D printing, the housings are crafted precisely between units. This preserves the quality and cohesion between earphones. KZ states that the resin used is skin-friendly, has high impact resistance, and offers high durability. Now, you have to realize that this is a huge set of earphones. They’re big folks! Smaller ears may not be able to accommodate the full girth of this set. Having said that, my ears are not big and the Sonata fits like a glove. Then again, any earphone in their lineup using this mold has fit my ears perfectly. Also, the Sonata doesn’t feel heavy, oddly enough. Maybe it’s the way KZ distributed the weight, but I don’t ever get any fatigue whatsoever when wearing. On the faceplates you’ll see a stainless-steel ornamental border which is a nice thing to see along with a larger vent on the faceplates as well. On the back of the Sonata, you’ll see the four dip-switches (I’ll explain next). The nozzles are right around 6mm in width, and they are a hair past medium length. Meaning, they fit fairly deep in the ear. In my opinion, the build is very good folks, nothing rattling around inside and everything just feels like a durable and well put together package.

Tuning Switches ​

The KZ Sonata comes in two different variants. You can purchase the non-switch variant which KZ refers to as the “Standard” model. Or you can purchase the tuning switch model which KZ calls the “Tuning Version”. Obviously, the set I have is the tuning version and I feel like this is the model which makes the most sense to actually purchase. I mean, why in the world would you not want more control over the sound? I think it’s great. However, there was a point in the recent past where people were beginning to complain about the switches on KZ/CCA earphones. I don’t get it, again I ask… why would anyone complain about having more control over the sound? You set them once and forget about them. Anyways, such is life.

What do they do? ​

So, the Tuning Version comes with four dip-switches and mostly those switches only control the bass. I won’t go into some long discussion on the switches, but I’ll instead keep things short and easy to understand. So, for review purposes, “1” means “on”, and “0” means “off”. So, if I have all switches “on” I will call it “1111”. If I have all switches off, I will call it “0000”. I personally enjoy “1110” or “1111” with the Sonata and now I’ll try to explain what those switches mean. Basically, if you flip on the 1st switch it’ll add about 1db of bass emphasis. Now, flip the next switch on and it’ll add another 1db of bass emphasis. Next, flip on the 3rd switch and guess what, it’ll decrease the highs by 1db. Lastly, if you flip the last switch on it also decreases the highs another 1 db. So, the 1st two switches’ controls bass emphasis, and the last two switches controls the highs. I’m telling you folks; KZ has figured out how to best use their switches and really dialed them in. Like I said, I mostly enjoy either “1111” or “1110”. For review purposes I used either one of those two switch settings. There isn’t some drastic difference between the two, other than some slight additional sparkles up top. So not much. At any rate, it’s all really easy to understand as KZ has made switches very simple.

Design​

Now, the actual design of the Sonata is not unlike a few other higher end KZ models. The look is similar to the AS24 and AS24 Pro for example. Once again, the Sonata appears more like jewelry in the ear than anything else. Also, once again, the look may be pretty polarizing for some folks. Not everyone wants a blingy look. Having said that, I actually feel the design of the Sonata is one of the best that KZ has ever come up with. The Shells are this dark transparent housing which allows me to see the drivers inside. While the faceplates have this gun-metal color stainless steel trim which borders the faceplates. Really, it’s one of the dopest looking sets! They really did a nice job on the design language. I like the darker setting, the less extravagant and blingy look. Much more unassuming. I won’t go too long here but KZ did a nice job. Of course it won’t be for everyone, but really… what is? Nice job KZ.

Internals ​

Now we get to the real mind-boggling detail about the KZ Sonata. Forget the switches, forget the unboxing, forget all of that because KZ actually squeezed 14 balanced armature drivers inside of these Shells. That’s quite impressive folks. Even more impressive is that they actually get all of those drivers to coexist and cohesively replay my music. But that’s for later. So, 14 drivers! To be exact that is one “22955” giant BA bass driver, two “26698” drivers covering the mids, one “30019” driver covering the highs, and ten “31736” drivers covering the ultra-highs. The 31376 drivers are actually BA arrays meaning every two is a back-to-back BA unit. So really, it’s five “31376” arrays of two. I hope that makes sense. Obviously, using BA arrays helps tremendously for fitting so many drivers within the shells. Beyond the drivers, KZ utilized a four-way crossover unit which separates the spectrum and coherently blends all of those drivers to form the sound that our ears hear. Truly a spectacular feat from KZ. I am impressed.

Fit/Comfort ​

I spoke on this briefly a few sections ago but the fit I get from the Sonata is about as good of a fit as I can get. Yes, the shells are enormous, yes, they are bigger than your average earphones, but they also fit better than most too. KZ must’ve done their homework here because I’ve never had even one issue with KZ’s larger shell molds. Very ergonomic for their size. Weight distribution is key, and I’d say they nailed this set perfectly. It should go without saying that I have zero idea how the Sonata is going to fit your ears, but I can tell you how they fit mine. Honestly, once I found the right eartips I was good to go. I’m assuming most other people will be in the same boat. Having said all of that, I do need to speak on the fact that you can get some pressure build up from the Sonata when putting them in your ears. My suggestion is to cycle through tips and insert them in a way that this doesn’t happen. I felt it a few times with the KZ tips which prompted me to change to KBear 07 tips.

