𝐇𝐞𝐥𝐥𝐨 𝐂𝐨𝐦𝐦𝐮𝐧𝐢𝐭𝐲

The unit from today’s tests is the renowned 𝐊𝐞𝐟𝐢𝐧𝐞 𝐊𝐥𝐞𝐚𝐧.

 Official price: €55–$64 (can be found much cheaper)

Purchase link

✔ 𝐏𝐫𝐨𝐬:
-Technical performance for the price.
-Excellent build quality.
-Detailed midrange.
-Energetic at both ends.
-The tuning nozzles are noticeable.

✘ 𝐂𝐨𝐧𝐬:
-With the black filter the treble becomes somewhat aggressive.
-Normal male vocals are somewhat thin.



 𝐈𝐧𝐭𝐫𝐨𝐝𝐮𝐜𝐭𝐢𝐨𝐧:

As I said a few months ago, in the review of the Delci AE, the name Kefine inspired subtlety in me, something pleasant, but how wrong I was!

The three IEMs I have from the brand are pure energy and muscle, sometimes bordering on madness, so much so that you have to apply a bit of control because they are like a wild horse: pure impetus.

Klean is the brand’s budget model but wow! It has a lot to say and a lot of fight left in it even well into 2026, although it will receive a revision shortly, where they will adjust the tuning and change the color.

𝐖𝐢𝐥𝐥 𝐭𝐡𝐞 𝐊𝐥𝐞𝐚𝐧 𝐎𝐆 𝐜𝐨𝐧𝐭𝐢𝐧𝐮𝐞 𝐭𝐨 𝐜𝐨𝐧𝐯𝐢𝐧𝐜𝐞 𝐭𝐡𝐞 𝐜𝐨𝐦𝐦𝐮𝐧𝐢𝐭𝐲



 𝐀𝐜𝐜𝐞𝐬𝐬𝐨𝐫𝐢𝐞𝐬:

-Two capsules.
-Two tuning nozzles.
-A set of ear tips sizes SML.
-Cable with 0.78mm terminations and 3.5mm connection.
-Carrying and storage case.
-User manual.



 𝐂𝐨𝐦𝐟𝐨𝐫𝐭, 𝐝𝐞𝐬𝐢𝐠𝐧, 𝐚𝐧𝐝 𝐛𝐮𝐢𝐥𝐝:

Kefine is a brand that bets on comfort. In this aspect, Klean does not stray from the other models I have tested (Delci AE and Klanar), offering products of fitted size and successful ergonomics.

Perhaps the weight is a bit above average, something typical of metal constructions, but it is not something that will make your ears suffer: the fit in your ear canal is deep and secure, facilitating adequate sealing and support with the stock ear tips which, although they do not stand out, are perfectly valid and I did not feel the need to change them.

The cable is tuned to the price range where this model lives. Somewhat average, well built, durable-looking, that does not tangle and the ear hooks do not move out of place. For me, it does a perfect job.

The design, as the brand has accustomed us, is discreet, without boasting, it is not the center of attention. Its faceplate with a checkerboard and the name Kefine engraved on it give a touch of joy to the set.



 𝐓𝐞𝐜𝐡𝐧𝐢𝐜𝐚𝐥 𝐚𝐬𝐩𝐞𝐜𝐭𝐬:

-1DD 10mm configuration.
-Sensitivity 107dB.
-Impedance 32 ohms.
-Response 20hz–20khz.



 𝐍𝐨𝐳𝐳𝐥𝐞𝐬:

I love these little things when they really work. Klean is another example of this. The nozzles, although slightly, change the sound signature. It is perceptible without much effort.

Black nozzle: gives air to the upper frequencies, with a slight increase in detail and clarity. The energy increases, reaching the limit of sibilance, but without causing damage.

Silver nozzle: offers a more comfortable sound, more for everyone. The low end gains body and spectacularity in the rumble.



 𝐏𝐚𝐢𝐫𝐢𝐧𝐠:

We do not need much to properly drive Kefine Klean.

The use of a neutral source, without coloration, brings out the strengths, which are many, of this set of monitors.

The amplification was set to low.

The nozzle used was the black one; I wanted it to show me what it is capable of and to move away from my comfort zone by listening to warm signatures more in line with my personal tastes.

The ear tips used were the stock ones.



 𝐒𝐨𝐮𝐧𝐝 𝐬𝐢𝐠𝐧𝐚𝐭𝐮𝐫𝐞:

Balanced and pleasant, with a bit more energy up top and bass with impact, but controlled. It sounds clean and musical, it does not exaggerate dynamics, which gives a relaxed listening if required or rhythmic, with detail, but without becoming extremely technical or clinical.

• 𝕊𝕦𝕓-𝕓𝕒𝕤𝕤: Deep and present without overwhelming. The slam of low frequencies is noticeable with weight and extension, but without invading the rest, adding body to genres with marked bass.
• 𝕄𝕚𝕕-𝕓𝕒𝕤𝕤: Slightly warm and with good thickness, it gives fullness to low notes without mixing with the mids, keeping rhythmic lines defined, with tact, precision, and speed.
• 𝕃𝕠𝕨𝕖𝕣 𝕞𝕚𝕕𝕤: Pleasant and clean texture, with enough energy not to sound dull. They help the music maintain rhythm and force without saturating other areas.
• 𝕄𝕚𝕕𝕤: Natural and transparent, with enough presence for melodies to be heard clearly and directly, without feeling hidden or dark.
• 𝕌𝕡𝕡𝕖𝕣 𝕞𝕚𝕕𝕤: Quite “cheerful” and with sparkle, where I could appreciate clarity and brightness. They give life to the mix, although they can feel too lively if you are used to softer profiles.
• 𝕋𝕣𝕖𝕓𝕝𝕖: Extended and with good clarity. They add air and definition to the upper part without becoming strident, although with the black filter there is a more vivid than smooth approach.
• 𝕍𝕠𝕔𝕒𝕝𝕤: Deep male vocals sound complete and warm, with very accurate depth; normal male vocals with good clarity but perhaps with little thickness, not sounding entirely very natural; and female vocals with detail and lightness without becoming harsh or unnatural.
• 𝕊𝕠𝕦𝕟𝕕𝕤𝕥𝕒𝕘𝕖: Moderate space. It is not very wide, but with a successful three-dimensional sensation that separates instruments well without feeling boxed in.
• 𝕀𝕞𝕒𝕘𝕚𝕟𝕘: Quite orderly and consistent. The localization of sources is clear and reliable, which makes it easy to follow the music without spatial confusion.
• 𝕃𝕒𝕪𝕖𝕣𝕚𝕟𝕘: Separates layers effectively, allowing background elements to be distinguished from the main ones, although in very dense passages it can feel somewhat simpler.
• 𝔻𝕖𝕥𝕒𝕚𝕝 𝕣𝕖𝕥𝕣𝕚𝕖𝕧𝕒𝕝: Surprisingly good for the price range where this Klean is located. I was able to perceive micro-details that raised the listening quality considerably.

 𝐒𝐢𝐧𝐠𝐥𝐞-𝐩𝐥𝐚𝐲𝐞𝐫 𝐯𝐢𝐝𝐞𝐨 𝐠𝐚𝐦𝐞𝐬:

Check my blog to know under what circumstances I analyze sound in this field. Source used FiiO K11 with filter no. 5 (neutral), stock ear tips, and gain on low.

• 𝔸𝕔𝕥𝕚𝕠𝕟: Bass impacts are felt with weight and authority without being excessive. Explosions and hits have body without saturating, excellently represented, adding quality to these moments, and the reverberation adds realism to the scenes. The cinematic experience that I always seek was well represented.
• 𝔻𝕚𝕒𝕝𝕠𝕘𝕦𝕖𝕤: Very clear and natural, the characters’ voices are smoothly distinguished from the effects, which makes it easier to follow conversations and narrative in a clarifying way, where, if needed, the voices turn out to have exquisite prominence.
• 𝕀𝕞𝕞𝕖𝕣𝕤𝕚𝕠𝕟: Environmental sounds are perceived with detail, enriching the atmosphere without eclipsing the main effects, which helps with the sense of space, of feeling inside, and of realism.
• 𝕃𝕒𝕪𝕖𝕣 𝕤𝕖𝕡𝕒𝕣𝕒𝕥𝕚𝕠𝕟: The different effects remain clear and differentiated even in complex scenes, with few confusing overlaps. It handled well the densest and most chaotic scenes of the video games I use for my tests.
• 𝕊𝕥𝕒𝕘𝕖: The frontal and lateral stage conveys good size for an IEM, offering dimension without feeling narrow. However, in terms of verticality it falls somewhat short for my taste, with an artificial and unrealistic distance.
• 𝕊𝕚𝕓𝕚𝕝𝕒𝕟𝕔𝕖: Well controlled in general, but with the black filter there can be a bit more energy up top. It can become somewhat annoying at times.
• ℙ𝕠𝕤𝕚𝕥𝕚𝕠𝕟𝕚𝕟𝕘: It allows sounds to be located with stability and coherence, making enemy movements or directional events be followed with confidence of appreciating a correct location.

