• I don’t read FR graphs. I only use my ears, as earphones should be used.
• Kefine sent this unit to me in an exchange for an honest, unbiased review. Rest assured that this review will do its best to devoid from any bias/es as much as possible.
• The following remarks and observations shall be made and owned only by me.
• No monetary compensation is/was involved before, during, and after the period of creation of this review.
• Your mileage may (and always, will) vary.

My personal preferences, in terms of sound, methodology, and music of choice:

• I prefer a “neutral/flat/balanced”, uncolored sound as much as possible.
• I prioritize technical over tonal performance.
• I listen to most genres existing on the internet.
• I use the included stock eartips and cable as much as possible to put myself on a consumer’s perspective, unless stated otherwise.

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Brain-burn-in time: 4-8 hours per day, 10 days.

Source/s used:

• - Non-HiFi smartphone (Infinix Note 12 G96), PC.
• - Hiby R4 DAP
• - IFi Zen Stack (Zen DAC V2, Zen Can)
• - IFi Zen DAC V2
• - Kefine Dongle
• - Fosi Audio SK02 USB DAC
• - Venture Electronics Odo USB DAC
• - Venture Electronics Devastator USB DAC
• - Venture Electronics Megatron USB DAC
• - Venture Electronics Galvatron USB DAC
• - DDHiFi TC44Pro E3 DAC
• - Snowsky Melody DAC
• - Aiwa XP-V710C CD Player (12 sec. EASS)
• - FiiO DM13 CD Player
• - Local Files via Foobar, YouTube Music, Deezer, and Qobuz with UAPP.

IEM/Earbud/Setup configuration: Stock medium white eartips, stock cable (4.4mm, 3.5mm, USB-C, any form of EQ or MSEB off, 40-60% volume.

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Additional note here: I will be reviewing the Kefine Klean SV first with its preinstalled silver nozzle, then compare it to the other two.

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Sound signature:

• Let’s keep things simple: The Kefine Klean SV is basically a more “neutral” Kefine Klean, catering those people who wanted a Kefine Klean but with less warmth and more controlled sound. If we’ll be specific, the Kefine Klean SV is a neutral sounding IEM, with a mild emphasis on its mids, particularly on the vocals.

Lows:

• Think of it this way: the first Kefine Klean has more bass quantity when compared here to the SV, so that automatically should mean that this IEM is not for bassheads. While the original Klean has a thick, mildly elevated bass response, the Klean SV has a more “neutral” presentation to it, with both midbass and subbass levels equal in presence. This in return results in a neat, well-controlled, punchy bass character that never sounded lacking for a neutral IEM, addressing the minor nitpick of some hobbyists wherein the bass of the first Klean sounded a bit “loose” to their liking. Personally, the bass response and character that the Klean SV represents is adequate to what I prefer. Even the Etymotic ER2SE, my favorite IEM, has lesser bass quantity than this, so the Klean SV’s bass will be pleasing enough for a 50 USD IEM, as long as the user prefers neutral sounding IEMs.

Mids:

• This region is one of the two parts where the Kefine Klean SV differentiates itself from its older sister. If you find the first Klean’s mids warm, bodied, and thick, the Klean SV shaves it further more, presenting it in a neutral manner, exhibiting nearly zero warmth while keeping an adequate body, enhancing articulation. As a result, the lower mids of this IEM are still as enjoyable compared to the first Klean, but this time it is now more versatile. This finding is evident on the voices of Brendon Urie and his latest remastered album, which is a delight to listen to since it shows how the overall sound of the Kefine Klean behaves in remastered and first pressing recordings. Upper frequencies here are about the same as what the lower mids have in terms of presentation, exhibiting a very good amount of air, sparkle, and clarity, without any unnatural peaks or sibilance present. I’m honestly even surprised that for a neutral IEM, the Kefine Klean SV is the second recent IEM under 50 USD I have heard of that is quite forgiving to poorly mastered or recorded tracks, which is a delight for those people that wants to enjoy their music with a neutral sounding IEM.

Treble:

• The Kefine Klean SV continues the character of its mids here in the treble. It is still well-extended, airy, and clear, while keeping the elevations and presence controlled enough to diminish any form of sibilance or harshness as much as possible. Those people with very sensitive sets of ears may find this region, along with the upper mids, a bit “borderline bright” to what they prefer, but won’t be a problem to most people at all. Detail retrieval is above average at best, rendering micro details and nuances easily.

Soundstage, Imaging and Separation:

• This is the second of the two things that the Kefine Klean SV differs from its older sister. Honestly, the first Klean was already a performer enough for me in the technical chops department under 50-60 USD by the time it was released, but apparently Kefine managed to improve this region further. Sure, it still has the soundstage that the first Klean has, and will not be a shocker in today’s 50 USD IEM market, but it is still wide and spacious enough for me to actually turn my head left and right as if someone’s opening the door or calling me, whenever I use it. Along with this one is of course, its imaging, wherein it is now much more precise and has clearer definition of vocal and instrument position compared to its older sister. The separation and layering are also noticeably improved here compared to the latter, especially when the busy passages and tracks hit.

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About the Kefine Dongle and their cables:

The Kefine Klean SV can be purchased in 3.5mm, 4.4mm, and in USB-C (DSP) configurations, depending on what you prefer. Their differences when it comes to sound, when paired with the Klean SV, are not that much and can even come as negligible. However, these are my personal findings for it, along with it silver nozzle, so take this with an additional grain of salt:

• 3.5mm connection - It is the standard, your usual neutral-ish sound, with slightly forward vocals.
• 4.4mm connection - about the same, but this time the overall decay of each frequency is cleaner and quicker. Might give a “bright sound” impression to some people.
• USB-C connection - apparently Kefine added a DSP chip here in this cable (KT0231). This made the sound of the Klean SV a little bit warm in the mids, and adds a slight body to it. It is still not as thick as the first Klean, though.