Drivability / Pairings ​

Output Power ​

The KZ Sonata “Tuning Version” is rated with an impedance of 22-50 ohms depending on your switch orientation. Also, the Sonata has a sensitivity of right around 110 db’s. What this basically means is that the Sonata is fairly easy to drive. I was able to use a regular smartphone and my iPad to drive the Sonata to decent enough volume. However, I’d be very much remiss if I didn’t also tell you all that the Sonata actually thrives with a bit more power. Unlike previous versions, namely the KZ AS24, adding more volume doesn’t hurt this set as much and in fact, I feel that more raw power helps the sound quite a bit. You’ll bring out all of the nuances in the drivers with some added torque. Enough to notice, let’s just put it that way.

How much is enough?​

I would certainly try to use a decent Dongle Dac with your Sonata, something with adequate power. What is adequate power? Well, my best guess is at least a 100 mw @32 ohms dongle. It doesn’t have to be some mega amp worth of power. Just a nice dongle dac. Having said that, without question my daps (which all max around 1watt) sounded best with this set. Many times, I question whether it’s the power that scaled the sound, or the actual better circuitry and better sources which scale my listening the most. I don’t know. I do know that any source which offers more output simply sounds better. No doubt about that. Still, I absolutely adore the Sonata on dongle dacs like the EPZ TP50, Hidizs S9 Pro Plus, Aful SnowyNight, Simgot Dew4x, EPZ TP35 and on and on. I should add that I always use high gain on all of my dongle dacs. So, to conclude this little section, try to find something with at least a moderate amount of power and the Sonata will reciprocate.

Source Pairing ​

Source pairing with your earphones is one of the most convoluted understandings within audio. We hear reviewers constantly speak on best sources to use with this or that set of earphones and folks… It Is only an opinion. That’s it. In my… “opinion” … the best source tonality to use with the Sonata ranges from neutral to warm. That means, neutral, warm/neutral, and warm sounding dac/amps, daps, dongle dacs etc. That’s my opinion. Others may love a bright/neutral source, who knows. I am somewhat against saying something “synergizes” with another thing because it’s based on subjectively driven criteria personal to me. Also, I don’t want you spending money off of something that synergizes to my tastes. Now, I do believe that “personal synergy” exists. I don’t want to step on anyone’s toes because some of the most awesome and Influential minds in the hobby use “synergy” often. I am hoping to help you, the buyer, as best I can. To do so I have to be upfront with you. I’m telling you right now that the KZ Sonata is not very picky about source tonality. For me, in my personal use, I don’t like anything bright with the Sonata. That’s me though. You may be different. You may greatly enjoy hearing even sparklier highs, further extended up top, more brilliance. I truly try to find a balance. Thankfully, the Sonata already has a nice tonal balance to work with.

What do you need? ​

To summarize what I just said, I think you should strive to get a decently powerful dongle dac. The Sonata will certainly reward better sources. It’ll show up in your listening. If you have a nice dongle dac that you enjoy, use it. Maybe put it on high gain and enjoy, wake up those drivers. However, if you only have money for the Sonata. You don’t have a dime more to put towards a dongle dac or dap etc. then i think you will still have a set of earphones that sound very nice even off of a 3.5 single ended jack on a smartphone (depending on the phone). Still, more power helps, better sources help.

Sound Impressions ​

*Note: I want to preface this entire sound section with a couple things. First, I did burn this set in (mostly out of habit). People say that balanced armature drivers don’t need burn-in but I burned-them-in anyways. About 40-50 hours, best guess. If I’m being totally honest, I didn’t think it did much. Lol. Full disclosure. On top of that, I did not like the included tips “sonically” with the Sonata and found that the KBear 07 tips did a wonderful job of opening this set up, so to speak. I also listen primarily using flac or better files stored on my devices. The music player I use mostly is UAPP (USB Audio Player Pro). However, for certain dongle dacs I do use Hiby Music Player and when I’m out and about I like to use Poweramp at times too.

A little context​

Ya know, one of the biggest gripes I have about this set, is that so many folks aren’t going to give it the time of day. Likely due to the name which precedes “Sonata”. That’s “KZ” if you didn’t know. Of course, before I say anything of substance (and there’s no guarantee I’ll accomplish that) I want to warn you that I’ll speak fairly highly of this set. Just lettin’ you know now. However, those words have to be put into context. After all, without context our words either incriminate us or mislead others and I don’t want to do either of those things. At any rate, please understand, I am judging the sound against iems within the Sonata’s price point. Please let that sink-in. When I say “great”, “awesome”, “wonderful” or “fantastic”, what I’m actually saying is “those words” within the standpoint of an iem ranging from $100 to, let’s say… $199. With that context I am absolutely describing exactly what my ears hear from the framework by which my auditory cortex associates the sound to my personal and subjective taste. Also, I don’t review anything I don’t enjoy, so obviously you already know I like this set.