 𝐅𝐢𝐧𝐚𝐥 𝐜𝐨𝐧𝐜𝐥𝐮𝐬𝐢𝐨𝐧 𝐚𝐧𝐝 𝐩𝐞𝐫𝐬𝐨𝐧𝐚𝐥 𝐞𝐯𝐚𝐥𝐮𝐚𝐭𝐢𝐨𝐧𝐬:

Kefine Klean is an IEM for everything, that masterfully handles any musical genre or content you put in front of it. I have not been able to feel that in anything it did not defend itself with excellent results.

Personally, I highlight its rhythmic capacity, noting well-defined and fast transitions between frequencies, technical, where the resolution is maintained, giving a gratifying and joyful listening, very balanced, where nothing stands out, everything is at a high level.

In single-player video games, my preferred field to analyze sound, the performance is excellent, but it could have been outstanding if in the densest moments it had behaved in a more clarifying way. Perhaps it is asking too much of a budget IEM; it may also be the fault of being used lately to higher ranges, but even so, I find no possible rival that can compete with Klean in this field.

It is no longer just an impression or something anecdotal for me: Kefine knows how to tune its products very well, with that characteristic touch of strength and dynamism that they implement in their monitors, without neglecting other aspects.

I knew from the community that Klean was an excellent option. What I was not convinced of is that it was, possibly, the best if what you like is to enjoy everything and with sovereign quality.

𝐑𝐞𝐜𝐨𝐦𝐦𝐞𝐧𝐝𝐞𝐝 𝐟𝐨𝐫eople who like energetic listening without losing detail or single-player video games of any kind.

𝐍𝐨𝐭 𝐫𝐞𝐜𝐨𝐦𝐦𝐞𝐧𝐝𝐞𝐝 𝐟𝐨𝐫: lovers of large soundstages and/or those sensitive to treble.

If you have made it this far, 𝐭𝐡𝐚𝐧𝐤 𝐲𝐨𝐮 𝐟𝐨𝐫 𝐫𝐞𝐚𝐝𝐢𝐧𝐠.
More reviews on my blog.
Social networks on my profile.
𝐒𝐞𝐞 𝐲𝐨𝐮 𝐢𝐧 𝐭𝐡𝐞 𝐧𝐞𝐱𝐭 𝐫𝐞𝐯𝐢𝐞𝐰

 𝐃𝐢𝐬𝐜𝐥𝐚𝐢𝐦𝐞𝐫:

This set of monitors has been sent by 𝐊𝐞𝐟𝐢𝐧𝐞. I sincerely appreciate the opportunity to be able to test one of their products at no cost and that no condition has been imposed when creating this analysis.

Despite this, my priority is to be as impartial as possible within the subjectivity that analyzing an audio product entails. My opinion belongs only to me and I develop it around the perception of my ears. If you have a different one, it is just as valid. Please, feel free to share it.

 𝐌𝐲 𝐬𝐨𝐮𝐫𝐜𝐞𝐬:

-FiiO K11 for music and video games on the main PC.
-FiiO KA13 while I work.
-FiiO BTA30 Pro + FiiO BTR13 for LDAC wireless listening at home.
-FiiO BTR13 + FiiO BT11 + iPhone 16 Pro Max for wireless listening on the street.
-FiiO KA11.
-FiiO JA11.
-FiiO Jiezi.
-BQEYZ Lin.
-Shanling M0 Pro.
-Amazon Music Ultimate.
-Local FLAC and MP3 files.

---

KEFINE Klean
1DD DLC Diaphragm
$49USD


Hi everyone, welcome back! In today’s review, we’ll be talking about the Kefine Klean, a $49 USD 1DD DLC IEM.
Before we get started, a big thanks to KEFINE for sending the IEM in for review, but as always, this review will be 100% my honest opinion.

Unboxing
Let's start with the box itself.
The box is just OK. On the front you can see the IEM, but too bad, the printing I think did the IEM dirty.
Why? While usually the picture on the box looks better than the real product, this one, the real product looks better than the picture.
On the back there’s the spec of the IEM.

Here’s what you get inside the box:

• IEM
• 2 pin 0.78mm type-c cable
• Manual, QC Card, Nozzle Card
• Eartips
• Case

Build Quality and Comfort

The build quality of the IEM itself is nice, I think the IEM is built from all aluminum or some kind of metal because it is cold to the touch.

The faceplate has this minimalistic pattern and the body of the IEM itself is kinda slim, I have 0 issues wearing this IEM for long listening sessions, pretty sure this IEM would accommodate everyone unless the individual has cauliflower ear.

The cable itself, KEFINE, was supposed to send me the single ended cable with a type c cable outside of the parcel, but for some reason they sent me a type c variant with another type c cable.

Anyway, the cable itself is quite nice, lightweight, and very malleable. The type C cable itself has a mic, the mic sounded just fine for daily conversation. It also have media control button.

Specs
They marketed the IEM for having DLC, which is kinda too old for 2025? DLC hype was like 5 years ago or something, but they said the IEM to have a powerful bass, warm midrange and smooth treble which is 100% true with the silver nozzle.

As for the cable, it uses a silver plated OFC cable.
OK without further ado lets talk about the Sound section of this review.

Sound
Setup Used:

• Kefine Klean, Stock Cable, 3rd party 4.4mm cable, Stock eartips.
• FIIO BTR11, JIEZI budget dongle from Jade Audio, Poco M6 Pro, Arturia Minifuse, FIIO QX13.
• Music from Apple Music (covering J-POP, Rock, EDM, Metal, Jazz, and Rap)

My first impression with this IEM is that, huh it sounds… Nice?
For the overall tonality itself, I would describe this as harman inspired tonality.

As for the bass itself, it has a very harman like tuning, with extra mid bass. It doesn’t present us with overbearing bass, but it's just right. Maybe balance is the more correct word to describe the bass.
Just as your typical DLC IEM, it has a snappy transient, which not gonna lie, very nice to use for double pedal music.
So not exactly powerful but just right, nice and balance.

Midrange? Yeah warm with the silver nozzle, though if you want more clarity you can use the black nozzle, though personally IMO the black nozzle made the IEM to be borderline shouty, 0 issues with the silver nozzle one.
This IEM is also free from the infamous metallic timbre ahem Aria 2.

As for the treble, It sounds smooth, not too extended but has decent detail for sub $50 USD IEM

Technicalities
Using the stock type c cable, for $50 USD the technicalities are good

Stage: medium sized for sub $50 USD

It still has this in your head presentation but definitely not claustrophobic.
The shape of the stage is symmetrical between width and depth.

Imaging: as always, I would categorize this as 2.5D sounding, and what do I mean by that, it's not holographic, but it doesn't just randomly throw sound at your ears either.
Though with a good cable, connected to QX13 from FIIO, this thing actually could present us with eerily close to be called for having a holographic imaging.

Separation & Positioning: Very good, since the overall tonal presentation is quite balanced, It affect the separation and positioning too, overall sound are decently separated and the positioning is quite sharp even with the stock USB cable.

Detail Retrieval: Decent, the DAC in the type C cable is definitely the limitation here.
Tested using decent 4.4mm cable with QX13, it has a very good detail retrieval though the extension is still just ok.

Comparison

EarAcoustic STA-K
Dual DD
$49USD
Bass focused, the build quality of STA-K is not as good as the Klean, It also has less detail, but more fun presentation.

Conclusion
If you are in the market for a sub $50 USD IEM, and you’re specifically searching for a harman like tonality with just a tiny bit more punch on the mid bass, this IEM got a YES go for it from me, it doesn’t have any flaws for its price. The price and value ratio is great.


OK that's all from me for now.
If you find this review helpful, leave a like, and kindly subs to my channel below, thanks !
[Video here soon]

I’ll catch you in the next one. Bye for now !

• littlenezt

---

Disclosure: I’d like to thank Kefine for providing me with the Klean for this review. All thoughts and opinions are my own, and Kefine had no say or input on the contents of this review.

You can view the original review on my website: https://www.hifioasis.com/reviews/kefine-klean-review/

At $49 for a single dynamic driver IEM, the Kefine Klean enters one of the most competitive segments in the IEM market, where every new release faces serious scrutiny from budget-conscious audiophiles waiting for the new best price for performance IEM.

What caught my attention with the Kefine Klean, though, is its approach to tuning. Rather than chasing experimental sound signatures, it follows the consumer-favorite 2019 Harman target, delivering a balanced, mildly V-shaped tonality with technical performance focused on holographic imaging. The hefty polished cast alloy metal construction and 10mm dynamic driver certainly don’t hurt either, creating a package that appears to punch above its modest $49 price tag.

Technical specs and marketing claims only tell you so much, though. This review examines the design, comfort, sound quality, and gaming performance to see if the Kefine Klean earns a spot in your collection or gets lost in an already crowded market. Let’s get into it.

