Eartips

To start, Kefine added in six pairs of eartips in total over two different styles. Well, I say “different” but really both styles of tips are very similar to each other. The first set of three (S, M, L) are white silicone eartips with a black stem, semi-firm, and they have a semi-wide bore. For me, I found the flange a hair too loose and flimsy, just a hair. I can still get a seal, but I have to work for it. The next set of three (S, M, L) pairs are dark gray silicone eartips with a black stem. Now these tips are much more firm at the flange. Also, these tips have a semi-wide bore and feel very similar to the KBear 07 tips. These also have a thick and rigid inner stem. I did want to relay to you all that for all critical listening I went with the dark gray included tips. I was going to go down the endless work of trying to find the best sonically paired tips and tip roll, but since the dark gray tips fit so snuggly, I didn’t bother. I’m sure you could tip roll and find something slightly better. I was thinking that Dunu S&S tips would be great, perhaps even Divinus Velvet wide bores, or Tenmak Whirlwinds too. Just speculation at this point though. All in all, for $54 getting six pairs of tips is not a bad thing at all.

Carrying Case 

The carrying case supplied with the Kefine Klean SV is a 4” x 3” fabric covered gray zipper case. I actually like this case folks. I say in every review that I rarely use cases, but I like this one because it’s only 1” deep. That means that I can put it in my front pocket without looking ridiculous. Just slides right in there without some huge bulge in my right pocket. Now, it isn’t the largest case I’ve ever seen and only really holds the iem and cable, but I’m good with that. Certainly nothing to write home about, but a nice addition. Shoot, most budget $60 and under iems come with no case at all. All good stuff.

Tuning Nozzles

Once again Kefine added in tuning nozzles to help to dial in the sound of the Klean SV and I’d say they did a solid job of doing so. I’ve gone back and forth between the three and I actually enjoy each one. I will speak more on that in a moment, but the nozzles really do provide three different versions of the same tuning style. Certainly, it is worth it to play around and find which nozzle fits you the best. I’ll add in Kefine’s frequency graph below. By the way, Kefine actually provides a frequency response chart which very closely aligns with 3rd party testers. Which is good to see. They don’t embellish with their graphs. Very cool. Anyways, let’s check out each nozzle and a brief description of what they do for the sound.

So, my least favorite of the three is the Gold Nozzle which also happens to be the brightest of the three, by a pretty good margin. I’d call the tonal coloration somewhere around neutral/bright. Having said that, for a brighter hue the gold nozzle actually stays in good control. One thing you’ll notice with the Gold Nozzle is a definite boost in midrange and lower treble emphasis adding a sparklier, more brilliant, and less bass enhanced sound. Definitely leaning bright. You also get a big boost in clarity, resolution, and perceived transient quickness. Micro-details come through better. Imaging & separation are more distinct too. I want to note that the gold nozzle is not “bright” to the point of true harshness. It’s simply a brighter version of the base tuning. Notes are slightly thinner with the Gold Nozzle, better crispness, more snap and acute edge to notes as well. Not bad, but not my favorite.

The nozzle, which is easily the warmest, richest, and most emotionally charged is the Black Nozzle. To my ears I’d call the Black Nozzle warm/neutral. Due to the less luminous top end, I find the bass region certainly comes across more forward, fuller, more substantial in weight and body along with greater perceived impact. Granted, the sound as a whole is the least resolute of the three nozzles too. Of course, that doesn’t mean it carries bad clarity. Note weight is slightly juicier, with the least chance of any fatigue over long periods of listening. The Black Nozzle has the least amount of pinna gain and though you’ll still hear some shimmer. I’d call this nozzle the most musically adept of the three and I’d call the Black Nozzle the most rhythmic and fluid too. For me, the Black and Silver Nozzles are both my favorites for slightly different reasons.

I find that the Silver Nozzle really does present a perfect in-between from the Gold and Black Nozzles. This is not the norm when these brands usually present tuning nozzles, in my opinion. Anyways, the Silver Nozzle definitely carries the best balance and comes across as almost dead neutral. I don’t hear a ton of coloration swaying the sound in either direction. The Silver Nozzle has a nice bass impact and body, still rhythmic in the mids, and plenty of sparkle up top. Again, a perfect in-between. Just so you are aware, I used the Silver Nozzle for all critical listening, though it’s in a straight tie between it and the Black Nozzle for my favorite.

 Cable

So, Kefine is just awesome. I really cannot begin to tell you how nice they are to review for. I say that because not only did Kefine send me a 4.4 balanced version of their cable, but they also sent me a 3.5 single ended and a 3.5 se usb-c dongle dac too. Always such a nice surprise. At any rate, for this review I will speak on the 4.4 variant that I mostly used for review. So, the cable that is provided is a somewhat thin cable, very lightweight, extremely comfortable, and never pulls or tugs on the Klean SV when in the ear. Sure, most of you may want to cable swap, but as far as usefulness and overall functionality the provided cable has been great. To be honest, I haven’t cable swapped at all. Maybe after the review but I’ve had a pleasant time with this one. So, I might as well explain the cable to you. Anyways, the provided cable is a 0.78 2-pin high purity silver plated copper wire featuring 2-cores in total and each one has 18 strands of 0.06mm wire per core. As honest as I can be, folks, this is no doubt a budget cable. Without question I have fatter and more luxurious cables to pair with this one and I likely will after the review. Still, if you are picking this set up and have no other cables and have no extra money to get another cable then don’t fret because the provided cable is great. Looks nice paired with the Klean SV, and it sounds great too.

Build Quality 

Once again Kefine goes beyond what almost all budget brands are doing as the Klean SV is built entirely out of injection molded metal alloy. Now, I have no idea what alloy it is. I could guess that it is made out of aluminum alloy, or some sort of magnesium composite material. Fantastic durability and quality for $50. I think anyone who has the Klean SV in their hands would never be able to deny that. Really a great build, just like every other iem they’ve ever produced. In my opinion, the Klean SV is right around what I’d call “mid-sized”, nicely compact, and should fit most anyone’s ears just fine. For corrosion protection and fingerprint protection Kefine added an anodized silver coating on the entire housing. Of course, the nozzles are also made out of metal and shined to a mirror polish. I can’t say enough good things about what Kefine has done for the cost. I should also note that the Kefine Klean SV only weighs around 10 grams, which is nothing in the ear. Lastly, the nozzles come in at around 6-6.3 mm in width, which is normal. Nice build once again Kefine.