What’s it sound like? ​

The words which first crest my mind are “full”, “immersive”, “voluminous”, “precise”, and for whatever reason the word “distinct” keeps creeping its way in. I suppose I’ll figure that through during this review. Truth is that the sound is how one should expect a total of 14 balanced armature drivers should sound while they are all in sync and at least marginally in concert with each other. It should be multi-dimensioned, sound coming from different partitioned off areas of the imaginary sound field in your mind. A lot has to do with the music of your choosing, your eartips, your source, and of course your personal taste. It’s a very nice sounding set, but it has to agree with you.

Best KZ BA? ​

The KZ Sonata ranges anywhere from neutral to warm, in my opinion. The way I choose to listen is with either “1111” or “1110” in my dip-switch settings, which is more like warm/neutral. There’s a very nice balance with both bass switches turned on and that balance drastically helps the overall sound which reaches your head space. Anywhere from V-shaped to U-shaped and again, the switches will certainly be the determining factor in that. Well, along with finding eartips which work for you. And please hear me now, eartips make a difference with this iem! From my perspective, the Sonata offers a big sound. It’s full, with a broad stage that encompasses all of my mindscape. Using my switch settings, I found the balance from bass to treble is really nice with a very impactful and energetic sound. The Sonata is mostly smooth yet with crisp highlights, very quick and decisive transients across the range and very good note density. Nothing papery here folks. I hear nothing weak about the sound of the Sonata. There’s a real symphonic quality to this set which isn’t easy to put your finger on. Certainly, a very musical sounding set in the “1111” or “1110” configuration while at the same time it comes across highly detailed, very solid instrument separation and good air between notes. However, what’s most impressive to me is the cohesion between frequency ranges. You don’t hear any crazy peaks or uneven moments throughout the spectrum. It’s all smooth and easy transitions with very solid timing and cadence. No doubt in my mind the KZ Sonata is the best all-BA set made by KZ. As much as it pains me to say this because I really love the AS24 Pro.

Condensed Sound Between the 20’s ​

The bass is very tight while in the same breath it can get reasonably deep and penetrative for a balanced armature driver. Without question it won’t heed the same depth and organic qualities of a dynamic driver, but boy-oh-boy is it close folks. Again, it depends wholly on your switch settings. No doubt the bass hits hard and with better impact than the AS24 Pro. It’s very nicely defined too. The midrange is certainly a vocal friendly midrange, somewhat forward, very clean, nothing grainy, metallic, and nothing sibilant. The midrange is a great mixture of technical ability and musicality. Just a pleasant-sounding midrange. The treble has plenty of brilliance, has some quality treble bite, is very well extended and doesn’t cause undue fatigue. Unless all bass switches are off, at which point the treble can start to become a bother without the offset. Still, the treble has a nicely layered sound, good treble punch, and even some haptic recognition in each note. As far as technicalities, the Sonata is a very well detailed set, nice and tight transients help instrument separation quite a lot. The Sonata is a highly resolving set of earphones where clarity is a mainstay. In truth, the Sonata certainly has some issues, and I will try to outline those in the coming sections. However, in terms of straight price to performance, the Sonata offers a very solid performance. Obviously, the sound may not be for everyone, but for what it is… the Sonata is a good sounding set of earphones for a relatively cheap price.

Bass Region ​

The low-end of the KZ Sonata is one which hits-n-gits. It has that very quick impulse attack with a punchy nature. It’s fast and can take on very quick bass passages with no problem. The recovery of each note is like any good balanced armature driver, it’s quick. What I noticed first was how deep and bullish this bass can sound though. You normally don’t hear this from a balanced armature. I said similar things with the AS24 Pro but this time around you have even more depth and layering to the sound. The bass on the Sonata isn’t even trying to be one-noted. In fact, note definition is very high. Each note is somewhat rounded, very chiseled, etched out, and with space between notes. Where a dynamic driver will usually sound more authentic, organic, and simply more atmospheric, the Sonata will cut off some of those resonances and so you really don’t have quite the depth of a DD. Not that I’m missing much either and you hardly even notice unless you are actively listening for it. Please trust me, it took three or four songs before I heard a large enough difference between the Sonata’s BA’s and a regular DD to even speak on it. This is a very fast bass yet with enough forceful oomph to accommodate genres that need some bulbous bass to satisfy. Of course, the Sonata is more balanced across the frequency range which means that it’s not a basshead set. It won’t rattle your eyeballs. It’s just a good strong and punchy bass with a solid snap on impact and some good ole’ quick recover speed density. Like I said, it hits-n-gits. Like most any BA or planar down low.

Sub-Bass ​

I won’t go too long in these upcoming sections, but I found the sub-bass to be decently extended into the lowest of lows. The Sonata can reach some deep pitched guttural sounds without breaking up and while maintaining control over the spectrum. You shouldn’t expect some bassist style heavy drone though; the Sonata cannot deliver the deepest lows like some of the heavier bass iems that we’ve seen of late. Instead, the Sonata stays clean, highly resolved, fast in its transient attack through sustain, and always adds some hard density to each note. Of course, every track will give you something different, but generally it is very hard for me to find complaints. Now, the sub-bass note weight is not super hefty. Nothing waterlogged or too bullish. However, there is some low droning grumble down low when a track calls for it. Tracks like “Tell Me What’s on Your Mind” by The Decemberists is a perfect example of the Sonata’s ability to take a completely growling and deep bass riff and replicate that with a low thrumming drone of its own. Basically, the sub-bass weight and density is there. It isn’t rolled-off or too light in amplitude like so many balanced armature sets out there. It’s hard edged, nothing soft, nothing pillowy and just enough haptic feel to the sub-bass along with a very crisp, clean, and well-defined sub level rumble. Let’s put it this way, I really mean it when I say that the Sonata has a very capable sub-bass which truly does a fantastic job for a balanced armature driver. Just as good as other BA sets which cost three times as much as the Sonata. I know because I’m literally listening to some of those sets right now for this review.