Key Specifications

• Product Page: https://www.aliexpress.us/item/3256807771678857.html
• MSRP: $49 USD
• Type: IEM (in-ear monitor)
• Driver Type: 10mm Dynamic Driver (DD)
• Impedance: 32 ohms
• Sensitivity: 107 dB SPL
• Weight: 9.8 grams per earbud
• Connection: 0.78mm 2-pin connector
• Detachable Cable: Yes

In the Box and Unboxing

• Kefine Klean
• 1.2m silver-plated copper wire cable with 3.5mm SE termination
• 1.2m silver-plated copper wire cable with USB-C termination (included with my version)
• Hard zipper storage case
• Set of S, M, L silicone eartips
• 2 sets of nozzles
• Manual

The overall presentation feels more premium than expected, with everything neatly organized and well-protected. The inclusion of interchangeable tuning nozzles stands out as particularly impressive, as this level of sound customization rarely appears at this price point.




The cable deserves mention here, too. It’s a 2-core oxygen-free copper design that feels substantial without being stiff. At roughly 1.2 meters long, it provides good reach while the 0.78mm 2-pin connectors create a secure fit. Microphonics stay minimal, and the strain relief looks adequate for regular use. While it won’t rival aftermarket cables costing as much as these entire IEMs, it’s significantly better than the typical budget IEM cable, and I really do like the feel and look of it.




The semi-rigid case provides decent protection for daily carry while remaining very compact and travel-friendly. The fabric material gives it a distinct look and feel, too. Not the most spacious of cases, but it gets the job done and is a solid value add here.

Design & Comfort

Picking up the Kefine Klean immediately tells you this isn’t your typical budget IEM. The full metal construction feels substantial and solid. The Klean uses metal injection molding to create its distinctive six-sided design, with a rectangular pattern etched on the faceplate and the KEFINE logo displayed prominently in white. The black finish looks sleek and holds up well to daily use, with gold-plated nozzles providing a nice contrast that adds a bit of elegance to it.







Each shell weighs about 9.8 grams, noticeably heavier than plastic alternatives due to the metal construction. The extra weight doesn’t become bothersome during regular use, though. The compact dimensions mean they don’t stick out much from your ears, making them practical for everyday wear and even sleeping while wearing them.




Two small vents, one near the nozzle and another on the inner face, contribute to the acoustic design. I appreciate that the Torx screw secures the back panel rather than sitting on the faceplate, keeping things clean-looking while also adding an industrial look to the IEM when you notice it.







Despite being all metal, these surprised me with how comfortable they are. The shells follow your ear’s natural shape well, though the nozzle diameter might feel slightly wide if you have smaller ear canals like I do, but the Klean didn’t cause any discomfort for me. The ergonomic shape provides good stability, but getting the right ear tips is crucial for a proper seal. Once you find the right fit, they’re comfortable enough for long listening sessions.

USB-C Cable

Kefine also offers a USB-C cable for the Klean that features in-line controls with a built-in microphone. The USB-C connection has an integrated DAC, so it’s just plug and play into any USB-C device. The DAC supports up to 32-bit/384kHz playback, at least from what I can see when I plug into a Windows computer.

There is no sound quality difference between this cable and the 3.5mm version, at least to my ears, so don’t expect any DSP magic. The cable also feels and looks exactly the same as the 3.5mm version, which, as you have already read, is a good thing.




The in-line controls work well and as expected. The Play/pause button is positioned beneath the volume buttons, which took some getting used to, but it is shaped differently from the volume buttons and has a small nub on it to help you identify it with just your fingers. Overall, I really like this cable as an option, and on top of using it with my smartphone, I even used it with some DAPs as it was very convenient.

Sound Quality

Sources used for this review:

• FiiO M21
• HiBy R3ProII
• Samsung Galaxy Fold 7 (USB-C cable)

Links to my music playlist used for the majority of testing:

Spotify: 

Apple Music:
Tidal: https://tidal.com/playlist/503485c7-7f3d-43f0-b904-4b9a89c33875



The Klean’s 32-ohm impedance and 107dB sensitivity make it easy to drive from just about anything, performing admirably even from a smartphone or simple dongle DAC. It does scale up nicely with better amplification, though, particularly expanding the soundstage width. I found the Klean pairs really well with neutral ESS Saber-based sources for a more technical presentation, while slightly warmer sources (like CX31993 chip devices) enhance its musicality without sacrificing detail.

The Kefine Klean follows a sound signature that balances warmth and detail with a mild V-shaped tuning that leans toward the Harman target curve. As I alluded to earlier, the Klean does include two different nozzles that affect the sound profile slightly. The nozzles are differentiated by the color of the mesh inside the nozzle itself.

Tuning Nozzles: Silver vs Black

The silver nozzles (pre-installed) offer a smoother, slightly warmer sound with more prominent bass. The black nozzles boost energy in the upper midrange and lower treble, creating a more V-shaped profile with greater perceived detail and wider soundstage. If you’re sensitive to treble, stick with the silver filters. Detail enthusiasts will probably prefer the black option. I personally found the silver nozzles to align more with my musical tastes, which you can see in the playlist links above. My subjective impressions below were all done when listening with the silver nozzle.

Bass

The bass extends impressively into the lower frequencies with a satisfying sub-bass rumble that never overwhelms the mix. Clean and controlled, it adds proper weight to tracks like “Angel” by Massive Attack, where you need that low-end foundation without muddying the atmospheric elements. The mid-bass delivers a tight, punchy performance with excellent speed and articulation. Though slightly woolly at times, it maintains enough definition to keep bass lines distinct even in complex metal tracks like “Ticks & Leeches” by TOOL.

Midrange

Male vocals sound rich and full-bodied with natural warmth. Female vocals shine with clean presentation and no harshness. Instruments maintain proper spacing and definition, allowing even complicated arrangements to sound coherent rather than congested.

Treble

The treble extends admirably, creating an open, airy sound that gives music room to breathe. Cymbals and string instruments present naturally with good micro-detail retrieval without becoming harsh or fatiguing. This balance makes the Klean suitable for extended listening sessions while maintaining enough sparkle to prevent it from sounding dull or boring.

Soundstage and Imaging

Soundstage width exceeds expectations for this price range, though depth is more limited. Imaging proves surprisingly accurate with good lateral panning and stable positioning of instruments. This creates a believable spatial presentation where center vocals have excellent definition and presence.

Gaming

For gaming, the Klean performs admirably for the type of games I play. Environmental cues are presented with good directionality, making it effective for casual gaming where immersion matters. The bass adds weight to explosions without masking critical dialog or positional audio cues. Competitive multiplayer games also perform well as the tuning presents a good balance of being able to hear footsteps and gunshots with accurate directionality.

Final Thoughts

The Kefine Klean may be my new favorite all-rounder IEM, as it performs extremely well in most music genres, balancing detail and musicality. At $49, this IEM delivers performance that frankly surprised me. What impressed me most was the technical performance. Soundstage width and imaging capabilities genuinely exceed what you’d expect at this price point, though depth does remain somewhat limited. The interchangeable tuning nozzles also add real value to the package.

The Harman-inspired tuning hits that sweet spot for most listeners, and for me. Bass stays controlled yet impactful, the midrange presents vocals with natural warmth and clarity, and the treble extends well without fatigue during longer sessions.

Gaming performance deserves mention too, as the Klean delivers solid positional audio capabilities, making it genuinely versatile for both music and gaming.

The metal construction does add some weight that might bother those seeking ultra-lightweight options. It’s not a deal-breaker for most ear shapes, but worth considering if you’re sensitive to heavier IEMs.

The Kefine Klean earns my recommendation as a legitimate standout in the budget IEM market. It proves that excellent sound quality, premium construction, and thoughtful features don’t require spending hundreds of dollars.

Kefine Klean Review

It’s me again, Mars Chan. This time, I got the Kefine Klean ($49). This is my first Kefine review, and I believe I’m slightly late to the Kefine Klean, but as the saying goes, better late than never.

The Klean was sent to me for review, but please be assured that any opinions expressed here are my own, based on my personal experience.

Kefine is a relatively new brand in the IEM market and has gained popularity quickly, which has made me curious for a while now about how the Klean sounds. Or more importantly, how the Klean compares to other popular single DD IEMs, including the Sivga Que UTG and Twisture Woodnote.

Let’s find out.

Features

The Klean features a 10mm dynamic driver with a diaphragm made from diamond-like carbon (DLC), which is known for its extended high-frequency capabilities while retaining the bass impact that dynamic drivers are renowned for. The impedance is 32 Ω, and the Sensitivity is 107 dB.

Klean’s shell is made of polished cast alloy metal, which is fastened by a screw rather than relying solely on adhesive to close the shells, as adhesive can fail on occasion, as I experienced with other IEMs.

Klean also features a pressure relief system, which prevents pressure buildup in the ear canal that might cause nausea and headache. I never experienced such issues with the Klean.



Design

Klean’s design is simple, clean, and unassuming. The black shell is ergonomically shaped, featuring a flat faceplate printed with patterns and the Kefin text. The gold-plated tuning nozzles are replaceable, and the Klean includes two pairs. There is a vent hole located near the nozzle, and another one is positioned further away.

I like the way Kefine placed the Torx screw at the back, rather than on the faceplate, making the Klean look clean, no pun intended. I also appreciate the knurled nozzles, as they make changing them easier.

Cable

My Kefine Klean sample includes a 3.5mm 2-core cable made with High-Purity Silver-Plated Copper Wire, which is neither too thick to affect portability nor too thin to tangle easily. It is also available in a USB-C version with a built-in mic and control.