Aesthetic 

Now, one thing that all Kefine sets have in common is that they are all designed in a very minimalist manner. This is something that I can very much appreciate. Now, the question is if “you” appreciate it. After all, you are the one reading. I think this set looks nice. They have a nice shape, and I do like that silver matte finish coating with the crosshatch design. Even more, I don’t think that the “Kefine” in the center of the faceplates looks bad or gaudy at all. Nothing flashy, nothing super ornate or over the top. This is a good-looking set folks. Having said that, nobody agrees on everything and I’m certain there will be those who find this set too simple. Still, in my opinion the Klean SV certainly carries a measure of class.

Internals

Kefine decided upon one of my favorite dynamic driver types. I should reiterate that this set is a single dynamic driver earphone using a 10 mm DLC (Diamond-Like Carbon) diaphragm which sits inside of a dual cavity structure. There really isn’t a whole lot to say about the Internals as Kefine made this one fairly simple. Simple but very good.

Fit / Comfort

The Kefine Klean SV isn’t large, it isn’t heavy, and it isn’t awkwardly built. There’re no rough edges, nothing sharp, everything smooth and ergonomic. Basically, what I’m getting at is that the Klean SV is a pretty comfortable iem. I have never had any issues with fit as the Klean slide right in and providing I have tips which work for my ears, the Klean SV also seals very well. Again, the cable is very lightweight and so you won’t have that pulling on your ears due to its weight. Honestly, I find this set to be almost perfect for my ears. Now, will the Klean SV fit you? That is a question that I have zero answers for.

Sensitivity

The Kefine Klean SV is obviously a sensitive iem. Just about any set you find under $100 will be fairly easy to drive. There are a few exceptions that are slightly less sensitive, but for the most part the grand majority of iems can run off of almost anything. In the case of the Kefine Klean SV this is certainly true. Rated with an impedance of 32 ohms as well as a sensitivity of 107 db’s the Klean SV can be driven quite easily off of even smartphones which have a 3.5 single ended jack. I can say this because I actually used the Klean SV with my old Android Samsung phone. Not that I have to convince any of you, but I actually tried the Klean SV with many weak sources (as I do with every review) including my iPad, multiple weak 3.5 single ended dongle dacs, the KZ AZ20, among others. The point is that the Klean SV sounds very nice without the need for more juice. However, that does not mean that the Klean won’t sound better with either better sources or with more power.

Scalability

I can testify that jumping up to a decently powerful dongle dac most certainly provided a more robust listening experience. Also, I feel that while the Klean SV does have a noticeable improvement technically, with perceivably tighter transients, a touch better micro-detail retrieval, somewhat expanded width of stage, and just more of a dynamically controlled sound. I wouldn’t say you need a ton of juice either. I’m talking about even somewhat weaker dac/amps with a minimum of 75 mW @32 ohms, and it helps to use a 4.4 balanced cable. I should note that almost every released dongle dac within the past two or three years which features a 4.4 balanced port will give you far more power than you’ll ever truly need when it comes to “power scaling” in the Klean SV. Needless to say, I hear this with almost all iems as there are very few which don’t scale at least partially well with a touch more power. Having said that, there is definitely a plateau point where the scaling seemingly becomes less apparent. Which is very normal. I actually feel that the Klean SV “scales” with the quality of your source… best. Again, which is normal. Still, for power alone the Klean SV certainly does tend to sound its best with more power than you’ll find on a smartphone or weaker devices.

Source Pairing

I think that source pairing is pretty easy with this set. The Kefine Klean SV runs anywhere from warm/neutral, to neutral, to neutral/bright. I just basically described each of the nozzles provided. I’d say that for the most part the Klean generally has a more neutral tonal color with slight shades one way or the other depending on what nozzles you choose. However, I told you that for critical listening I used the Silver Nozzle (most balanced & neutral) and so my recommendations will be in regard to that nozzle. One thing about a neutral set is that usually you can go either way with your source tonality and usually you’ll be good to go. I find that a warm/neutral source typically pairs best, but I have plenty of neutral sources which sound very nice as well. The EPZ TP50, the Shanling UA6, Shanling UA7, M1 Plus, Hiby R3 Pro II, Fiio JM21, and many more really sound great. In fact, to my ears the Klean SV is sort of a chameleon when it comes to adapting to sources. Of course, I found my more talented sources to be best. That is my more expensive daps like the Shanling M6 Ultra, the iBasso DX240, the Fiio Q15, and the Hiby R6 Pro II 2025 among others. Those sources with better dac chips, cleaner and more powerful amps, better circuitry and innards altogether. As I said before, the Klean SV will reward you for using better sources. Also, yes, that was a very obvious statement. At the end of the day, just try to find a warm/neutral to neutral source with decent power and you will likely be very happy with how the Klean SV reciprocates.

Sound Impressions

 
*Note: Before I speak on the sound, I first have to add a few critical listening caveats. First, I did burn in the Klean SV for roughly around three full days (what I typically do) using pink & white noise, tones and sweeps, as well as a mix of different melodies meant for burn-in and running on a loop. I don’t feel that I heard any monumental changes after this period. The only thing I really heard that changed was the bass sounds a tad more precise. That is highly debatable though, especially after three days between listening. So, take it as a grain of salt. I used the stock dark gray eartips as well as the stock cable. All of my critical listening was done using flac or better files which are stored on my devices. The Android music player of my choice is mainly UAPP (USB Audio Player Pro), Hiby Music Player (at times) for some daps, as well as Eddict Player for others.

Stands On Its Own Merits.. 