Mid-Bass ​

Just like the sub levels, the mid-bass is no slouch whatsoever. Switch on your bass switches and you’ll hear what I’m talking about. Like I said, you won’t get that long decay and atmospheric type of dynamic driver depth. Yet you are getting some nice BA bass for a set costing under $300. It easily hangs with sets like the Hiby Yvain, Kiwi Ears Orchestra Lite, and Softears Studio 4. The fact that the $149 Sonata hangs with those sets down low is somewhat of a testament to the quality of drivers and tuning from KZ. Furthermore, I could name many more all-BA sets that I feel cannot stand next to the Sonata in overall weight, density, or quality. The Sonata can flat out bang at times folks. However, that “bang” is tight, it’s quick, it’s mostly impactful, very punchy, very exact in its approach. I hear a snap on its attack, a certain crispness, a vibrancy. It isn’t simply a bland and dull thud. It’s a quality bass. However, please remember this is with both bass switches turned on and at least one treble switch turned on (which means less treble). One song which will show you the dexterity, solid surfaced slam, and speed of the Sonata is Daft Punk‘s “Get Lucky”. I truly enjoy the dynamic volume and robustness that each beat carries while maintaining a condensed and clean slam. I hear roundness to each note, there’s depth there, it isn’t some one-dimensional and one noted affair. No sir, this bass is agile in a way similar to a solid planar. Is it perfect, absolutely not. It’s pretty nice for a balanced armature set however, but I think I’ve established that.

Slight lack? ​

Beyond that, there may be some kick drums which don’t feel as authentically textured or swollen in hollow brunt force as some sets. Not that I think they lack either. It’s just better to temper expectations a bit. Especially if you are used to dynamic drivers. Like “Billie Jean” by Weezer. The kick drums were a hair less pointed in their forcefulness and boom. Slightly doughy. Not bad though, still fast, still pleasing. Just not a dynamic driver. I should also add that other examples render a completely different result. Which is at least mildly strange. Now, bass guitar usually does have enough of that fullness. Again, I never feel as though what I’m hearing is lacking. I still hear enough of a foundational bass guitar backbone to carry most tracks just fine. In fact, some of you may feel the bass is too emphasized. Still, in the case of the Sonata there are some tracks which truly sound about as close to a DD as a BA can get. There’s always this richness to the sound, a certain power, a voluminous nature to the sound which is compelled by the bass more than anything.

Downsides to the Bass Region ​

The biggest drawback of the KZ Sonata’s low-end is that it simply isn’t a dynamic driver. Let’s face it, most anytime that you see “balanced armature” providing the bass you will also likely not get the forcefulness and organic depth that a dynamic driver naturally provides. It’s just the truth. Having said that, I know so many folks who disagree with that and who much prefer BA bass. I think they are probably in the minority, but hey, it takes all kinds. The low-end isn’t atmospheric and won’t give you that realistic resonance decay. Also, it isn’t the most sonorous, stentorian, low droning, or deepest sub-level bass ever made. Or just in the $149 price range. So be aware of that. This is not a basshead set and won’t appeal to those who love that long lingering decay and reverb. However, in my opinion the cons stop there because the Sonata sounds flat-out nice for what it is and how it was tuned. It’s a clean bass, has enough meaty weight for most any genre (at least to an extent) and can hang quite easily with much better all-BA iems in the bass region.

Midrange ​

The midrange is (in my opinion) the focal point of the Sonata. I wouldn’t say it’s a bona-fide slam dunk that the mids play this role, but it’s definitely the region which forces my focus with most genres. I said in the “condensed” sound opening that the midrange is a nice mix of technical and musical and I stand by that. That said, the Sonata’s midrange is one of tighter transient attack & decay. It’s fast, nimble, dexterous, and ductile in its ability to attack and then recover quickly while never losing the round dimensional body of its notes. Usually anyways. That quickly paced rhythmic sound is ushered in with what I’d call a semi-natural note weight (perhaps a hint thin at times) and a very detailed sound. There’s a vibrant nature to the mids while coming across as warmly toned with semi-energetic and smooth dynamics. The atmosphere has a warmth to it, not a veil, and not muddy, grainy, or rolled off sounding, yet there’s still vibrancy, some luster, some tinsel glittered across the crest of each note, so to speak. But there is a pervasive warmth which cascades. It’s not super easy to explain a warmth which doesn’t make the overall sound overtly… warm. You won’t hear a huge contrast in its dynamism, but I don’t think that is something to judge against the Sonata for. You see, the sound is enthralling, even engaging in the layered display of the sound field. The stage is absolutely grandiose with a very holographic take on my music. You will hear this right away folks. Just a very upbeat sound that’s again… also very quick. It can take on even complicated passages with relative ease.