Comfort and Isolation

I experience excellent comfort with the Klean, thanks to its medium size and ergonomically shaped shell, as well as the inclusion of a pressure relief system. I find it suitable for long listening sessions. Although I wish it were a little lighter than its measured weight of 9.8 grams, 7.5 grams should be perfect.

Isolation is good; the large 6.4mm nozzle and the stock ear tips provide a good seal and effective isolation from ambient sound. The overall sound isolation is average, comparable to most IEMs I’ve used.



Packaging & Accessories

Packaging is smart, simple, and practical. The mid-sized white box features a photo of the Klean at the front and text all around, and measures 110 mm x 128 mm x 37 mm in dimensions. Another box slides out from the right side, which contains all the accessories.

The package includes a pair of IEMs, two pairs of nozzles, three pairs of ear tips, user manuals, a carrying case, and a 3.5mm cable.



Measurement

My measurement reveals an almost perfect channel balance, indicating a high manufacturing quality (see photo). The difference between the black and silver nozzles is shown in another graph.

Regardless of the nozzles used, the graphs display a moderate V-shaped to V-shaped sound signature.

Listening Condition

Before seriously listening to the Klean, I spent more than 30 hours of burn-in time using a DAP playing music for about 8 hours per day for several days. I notice improvements in sound after the burn-in; the Klean sounds more open in the midrange, the treble has become smoother, and the bass has become tighter.

I used a wide variety of sources, including the iBasso DC Elite, TRN Black Pearl, paired with my OnePlus 13 phone, and Fiio M15s. Stock ear tips and cable were used, and the default sound settings were employed without any sound enhancement or equalization using Poweramp and UAPP music player apps.

Sound Signature

Of the two kinds of nozzles, I only used the default one, which is the silver nozzle, as I find the black nozzle produces too much upper midrange and lower treble for my taste.

That said, Klean has a balanced, moderately V-shaped sound signature characterized by a moderately boosted sub-bass. A barely recessed perceived midrange response, a mild upper midrange presence, and a boosted treble that balances the boost in the bass.

I like how the bass balances between sub-bass and mid-bass presence, which makes the sound rumbly when needed yet tight, articulate, and detailed. The lower midrange is clean and uncolored by artificial warmth and bleed from the bass.

The upper midrange has good presence yet is never overbearing and shouty. It balances well with the lower midrange, avoiding the instruments and vocals from sounding thin or dark. Instruments and vocals have the right presence, but without the shoutiness that caused fatigue.

Treble is mildly elevated in perceived response; it sounds smooth and extended with good detail, air, and atmosphere. I was surprised by how many micro-details it reveals. The Klean approaches the sound of a well-implemented hybrid set without the coherency issues typically associated with hybrids.

I like the way the treble sounds detailed, slightly boosted, and lively, without sounding sharp, metallic, and fatiguing.

Technicalities

Soundstage size would also depend on the quality of the sources used; that said, with the sources used in this review, Klean has a satisfyingly above-average soundstage size and a delightfully spherical shape, which makes me feel like I’m in a natural environment surrounded by sounds.

Imaging is also above average; there is good lateral panning of the images without breaking apart between panning, and they remain defined and stable. There is good holography of the images, where the images appear to be floating in the air with nicely defined edges.

Center vocals have good definition, presence, and palpability. It appears in front with good realism, as if you can almost touch it. At the same time, the background instruments play separately behind the singer, indicating that the Klean has good image separation and layering.



Pairings

Klean pairs nicely with my iBasso DC Elite, TRN Black Pearl, and Fiio M15s. It effectively reveals the nuances of each source.

I prefer the Klean to be paired with neutral and transparent-sounding sources and would avoid sources that have harsh treble or thin-sounding tonality.



Comparisons
Sivga Que UTG

Description

Que UTG features a 10 mm flat, ultra-thin glass diaphragm driver, unprecedented in single DD IEMs, and promises unrivaled detail and resolution. It has an impedance of 32 Ohms and a sensitivity of 103 dB.

UTG’s shell is made entirely of zinc alloy metal, finished in titanium-colored paint, with a piece of sandalwood at the faceplate. There is a vent hole near the nozzle and another near the recessed 2-pin connectors. It includes a detachable 2-pin modular cable with replaceable plugs.

Sound Quality

UTG has a neutral bass and midrange, with the treble more elevated, giving the impression that it has a leaner note weight and tonality compared to the mild V-shaped sound of the Klean, which features thicker bass and less elevated treble.

Although both have good depth and size in sound staging, I find the Que UTG to have a wider sound with less depth, while the Klean is more rounded and even in every direction, making its imaging performance more holographic.

In terms of dynamics, both are lively and energetic, and never sound dull. However, I find that the more bass presence in the Klean gives it an edge over the Que UTG in terms of dynamics.




Twistura WoodNote
Description

Woodnote features a 10mm Dual-Magnet, Dual-Chamber, Revitalized Wood Diaphragm dynamic driver for natural sound. It includes three pairs of tuning nozzles, has an impedance of 18 Ohms, and a sensitivity of 125 dB.

Woodnote utilizes silver-anodized, CNC-machined aluminum Alloy Ear Shells. There is a vent hole near the nozzle, and a slotted port hole near the 2-pin connectors. It included a thick and attractive-looking 2-core copper cable with replaceable plugs.

Sound quality

Using the Woodnote with the default nozzles and stock ear tips. Both sounds are reasonably neutral, with a slight V-shape in their tonality; however, I find the Woodnote to have a slightly more prominent bass and upper midrange, which gives the instruments more presence and forwardness in their presentation. The difference is small, though.

Regarding soundstage and imaging, both are not far off; however, I find the Woodnote has less depth and a more forward and in-your-face presentation due to its more elevated upper midrange response, while the Klean presents a more balanced and rounded soundstage with a more holographic imaging presentation.

I find the Woodnote to have a slight advantage in terms of dynamics, as the elevated bass and the more forward upper midrange give it more punch and a more immediate sound presentation. The Klean is still dynamic-sounding but not as dynamic as the Woodnote.



Dunu Falcon Ultra Ti
Description

Falcon Ultra features a 10.7 mm pure metal foil (completely non-polymer-based) lithium-magnesium alloy dome diaphragm with separate suspension. It has an impedance of 16 ohms and a sensitivity of 108 dB.

The compact shell is made of CNC-machined stainless steel in Meteorite Titanium paint finish. It includes two pairs of replaceable nozzles. There is a small vent hole near the nozzle and two bigger vent holes near the MMCX connector. A MMCX cable, made with high-purity Furukawa single-crystal copper and silver-plated wire cores, features a replaceable plug and is included.

Sound quality

Using the Falcon Ultra with the gold nozzles and ePro EP00 ear tips, the tonality is close, with the Falcon Ultra being slightly more neutral and having a flatter frequency response. In contrast, the Klean has a somewhat more prominent bass and treble, resulting in a more V-shaped sound. Both models have a natural sound.

They are about equal in terms of sound staging and imaging, but I find the Falcon Ultra to have a slightly larger sound stage and more holographic and defined imaging.

I couldn’t tell them apart in terms of dynamics, even when the Klean is slightly more V-shaped in sound signature. They are very similar in liveliness and energy, and they never sound dull.

Kefine Klean Technical Details

Style: In-ear

Driver Type: Dynamic Driver
Driver Size: φ 10 mm
Frequency Response: 20 Hz - 20 kHz
Sensitivity: 107 dB ± 3 dB
Impedance: 32 Ω ± 15%
Cable Length: 1.2 m ± 0.2 m
Plug Size: φ 3.5mm SE
Weight: 9.8 grams each without ear tips and cable
Nozzle size: 6.4mm

Pros
Nicely balanced, moderately V-shaped tonality.
Good technical capability without sounding cold.
Detailed midrange and treble with no metallic coloration.

Cons

I wish it were a little lighter.

Conclusion
I appreciate Kefine Klean’s balanced, mild V-shaped tonality and its technical performance, particularly its holographic imaging capabilities. I also appreciate the clever way it placed the faceplate fastening screw at the back, rather than on the faceplate itself, which makes the design look clean.

However, I wish they made the metal shells thinner or smaller to make them lighter, as I am a fan of lightweight IEM shells, because I use IEMs during my walking exercises. At 9.8 grams per shell, it’s not a deal breaker, as many more IEMs are heavier.

That said, as a late reviewer of the Kefin Klean, I never knew that I’ve been missing out all this time on a clean, technically competent, and tonally pleasing-sounding IEM at an entry-level price point. Kefine Klean sounds good regardless of price, and thus, is recommended.

Non-affiliated purchase links:

https://www.aliexpress.com/item/1005007957993609.html

https://www.lazada.com.ph/products/...863640.table_online_product.33.19d81e13BMIMsu

When this came out in the market I always kept hearing this offers so much value, it punches way above its price point.

and spoiler alert it held that up for me



Test Gear
Fiio KA13
Luna
Zen Stack
Usual Test Track Playlist

So let's talk about the Build and Design

These are very sturdy and well made. I love the design of these very much. The faceplate has a smooth touch to it as well.