It’s the sound which truly defines the Kefine Klean SV. This is a set which can easily stand tall on its own merits, but full fills the successor role very well. So often when dealing with “series” in the audio world, you’ll often see brands over correcting or changing the sound tuning entirely. In a hobby as diverse as personal audio these brands will always read and hear opinions of all kinds about their products. If these brands are worth their salt they’ll try to address some subjective dislikes of “some” people. Within reason. Often, these brands will over-inflate-over-correct what a handful of people/reviewers have subjectively decided were “issues” and totally walk away from the heart of the series’ tuning. We see this ALL OF THE TIME. However, I found that the Klean SV sticks to the series tuning philosophy very well. In my opinion I’d say it is a slightly more resolute and sprightlier version of the same base tuning that we found in the OG Klean. No over-correcting, no vast differences, but instead a cleaned up and slightly more precise sound with the same solid timbre, solid stage, and good balance across the mix. The Klean SV will certainly be a step up in certain areas for some, and for some it may not be. One thing is clear; this set has a very high sound value for an iem only costing $54. Basically, a very solid option for a flooded market that assuredly can stand on its own merits.

What’s It Sound Like? 

To my ears the Klean SV runs anywhere from warm/neutral, to neutral, to neutral/bright-ish depending on what tuning nozzles that you choose. As I said earlier, for this review I am going with the more balanced of the three tuning nozzles using the Silver Nozzle for critical listening. I do find that the Klean SV does have a mild warmth added from the bass region, yet as a whole this set sticks quite close to neutrality. The Klean SV is actually very…clean. This is a high resolution single dynamic driver offering which really does perform well against the others which I’ve heard under $75. In my opinion I’d call the Klean SV a very mild V-shaped signature and wouldn’t argue with anyone if they called this a U-shaped sound. No doubt the sublevels are emphasized, and there is certainly a treble lift along with a non-recessed midrange. Again, the Klean SV has a very nice dynamic balance across the mix with solid energy, good macro-dynamics, with transients that are on the tighter side leading way to solid sound separation, snappy notes, and very good sound resolution for the cost. Furthermore, I definitely hear more crispness than I do anything smooth, soft, or blunted, and nothing even close to veiled, murky, or pillowy. Everything is hard edged and fairly precise for a $50 single DD.

Named “Klean” for a Reason

Now, I wouldn’t call the Klean SV a “super fun sound” in a traditional sense. While it certainly has some musicality and a melodic nature, I wouldn’t say that it leans that direction. In my opinion the musical/analytical split is closer to 40/60 with a majority clinical and transparent sound which can handle those complicated passages with relative ease whilst not coming across as too dry or too etched sounding. Detail retrieval is also solid; sound separation is distinct as well. However, the Klean may be clean, even predominantly analytical, but it isn’t devoid of musicality and does carry a melodic enough tuning. No doubt about it. Just don’t expect anything warm leaning, bassy, or as emotionally charged as some sets we’ve seen of late. Having said that, I find that timbre is pretty close to natural with the only veering from that coming from its tighter transients. Still, timbre comes across as that nice neutral-natural style with a pretty clean-lined and fine-lined presentation where note outlines aren’t mooshy, gooey, and they never sound fuzzy or out of focus at all. They named this set “Klean” for a reason folks.

Nothing Harsh

Before I deep dive into each 3rd of the mix, I do want to state that even with the Klean SV’s clean sound, detailed sound, and very resolute sound with that nice balance I really don’t hear anything that I’d call “harsh” or too sharp for my ears. I spoke briefly on timbre, but I’d also like to add that I don’t hear anything I’d call metallic, sibilant, or overly shouty. Maybe for some very sensitive listeners, but for the most part the Klean SV stays in solid control for a budget sector offering. Kefine really did a nice job on this set as it does everything pretty well. Almost to the point of an all-rounder status but just missing that moniker for me. In truth, the Klean SV is very pleasant to the ear, as I expected. Also, very-very nice for anyone who is seeking out trying iems for the first time and also fantastic for those of us who simply like things that sound good. Sure, it has some subjective issues and I will explain those, but for the most part you are getting a very clean, technically savvy, nice timbre, it’s a very fun energy set that is never over-the-top with its upper end brilliance, has a fun and punchy bass, and doesn’t sound too recessed in the midrange. With that all said, let’s check out each 3rd of the mix shall we…

This is the only graph showing all three tuning nozzle frequency responses. Kefine graph

Bass Intro

If you ask me the low-end on the Kefine Klean SV is what I’d call moderately lifted, very punchy, tight, nothing lagging, and it has solid low-end timbre without ever clogging the mix. When I say “moderately” lifted, I mean something close to a 7-8db bass shelf that maxes out in the sublevels. I feel this is one of those bass regions which almost perfectly balances with the rest of the mix which has many rewards that come with that. However, if you are a basshead you might as well stop reading because this set is not overly lifted or bullish. In my opinion, the tuning down low has that perfect balance with impact focus and clarity focus. What I mean is that you’ll never hear this set mudding-up the midrange, it doesn’t clog spaces between notes, very nice sub-to-mid-bass separation, well defined notes, doesn’t veil the mix, and always remains tidy. It keeps clarity across the mix and is never a hindrance to that clarity. However, I also said it remains balanced in its impact as the bass is also very textured (for the cost) with that nice hard-edged punch which is just full-bodied enough to feel substantial enough for bass guitars and has plenty of low-end presence for genres like Rock, Metal, Hip-Hop etc. Essentially, the Klean SV’s bass region is just as engaging as it is clean. For instance, kick drum skins have that taut initial hit, and those synth bass runs have enough growl too. So, the bass is certainly rhythmic and fluid enough, yet that solid DLC driver has the technical acuity to remain tight and very agile, ductile, keeping notes textured and realistic rather than boomy, loose, or flabby. It definitely is not any of those descriptors. Again, not for those of you who love that rich, warm, and bass dominant sound, but great for those budget sector consumers who want a quality bass which doesn’t oversaturate the mix.

Use the Black Nozzle

I want to also add that if you choose the Black Nozzle the bass will sound a hair more prominent. Not because you have a greater bass emphasis, but because the top end is less lifted. The Black Nozzle adds a touch more weight and a slightly less contoured note delivery, still very textured, less acutely resolving. Please understand that these are very small but noticeable differences. A bit more impact and a hair more robust flavoring.