Timbre ​

Now, at times the sound can come across more natural than others. Timbre is not organic as in the way a DD can come across organic. However, solid for a $149 balanced armature set and better in my opinion than the AS24 Pro. Which is saying a lot. It takes at least a small measure of an acquired taste if you are coming from a very natural and organic sounding set. Let’s put it this way, I just finished my review of the ultra-realistic and natural Dunu Kima 2 (Kima 2 Review) and so there was some listening I had to do for the Sonata to truly resonate. I certainly wouldn’t call the Sonata an artificial sounding set either, but there’s just so much for the mind to pay attention to as details, layers, micro-layers, separate and distinct instruments, and micro-dynamics, all play for space within the mind. Especially in complicated tracks. However, in slower and more melodic music the Sonata is exactly that… melodic. For a $149 all BA set, that is. I hear zero metallic or plasticky type of timbre. There’s a certain density to every note. Even though I wouldn’t necessarily call the Sonata a rich or lush set when it comes to note body. To be perfectly honest, different songs render different results, but mostly it’s a mature sounding midrange with some wisps of musicality and fun. Highly detailed, great separation, distinct layering, 3D in its psycho-acoustic display of the sound field, a hint of warmth and it carries a smoother demeanor. Score one for KZ folks, it may not be a picture-perfect midrange but it’s very nice for the cost of ownership.

Lower-midrange ​

The low-mids could use some weight I suppose, though they aren’t the type which feel they are in much need of anymore bodily support. Also, they don’t come across too far pushed to the rear of the sound field or too recessed. Nothing sounds out of place and the low-mids generally have a decent presence. Now, the bass doesn’t encroach upon the mids to the point of adding warmth and voluptuous notes. Perhaps to an extent but nothing which gives males that truly authoritative robustness that some male vocalists thrive with. Not that the Sonata has anything to be ashamed of as males sound nicely centered, and vocally very clear against the musical backdrop. If anything, I’d say the low-mids are more like “lean yet condensed”. There’s nothing worse than thin and dry and I can tell you they aren’t that.

Low-mids cont… ​

There is some density, some forward leaning presence which helps a singer like Dermot Kennedy in the track “Rome” to come across smooth in rhythmic flow yet with a clean edge to his vocal delivery. If you’ve ever heard him, his voice has a natural sharp edge to it. There’s an abrasiveness to his powerful voice. This is where the Sonata does very well at sanding down those coarse moments offering a pleasing take on his and many other male voices. Personally, I enjoy a bit more weight, providing that weight doesn’t widen the presence, or make males sound too dull or too unenergetic. females are also very well centered while instrumentation is placed almost perfectly in the periphery. The Sonata does seem to have a mid-focus by a small margin. Though I also usually enjoy at least some vibrance to the sound. Thankfully, the Sonata seems to have enough vibrance and clarity to help males to stand out, and great imaging capabilities to keep them stationary and centered.

Upper-Midrange ​

The upper midrange certainly offers a more forward portrayal of female voices and instruments. I hear some subtle radiance and crispness which provides some shimmer to this region, just a bit of sparkle. Enough to sound energetic yet not enough to sound glaring. Just a touch. Females like Olivia Rodrigo in “Deja Vu” sounds really nice actually. Her voice has that realistic quality which never sounds too uplifted in lustrous vivacity. Never too forward. She sounds smooth, and buttery, enough for an emotional tilt to her voice. Again, presence is great, and her voice is centered very well. The pinna rise is not one which peaks too early, and there isn’t some steep uphill climb in the pinna resulting in any real shout. Everything is kept in pretty nice control. Again, clarity is very high, details are easy to distinguish, it’s a nicely tuned upper midrange which fits the overall tuning nicely. Honestly, females come across very nicely and I have plenty of examples of this. From sweetly breathy in “I Love You, I’m Sorry” by Gracie Abrams. To bold, and downright resounding in Sia’s “Unstoppable”. Voices are never artificial to me, and they are always well centered in the sound field. Very nice note structure and image placement.

Downsides to the Midrange ​

I’d say that the biggest downside would be for those completely organic lovers who like a more earthy sound. The Sonata is again, not artificial sounding, but it is a fast-decaying balanced armature midrange which leaves harmonics cut back at times. Thankfully we don’t hear any of that metallic timbre though, and trust me if I did hear it I would speak on it, because I cannot stand it. However, nothing is for everyone, ever. That all said, I think the midrange is actually very nice and you can always use the switches to change things up a bit if you’d like. It is a very pleasant-sounding midrange with a highly technical side to a musical tuning. Not an easy thing to tune into a set of earphones. Not that I’ve tried. At any rate, at the end of the day the Sonata is a very nice sounding all-BA set and the mids are a big reason for that.

