DISCLAIMER
I would like to thank Kefine for providing this review unit.
The Kefine Klean can be gotten here: https://keephifi.com/products/kefine-klean-10mm-dlc-diaphragm-dd-in-ear-earphones-two-interchangeable-nozzles-two-different-sound?_pos=1&_psq=kef&_ss=e&_v=1.0 (no affiliate links).
I would like to thank Kefine for providing this review unit.
The Kefine Klean can be gotten here: https://keephifi.com/products/kefine-klean-10mm-dlc-diaphragm-dd-in-ear-earphones-two-interchangeable-nozzles-two-different-sound?_pos=1&_psq=kef&_ss=e&_v=1.0 (no affiliate links).
SPECIFICATIONS
ACCESSORIES
Other than the IEM, these are included:
- 3 pairs of wide-bore silicone eartips (S/M/L)
- Cable
- 2 pairs of tuning nozzles
- Carrying case
The accessory line-up is okay for the sub $50 USD asking price, nothing ground-breaking, but focusing on practicality.
- Driver configuration: 10 mm DLC diaphragm dynamic driver
- Frequency response: 20 Hz - 20 kHz
- Impedance: 32 Ω
- Sensitivity: 107 dB
- Cable: 2-pin 0.78 mm; silver-plated copper cable; 3.5 mm termination
- Tested at: $49 USD
ACCESSORIES
Other than the IEM, these are included:
- 3 pairs of wide-bore silicone eartips (S/M/L)
- Cable
- 2 pairs of tuning nozzles
- Carrying case
The accessory line-up is okay for the sub $50 USD asking price, nothing ground-breaking, but focusing on practicality.
There is only one set of silicone eartips included, with no provision for alternative types or foamies. Nevertheless, this sole set of tips are serviceable from a sound and comfort perspective.
Included is a stock silver-plated copper cable. This is on the thinner side, but is braided well with minimal tangling. There's a chin cinch for added grip, with negligible microphonics.
We have a small carry case, which is semi-rigid externally, with inner webbing. It isn't that big, but should be able to fit the IEM and cable at least.
Lastly, we have 2 pairs of tuning nozzles, which we will dive into below in more detail.
The rest of this review was done with the stock cable and stock silicone tips. No aftermarket accessories were used, so as not to add any confounders to the sound.
BUILD/COMFORT
The rest of this review was done with the stock cable and stock silicone tips. No aftermarket accessories were used, so as not to add any confounders to the sound.
BUILD/COMFORT
The housings are manufactured from metal-injected mold, and are built like a tank, culminating in a smooth matte finish. The inner aspects are comfortable to be worn for longer listening sessions.
Being a vented IEM, isolation is below average. I did not encounter any driver flex on my set.
DRIVABILITY
I tested the Klean with the following sources:
- Apple dongle
- Cayin RU7
- Chord Mojo 2
- Fiio KA11 dongle
- Fiio KA17 dongle
- Khadas Tone Board -> Schiit Asgard 3 amp
- Onix Alpha XI1 dongle
- Questyle M15 DAC/AMP dongle
- Sony Walkman NW A-55 DAP (Walkman One WM1Z Plus v2 Mod)
- Sony Walkman NW A-55 DAP (Walkman One Neutral Mod)
- Sony Walkman NW WM1A DAP (Walkman One WM1Z Plus v2 Mod)
- Smartphone
This IEM is easy to drive, with no hard requirements for amplification.
INTERNALS/TUNING NOZZLES
The Klean utilizes a 10 mm DLC diaphragm dynamic driver.
This IEM is quite versatile, boasting of 2 sonic options via tuning nozzles:
DRIVABILITY
I tested the Klean with the following sources:
- Apple dongle
- Cayin RU7
- Chord Mojo 2
- Fiio KA11 dongle
- Fiio KA17 dongle
- Khadas Tone Board -> Schiit Asgard 3 amp
- Onix Alpha XI1 dongle
- Questyle M15 DAC/AMP dongle
- Sony Walkman NW A-55 DAP (Walkman One WM1Z Plus v2 Mod)
- Sony Walkman NW A-55 DAP (Walkman One Neutral Mod)
- Sony Walkman NW WM1A DAP (Walkman One WM1Z Plus v2 Mod)
- Smartphone
This IEM is easy to drive, with no hard requirements for amplification.
INTERNALS/TUNING NOZZLES
The Klean utilizes a 10 mm DLC diaphragm dynamic driver.
This IEM is quite versatile, boasting of 2 sonic options via tuning nozzles:
With the black nozzles installed, we have a bright U-shaped curve, which is very resolving. The bass is tight and fast, with crisp transients. The treble is clear with solid technicalities, though it may be spicy and sibilant for the treble-sensitive.
On the other hand, the silver nozzle confers a warmer and bassier signature, with thicker note weight and less sizzle in the top-end. This setting is definitely more relaxed and smoother, though we lose technical chops compared to the aforementioned black nozzles.
SOUND & TECHNICALITIES
The following impressions are done with the black nozzle in use.