Sub-Bass

I find the sub-bass actually extends very well. This is not a rolled-off sub-bass. I hear this on multiple test tracks where the sublevels remain voluminous in the lowest of the lows. Though, instead of ultra guttural and juddering, the sub-bass has a more controlled rumble, less profuse and sonorous. Again, moderate. However, “moderate” doesn’t translate to “weak” like some people would have you think. I still hear plenty of nicely bulbous notes when a track features such a thing. This is very important. For instance, the track “Flight of the Cosmic Hippo” by The Flecktones (Bella Fleck) is a track that has some very meaty, grungy, and densely weighted bass and the Klean SV reciprocates. The track is calling for it. Actually this “moderate” sublevel rumble sounds very tactile first, but also penetrative with a moving-air feel of a bodied bass when listening to those fretless strings. Again, this sublevel experience will not make its mark in the rest of the mix by muddying up anything. Even in a larger bass production the Klean SV proves to be tactile, textured, and not too rounded and never smeared. But it can thump nicely…to a degree. Like in the track “Doin’ It Right” by Daft Punk featuring Panda Bear. The rumble in this track has that haptic feedback while never masking Panda Bear’s vocals. The bass is just like I’ve stated, it’s tactile, it brings the weighted muscle with a healthy boom whilst remaining clean and not bloomy or too boomy.

Mid-Bass

The mid-bass does have a slightly less obvious weight, but I’d honestly say almost the same exact descriptive words. Again, tight, textured, never bloomy, always well controlled, never really masks, and provides that tight resonant boom when a track calls for it. I always use Weezer’s cover track “Billie Jean” because it provides a wonderful test for any set. Those kick drums which begin this song are fast, full-bodied, and there are a lot of them. Great for testing. The first thing I notice is that there’s nothing fuzzy on attack. That initial hit is pretty darn clear, and it has that tacky snap. I like the connecting boom of the resonant drum kick as you get the bigger fundamentals without lagging harmonics. Basically, each kick has that tidy thump which never sounds blended. Really pretty satisfying. Now, some bass guitars which aren’t as prominent may sound a hair less authoritative. Actually, that goes for any instrument of vocal which isn’t focused and prominent. Like I said, the bass will never evoke its will frequency-wide. Only when a track presents such a thing. Other than that, the mid-bass (and the sub-bass for that matter) keep to themselves. I also don’t hear a ton of bleed into the midrange. There is some bleed, but it isn’t to the point that the mids sound overly warmed or lush. They remain fairly clean with only a hint of bolstering warmth.

Downsides to the Bass Region 

I think the obvious issue that many people will have is that the bass simply isn’t quite as authoritative as the original Klean. However, even more so the bass will become a problem for those bass-bois in the community. Again, if you are a basshead you should just move right along. Well, unless you like tape mods. That’s way beside the point. Anyways, bassheads will be a no-go and those who much more prefer a bass which skillfully impacts the midrange adding a richer flavor to the note body as well as those who desire more of a bleed for that warmer sound. Honestly, that’s all I’m willing to speak on here because for all intents and purposes the bass region is highly skilled for a set at this cost. Very clean, reasonably detailed, well defined, well separated, and still has enough emphasis to represent most genres and tracks.

Midrange Intro

The mids on the Kefine Klean SV are definitely not the type of midrange which feels, or more importantly sounds recessed. The mids (as a whole) are what I’d call semi-forward where vocals, piano, guitar etc. breathe easy and have that clarity-rich type of presentation with focused lean density. In fact, one of the Klean SV best qualities is the presence that the mids seems to carry. Certainly not forward, not in your face, not wonderfully intimate or vocal-centric and nowhere even close to boxy, but it has a charm to it. This clean-lined and coherent charm does a solid job of keeping that nice tonal balance while also sounding more tuneful than most budget range analytically adept iems. Please believe me on that. No doubt the budget range has some solid sets, but not all of them put it together perfectly. To me the midrange comes through with nice transparency for such a low-budget offering and even more-so for a single dynamic driver. As I said before, the Klean SV carries some solid neutral-natural timbre. Not natural as in… “earthy” or “warm-organic” … but cleanly rendered without too much coloration sewing this set from that neutrality when using the Silver Nozzle. The timbre sounds realistic, a touch of warmth, a touch of vibrance, and nothing oversaturated. So… neutral-natural. There simply isn’t much tonally which masks, congests, or smears the Klean SV’s clean sound.

Midrange cont… 

Having said all of that, the Klean SV also isn’t the type of sound which would be considered “musical” per se while still carrying adequate musicality. But that neutral-natural sound does a good job of rendering stuff like snare snap, string plucks, cymbal fundamentals, the satisfying edge of a silvery violin and even vocalists come across in a fairly lifelike manner. But it won’t be the type of midrange which will effortlessly draw the emotion from every track quite like some other more smoothly refined sets. Not that it can’t either. So, there is a little bit of give and take. The midrange is going to sound nicely polished in the way that elements within the sound field come across separate from each other. Nothing really overlapping, no converging and sloppy note outlines. This is a midrange which is going to do a very solid job placing instruments left to right while vocals are stapled dead center. Micro-details are typically pretty easy to discern too. The flipside is that note weight is on the thinner side (lean-density) and there is a subtle touch of dry timbre.

Lower-Midrange

The lower mids carry an ever-so-slight warmth, they’re very well textured, there’s some crispness too along with better note body than the upper midrange. Males do carry a hint of chestiness sounding more anchored and grounded than the rest of the midrange coming across fairly authoritative without necessarily sounding robust. I’d also say that the lower midrange doesn’t sound badly recessed either as this region really does have some decent presence. I can hear this on quite a few tracks with male leads. Tracks like “Better Me for You” by Max McNown is a solid example as Max’s already chesty delivery almost comes through with more finely defined intonations sounding somewhat embossed and not drowned out by the rest of the mix. The timbre of his vocals is what stands out for me as there’s nothing which feels or sounds “off” to me. I think that nice mix of clarity, clean-lined transparency, and decent note body helps his voice quite a lot. Of course, there are plenty of examples of this where that lean-dense presentation only aids male voices. I personally would enjoy a hair more warmth, but I cannot complain about the Klean SV’s lower midrange at all.