Treble Region ​

The treble region all depends on what your switches are set to. I made sure to leave one of the treble switches on while the other drops back the emphasis a couple db’s. Add in the fact that I have both bass switches on and the balance sort-of tilts towards the warm. Having said that, I feel the treble on the KZ Sonata has a very nice emphasis. It has a brilliant sway over the frequency without being all-consuming. I hear a very fine-tuned control over the spectrum, and nothing sounds out of place. I don’t hear anything sharp from the treble region and I don’t hear anything splashy either. It’s a nicely tuned treble region. I’d say it is smoother than it isn’t, with adequate bite to treble notes, depending on the song of course. I like that I have some control of the output in the treble region and how the treble impacts the rest of the mix. In my opinion the tonality and timbre of the treble is actually very nice for a balanced armature set as well. I’d call it an upgrade over the AS24 Pro, with some extra extension into the upper treble region, better precision, and a more layered sound up top. Really a nicely tuned iem as a whole, and the treble is a huge player in that.

Nothing forced​

The treble is clean, bright, crisp and detailed. Upper harmonics from vocals are smooth, enhanced and clearly audible. Sopranos come through with elegance, and a very vivid note body. The definition of instrumentation is clearly evident as well. There’s an audible snap and crispness up top as well as some vibrant impact for percussive instruments like snares, cymbals, hi-hats, and other pointed impact instruments. Electric guitar is never too abrasive or shreikingly sharp. Stuff like violin, mandolin, flute, and many other instruments generally come across believable and nicely crisp at the crest of their notes while never really crossing that artificial line. There’s nothing forced here folks as KZ walked a very tight line in their tuning. Again, you can add or take away some emphasis in this region and eartips do make a world of difference with this iem. However, as a whole, really some good treble.

Examples​

Furthermore, the Sonata also carries a nice bite in this region. I am happily impressed by treble notes. Take the track “Magnetic Fields, Pt. 1” by Jean Michel Jarre which is littered in treble activity and comes through from all sides and speeds. Very precise, but also pretty elaborate electronic treble beats. The Sonata has nicely defined note outlines, clearly refined and articulate without losing the note edge. Very nicely rounded notes as the Sonata is a clear and definitive upgrade over the AS24 Pro. I don’t mean to beat a dead horse with that point, but to this reviewer that’s saying quite a lot for KZ. I just love that you are getting such a mature sound out of this set. All Balanced Armature iems are not the easiest to tune in a believable way at these prices. Another track is “Evil Twin” by Lindsey Stirling. The Sonata does a wonderful job of maneuvering around the complicated treble without coming across shrill. The violin sounds nicely silvery without sounding too sharp, even at louder volumes. Those violin notes treble is well timed and with great cadence and nothing sounds unauthentic, coming through clean and clear with fairly exact and taut notes. Same can be said of the piano play during this track. Very rich in tonality, very nice and natural note body, and very tuneful, resounding even.

Extension​

Now, one of the biggest differences from the previous best all-BA set under $150 (AS24 Pro) is the fact that the upper treble has been addressed in a more refined and mature manner. I’m assuming those last two upper treble BA’s are there simply for this purpose. At any rate, I feel I am missing nothing up top, as info is coming in from all sides. The Sonata carries fairly good extension into the upper treble without coming across artificial, tinny, or splashy. Those are three descriptors that I’d recognize right away, and I certainly haven’t heard that, or anything other than a clean and mature tuning from this iem. I’ve been very impressed. This extended “air” region provides plenty of info past 10k but also adds air to the sound of the Sonata. It provides certain instrumentation the feeling of some breathing room, giving my music a sense of space and some separation. Not bad at all KZ.

Downsides to the Treble Region ​

The one downside in the treble will be for those who love a more dark, less fatiguing and even rolled off treble region. If anything, the Sonata has spruced up the upper end of the frequency this time around. They elevated the overall grandeur of the treble allowing a more expressive sound, a more extended sound, and a wider presentation. Remember, they added in no less than ten balanced armature drivers simply to take on the upper treble region. Obviously, KZ feels that this is an important area that needed addressed. I would also think that treble heads would probably want a hair more of an emphasis with even more punch in the upper frequency. While the treble is nice on the Sonata, it still could use some more haptic recognition to notes. However, I cannot walk away from this section without giving KZ a huge thumbs up. In my opinion the Sonata marks an improvement up top. The sound is very nicely detailed, bright enough, clean, precise, clearly defined, and isn’t particularly shrill or sharp.

Technicalities ​

Soundstage ​

One of the other bright spots with the Sonata’s tuning can be hard in the soundstage. I hear a very wide, tall and even deep sound with multiple layers, nice dimensions and a nice outward presentation which feels and sounds expansive. Well, to the extent that a $149 in-ear monitor can sound expansive. Perceptibly, I’d say the stage as a whole comes across as a slight upgrade from previous all-BA KZ iems. Now, some tracks will come across more intimate than others, and I don’t want to oversell what I’m hearing, but it’s unmistakable that the Sonata does a very nice job of introducing a diverse and well dimensioned soundstage.

Separation / Imaging ​

As far as instrument separation the Sonata also does a very fine job. Like I said earlier, the overall sound is airy, transients are exact, and there’s a high level of clarity and resolution. Notes on the Sonata are generally clean (depending on the track) sounding which all bodes well for a set to have fairly distinct note outlines and separation. I wouldn’t call it “best in class” or anything like that, because the Sonata is not one of those analytical, dry, or clinical type iems. There is plenty of smooth musicality with this set too. Granted, I’d still say that the Sonata will at times almost force your mind to hear the finer stuff, especially in more complicated tracks. Like I said, it’s a nice mix of technical and musical. Imaging follows suit nicely as I clearly hear well placed instruments within the sound field. Vocals are always dead center as well. You have some very nice layering of sounds which provides some front to back depth for instruments as well. Again, not every track is recorded the same and so I’d temper your expectations a little bit, but by-and-large the stage of the Sonata is well delineated and well placed.