The cable is a tad bit thin for my liking but still it's a really good cable for the price point, and yes it does behave well. It's Roadie Wrappable
 

Comfort on these is A+, passed my sister's ears so it'll fit the majority of people out there.

Talking about the eartips - i didn't like the stock tips at all. Final E is what I went with and it was perfect for me. Also the stock tips that I got from C4 were nice as well.



Now let's talk about the sound

As you can see from the graph, it's a sort of U shape sound signature which has a controlled sub bass boost. Which leads into a warmish tonality to the sound signature. Let's talk about the sound in detail




Bass
I feel the bass is the most impressive thing on the Klean apart from its amazing build. The sub bass boost is really well done leaning into a basshead category but not so much. It has the rumble and you can feel it each hit. It's deep, has that body,it's punchy and a fair amount of texture as well.

It has more of a mid bass than a sub bass representation and I felt the sub bass to be not as prominent. But still its not something i would complain in a set like at this price range

To nit pick about this i would love a bit more thump in the sub bass region but overall very good bass presentation


Midrange
The overall midrange is a bit warm and lush. Especially in the lower mids which are lifted up.
These make the male vocals really good but it takes away the naturality.

For upper mids it has a forward nature but doesn’t sound as warm compared to the lower mids.
Female vocals are alright for the most part.



Here I would love a bit more openness and a bit more emphasis on the upper mids but that is understandable since they lifted the lower end.

Overall very engaging mids nonetheless

Treble
Treble is very well extended and is airy, I love the treble representation on these. It's exciting and yet not so sibilant but I can find people finding it sibilant.

It doesn't come across as incisive here but it gets the job done to make your head turn.

It also has a fair amount of details as well which is justifiable for the price range.

Technicalities
In terms of resolution, Klean does a pretty good job, nothing that would wow you but for the price point it offers it stands tall.

Detail Retrieval, Texture, the transients are something that you would expect in this price range and that's more than enough for what it comes with.

Soundstage is good as well with a fair amount of width and imaging for the most part is done well.


Comparison
If i were to compare this with, i will compare this with EW200 which was one of the default sets that were recommended under 5k.


For the bass
I would choose the Klean for its emphasis in this region whereas EW200 offers a bit more relaxed approach

For the mids
This is a toss up really, i love the upper mids on the EW200 and the lower mids on the Klean
This is all about preference here.

If you want an overall warmer mids go for Klean, if not vice versa.

For the treble
This is a toss up again where the EW200 is more sparkly and has the attack, whereas the treble on the Klean is a bit more relaxed compared to it and yet very engaging.

Techs
EW200 just offers better texture and detail retrieval here being the overall incisiveness across the board, i just love how it is represented here.

If i had to choose one i would pick the Klean for its overall package and engaging sound signature that it offers.

Surprisingly it kinda reminded me of the tuning of Moondrop May

Conclusion
Kefine Klean nailed the market with this launch of a fun and exciting sounding set that is very consumer centric and does the right job with everything.

I would rate it 4/5 and I can safely say this is a good set overall.


Thank you guys for reading my review, appreciate it.

In the Box

The Kefine Klean arrives in minimalist but attractive packaging. Inside, you'll find:

• The Klean IEMs
• Detachable 2-pin cable
• Multiple sizes of silicone ear tips
• A compact carrying case
• User manual

While simple, everything included feels thoughtful and of good quality, especially considering the budget-friendly price.

Build and Comfort

Klean’s resin shells are sleek and ergonomically contoured to sit flush in the ear. The faceplates feature a unique marbled aesthetic, giving them a custom look. The nozzles are well-angled, aiding in both seal and comfort. Long listening sessions are fatigue-free thanks to their lightweight build.

Sound

Bass

Klean delivers a warm and well-textured bass response. Sub-bass extension is solid but not overwhelming. Mid-bass is punchy and provides body to instruments and drums without muddying the mids. Bass is more about musicality than raw impact.

• Compared to the Moondrop Aria, Klean offers slightly more mid-bass punch and warmth.
• It is less sub-bass focused than the 7Hz Zero 2, but more organic sounding.

Overall bass is smooth and pleasant; great for those who enjoy a musical low end without excessive thump.

Mids

Mids are slightly warm and intimate. Male vocals sound full and rich, while female vocals retain clarity and emotion. Instrument timbre is natural, with acoustic guitars and pianos sounding particularly lifelike.

• Compared to CCA CRA+, Klean’s mids are less recessed and more natural.
• Not as dry as some Harman-tuned competitors; retains a lush character.

Mids are standout aspects of the tuning, well-suited for vocal and midrange-centric genres.

Treble

Treble is smooth and non-fatiguing. There’s enough sparkle to keep things engaging, but it never veers into harshness. Detail retrieval is above average for the price range, with cymbals and strings sounding realistic.

• Less aggressive than TRN MT4, which can get peaky.
• Not as airy as more expensive IEMs but strikes a good balance.

Treble is easy to enjoy across genres, especially for treble-sensitive listeners.

Technicalities

• Soundstage: Moderate in width, slightly more intimate than wide.
• Imaging: Clean and accurate; instruments don’t blur together.
• Separation: Good for a single dynamic driver—each element has space.

Not a technical monster, but performs very competently within its price tier.

Tuning Philosophy

Klean follows a balanced-warm tuning style, aiming for a musical and fatigue-free listening experience. There are no tuning switches, which simplifies the user experience and reflects a focused tuning philosophy.

Conclusion

The Kefine Klean is a well-tuned single dynamic driver IEM that balances warmth, clarity, and comfort. It stands out in the budget segment for its natural mids and enjoyable, non-fatiguing tuning. While it may not excite treble heads or bassheads looking for extremes, it's a great “daily driver” IEM that most people will enjoy straight out of the box.

The Kefine Klean is a 10mm DLC diaphragm driver IEM, with an all black metal shell sporting the Kefine logo in a good looking white font over a diamond pattern on the face plate. It comes with a silver 3.5mm cable, 3 sets of different sized ear tips, and grey fabric hard case also with the Kefine logo. The Klean also has 2 sets of different threaded nozzle caps, silver and black, with the black being noticeably brighter than the silver.


This set was provided directly from Kefine in exchange for my honest opinions, and I thank them very much for the opportunity to try out this great set that I've heard so much about.



~Unboxing~



Unboxing on the Klean is pretty nice. Slides open from the side and opens up to reveal these gorgeous IEMs inserted into all black packaging. The little box inside has the case, which is nice and premium feeling. Inside the case, is the other set of nozzle caps, 3 sets of ear tips, and a 3.5mm cable. I have a lot of IEMs, cables/tips, and swapped a GY HiFi-230 4-Core Desert Rose cable onto the Kleans along with some latex H570 ear tips, and I'm ready to go.




~Sound Impressions~


Klean is a brighter, decently bassy set, and doesn't lack in either sub bass or mid bass, as both come through well. Mids are a little bit recessed but it's not extreme. Everyone seems to be using silver nozzle caps. I like the extra energy at 1.5k-3khz on the black caps, but 5khz seems to be peaked too high for me with these looking at some graphs and hearing it in person. I used the silver nozzle caps for my impressions.


It's a really versatile set. Most songs play well with Klean and sound fantastic. Harsher songs might be a little piercing, so do keep that in mind. Surprisingly, a lot of the songs I usually use for sibilance testing did pretty well. Live recordings sound very good also, and detail retrieval/resolution seems perfectly fine for this price range. I didn't feel like I was missing anything listening to music.


I'm pretty impressed. This is tuned basically to my preference and I can listen to it for long periods without fatigue or discomfort. Whether I'm playing bass-heavy tracks, or slower, vocal songs, it performs very well. It might not be everyone's $50 king, but the only set around the price I have that comes close is my EW200 with EQ. I find that I don't need any EQ with Klean, it's basically just right for me.



~Conclusion~



Klean is a wonderful $50 set in my opinion. Great looking black metal shells, convenient swappable nozzle caps, decent cable and case, and very good overall sound and tonality. If you like it a more bright like I do, with bass to back it up, it shouldn't disappoint. I would feel comfortable recommending Klean at this price with the understanding that the treble at high volumes on occasion can be a little unforgiving with certain songs. I would like to see a 4.4 option as well.



Thank you very much to Kefine for providing the Klean for review. Can't wait to see what's next on the horizon for Kefine. And thanks for reading!

KEFINE Klean - Review 

Disclaimer:

*As always, with each review I try to improve and better demonstrate my experience as a regular but avid and passionate user!

*If you are looking for a super technical and in-depth analysis, please feel free to look for another review. There are many guys here who have much more knowledge than me and have been doing this for much longer.

*This time, the unit to be reviewed was kindly delivered by KEFINE and Collin Yang in exchange for my honest opinion/review.

*I will try to be as brief as possible, "straight to the point!" And as unbiased as possible.

---

Gear Used:

· EPZ - TP35, TempoTec V3 Blaze (WAV, FLAC files and Tidal)

· Motorola Edge 50 Pro (UAPP), (Tidal)

· Notebook (Windows), (MusicBee), (Tidal)

· Penon Liqueur O (best match/ fit) and B, Dunu S&S, Whizzer ET100AB, Bamboo Tips, TRN T, SoundCocoon, ddHIFI ST35, Eproo 00

· 4.4 bal. Cable, and High Gain as always

---

Specs:

Drivers Config: 10mm DLC Single DD

Sensitivity: 107dB

Impedance: 32Ω

Frequency Response Range: 20Hz-20kHz

---

Unboxing Experience:

This time I won't go into too much detail here.