As per the graphs in the previous section, this setup furnishes a bright U-shaped tone.
This has a sub-bass focus, with decent descent but no big basshead reverberant rumble. The bass is however, very tight and clean - as its "klean" namesake would suggest - and bass texturing is well done for its $40ish pricing. So it is a case of quality over quantity.
The lower midrange has a slight dip, and then we hit a 9ish dB pinna gain, which translates to forward vocals that are just at the edge of shout (it may be more prominent at louder volumes as per the Fletcher Munson curve).
The black nozzle provides decent treble extension with good resolution and clarity. Micro-details are captured well, though cymbals and high-hats may be a tinge spicy, with some sibilance in play. This black nozzle setup would be a kindred spirit for trebleheads, though treble-sensitive peeps better keep to the tamer silver nozzles to reduce fatigue.
In the area of timbre, the Klean performs okay, it is bit thinner in note weight on this black nozzle setup, with the silver ones giving a thicker and fuller sound.
In technicalities, the Klean has above average soundstage. Micro-detailing - as alluded to - is pumped through well in the mix, and for a sub-$50 set, imaging and instrument separation are well above average.
COMPARISONS
On the other hand, the silver nozzle confers a warmer and bassier signature, with thicker note weight and less sizzle in the top-end. This setting is definitely more relaxed and smoother, though we lose technical chops compared to the aforementioned black nozzles.
SOUND & TECHNICALITIES
The following impressions are done with the black nozzle in use.
As per the graphs in the previous section, this setup furnishes a bright U-shaped tone.
This has a sub-bass focus, with decent descent but no big basshead reverberant rumble. The bass is however, very tight and clean - as its "klean" namesake would suggest - and bass texturing is well done for its $40ish pricing. So it is a case of quality over quantity.
The lower midrange has a slight dip, and then we hit a 9ish dB pinna gain, which translates to forward vocals that are just at the edge of shout (it may be more prominent at louder volumes as per the Fletcher Munson curve).
The black nozzle provides decent treble extension with good resolution and clarity. Micro-details are captured well, though cymbals and high-hats may be a tinge spicy, with some sibilance in play. This black nozzle setup would be a kindred spirit for trebleheads, though treble-sensitive peeps better keep to the tamer silver nozzles to reduce fatigue.
In the area of timbre, the Klean performs okay, it is bit thinner in note weight on this black nozzle setup, with the silver ones giving a thicker and fuller sound.
In technicalities, the Klean has above average soundstage. Micro-detailing - as alluded to - is pumped through well in the mix, and for a sub-$50 set, imaging and instrument separation are well above average.
COMPARISONS
The Klean will be compared against other single DDs below $50 USD. Hybrids, multi-BAs, and planars, which have their own pros and cons, are left out of the comparisons.
Once again the following impressions are done with the black nozzle in use.
Tin HIFI C2 2025
The Klean kills the lacklustre C2 2025 easily in every technical department, from imaging to micro-detailing to soundstage.
The C2 2025 is however, smoother in the treble and thicker in note weight.
EPZ Q1 Pro
The Q1 Pro is more Harmanish, with a mid-bass scoop out and a more sedate top-end.
The Q1 Pro is weaker technically, with a smaller soundstage with less pronounced micro-details and imaging.
CONCLUSIONS
Once again the following impressions are done with the black nozzle in use.
Tin HIFI C2 2025
The Klean kills the lacklustre C2 2025 easily in every technical department, from imaging to micro-detailing to soundstage.
The C2 2025 is however, smoother in the treble and thicker in note weight.
EPZ Q1 Pro
The Q1 Pro is more Harmanish, with a mid-bass scoop out and a more sedate top-end.
The Q1 Pro is weaker technically, with a smaller soundstage with less pronounced micro-details and imaging.
CONCLUSIONS
For sub-$50 USD, the Kefine Klean is a solid choice, espousing good price-to-performance ratio.
This IEM is quite a versatile beast, with 2 tunings on offer - a laid-back and relaxed thicc sound versus a more technical and brightish affair with a "klean" and textured bass. However, there are some trade-offs among the 2 signatures, with the silver relaxed nozzle sounding a bit lowFI, and the black analytical nozzle having some treble fatigue and sibilance. Timbre is otherwise quite natural, more so on the silver nozzle.
In the non-sonic arena, build is solid, with easy drivability and comfortable ergonomics.
All-things-considered, this IEM should be in the conversation for a budget introductory pair, and is kind of a jack-of-all-trades.
This IEM is quite a versatile beast, with 2 tunings on offer - a laid-back and relaxed thicc sound versus a more technical and brightish affair with a "klean" and textured bass. However, there are some trade-offs among the 2 signatures, with the silver relaxed nozzle sounding a bit lowFI, and the black analytical nozzle having some treble fatigue and sibilance. Timbre is otherwise quite natural, more so on the silver nozzle.
In the non-sonic arena, build is solid, with easy drivability and comfortable ergonomics.
All-things-considered, this IEM should be in the conversation for a budget introductory pair, and is kind of a jack-of-all-trades.