In-Ear Fidelity

BLON BL03 Review: Beyond the Hype


For those interested in non-audio opinions, please refer to the unboxing post.

I don’t even know where to start with BLON, but it seems that they are now a company that needs no introduction. So let’s keep this section short and sweet.

The BL-03 is their newest golden goose, often compared to established models like the Moondrop KXXS or the Tanchjim Oxygen despite its price. There are rumours that this was tuned by the same guy who tuned the Oxygen, but nothing has been officially confirmed.

I’ll take this opportunity to clown on BLON’s name, which stands for: “Belief, Letmusicburn, Oppoty, Nevergiveup”.

Oh China. Never change.

Product page:

MSRP: $39

The BL03 was kindly provided by Linsoul.


I’m going to do something a little different for this review and just drop my letter grade right now.

Grade: C+ ★★

More info on the “Stars à la Cenric” award system

So now, I’ll address the giant white elephant that I released into the room. To anyone who already bought or own a BL03, this review isn’t for you. I’m not here to preach to the choir, neither am I here to “destroy the hype”. My job as a critic is to evaluate a product beyond the lens of popular opinion, beyond the expectations that people may have already set on my behalf, and so provide a fair and balanced analysis based on my own expertise and experience.

If this article agrees with your impressions, power to you. If it doesn’t, that’s fine too! I just hope that people can respect differing opinions without attacking each other.

My only request is for people on both sides of the fence to simply… read on. I may confirm some of your beliefs, while simultaneously disagreeing with others. As I’ve preached many times over and over, I’m just one guy on the internet and I should not be your only source of impressions and/or criticisms.

Some additional details:

  • I received three different BL03 samples, all from different batches (according to Linsoul).
  • None of these samples have the linear 400Hz-1kHz response that other measured units seem to have.
    • The unit variance of my own three samples is a concern, but still expected for an IEM that retails for $30 on the street.
    • You may receive an “ideal sample” with the aforementioned linear response, or receive a unit that’s similar to the three that I have. It’s all lottery and I cannot guarantee anything.
  • I removed the memory wrapping around the stock cable to improve fit. The BL03s stay in my ears properly now.
  • Stock tips fit fine for me and so this review is all based on the sound on stock tips.
    • This is done intentionally so as not to alienate anybody who may not have aftermarket tips lying around. The BL03 will most likely be the many newbies’ first IEM purchase due to its price point and so this is (IMO) a valid assumption for most BL03 owners.
    • The additional costs of aftermarket tips and cable may also strip the BL03 of its “★★ value” after it is factored into the total price of the resulting setup.
  • This review is based on first, original sample sent to me. It is labelled “sample 1” on the database.

The subjective


I can see the BL03 being described in different ways. Neutral with bass boost, perhaps mildly V-shaped if one is sensitive to treble, but in my books I’d classify it as simply “warm”.

There is a wide-band lower frequency boost that encompasses almost the entire region of 20Hz to 1kHz which makes the BL03 generally bass boosted rather than any focus in sub-bass or midbass frequencies. The mids are in-line with the treble to my ears, with it being neither at the forefront nor the background of the overall mix. The treble is inoffensive yet decently energetic, with enough extension to not feel lacking.

The Bad

Alright, ready your pitchforks.

The BL03 doesn’t sound like a particularly technical or detailed IEM to me. The attack is a little blunted, the decay is extended just a tad too long for my liking and the notes demonstrates hints of smearing into one another, though not to the extent where I would call it “muddy”. It’s pretty standard technicalities as far as a cheap, budget IEM is concerned, so I would not personally recommend anybody getting the BL03 if they prioritise sheer clarity and detailing in their music presentation.

The bass presentation is a little bloated to my ears, with percussive hits ringing a little too long and so bleeding slightly into the midrange. It is to be noted that I have definitely heard far, far worse from more expensive IEMs, so this isn’t me stating that the BL03 is a bloated mess, but rather that this is a concern that potential buyers should at least consider before making a purchase. Many are satisfied with this kind of bass, but my personal standards are rather high so YMMV, sound is subjective and all that.

Imaging is a metric that I usually don’t talk about because a vast majority of IEMs are average to me in this regard, but I will just touch on briefly. The instrumental positioning and soundstage size of the BL03 is nothing special to me. It’s not an absolute con by itself considering again, very few IEMs actually get my thumbs-up in these qualities.

The Good

If there’s one thing that the BL03 truly excels at, it’s in its tonality.

I don’t think I’ve encountered anyone who will outright state that the BL03 sounds “wrong”, and I think that’s why it’s been such a popular IEM as of late. It is tuned very well, and while the dynamic driver inside it isn’t the most capable, I think the sound engineers did the best that they could with the cards they were dealt with.

The BL03 kind of has everything that makes it pleasing to a vast majority of ears out there: enhanced bass response, thicker-than-neutral notes, proper midrange tone, and treble that is neither too sharp nor too dark. I wouldn’t call it an exact Goldilocks situation, but it comes reasonably close. The BL03 is an IEM that just roughly fits into most people’s general preference, even if it may not be a perfect fit.

The Rank Justification

Now I know there has been… high expectations for my opinion on the BL03. It certainly has not made writing this review any easier, especially when I’ve been seeing people so confidently predicting that I’d rank these in the B ranks or even up in A!

