KeepHifi generously sent these to me for review asking nothing but an honest review.
Which is lucky because that’s the only type I give.
Everything below is based on my personal experience—using only my ears, my gear, and my preferences.
Background:
I’m relatively new to the IEM world—just six months ago, I didn’t like them at all because of the pressure they created in my ears. I still get that feeling occasionally, but I’m now thoroughly enjoying the differences between IEMs and my over-ear headphones (of which I have many).
I’ve owned and loved the Yanyin Canon 2s (before losing one), replaced them with KZ Sonatas (Tuning Version), and also had the CCA Polaris (which I passed on to a friend starting their IEM journey). Right now, I have the Xenns Mangird Tops on loan, but I won’t compare them to the KB02s—that wouldn’t be fair. However, I will compare them to the KZ Sonatas ($179 USD) to give some context.
I always take my IEMs and a pair of cheap-ish closed-back headphones when I travel. My portable listening source? Fiio M23—an amazing DAP!
Note:
I have had no experience with bone-conduction so I can’t compare it to anything. It mentions on the website “Best Bass In-ear Earphones Beryllium Dynamic Driver Hybrid HiFi Elastic-piece Type Bone Conduction Best IEM Headphones for singers” and “Due to bone conduction, coupled with the vibration of the shrapnel, the low-frequency effect is particularly prominent and strong. The tone is bright and smooth, and the whole is transparent without losing atmosphere”. Well, the bass is certainly excellent. And there is a shake inside the iem when flicked or banged lightly, like there’s a spring inside – is this the “vibration of the shrapnel”?
Design, Fit & Accessories:
First impressions: they look and feel great. The cable? It’s fine for the price, but a bit short (1m). I prefer 1.5m for portable use and 2m+ for desktop sessions.
The fit is comfortable (I only tested the large grey-and-red tips). The package includes three types of ear tips—black, white, and grey with red. The packaging is simple, but that’s fine. I’d rather see every cent go into the product itself!
Sound Breakdown:
Bass:
Wow. Deep, controlled, and no roll-off. It slams when needed and stays polite when asked. If you love rich, satisfying bass, you’re in for a treat.
Mids:
Well-balanced. I get easily fatigued by mid-forward tunings, but that’s not an issue here. The KB02s don’t push vocals too far forward, making them easy to listen to for extended periods.
Treble:
Neutral—neither bright nor shrill. There’s enough detail and clarity to make me reach for them repeatedly. Are they endgame in clarity? No, but for $40, they’re fantastic.
Soundstage & Imaging:
The soundstage is very good for the price—more left-to-right than top-to-bottom or full 3D. Instruments are well-separated and placed nicely in the mix. Not intimate, but not huge either.
Timbre:
Natural. No fake or plasticky tonality. Some reviewers pick up on subtle timbre differences—I don’t hear anything "off" here.
My Motley Crew of listening pleasure:
Bobby Bass – Hoist the Colours, and O’ Death (haunted version). Bass is just amazing on both tracks. It literally rumbles but it it’s not overpowering. Vocals go deep and aren’t forward. Treble is very good also.
Sister Doll (a great Aussie glam rock/metal band) – Purgatory (instrumental) and Change. Spanish style accoustic guitar sounded crisp, clean, with depth of sound on Purgatory. Electric guitar was just on point. Wow. On Change, distortion from electric guitar was….well, electric!! Mids and treble here were lush and sweet. All balanced so well.
Jamie Berry – Lost in the Rhythm and Grandiose – punchy, energetic, dynamic, clear and bassy (as it should be). Engaging and fun. Bass really does go low.
Deadmau5 - I remember – bass bass bass. Clarity shines here. Fun, dynamic and no distortion as I go to dangerous levels (only for a couple of seconds).
Toto – Hold the Line – Clarity, excellent detail and separation, engaging. Everything has it’s place and is well balanced. Timbre is very natural to me.
Kansas – Carry on Wayward Son – this is quite a well staged (wide sound) song and it excels on the KB02s. Once again, everything is in balance with no complaints from me at all. When the piano kicks in, it’s just beautifully done. The timbre of the piano is natural and lively, then the bass guitar enters the scene. Wow. Lovely gobs of clean, well controlled bass. Great song to listen through the KB02s.
The Omnific – The Labryrinth Chronicles (instrumental). Bass is clean, deep and slappy (it’s a slappy bass-driven song). Really exciting, energetic and punchy.
Scalability – Big Surprise!
I hooked the KB02s up to my Burson Soloist 3X GT, Geshelli J2 DAC, and Eversolo DMP-A6 on low gain, 3.5mm output and...
Everything improved DRAMATICALLY!!
Soundstage expanded.
Clarity improved.
Everything became weightier and more solid. A real step up from the M23.
I could now here instruments expanding wider and placed more spaciously. Clarity improved (without showcasing more treble), and everything was, for want of a better term, weightier and more solid. These did not sound like $40 iems on my Fiio M23. On my desktop setup, they genuinely sounded like $200+ iems. The improvement was amazing!!!
Cable – way too short for desktop, but that’s a minor complaint.
Comparison:
KBEAR KB02 vs. KZ Sonatas ($179 USD)
The KZ Sonatas are better, as expected for 4x the price:
✔ More open and full-sounding across all frequencies.
✔ Better separation and staging—closer to a "hall" effect.
✖ Less prominent bass—more neutral tuning.
However, considering the KB02s cost just $40, they hold their own incredibly well.
Final Thoughts – Are They Worth It?
Absolutely.
✔Do you love great bass? Buy these.
✔ Want excellent value? Buy these.
✔ Not unfairly comparing them to much pricier IEMs? Buy these.
Would I take them when I travel?

Happily.
Would I be okay with just these if I lost my Sonatas?

Yes, yes, YES!
KBEAR, you’ve made one hell of a budget-friendly bone conduction IEM. Well done!
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Build/comfort/aesthetics – 8/10
Sound quality – 8/10
Value for money – 9/10
Overall Score: A solid 8/10, especially considering their low price.
Would love to see a longer, thicker cable, but aside from that? A total steal at $40.