A very simple unboxing, with a good presentation.

A small and well-protected box, with a sleeve, then a black box containing the shell in fa foam piece, which is very secure, and another black box with the case where we find the cable, and the exchangeable nozzles, plus the eartips and a small manual.

*When I go into too much detail about this part of the unboxing in an iem under $50USd, it's because the brand is different and decides to stand out in this area. Which is not always positive.

---

Overall Build:

The shell is very minimalist, made of aluminum alloy made using a CNC machining process.

Very light and low profile.

The two interchangeable nozzles and, to my surprise, work significantly and efficiently. They have a slightly aggressive lip, while they will hold your eartip in place, they may cause discomfort to some people. They reminded me a bit of the Wan'er S.G. nozzle.

A beautiful white/silver braided two-core cable with well-made black hardware, but a bit too thin for my taste, made of silver-plated copper. In the traditional 2-pin model and with a 3.5mm plug, it is unfortunately the only option.

Also 3 pairs of eartips and a case, which accommodates the Klean well if used with the stock cable.

But for the purpose of this analysis I used a balanced cable. I used the Yongse Warrior cable.

*As for the eartips, as always, unfortunately the tips that come with most sets, regardless of the brand, don't fit me well and regardless of that, I always try to find the perfect tip for my taste, the tip that I think sound and seal best with the iem and my tiny ears. In this case, the Penon Liqueur Orange was used.

---

Sound Impressions:

Overall, The Kefine Klean is a true all-rounder, great bass, warm and fuller mids with a secure yet engaging treble.

---

Bass:

The Klean's bass is very pronounced and will definitely satisfy those who like good bass.

With a noticeable rise in the sub-bass, soon moving into the mids-bass, which naturally bleed a little in the mids, giving the mids a warmer and thicker character.

The bass overall is meaty, full and definitely punchy but still clean and very balanced.

It has a good texture, speed, it's a bass that gives you fun without compromising technicality.

---

Mids/ Vocals:

The mids were greatly benefited by the bass, the word clean appears again. It has plenty of body, it is on the warmer side, with good resolution.

Both male and female vocals are in the right place, although I like the vocals a little behind everything else here at Klean, they are right in the middle. The female vocals are a little bit forward since the uppermids are more forward than the rest of that frequency area. In the right spot.

---

Treble:

Guess what word will appear here again, clean!

The highs are clean and well controlled with good extension and air, they are a little energetic depending on which nozzle you choose but by any means sharp or harsh.

Overall it complements the rest of the frequencies very well and even with the most energetic nozzle I still find that the highs are safe, enough to listen to for a long time, without any irritation or fatigue.

---

Technical Performance and Soundstage:

The separation, layers and overall technicality is really good, It has an excellent image

I managed to get each instrument and all the elements of the mix well separated and well defined, each in its own place.

The soundstage is kinda ok, nothing outstand, it's average, side by side with the competitors in its category. (OK=GOOD)

---

Overall Verdict:

The Klean is really clean. Now I understand why this IEM was and still is so successful. It is exciting, cohesive in all frequencies, musical and technical enough.

Under $50usd, what more can I ask for?

It is truly a top performer all-rounder!

*Again, thanks to KEFINE and Mr. Collin Yang for kindly sending me these unit.

ADHD Reviews presents!

Short attention span reviews for the masses!
Kefine Klean!



The Klean is a Single Dynamic DLC Driver iem with
balanced tuning, good subbass rumble, and a nice mid bass punch.
Klean is an iem that handles many genres well and for MSRP of 50$, it has a the whole package, good build, good technical abilities, replaceable nozzles, it's one of my favorite recommendations for newcomers, and even advanced hobbyists will enjoy it.


Silver/Black Nozzles:
I don't feel a HUGE difference between them, black nozzle feels a bit brighter.

Bass:

The bass of the Klean is something that I really love, the DLC Driver gives you a very full and juicy bass with fast response, a good slam, and it works great for fast drum peddaling like those that you can hear on metal tracks.

Mids:

Male and female vocals comes out fine without distortion even though they feel a little laid-back for my taste when I say a little I mean a little, not distant, it's a nitpick for my taste.

Treble

The treble of the Klean is sparkly but not well extended as i would like it to be , as a whole "sound" it works together great and compliments the mids and the bass but for instrumental tracks I'd like to have a little more extension.


Sources:
Tempotec Sonata BHD Pro
Tempotec Blaze V3


Final thoughts:
Klean is a very good pick for it's price and I'd recommend it to anyone who wants to try something that wont break the piggy bank.
it gives you everything you need.
I'd like to thank Collin from Kefine for sending me this iem for a honest review.

Non-affiliated purchase link
https://a.aliexpress.com/_oDqryfh

INTRODUCTION:
Kefine, has consistently impressed with their innovative audio solutions. Having personally experienced their products, from the esteemed Klanar onward, I eagerly anticipate diving into the sonic depths of their latest offering, the Klean. Now, Kefine has extended its reach to a more budget-conscious audience. Priced at an affordable $49, the question arises: Can such a modest price tag deliver a truly satisfying audio experience? Let us embark on this auditory journey to uncover the answer.

INCLUSIONS:
CABLE:
The included cable, while functional, is rather generic and lacks any notable frills. For those who believe in the significance of cable quality, the Klean offers the flexibility to accommodate third-party cables. The stock cable, though lightweight and discreet, is presented in a simple white color. Termination is only available on 3.5mm.

EARTIPS:
The Klean comes with a single eartip option, a necessary cost-cutting measure at this price point. While these tips are functional, audiophiles may wish to experiment with different eartip configurations to further refine the sound signature.

CASE:
Kefine's inclusion of a carrying case at this price point is a commendable gesture. While a pouch might have been a more cost-effective solution, the brand's decision to provide a full-fledged case is certainly appreciated.

TUNING NOZZLES:
The Klean offers a customizable listening experience with two interchangeable tuning nozzles. The silver nozzle provides a warmer, more relaxed sound signature, while the black nozzle delivers a brighter, more forward-leaning sound with a focus on midrange and treble. As a fan of a brighter sound profile and enhanced technical detail, I opted for the black nozzle.

COMFORT AND WEAR:
The Klean offers a comfortable and secure fit, easily forming a tight seal. While lightweight, it remains substantial enough to provide adequate grip and isolation. Extended wear, including during naps, proved to be entirely comfortable, making it suitable for both casual listening and professional applications such as recording and stage performances.

SOUND IMPRESSIONS:
SOURCES:
1. Ovidius B1
2. Centrance Dacport HD
3. Hiby FC6
4. Fiio M11 Plus Ltd
5. VE Odo
6. VE Abigail
7. Apple music subscription
8. Qobuz Studio subscription
9. EPZ TP50
10. EPZ TP35

TECHNICAL SIDE:
The Klean boasts an above-average soundstage, with a respectable width but less pronounced height and depth. This is expected for an IEM at this price point.

The Klean's sound signature leans towards a smoother, less analytical presentation. Bass guitar and percussive instruments are rendered with a reduced level of grit, resulting in a more relaxed listening experience.

The dynamic driver employed in the Klean offers adequate speed, capable of handling fast-paced tracks with aplomb. It may struggle slightly with highly complex musical passages, with a rather soft attack compared to some sets I have around the $200 bracket.

One of the Klean's standout features is its imaging capabilities. At this price point, it excels in instrument placement and vocal separation, creating a sense of 3D sound that belies its relatively modest stage depth.

The Klean's accurate timbre further enhances the listening experience. Instruments and vocals sound natural, organic, and realistic, adding to the overall authenticity of the sound.

SOUND PROFILE:
The Klean's bass performance is characterized by its emphasis on punch and mid-bass, rather than sub-bass rumble. While it can deliver some low-end impact, the decay is relatively quick, resulting in a balanced and cleaner overall sound. The bass quantity is sufficient to induce head-nodding, but it lacks the chest-thumping intensity of more bass-oriented IEMs. Additionally, the smooth presentation of the bass contributes to the Klean's less analytical character.

The midrange is undoubtedly the Klean's forte. A forward and present midrange allows for a clear and detailed presentation of instruments and vocals. This characteristic is particularly appealing to midrange enthusiasts, as it prioritizes the core elements of the music. Jazz and vocal tracks benefit significantly from this tuning, as the relevant instruments and vocal performances take center stage. The midrange is not thin or anemic, possessing a satisfying weight and thickness.

The Klean strikes a balance between energy and smoothness, avoiding excessive brightness or sibilance. The treble offers a suitable amount of shimmer and detail without becoming fatiguing. While treble-heads may yearn for a slightly more aggressive presentation, the Klean's treble tuning is likely to appeal to a wider audience, especially those sensitive to high frequencies.