Detail Retrieval ​

I feel like you can guess what I’m about to say. No doubt about it that the KZ Sonata has a very detail-oriented sound. In fact, there are moments that all I’m doing is hearing the details. After you toss in the fact that the stage is large, wide and fairly vast you begin to seek out details even when you aren’t listening for them. This can be a problem for some. That said, I feel there’s actually a nice mix of musicality with those details and so I certainly don’t find it to be a problem. Perhaps for those who only enjoy fluid, rhythmic, tuneful and musical. Those folks may want something different. However, I think it’s a bonus that the Sonata has enough fine-lined micro-dynamic illumination to pacify those who really enjoy hearing the subtleties, the micro-details, the breath in mics, clear harmonics, fingers on strings, lip smacks, stuff like that. Now, I’m not saying the Sonata is a detail monster, detail beast, or anything alluding to a detail focused set. Fact of the matter is that the Sonata has much more going for it than simply calling it a detail first iem. Nevertheless, the Sonata is a skilled iem and can easily hang with those detail first sets.

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Is it worth the asking price? ​

How many all-BA iems have you seen costing $149? Wait, let me rephrase that. How many 14 balanced armature driver iems have you seen that cost $149? Hold on, there’s more. How many 14 BA iems with a solid balanced tuning, dip-switches which work, a nice unboxing and one of the better tuned all-BA iems anywhere near its price point? Folks, I can’t tell you that the KZ Sonata is going to be right for you. I can’t do that, nor would I. I can tell you that from all of the iems that I’ve had the pleasure of testing, that for me, there is no world in which I wouldn’t say for certain that the Sonata is worth every single last penny of that $149.

Of course, like anything in this crazy hobby, the Sonata obviously has to fit your particular preferences. I wish I could answer for every reader if this set would satisfy you. I would tell you in a heartbeat. Truth is, all that I can do is present what I hear, what I see, and what my opinion is. Still, no doubt the Sonata has its issues. Yes, there are some subjective gripes which some of you may have. No doubt the Sonata could use some more bass emphasis for those who desire a bass-boi caliber set. No doubt transient attack and decay is quicker, tighter and not everyone desires such a sound. Also, there’s no doubt in my mind that there may be other talented iems which could command your attention easier. Shoot, that’s the issue with every single iem put to market. Though if you are still reading this then I’d say you are at least mildly interested.

The Why… ​

Because you are getting what KZ refers to as their premium line iem and without question it is KZ’s flagship iem thus far. Without question the Sonata is one of the most refined and mature iems that KZ has ever created. Be that as it may, the Sonata also happens to have a very nice unboxing with a nice budget upgrade cable to boot. Really a solid unboxing experience, and trust me, I cannot remember the last time I’ve said that about a KZ set. It’s built very well, very stout, obviously very durable. The design will go one of two ways with most people, but I think it looks sick. That’s “sick” as in “great”. You have actual working switches which can help to dial in the sound a bit which is a nice thing to see.

That sound though… ​

However, all of that stuff is meaningless if the iem I’m referring to doesn’t actually sound good. Speaking of which, the KZ Sonata just so happens to sound very nice. What were those words I said earlier, “full”, “immersive”, “voluminous” and “precise”? Oh, and “distinct”. Each of those words checks out. The sound is full, it’s big, it’s holographic and immersive yet at the same time there is a certain precision within the sound of the Sonata. All of these attributes certainly make this set very distinct within an Audioverse chock full of copycat tunings. The Sonata is different folks. Bass is tight, punchy, deep and great for an all-BA set. The midrange is forward but not to a fault, very clean, very detailed, and also musically gifted as well. The treble is airy, open, very well extended, brilliant enough, very technical, and it has some bite to each note. The stage is big, wide, and 3D. Each note is separated, and the sound field has solid imaging capabilities. Folks, it’s worth every penny.

Ratings (0-10)​

Note: all ratings are based upon my subjective judgment. These ratings are garnered against either similarly priced sets or with similar driver implementations or styles with the unique parameters of my choosing. In the case of the KZ Sonata ratings below, that would be $100-$200 earphones of any driver configuration. Please remember that “ratings” don’t tell the whole story. This leaves out nuance and a number of other qualities which make an iem what it is. A “5-6” is roughly average and please take into consideration the “lot” of iems these ratings are gathered against. $100-$200 is a fairly large sized scope of iems. So, It should be noteworthy to see a rating above a “9.0”. My ratings are never the same and each set of ratings tells a different story. Each time you read one of my ratings will be unique to that review. Basically, I create a Rating that makes sense to me.

Aesthetic ​

–Build Quality: 8.7 Well built, 3D printed, clean build

–Look: 8.9 Very unique and cool design.

–Fit/Comfort: 9.1 Fit and comfort is very good for me.

–Accessories: 9.0 One of the best KZ unboxing experiences.

–Overall: 8.9

Sound Rating ​

–Timbre: 9.0 Great timbre for an all-BA set.