Upper-Midrange

Now, the upper-mids will sound more forward, more vibrant, and more shimmery and they also sound a touch drier, more effervescent, airier too. I find that the upper mids have that anterior forward positioning coupled with some sprightly energy which comes across much more as “good presence” rather than shouty or glaring. The upper midrange has about a 7-9 dB pinna gain which takes on a very slow and gradual rise. Something I find to be tastefully done providing this range with all of the shimmer and without the listening fatigue as well as a solid canvas for the subtleties within my music to rise to the surface. In truth, the entire upper midrange area has that transient tight and articulate sound where nuances within my music come through nicely. However, as articulate as this area is, it’s also one which I’d call very dulcet, harmonious, and sweet-toned. There’s some dryness, it isn’t all moist and note weight isn’t rich in body but definitely defined and rich in clarity. Notes have solid snap, there’s some subtle bite, and very composed energy shifts, punchy enough shifts in volume creating a nice sense of scale in conjunction with the bass and treble creating expressive macro-dynamics. It all comes together nicely folks. Especially for a budget single DD. Hence why so many people enjoy this series.

Females

I think that females come across pretty nicely, but they will likely be a question of taste for some people. Meaning, females don’t really have that lush, richly engaging, warm (and romantic style tuning. I’d say there is certainly a high engagement factor, but it has much more to do with how polished, crisp, and forward leaning they ńu( are in the Klean SV. To me the Klean SV has a clarity-rich sound with clean edge to notes rather than a lush and moistened presentation. Due ń the slightly V-shaped tuning you’ll have some more luminous upper mids which really does give females this sense of promptness, or immediacy as well as that good articulation I was talking about. At any rate, females like Lady Gaga in “Vanish Into You” clearly sound fantastic on the Klean SV. She is such an expressive and dynamic singer, so resounding and well controlled. The Klean SV props up her voice with the vibrant upper midrange boosting the presence of her voice, every vibrato, and her voice cuts right through the equally vibrant melody surrounding her voice. Or Norah Jones in “Swept Up in the Night” is another track where Klean SV almost puts her vocals on a pedestal. Noah’s voice/style is much different from Lady Gaga where softer and more velvet inflections need to stand out. Her lower-register huskiness seems to retain some body, though the Klean SV can sound a hair too crisp at times. Still, that upper mid breathiness sounds very clear and her voice as a whole sounds both intimate and very clear. Definitely a touch more warmth will always help Norah Jones, or someone similar to her. Hence why I chose to speak on her voice. But the Klean SV still does a nice work replaying her voice.

Downsides to the Midrange 

Without question the first complaint that you’ll hear is from those folks who own and know the original Klean very well. They will likely speak on the Klean SV being less rich or thinner in note body. Also, those folks who enjoy a warmer midrange in general will not be completely happy with the way the Klean SV is tuned in its midrange. I also think that those brilliance-sensitive listeners may have a problem with the upper mids too. Let me say that I have zero problems… at all. I personally don’t find this set shouty in the slightest. However, I also know the community. Without the shadow of a doubt there will be plenty who don’t jive with the forward and semi-bright nature of the upper-mids. I should note that the Black Nozzle helps tremendously with this issue. There is a fairly large difference between the Black, Silver, and Gold Nozzles. No doubt the Black Nozzle has a less intense (intense is the wrong word), or less vibrant upper midrange pinna rise. All things considered, I find the Klean SV sounds great for the cost and very nice for the tuning style as well. Kefine did a nice work on this one.

Treble Intro

The treble region is one which takes me right to the brink of sharpness, and stops just short, featuring a semi-brilliant and crisp sound and solid extension past 10k. Not quite a treble that treble junkies could get behind as it’s too balanced with the rest of the mix, but there is definitely a slight focus on the treble. Certainly, on the brighter side and even more shimmery when using the Gold Nozzle. However, with the more balanced Silver Nozzle I find the treble to be very nicely displayed. I keep saying “for a budget single DD”, but I honestly mean it folks. It isn’t every day that you have a nicely boosted treble on a budget iem which doesn’t have some coherence issues, some timbre issues, or that isn’t flat-out harsh. Kefine really knows these shells/acoustic cavities, this driver, and what to expect from this setup very-very well.

Treble cont… 

I definitely hear a forward lower treble from 4-7khz which never sounds overbearing or oversaturated, but rather, it feathers-in seamlessly from the upper midrange. This region also adds some nice sparkle and treble glitter sounding lively and even engaging for me. I cannot leave this treble portion without commenting on the nice transient speed from this DLC driver and how natural everything sounds in the face of that speed. Seriously, you have plenty of subtle treble bite, that crisp attack, quicker decay, you even have a slight bit of treble punch, and the Klean SV is not getting tripped up in more complex treble passages. At least not nearly as bad as it should. Certainly, the treble can be described as (at the least) semi-dynamic and energetic. Really, some nice note bite and cleanly rendered edginess in respect to the price and tuning. This is not a very smooth treble, but it is very even, not jagged, not peaky or sharp, and all of the more dynamic moments in my music sound very much tolerable, even good.

Technically Speaking 

When it comes to the Kefine Klean SV’s technical ability within the treble region I find that while it isn’t necessarily a “technical beast”, it is very proficient in many different ways. As I said, transients are fairly quick as attack through sustain comes and goes with clean agility. However, not to the point of a straight analytical iem. Trust me, there is a distinction. The Klean SV still has a musically engaging sound after all. At any rate, the detail retrieval within the treble region sounds well enough illuminated for those reverb trails, stuff like string plucks/noise, and different treble textures come through reasonably well. Remember, the treble is certainly luminous enough to lift the overall tonal coloration of this set. This luminance does help to draw the minutiae to the surface surprisingly well. Couple that with the fact that the treble has nice extension leading to nice air and openness, nothing congested, and I hear very little treble smearing going on. So, details are nice. Again, I hear that nice textured bite too. Not top-class levels, but proficient, good. I find that sound separation is also a solid quality as even in busy mixes there isn’t a whole lot of blending of those sounds. Furthermore, Imaging is also better than one may expect for a $50 iem. Granted, it isn’t the easiest thing to listen for but if you do there’s a good chance that you’ll say similar things as I am. This is a quality treble, but not quite treble head worthy. Very solid technically for what it is whilst not losing that touch of musicality.

