Recently, KEFINE has decided to revisit one of its most popular sets, the Klean, and recreated what to me - seems like a very good representation of an audiophile's journey. Although I can't speak for everyone, for me and my clique at least, we started off with very V-shaped sets, and now we are at netural preferences. Instead of focusing on V-shaped funness, we gravitated to a more flatter response, which allows us to have a clarity and engagement of the entire spectrum. And, the KEFINE KLEAN SV embodies that quite well.

Specs :
Driver : 10mm DLC Diaphragm Dynamic Driver
Sensitivity : 107dB
Imperdance : 32 Ohms
Cable : 18 strand SPC 2 core cable

Price : 54USD (3.5mm) , 56 USD (4.4mm/USB-C)

***Reviewer’s Note***
My judgement on how an IEM sounds will always be done with a relative comparison based on it’s MSRP. Technical aspects such as dynamics, staging, imaging, and detail retrieval is as equally important as the general tuning of the IEM.
As always, this is a hobby which everyone has different preferences. Although I try to be as objective as possible, I do not dare to say I can be 100% unbiased.


How Does It Sound?
Tested with :

• MacBook Pro M3
• HiBy R6 iii 2025
• ifi GO Bar Kensei
• Fosi Audio ZH3

For the purpose of this review, it will be reviewed in the silver nozzle. Differences of the other nozzles will be written seperately
The KEFINE Klean SV has been subjected to ~ 100 hours of burn in prior to evaluation

First Impressions

• The KEFINE Klean SV is tuned to be a neutral balanced set with slight tilted emphasis on treble
• Tonality of this set is netural throughout and has a clean response
• This pair overall has a more transparent presentation - synergy with source is very significant, hence with better sources will give an even better experience

Bass :

• Bass presents itself with a more lean approach with how it’s tuned, so not one for bassheads
• Subbass is given in a more airy recreation
• Lower and Midbass has good clarity and is on the colder side
• Definition on the lowerend is the Klean’s strong suit, giving it a clear intention to showcase bass licks

Vocals :

• Positioning is quite forward with some good distance to not feel too intimate
• Tonality and timbre is neutral and transparent
• Thinness slightly present for vocals throughout the spectrum, but nothin
• Female vocals will tend to sound brighter

Midrange :

• The midrange shows the strong suit of the Klean SV, with its transparency and clarity gives instruments a little more saturation for a richer feel
• Lower-midrange complements well with midbass to give you a more dimensional piece
• Instruments in the lower-midrange provides a complete coverage but has not bloat or congested feeling
• Characteristics of strings overall sound very full and well reciprocated, specifically for acoustic guitars, where strums on the strings sound quite realistic
• Macrodetails of instruments are quite well reciprocated with slight vibratos picked up by the Kefine Klean SV with ease (Vincent Belanger - Songe, strings occasionally have slight vibratos which are noticeable easily)

Upper-Mids and Treble

• The Kefine Klean SV gives off a bright response with surgical precision of emphasis
• Timbre is also of a clean nature with no hints of tinny or metallicness
• Treble extension is not as prevalent, sometimes might perceive as dry slightly
• Instruments in this range is very frank and realistic, giving you what it intends with no coloration
• Microdetails are engaging, with nuances of bells, chimes, any bright clings. All of those are presented with amazing resolution
• Do take note the Kefine Klean SV sounds brighter, so might come off as shrill to some.

Technicalities

Dynamics - Solid throughout, noticed after burn-in period definitely helps with some initial slight pockets of incoherencies out of the box which mainly targets the consistency going from mids to upper-mids

Staging - For the price it certainly rivals IEMs double its price, with a respectable amount of width and depth, height is surprisingly tall

Imaging and Seperation - Separation is clear and concise, however imaging seems to be quite dependent on source synergy. On the ifi GO Bar Kensei and Fosi ZH3, imaging is quite spacious and free, on the Hiby R6 iii 2025 it feels somewhat limited.

Detail Retrieval - Above Average. The Klean SV makes you unconsciously forget you paid only less than 60USD for something that sounds double the price

Nozzle Talk
The sonic changes that the nozzles give for the KEFINE Klean SV is not extreme, but allows some fine adjustments for certain things

Gold Nozzle
The gold nozzle overall has a more airy emphasis on the upper-midrange, giving it a more fun lift on that end. With that said, it also slightly increases the brightness.
Black Nozzle
The black nozzle's most apparent in pushing the vocal range slightly forward, which gives more intimacy.


Comparisons :

BQEYZ Ni
Although within the same price bracket, both IEMs approaches tuning very differently. With the Kefine Klean SV, this one is what I would describe to be an even more mature tuning than the Ni, whereas the Ni, with a Balanced presentation sounds more “fun”. Although I can say the Ni might be slightly better in technicals only by a hair, both are neck-and-neck in terms of being able to punch themselves over their weight class. It honestly just comes down to preference on tuning.

You would like the BQEYZ Ni more if :

• You want a more balanced tuning
• You want some slight warm tonality
• You want a more musical experience

You would like the KEFINE KLEAN SV more if :

• You want a neutral set with a neutral tonality
• You prefer a leaner presentation of bass with greater tonal accuracy
• You want a more clinical and transparent experience
• You'd like a more brighter treble presentation

 

 

Final Thoughts

With a more mature tuning approach, the KEFINE Klean SV definitely gives a better perspective that allows people to appreciate every part of the song with equal emphasis throughout. For me, jazz, soul, funk, and indie rock gives the best experience with how transparent and clean it articulates the track. And if it's a live set, upper-mids will definitely be giving you a good ride as well with somewhat surgically accurate transients that is both energetic, and non-intrusive.
I definitely recommend the KEFINE Klean SV for those who wants to try out something a little more different, that allows one to appreciate music more.

I'd like to thank Collin and Lina from KEFINE for sending these over for an honest evaluation.

For anyone interested, (unaffiliated) links are down below :

HIFIGO : KEFINE Klean SV
AngelEars : KEFINE Klean SV