VERDICT:
Kefine deserves commendation for delivering a high-quality audio experience at a more accessible price point. The Klean punches well above its weight, rivaling its more expensive Delci siblings in terms of musicality, timbre, and technical prowess. Kefine has once again demonstrated their mastery of sonic balance, ticking all the right boxes for discerning audiophiles. Looking ahead, I'm eager to see Kefine explore more complex driver configurations, perhaps incorporating balanced armatures. They have earned my recommendation as a brand to watch, and I anti
cipate their continued rise to prominence in 2025.

If you're interested in graph comparison, here's link
Disclamer:

+ I'm a normal asian dude with some music producing background
+ I like clean balanced sound signature with focus on sub bass and lower treble
+ Can consider myself as treblehead
+ 60-68db listening session
+ Avarage 4/10 (Quarks/ 7hz Zero), Good 6/10 (Tanchjim Kara), Endgame 8/10, Bias Endgame 10/10
 : Good, but with a catch
 : Worth the money
 : Specialist at something else
 : A Very close to perfection
: Perfect for me

Click to expand...

How to read my review: (Which bold font is x2 in score)

. TONE
- Timbre: How sounds projected, usually free score for most iem. Only GK10 would get a 2 from this
- BASS: (20hz - 500hz)

Depth	How low can i hear (physically, not graph)
" /; \; =" + "number hz"	/: rolloff, \: upward, =:flat after Hz of the highest spot i heard
Decay	Decay + Sustain, usually the mid bass and flexability of driver
Resonance (or Release)	Driver + tune. The bass after kick drum
Air	Flexibility of bass. effect by tune and driver
Tone	Based on how balanced it is
Tech	Detail (Texture, Fastness). Effect mostly by air

- MID: (500hz - 5khz)

Acoustic	Piano, Violin, Strings basically, flute, ...
Electric	Synth, Lead, Pluck, Electric guitar and Bass guitar, ...
Tone	Based on how balanced it is
Tech	Detail (Texture, Separation). Effect by tone

- TREBLE: (5khz - 16khz)

Extension	The upper end of high, quite easy to hear if you don't have hearing loss
Air	Spacing between instrument, cymbal
" /; \; =" + "number hz"	/: rolloff, \: upward, =:flat after Hz of the highest spot i heard
Sparkle	Attack and Decay of cymbal. Is tonality element
Shimmering	Sustain and Release of cymbal. Is tonality element
Tech	Detail (Texture, Separation, Transients). Effect by tone and air

- OTHERS:

Vocals	uhm. Vocals?
Drum	uhm. Drum?
Percussion	most of the clack clack click click lol. Effect by texture in mid
Resonance	The one that will let you know if transducer good with rock or not
Dynamism	Ability to make emotion
Sibilance	10 meant no sibilance.

. TECH
- Detail: Bass + Mid + Treble
- Soundstage: Rough description wall of sounds
- Imaging: {Width, Depth, Height}, {blurry, solid (better than blurry); Phantom (Good microspacing)}

Click to expand...

First, a big shoutout to KEFINE for giving me this set to make this review and to give it my sincere opinions and impressions. The KEFINE Klean is an IEM launched back in 2024 with high praise from other reviewers and the community in general, but I wanted to see with my own eyes and hear with my own ears if it is up to the hype, and that’s why I contacted Kefine asking for a sample to review myself. The Klean is another product who follows the success of the Klanar, Delci and the Delci x AngelEars, driven by a 10 mm DLC dynamic driver, and at a MSRP of 49 USD (usually less on sale) the Klean shows how is not needed to pay a lot of money for a wholesome experience into the world of HiFi.
You can find it at https://www.kefineelec.com/en/ProductDetails.aspx?iProId=25 who redirects to their AliExpress official store, also available in other minor retailers online.
TDLR; One of the best IEMs in the 50 USD dollars or less market, a neutral (natural), technically impressive, bassy and musical experience bring by KEFINE to offer a mature and fun sound to beginners and experienced audiophiles for an affordable price.
The KEFINE Klean presents a neutral (natural) sound with a nice bass boost, with plenty of technical qualities, a nice extension into the lower and high frequencies, and a building and packaging who puts in shame other competitor products in the market, with a very affordable price and punching way above its weight.
Technical specifications:

• Driver Type: 10mm dynamic with DLC diaphragm with N52 neodymium magnet.
• Frequency Response: 20Hz-20kHz.
• Sensitivity: 107dB ± 3dB.
• Impedance: 32Ω ± 15%
• Jack connector: SE 3.5mm.
• Connection Type: 2Pin, 0.78mm.
• Cable length: 1.2m ±0.2m.
• Weight: 10g on each side.

What comes in its package?: The IEMs themselves, the manual and warranty card, a quality card, a nice, well-built and very versatile case with the KEFINE logo; inside the case there’s its gorgeous cable, a perfect match for the IEMs ( I don’t feel the need to replace it) which is a 0.78 mm 2 pin, two cores twisted, silver plated free-oxygen copper cable with a 3.5 mm single ended plug, a set of balanced bore eartips (SML sizes) and the other set of nozzles (black, the silver are the ones installed).
Its cable looks very nice and well-built, and it matches perfectly with the shells. The shells are made of metal, well-constructed, with a beautiful faceplate in which you can see the KEFINE logo in white, the housing doesn't seem prompt to scratches or so, for $49 you are expecting a quality product to last. It is comfortable to wear for long periods of time, with a nozzle who fits so well in my ears (> 6 mm diameter) but I advise seeing if is a nice fit for you because it goes in the medium to large size in comparison to other sets.
How the KEFINE Klean sounds:
The Klean with its 10 mm DLC dynamic driver offers a very Klean (pun intended) and natural sound with a nice subbass boost and midbass presence with a nice extension into the lower and high frequencies, and a technical capacity who excels sets in the same segment of price and punches above its weight, offering a neutral (natural), full of macro and microdetails all-rounder who offers a very immersive, musical and fun presentation of sound, in the soundstage department it is impressive, the resolution and imaging are very remarkable, and you can distinguish all the instruments and other tracks in the music, this is no-brainer option for its price IMHO. For this review, I only used the installed nozzles (Silver).
BASS: The Klean offers a satisfying bass shelf, with a more than decent quality and quantity of subbass thump and midbass bump, clean, fast, resolving, well extended into the lower frequencies, so bassheads can be satisfied in this aspect, it bleeds slightly into the lower mids without mudding male vocals, it sounds very natural and adds a nice flavor to the overall sound delivery. In songs like “Alone” by The Cure you can feel the weight of the bass guitar and drum kicks in a delightful and engaging presentation, in “Long Live” by Atreyu, the Klean shows how its bass delivery puts you in a state of unconscious headbanging (?).

MIDS: As I mentioned before, the midbass bleeds slightly into the lower mids but male vocals and bass kick are not muddy, neither veiled, with a tiny dip until its forwarded and enters the pinna gain with a smooth but not sibilant approach of cleanliness and enough presence and resolution, with a 5 Khz peak to add to the feel of those plates and cymbals, female vocals are forwarded as well, neither sibilant nor fatiguing, a nice 6 kilohertz dip to crank the volume up if you feel the crave for (in my case I’m finding doing this a lot). In songs like “Knife in the Safe Room” by Darkest Hour you can see how the plates and cymbals are presented with an impressive quality and not much sibilance, the vocals of Joss Stone in “You Had Me” in her album Mind Body & Soul puts me to dance with the music, sounds so cool!

TREBLE: This portion of the frequencies comes with a very good extension without so much sibilance, very clean, crisp and sharp without too much harshness, handling the sibilance so well, I’m finding myself listening to music at mid to high volumes and having to lower that volume knob to take care of my hearing, so it’s not fatiguing in long sessions at least for me (And I have a mild treble tolerance). Songs like “The Ninja” by Jason Becker and Marty Friedman’s Cacophony is shown all the drums and guitars details and colorations in the production of the album, in “The Metulsky curse” by Long Distance Calling you can just put the Klean in your ears, close your eyes and enjoy the ride for the duration of the song.

TECHNICALITIES: The upper treble extends so nice, presenting an airy and spacy sound, the soundstage is very wide, and it gives you a plentiful sensation of space and depth. In songs like “One (Live)” by Metallica in their album S&M from 1999 you can feel inside the scenario in which they recorded the music, with all the San Francisco Symphonic Orchestra playing with the band. The Klean has a very resolving presentation of sound with a separation of sound more than average for its price, with busy and complicated tracks like “Hessian Peel” by Opeth you can be sure to hear all its pieces and instruments in the soft and heavy parts of the song without missing anything from the start to the end of the track.

Closing thoughts and conclusions:

The KEFINE Klean stands out as an impressive offering and one of the best options to buy in the 50 USD or less segment, its immersive naturalness and bass and treble extension put it as an overall excellent all-rounder with a technical, engaging and musical character, making it ideal for mature and newbie audiophiles and other listeners who want a very high-quality audio experience at an affordable cost. Is one of the best all-rounders for its price and in various cases a set who presents a better choice in a very competitive market than more expensive sets.

The KEFINE Klean with its 107dB ± 3dB sensitivity is very easy to drive, even with a phone, but as a dynamic driver IEM it is benefited of source interchanging, with a neutral and uncolored source like the ESS Sabre chips it is presented as more technical than warm, but with a warm source it doesn’t lack technicalities (sources with CX31993 chips for example), and scales very well with more power. The included eartips are more than fine to use it out of the box, but if you want to change them, my advises goes to offers in the market as the Penon Liqueur Orange, Tangzu Tang Sancai Balanced and TRN T eartips.