Extension

Another quality technical trait is the Klean SV’s ability to reach into the upper treble with good extension. Remember, this is a single DD and while they are great for many things, treble extension typically isn’t one of their cornerstone qualities. I think you’ll find that extension into the upper treble is pretty solid while not losing that neutral-natural timbre and not dissolving into a splash fest up top. Which, you’ll hear more-so from budget sets, but I find this in just about every price segment. I also find that the treble extension does help to slightly extend the stage in a psycho-acoustic manner as well. One thing I could point to is the secondary harmonics of a cymbal strike which tend to decay in a natural way. I don’t hear overly extended decay trails on this set. I’d also say that those highest and typically most piercing octaves really don’t reach that level on the Klean SV. Nothing sounds ultra-etched or too abrasive either. In all honesty, if I’m not thinking about actively paying attention to the air region, then I really don’t think about it at all (not often anyways) which in the case of a budget set like this is a good thing. Having said all of that, the upper treble on the Klean SV does provide some added air to the tuning which does wonders for stuff like instrument separation, clarity, even detail retrieval, and it helps in some ways to present imaging in a more defined way. Altogether not bad at all. Nicely done.

Downsides to the Treble Region 

If I were to call out some potential issues that some folks may encounter, I’d first call out anyone who is sensitive to a slightly more uplifted treble. We all know some people who simply don’t prefer a treble with some exuberance. Granted, the Klean SV offers some pretty good control up top, stopping before most folks would become treble-triggered and need to turn the volume down. It’s a very fine line to walk and much of the time will be a hair polarizing for some listeners. Obviously Kefine knows exactly what they are doing. On the flipside of that coin are those who desire an even brighter, more refulgent and radiant treble who are seeking out a budget bright set which can give them those treble head vibes. I’ll be honest, I wouldn’t recommend anyone seek out treble head worthy “budget” sets, but by all means… You do you. The Klean SV has a quality treble which stays comfortably within the framework of a balanced sound. Kefine did a tremendous job keeping control over the entire spectrum while also pushing that clarity without the treble sounding forced. I haven’t heard anything on the Klean SV that comes across as straight artificial sounding and while on super brightly recorded tracks things may get a hair too bright, those instances are very few and far in between. Folks, I’m done scratching and clawing for issues because for $50 it is petty beyond belief.

Soundstage

Okay friends, we have to remember that the Kefine Klean SV is a budget set. I’ve tried to squeeze that in as much as possible in this review to hopefully keep everyone (and myself) grounded to that fact. Friends, this stage is not some enormous and cavernous stage. I found the stage to sound… natural. It’s a stage worthy of the pedigree of the Klean series. Basically, it’s a good budget stage. Very respectable for a set which costs under $75. Of course, Kefine wasn’t trying to artificially and psycho-acoustically boost the stage size. Why would they? That would completely alter the tuning and thus completely change what makes this set good in the first place. It’s a natural stage, good for the tuning, where Kefine prioritized coherence and balance over an exaggerated or “out of head” experience. In truth, I don’t think they were thinking about that at all. Anyways, to my ears the stage width has moderate extension to the right and left. Stage height is proportional to the overall sound and does offer some vertical layering. However, what I find to be the best part of this stage and not very surprising too is the depth. The original Klean had good depth of field and the newest Klean SV is no different. You have budget sector solid depth and layering which has vocals up front and softly layered instruments dimensionally placed behind them. Nothing that will blow your mind, but good. Nothing feels cramped or congested, nothing narrow or overtly 2D and flat. It’s good.

Separation / Imaging

Now we get to one of the best highlights of the Kefine Klean SV. That is… instrument separation. Without question the Klean SV does a marvelous job distinctly separating and parsing out clear lanes of sound for instruments to breathe. I’m talking vocals, basslines, guitars, percussive instruments, along with woodwinds of all kinds. They all sound well separated to my ears. Sure, on super busy tracks you won’t have quite the same separation, and you can hear some overlapping. In fact, you will hear overlapping and even on some occasions some masking too. But those are rare and situational. Imaging is the same. I always feel that instruments are stapled in place, vocals dead center with a clear center image. You don’t have any instruments wandering around the stage. It’s my opinion that height and depth does add dimensional cues and helps the imaging to sound slightly more spherical and not some flat 2D plane of sound. The tuning has a lot to do with how clear the image is as well. Many times, you’ll hear thicker or warmer sets with solid imaging, but the actual clarity may suffer making it a less intelligible mental picture, if that makes sense? I have nothing bad to say about either of these two attributes.

Detail Retrieval 

Detail retrieval is another aspect of the Kefine Klean SV which does well and falls right into line with the SV’s ability to place instruments coherently, and image the stage with clarity. It’s just a clean sound. The Klean SV also has an airy enough sound, tighter transients, no real congestion and limited masking with that fine-lined ability to contour notes in a vivid way. Detail retrieval is pretty good folks. I would never call it anything but very good for the cost. Especially since the Klean SV is not an analytically focused iem with no musicality. This set has plenty of melodic and musical traits which makes its ability to draw out those subtle sounds all the better.

Comparisons 

Kefine Klean ($45)

I reviewed the Kefine Klean OG all the way back in November of 2024 (Klean Review) and it absolutely made me a believer in Kefine. Well, to be truthfull, I was already sold on this brand, but the Klean was some pretty bold reinforcement of that belief. Now, I couldn’t have a Klean SV Review without a comparison against its predecessor. However, I’m going to keep things pretty short as I don’t think that you need all that much more comparison points as this whole review has been somewhat littered with those. I can tell you this, both sets most certainly stand very-very tall against the $40-75 competition in my eyes. Kefine did a very nice job on both and both deserve to be placed on a pedestal in my opinion.