–Bass: 8.9 Punchy, textured, clean.

–Midrange: 9.3 Highly detailed, great clarity, tuneful.

–Treble: 8.9 Non-Offensive, sparkly, extended well.

–Technicalities: 9.3 Technically astute iem, great details.

–Musicality: 9.0 Musicality is nice, rhythmic sound.

–Overall: 9.1

Ratings Summary:​

This is one of those sets where I could see someone arguing with me over just about every rating. In the same breath, I could see someone wondering why I scored this set so low in some areas. Well, the truth is, I am comparing the KZ Sonata against any and all iems of every driver configuration between the prices of $100 and $200. Do you have any clue how many great iems are between those prices? I know I do. It’s quite literally one of the most fought over ranges within the entire audio game. I did say “one of”. Now, the Sonata had an uphill climb. I know this, you know this and I’m fairly certain that KZ knows this. Thankfully they put their best foot forward and came up with a set that could easily hang with any set I put before me to listen to during this rating. It wasn’t the best at anything. Let’s just get that out of the way. There were other sets which scored higher in every rating. This is why I say that ratings are bogus folks. No, the Sonata doesn’t win out in anything in any one area. What makes this set special is that it’s good at literally everything. Now we can disagree on that, and that’s perfectly fine. But I am going to rate this set with my ears and tell you exactly what I think in my bogus ratings. You’d be wise to just skip this section altogether.

Explain Yourself!! ​

Now that I’ve said all of that, I don’t think there’s much to explain. Not with the Sonata. I know you see a “9.3” in the midrange and you may think this is very high. Well, there’s about five other sets which rank higher for me. Also, “midrange” is such a bloated and broad thing to rate. I really have to change how I do this. Anyways, what do I mean by “midrange” in the first place? What I mean by “midrange” is how it sounds to me, for me, and against other sets in front of me. There’s no grand and sophisticated way in which I judge. I listen for timbre, cleanliness, vocals, transients, if it’s shouty or not, sibilant or not, detail retrieval, and simple and raw musicality among about 10 other attributes which are too boring for me to write out. However, what I basically do is just listen. Again, this is why ratings show zero nuance in a hobby which is 100% nuance, all the time, every day of the week. Believe me, I could do this for every rating category, but I’ll spare you the word babble. In the end, that “9.1” overall sound rating doesn’t reflect how I actually see this set. To me, as a whole, it should be higher. That number is derived simply from adding up every rating and giving you an average. That’s it. The Sonata is a very nice iem for what it is, and for the cost to own it.

Final thoughts on the KZ Sonata before I conclude ​

I’ll keep this brief. I think I’ve said enough in this review for everyone. Also, I’m climbing close to that 10,000-word mark and I really try not to go over that. Psst, I always do. As honest as I can be, the KZ Sonata represents a new voyage in the journey that is Knowledge Zenith. They crafted one of the best all-BA sets that money could buy under $200 in the KZ AS24 Pro last year. I didn’t hold onto any hope they would trump that set. Well, lo and behold, KZ went and did just that. I feel that I can comfortably say that the Sonata is likely the best $150 all balanced armature earphone in the business. It’s a debatable thing to say, I get that. Still, for me I don’t think there’s much in the way of competition in that regard. There’s a few, and they aren’t slouches either. Sets like the Aful MagicOne ($139), or the CVJ Kumo ($179), the AS24 Pro as well. There’re a few others, but the point is, the competition isn’t very great concerning all balanced armature earphones in this price point. So, if you are someone who is looking for an all-BA set around this price then there is a very good option out there in the Sonata. Now, I don’t think that the Sonata is necessarily an “all-rounder” type set. Not that it cannot perform admirably in most genres. However, any genre which requires that deep authentic bass perhaps won’t completely satisfy the listener at all times. Of course, a lot has to do with your personal taste. Beyond that, I can’t leave this review without personally recommending the Sonata. Truly a very solid offering from KZ.

Conclusion ​

To conclude my full written review and feature of the KZ Sonata, I first want to thank KZ & Tyvan Lam for providing the Sonata in exchange for a review and feature at Mobileaudiophile.com. KZ has always been very good to me over the years and has never expected anything out of me. Never have they requested anything of me other than a truthful review. Whether my review has praised their products, or it was less than stellar, KZ has always been reliable, and they live with the results. I suppose it doesn’t hurt that they’ve had some real bangers of late. Still, I have absolutely nothing negative to say of my many years cooperation I’ve had with KZ and I’m very thankful. Always. I’m also thankful to you, the reader, for taking the time out of your busy schedule to check out my words in this set. It means the world to me and everyone at Mobileaudiophile.com. Thank you so very much.

Different perspectives ​

As I always do in each and every review, I must ask you to please check out other thoughts about the KZ Sonata from other reviewers, as it’ll most certainly only help you to make an educated purchasing decision. $149 is a lot of money to many people around the globe, and so getting the best understanding possible from as many reviewers as possible can only benefit you. We are all very different friends. We have different gear, music libraries, likes and dislikes, and we haven’t all been down the same journey in audio. Take the time to research a bit and you’ll be better for it. With all that said, I think I’m done folks. So, please take care, stay as safe as possible and always… God Bless!