Can I recommend it? Of course, YES! The KEFINE Klean is one of the best options for its price segment and offers a sound you find in more expensive sets, with the KEFINE seal of quality, it is in my collection, and I’m not giving it away soon.

Again, thanks to KEFINE for giving me this IEM to testing it, enjoying it and giving me the arguments I needed to recommend it as a product who excels its hype and deserves more praise . Thank you, the reader, for visiting my review, and happy listening!

Introduction

Kefine is one of many audio brands that just appeared in the recent years. They were most famously known for the Klanar - their first ever iem. At the time, back in 2023-2024, it seems to be one of the most sound value planar iem in the market. Then they release another iem called the Delci, which is also a highly successful release. And then they released their 3rd iem called the Klean. The Klean is their most budget offer, featuring 1 dynamic driver with a DLC diaphragm.

You can find more info about the Kefine Klean here: linsoul.com/products/kefine-klean

Disclaimer: I would like to thank Mr Collin Yang from Kefine for sending this unit for touring purposes as well as making this review possible. I did not receive any financial benefit from him. Everything I said in this review will be my subjective opinion only.

Packaging

The package of the Delci is quite minimal. It arrives in a small rectangular box. Open it up, you’ll see the iem and the accessories

The accessories include:

· A cable

· A carrying case

· 3 pairs of normal bore silicone tips in 3 different sizes

· Two pairs of screwing nozzles

· A user manual

· Warranty certificate


Design/Build quality/Comfort

The Klean has a full metal shell and faceplate. It feels quite heavy and dense on the hand. The faceplate has the Kefine logo on it. The paint finish doesn’t attract fingerprints as well as fine scratches. There’s also a single hex screw on the inside to secure the housing in place. I have no complaints regarding the build quality of the Klean.

That being said. With the shells being made out of metal, it’s also highly conductive. Sadly, I usually get zapped on the right side of my ear when using the Klean with a plugged-in laptop. The cause of this is due to the bad electrical grounding on my part, but I think it’s also because of the internal wiring and the driver touching the shell body, which then directs the current onto my outer ear. I can mitigate this issue either by installing some grounding wires for my laptop or by listening to the Klean with my ipad/phone with a dongle most of the time.

The Klean is an iem with changeable nozzles. Well, not nozzles but more like filters. It’s different from the swapable nozzles of Simgot EA’s lineup, more similar to the Hidizs MP145/MP143’s type. I really like that Kefine has included some diamond pattern ridges on the filters so that it’s easy to screw and unscrew.

The comfort is only so-and-so. It doesn’t have the most ergonomic shape to them. It has a sort of industrial design language to them. The housing is on a smaller side, so it doesn’t impede too much against the outer ears. Isolation is only average.


The cable is a dual core, SPC cable with 3.5mm connector. It’s soft, neither too thin nor too thick and has very little memory. Other hardwares of the cable is made out of metal too. Overall, this is quite a decent cable for the price.

Sound impression:

*Test gear:

Source: Poco F3, Dell laptop

DAC/amp: Ibasso DC07 Pro, E1DA 9038D

Eartips: EPZ liquid silicone eartips, stock tips

Cable: Stock cable


Tonality: Warm neutral / Harman-ish

Bass

The Klean has quite a healthy dose of bass boost. It’s definitely not a bass lite iem. It has a subbass over midbass presentation. The subbass reaches deep with good air movement and lingering sensation to them. With “Why So Serious” – Hans Zimmer and “Chameleon”- Trentemoller, it shows a densely pack subbass rumble with really nice tactile feedback.

Midbass wise, it’s thick, heavy and rounded with a decent texture to them. Kick drums are authoritative with good body to the hits. The plucking of the contrabass feels dense and heavy while the cello sounds quite warm yet vibrant. The Klean’s driver doesn’t have the fastest attack and decay, doesn’t feel very agile or responsive with aggressive, super fast pace metal tracks like “Sugar Daddy” – Brutal Truth or “Distress Rehearsal” – Every Time I Die. With slower paced genres like jazz or slower paced rock, the Klean can handle it just fine.

Midrange

There’s quite a lot of warmth and coloration in the lower midrange – direct result from the bleeding into the midrange of the bass region. It’s lush and thick sounding, and feels slightly muddy. Regarding the upper midrange, the Silver screws dampen them more than the Black screw. With the Black screws, female vocals pop out more, can feel more energetic but also more shouty and in your face. The Silver screw gives you a smoother, tamer presentation without sounding too dull. It also allows you to listen to the Klean at slightly higher volume.

When listening to Frank Sinatra, Grover Washington and Michael Buble, their voices sound meaty and have a good amount of grunt feeling to their voices. When listening to Christina Aguilera, Celine Dion, Ariana Grande, they all sound emotional with an ample amount of richness and liveliness to them. I certainly would’ve enjoyed a bit of a cleaner midrange presentation, but I understand the limitation from the tonality that Kefine is going for with the Klean.

Instruments have a very natural timbre to them, nothing sounded off. I personally like the Silver screw most of the time, both for listening to vocals and instruments. Piano sounds quite pleasant and easy on the ears. Violin feels smooth with a good texture to the bow stroke. The note weight leans more on a heavier side

Treble

The treble performance of the Klean is quite decent for the price. It is decently extended, with a good amount of air to them and it doesn’t feel too peaky/not the smoothest. There’s air and brilliance, but not a lot of them, not packing much bite or micro details. Cymbal crashes have decent shimmering and sparkles to them. Hihat sounds nice and has a cool wispiness/softness to them. Overall it’s just a well done, above average treble quality from a 1DD iem, nothing to write home about.

Tech

The Klean has around average technicalities. It has around average stage size, with quite decent width but lacking stage depth. Imagine is also quite well done and accurate, although the layering and separation are not as good.

Comparison

Vs Kefine Delci

The Delci is only a bit more expensive than the Klean, selling at around $75 (usual sale price is ~60$). If I recall correctly, the Klean uses a similar quality DLC driver like the Delci, but since the Delci’s shell is made out of CNC aluminum, it’s cheaper to produce the Klean. The ergonomics of the shells feel better on the Delci. The stock cable feels a bit better on the Delci.

Sound wise, there are some differences here and there. The Delci have a bit more subbass than the Klean while the midbass is similar in quantity with very similar texture. The mids feel a bit leaner on the Delci, cleaner dare I say. It just feels more open and revealing. The tone of instruments and vocals overall feels a bit more “natural” and having more texture, feeling better overall on the Delci. That said, the Delci does have a bit more energy around 7-8khz region which makes Delci occasionally more metallic/rougher. The Klean packs more air and sparkles into the treble region, feeling more detailed and resolving overall.

Technicalities wise, the Klean feels a bit more open – with a wider stage – than the Delci with better imaging overall.

Vs Simgot EW300 HBB

The Simgot EW300 HBB is 25$ more expensive than the Klean. The EW300 is a tribrid iem, with 1DD + 1 Planar + 1PZT inside of it. Build quality wise, both iem’s shells are made out of metal as well as having changeable nozzles. However, the surface of the EW300 HBB feels more matte/less smooth than the Klean’s. The Klean feels more comfortable in my ears than the EW300 HBB. The stock cable of both iem feels similarly soft, but I’d lean slightly more towards the Klean in terms of quality

Sound wise, I’ll mainly compare the Klean with silver nozzles against the EW300 HBB with the red nozzles.

Despite the bass shelf looking similar, I’d say the Klean has a superior bass region overall. The Klean’s bass has more sense of depth and air movement to them, leading to a more satisfying and fun bass experience overall. The bass texture feels a bit chunkier, thicker on the KleanThe bass speed and decay feel relatively the same, meaning that both can’t handle that fast, aggressive bass line from many metal tracks.

Midrange wise, both iem have similar note weight to each other. Instruments timbre sounds more natural on the Klean as it doesn’t have that mild planar/pzt timbre in the EW300. Vocals sounds a bit livelier, more energetic and truer-to-life on the Klean

Treble wise, the Klean packs more air and extension, feeling more resolving. It feels smoother overall too. The PZT just stands out too much from the bass DD in the EW300, making it sounds not as coherent. Cymbals and hihats has more shimmering and sparkles, crispier on the Klean overall.

Technicalities wise, the stage size is quite similar between the two iem, but I’d say the Klean has better imaging and separation overall.

So yea. Through this comparison, I think the Klean is a better valued iem overall than the EW300 HBB.

Conclusion

The Klean in and of itself is a really nice product. I’d say, if you’re a newbie and are searching for an iem with an easy-to-enjoy tonality, with premium build quality for just around 50$, I think the Klean is quite a safe choice to pick. That being said: There’s a lot of iem with similar sound quality to the Klean in the market, in all sorts of price range, from 20$ up to hundreds of $. The Klean is just another iem is this large pool, which sadly makes it quite forgettable in the long run. If you already have an iem with something along the lines of Harman-ish or similar tuning, I think you can pass on the Klean for now.

That’s it for my review and thank you for reading.