Non-Sound Stuff

As far as the non-sound differences between the Klean and Klean SV, there really aren’t many of them. Almost every factor from the packaging to the unboxing, the build, to the design is basically the same although the new Klean SV obviously has a new paint job. Really, everything is almost exactly the same. Really the only difference is that the Klean SV comes with three more sets of eartips. That’s it. Oh, and the Klean SV is about $10 more in cost.

Sound Differences

If I were to characterize the sound difference between these two, I would say that the Klean SV is like a refined version of the same set. Refined as in… more precise and better clarity. However, there is more than that. Although, it is clear that both sets follow the same tuning philosophy just with slightly altered end results. For the record, during this comparison I used the balanced tuning nozzle for both sets.

Between the 20’s

Most certainly the OG Klean has a more pronounced low-end which offers a hair more bleed into the midrange, though neither sets bleed much at all. The Klean SV does have a better defined low-end with tighter sublevel rumble, closer to neutral with only hints of weighted warmth, yet equal in presence to the OG. Both have rather tighter bass replays, but the OG simply has a touch more. Now, the midrange shows the OG being a hair warmer with a slightly richer note body while the SV has a more clarity-rich sound, better detailed, more separation and fine-lined resolution. The OG is more musically capable with a more fluid and rhythmic disposition. The treble of the SV has more exuberance, cleaner, slightly more crispness and bite and is better extended. The OG is a touch less vibrant and smoother too. Almost all technicals go to the SV. Which stands to reason. Better detailed, better instrument separation, slightly more focused and clearly distinguished imaging, but both sets offer a decent stage.

Final thoughts on this comparison 

Honestly, both sets are awesome, and both represent subtle tweaks from each other. They are so close tonally folks. Upon first listen I honestly could barely hear those differences. It took a very focused two-hour session to really begin to see the obvious differences. Hey, sometimes it takes a minute for me. Anyways, both are clearly awesome budget offerings from Kefine. You simply cannot go wrong here with either. If you like a slightly warmer and more musical approach go with the OG. And, if you desire a more technically adept and cleaner version of that than go with the SV.

Kefine Delci ($58-$75)

Naturally I had to compare the Klean SV’s older and more expensive brother, the Kefine Delci. I reviewed the Delci (Delci Review) even further back in April of 2024 and it was the first Kefine review that I had conducted. Once again, the Delci was another Kefine set which really jived with me. The Delci is also a single DD iem with a 10mm DLC driver and built very well. Instantly this set became a monster classic, and I couldn’t resist it at the time. Everyone wanted to know about the Delci. I was happy to oblige and give my opinion. Friends, I still love this warm and musical single DD. These two sets represent different sides of the musical scale. Let’s check out some differences.

Non-Sound Stuff 

To begin, the Delci does come with a slightly better cable, a better carrying case, and one more pair of eartips. Only, the Delci comes with both semi-wide bore tips as well as wide-bore tips. As far as build, both sets are wonderfully made, both alloy although the Delci is made using lighter aluminum. The Delci weighs only 5.3 grams and the Klean SV weighs approximately about twice that. In fact, Kefine used the weight of the Delci as a marketing point. No doubt it holds up, that set feels like nothing in the ear. Neither set fits badly for me and both are still relatively light in the ear. As far as design goes, I do like the rounder and even more minimalistic design of the Delci a bit more, though both have a nice look. I also need to note that the Del I does not come with any tuning nozzles which may impact your purchase. I do notice that the Delci is a touch easier to drive, but both are sensitive sets.

Sound Differences

As far as sonic differences, there’s a lot of them. These two sets are almost polar opposites whilst keeping that same Kefine signature quality timbre. The Delci is much warmer, less fatiguing, and easily the more emotionally charged and musical. The Klean SV is closer to neutral, much more clean-lined, more vibrance across the mix, and simply more technical in nature. Both sets have awesome timbre for being budget offerings and both represent solid timbre for their respective tonal coloration. The Delci has that warm-organic sound while the Klean SV carries a more neutral-natural timbre. Both great.

Between the 20’s 

Definitely the Kefine Delci has a much weightier and more booming bass region which is both less defined and slower in transient ability. However, the Delci bass has a much greater impact on the tonality making it far more emotionally gripping. The Klean SV has the more sprightly, agile, dexterous, and better separated bass region and is higher in apparent quality. Though, that is definitely debatable since they are so different. The midrange of the Delci is warm, rich, with weighted notes, and its midrange is a touch more recessed in comparison. While the Klean SV has that cleaner, cooler, more vibrant feel with a better technical package sounding leaner and better detailed, better imaging, and also more fatiguing for those sensitive. The treble is the same story, the Delci rolls off sooner, less vibrant too while the Klean SV has much more crispness, better note bite, more edgy, and much-much better extension into the upper treble. The Klean SV is also much-much better in every technical trait. Details, separation, Imaging, layering, transient speed, and it has better sound field dimensional cues.

Final thoughts on this comparison 

Two totally different takes on sound and neither is better than the other. They’re different. Any day of the week I’d choose one or the other. Lately I’ve obviously went with the Klean SV and if I’m being honest, I do like it a hair better. Having said that, the Delci really does perform a musical sound exceptionally well for costing under $75. It really comes down to what you want and what you prefer. Hopefully this comparison helped you in some way to understand the Klean SV a bit better.

Okay, so before I speak on what I believe to be the better or slightly worser genres for the Kefine Klean SV, please understand that these are very-very loose beliefs. Within every good genre I can find many tracks which go against what I’m saying. Also, in every worse genre for the Klean SV I can find tracks which suit it just fine. Friends, on too many occasions I’ve learned this with just about every set. Now, these opinions are also very broad and are grossly generalized. Nothing set in stone and I argue with myself more than I care to admit when thinking this through. So, I wouldn’t take it for a grain of salt, but I also wouldn’t base my buying decision off of this section.

Genres Which Work 

From my experience I find that any Rock music works well. Whether Alternative, Classic Rock, or what I’d consider Hard Rock. You have that tight moderate bass, it’s speedy, along with crystal clear vocals and very good note separation. All of those attributes work in favor for me with these. To go a step further I think that Metal is generally very solid in this set. For much of the same reasons. The only drawback is that the bass isn’t quite as bullish for some tracks as other sets. Not really a genre, but anything vocal-centric where females are the lead singer. Sure, there are some which won’t suit it perfectly, but most females sound very nice on this set. I also find that the Klean SV does very good with a y form of Pop music, some Hip-Hop is great, R&B is also very solid along with those acoustic style Jazz tracks. Actually, the Klean SV is awesome for acoustic Jazz. There are more as there are so many genres, but this hopefully gives you an idea.