There is also a USB-C dongle made by them that uses a Conexant DAC chip (CX31993). When paired, the Klean SV sounded slightly v-shaped to my ears, with a noticeable bass and treble coloration. It is still fairly clean though (pun intended) but this time it adds a little bit more fun to the mature sound of the Klean SV.

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Kefine Klean SV and its modular nozzle comparisons!

• Gold filter - made the sound neutral-borderline-bright. Enhances the treble and the upper mids further in terms of presence. It is not as bright when compared to the first Klean and its bright filter, as it does not have any sibilance, but potential peaks can show on sibilant prone tracks.
• Black filter - made the sound warmer, but still not as warm compared to the first Klean. It is also now a bit thicker, with its upper frequencies a bit more relaxed when compared to the other nozzles. The technicalities degrade a little bit but negligible, particularly on the separation and layering.

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Other IEM Comparisons!

Simgot EW200

• Both of these IEMs still aim for neutrality. Their differences however, despite that characteristic, are noticeable. When compared, the EW200 is the brighter set among the two IEMs. It is also wider in stage and has a tad bit better detail retrieval. The Kefine Klean SV makes up for it by presenting its sound more neutral and fatigue free, with a sufficient body to the mids. The EW200 has a leaner, brighter, and a slightly sibilant upper frequencies that were experienced by the hobbyists, which the Klean SV solves.

Sivga SM100

• Ah yes, the current contender of the Kefine Klean SV in my humble opinion, the Sivga SM100. As a person prefers neutral and technical, I really love both of these sets a lot, so choosing which is which will all boil down to your preference. When compared, the Sivga SM100 a a bit leaner in body, but has a more articulate and sparkly upper mids. It also has a bit more subbass presence going on, up to the point that it sounded u-shaped to my ears when compared to the Kefine Klean SV, specifically when compared side by side. It also has a larger soundstage, particularly in its height, making things immersive. The Kefine Klean SV on the other hand, is more bodied and controlled in every frequency, which makes it more “neutral” but not by a lot, when compared to the SM100. Both of these IEMs are easy to drive. These IEMs are both comfortable in terms of fit as well, to my ears, at least.

Kiwi Ears Belle

• Right out of the bat, the Belle is the warmer and thicker sounding among the two IEMs, although not by a lot. It is still neutral to my ears, but a bit laid back, when compared to the Kefine Klean SV. That also means that it is the safer option for those people with very sensitive sets of ears.

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Pros:

• A refined, more neutral version of the 1st Klean! (subjective)
• Fairly “neutral”, well-bodied sound signature! (silver nozzle)
• Warm-neutral sound signature! (black nozzle) (USB-C cable)
• Controlled yet non-lacking bass response! (for a neutral-aiming set)
• Vivid, vocal-forward mids!
• Well-extended yet non-fatiguing upper frequencies!
• Noticeably refined technical performance compared to the first Klean!
• Very comfortable fit, comfort, and isolation!
• Durable, solid IEM build quality!
• Visually pleasing details, harmonious motif of cables and IEM itself!
• Decent quantity of accessories!
• Has modular tuning nozzles!
• Easy to drive and scales well with source!
• More possible cable configurations, they even offer a dongle now! (sold separately)

Cons:

• May come across as “bright” to those some extra sensitive ears due to mildly forward upper frequencies (Gold filter).
• Nozzle filters do not exhibit night-and-day differences to each other (this can be a pro or a con to you in all honesty, this is just my nitpick)
• Cable is non-modular.

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Kefine did a very good refresh here with the Kefine Klean SV. No wait, let me scratch that: Kefine made a really solid updated flavour (if you may) here with the Kefine Klean SV. It seems that they addressed all of the concerns that the Klean had, and improved pretty much everything here with the Klean SV. Would I call it an upgrade? Well, yes and no. It can be an upgrade because its overall frequency control and technical performance are noticeably improved, even when the busy tracks and poorly recorded tracks hit. On the other hand, I would call the Kefine Klean SV not an upgrade, but a different flavour, since its doing its best to differ itself from its older sister, from the shell colour, down from its neutral sound, catering those people that loves the Kefine house sound but wants it in a neutral manner. The Kefine Klean SV easily lists itself as one of my top recommendations under 50USD for a person that needs and wants a neutral-sounding IEM that isn’t too clinical or too boring. I thought this would be named as the Klean AG, Kefine!

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Pairing recommendations:

• Source: The Kefine Klean AG is easy to drive, but definitely benefits from a source that has at least 2VRMs of output power. Kefine also offers a dongle of their own that fits the bill. You can still use your preferred dongle.
• Eartips: They included 2 sets of eartips here, which both do not affect the Klean SV’s sound in any bad way. You can still use your preferred eartips with this set.
• Cable: Kefine offers different cable configurations for the Klean SV. You can pick what you prefer, as these cables matches the IEM’s motif and hardware. I wish they made this cable modular though, but you can always use your preferred 2pin cable for this.

Thank you for reading!

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Non-affiliated links here:

• https://www.lazada.com.ph/products/...4863640.table_online_product.1.19d81e13BMIMsu
• https://shopee.ph/product/1602543198/42467589802/
• https://www.lazada.com.ph/products/i5311381630.html?urlFlag=true (dongle)
• https://ph.xiapibuy.com/KEFINE-HiFi...extraParams={"display_model_id":445128393602} (dongle)