Not Perfect Genres

So, I know I said Hip-Hop is solid. Actually, I said “some” Hip-Hop, which I stick to. However, what I really mean for this section is super bass heavy Hip-Hop. In the same breath and for the same reason I’d say bass focused EDM. I just feel that while the sub-bass is rumbly enough for most genres, it will not satisfy anyone who is a true-blue fan of these genres in particular. I’d also say that while the Klean SV suits many Orchestral tracks there are those really complicated and densely packed Orchestral songs which do tend to get a bit too congested sounding. Friends, this is a budget set, and we have to know what to expect. Yes, the Klean SV can handle many Orchestral tracks beautifully, it will not handle everything perfectly. There are also other less perfect genres, but these are the ones which stuck out to me.

Have I ever told you that I absolutely adore a good budget set. Most people would not share the same opinion. However, I love something good for less. Perhaps that is due to my poor upbringing, never having anything and always seeking out treasures for less. I’ve carried that into my adulthood and still champion brands who desire to provide price to performance before anything else. Everyone wins in that scenario. Folks, please hear me, when it comes to good sound, whether kilo-buck or ultra-budget, I do not discriminate. When I hear something good, I want so badly to tell you about it. It is the very reason I review at all. Folks, the Kefine Klean SV is unquestionably, unequivocally, and most certainly one of the better iems being sold right now under $60 for anyone who desires a very clean sound which isn’t warm, rich, or bass focused. There’s no question. This is coming from someone who has heard a monumental amount of iems. I don’t say that to pat myself on the back, I don’t give a damn about recognition, and I could care less what anyone thinks of me and my style, but I do care a lot that you find what works for your life. I really-really feel that the Kefine Klean SV is very solid for its tuning. However, you have to enjoy what I’ve described in this review…

Not for Everyone 

Now that I’ve declared all of that, I desperately need each and every one of you to understand something. Because this fact is somehow lost on so many people in this hobby. That is… we aren’t all the same. I get more messages from people in this hobby telling me that what I’ve described as something “good” is not good to them. At which point I go through the reasons why they are not thinking clearly. Not because they are wrong either, but because we both are right. This is a constant battle that has absolutely befuddled me since I started reviewing. How anyone could argue anything with anyone is completely contradictory to the nature of this subjectively judged hobby. I say this because I truly feel that if you enjoy a cleaner and slightly analytical tilt to your music that the Kefine Klean SV is going to be a solid purchase at $50. Again, the Kefine Klean SV is going to be very good for many hobbyists, and in the exact same sentence it will also not fit many as well. Welcome to the hobby of personal audio. I wish I didn’t feel the need to even address any of this, but it seems a requirement anymore. I have to add a paragraph in this part of my review telling the reader that the set I’m reviewing won’t be for everyone. This should be a given, well understood, and easily accepted, but to a few folks it remains a difficult understanding to accept. Lol. Anyways, I’m sorry for that, moving on. Anyways, I most certainly feel that the Klean SV is a solid purchase and one that is worth every last penny of the $50-$54 that Kefine is asking.

The Why… 

Because the Klean SV is built extremely well. Sure, there are iems built all-alloy, but the Klean SV goes a step further and adds that anodized finish, the matte look, the simple but aesthetically pleasing design. No doubt this set will look pretty dope walking around the market. It’s a slick set built well, very durable, and offers zero wear fatigue. Also, if you have human ears, I’m pretty sure that the Klean SV is going to fit you. However, it’s always about the sound as to why a set is worth its salt. The reason the Kefine Klean SV is worth every penny is because it is tuned very well per its target sound. It carries that refined neutral-natural timbre with nothing at all which is overtly artificial apart from faster transients. Which is usually a good thing. The bass is tight, well defined, well separated, and it still can rumble nicely. Next, the mids have that nice clarity and transparency providing great detail retrieval and a very intelligible and fine-lined sound without feeling recessed and better than one may think for vocals. Also, there’s nothing which sounds overtly glaring or shouty. At least for anyone who isn’t sensitive. Also, the treble has that good clarity too. It’s vibrant, semi-brilliant, and well extended adding air and openness. I hear solid enough bite to notes, nice note contours, and also a very transparent region. Details are illuminated well across the mix, note separation is well done and distinct, Imaging is very coherent with well-placed instruments for the cost, and you even have some solid top to bottom and front to back layering for $50 too. The stage is very natural, good spatial dimensions, and nothing feels or sounds congested or narrow. Friends, this is a no brainer, of course the Klean SV is worth every penny. Easy rec.

To conclude my full review and feature of the Kefine Klean SV, I first have to give a big thanks to Colin Yang and the good folks over at Kefine Audio. Thank you very much for your kindness. This was a very enjoyable review period that I was thrilled to be able to speak on. Thank you. Also, thank you, the reader, for taking the time to click the link which got you here. As always you are the reason that we do what we do at Mobileaudiophile.com. Thank you so very much. Every click and minute spent on any review means everything, I hope these reviews help you.

Other Perspectives

Another thing I speak on in every review is I try to compel you to check out “other reviews” now that you’ve read mine. This hobby is always and forever so very diverse. Diverse in the products, diverse in brands, diverse in tunings, philosophy, and there’s a lot of diversity in the people of this hobby. We are all so very different in so many ways. How often do you see a review praising something only to turn around and check out a review that speaks terribly of the same exact product? It happens constantly. There is no right or correct sound. That doesn’t exist. There are differently tuned products and our individual subjective feelings towards those products. And often… those feelings differ. That’s the hobby. I say that because I really want each of you to click some more links to get some different perspectives from some different reviews. Read, or watch other thoughts. Hopefully, you will gain enough of an understanding to make a purchase which will be meaningful. With that said, I’m done folks. So, please take good care, stay as safe as possible and always… God Bless!!