So where I’d just drop the rank and run in my other reviews, I’ll switch it up a little with this one and sort of put into writing my thought process. Just looking at the more notable IEMs that I’ve rated at B- (excluding the MH755 for outlier reasons), we have the following:

  • ikko OH1 (OH10 as well)
  • Tin HiFi T4
  • VSonic GR07

All of which are many times more expensive than the BL03, but when in direct A-B comparison in the complete absence of price-to-performance value, I personally did not find the BL03 matching up to their levels of technical performance.

Now I will note one thing: I actually preferred the midrange tone of the BL03 to all of the above. The T4 and OH1/OH10 were a tad too shouty in the upper midrange for me, while the GR07’s treble response left something to be desired. The BL03 balanced upper-end energy without being overly-forward, and the “safeness” of its tuning is therefore its greatest strength.

But is its tonal balance enough for me to overlook its shortcomings in technical performance? I’d argue no to that. But on that note: is its tonal performance enough to distinguish itself from being simply “average”? Certainly.

Even as a C+ IEM the BL03 can still thrive extremely well, being one of the few handfuls of sub-$50 IEMs that I would recommend when asked. Its immediate competition is really only the following:

  • The Tin HiFi T2, an IEM with a completely different signature (neutral) and is still more expensive than the BL03 at its cheapest
  • The CCA C10, arguably the biggest threat value-wise due to its lower street price
  • The Zero Audio Carbo Tenore, which is rather hard to find these days and comes with worse build quality compared to the BL03 (such as the lack of detachable cables, for instance)
  • The Final Audio E1000/E2000, which has the same problems as the Carbo Tenore but with even worse QC issues than the BL03, and so hardly gets my personal recommendation

In that regard, the BL03 is still one of the most value-for-money IEMs out there, even if it may not be the ultimate market shaker that everyone seemingly wants it to be.


At an MSRP of $39 and a “street price” of $30, the value of the BL03 as an audiophile-oriented budget IEM is something we can all agree on, whether you’re someone who believes that the BL03 deserves a far higher rating or somebody who thinks that the BL03 is far too overhyped.

While I may not feel that the BL03 is a giant killer by any means, it certainly redefines what we should expect when we put down $30 for an IEM. Future budget IEMs have a high bar to clear.

Support me on Patreon to get access to tentative ranks! My usual thanks to all my current supporters and shoutouts to my big money boys:


62 thoughts on “BLON BL03 Review: Beyond the Hype”

    1. You need to replace the Cable and use better eartips to get the best out of the BL03 — a curious fact.

      Tripowin Cables work well.

    1. Well Lord Oppoty, this i am astounded to hear, for SOOTB what dismayed me right away was the submerged vocals… In tracks where vocals and loud electric guitars etc are happening together, the voice barely rises over the mix, and this I have found to be rather intolerable, quite regardless of anything else…

      1. I had this exact problem with my onkyo amp but when I used my Hiby w3 the submergence of vocals you’ve experienced completely and I mean utterly completely rise to the surface and give an incredible experience. It seems totally dependant on the source for my pair anyway.

        Hope this helps

        1. And that’s one of the issues with the W3, even if might happen to beneficial in context; combined with the “touch less” button .. >.>

      2. It’s night and day honestly. Try different sources, I don’t know what’s up with my Onkyo TX-SR313 but when using it with the Blon 03, it gives as you said the muddy almost underwater quality to the vocals when listening to heavy rock/metal. Changed the source to my phone through Bluetooth to the Hiby W3 and it’s utterly incredible.

        Again good luck and persist, it’s bluddy worth it.

  1. One thing I have noticed in BLON BL03 is that it has no Soundstage and sounds very close, TinHiFi T2 and Sony MH755 have way more better Soundstage than this.

    1. I agree with you on the soundstage, I feel offly suffocating by how small it is especially with male vocal and more bassy songs.

    2. strange, soundstage in my blons is much wider than my mh755 and T2. The biggest blon problem is the QC

        1. I am also using CP100M tips on my Blons and find the soundstage much better than my T2, MH755, and ZS10. In fact it was actually the soundstage that surprised me most after the tonality.

          1. I just replaced the stock cable with Kanas pro cable, now i am getting proper stage from BL-03 and it is better than T2 and MH755 in terms of soundstage.

    3. I can confirm this also. Soundstage has a noticeably intimate presentation compared to my other IEMs. I’d say it’s as congesting as the T2.

    4. Exactly! I have the same problem, I was wondering what all this hype about soundstage was, they sound no different than my other cheap iem lying around, mayeb a bit clearer but that’s all.

  2. If you remove the nozzle screens, it becomes a lot more neutral. It reminds me of Tin T2 with a little bit more bass and less but smoother upper frequencies.

      1. I stuck a thin needle into the edge of the metal filter screen, then gently pried and removed it. Another method is to slowly push it in just a little bit using for example a cotton swab (the screen is very flexible, so it’s easy to do), so it will peel off and then you can take it out.
        You should be aware that you might destroy the filters during this process and might not like the new tuning, so it would be safe if you had some spare ones.

        1. with a small tweezer i managed to remove the filters without any damage, stick them on a clean surface in case you want to reverse the mod and enjoy 😉

  3. I think that this was an exceptionally fair review, and there was perhaps no need to be so concerned about stoking people’s feelings.

    Many people who talk about the BL-03 on-line are measured in their evaluation. I think there is a general understanding among enthusiasts that the BL-03 has excellent tone for a chi-fi IEM, but suffers in technicalities. In particular ‘bass bloat’ is a term that has been thrown around regarding the BL-03, and I think it is entirely justified.

    You buy the BL-03 to get an example of pleasant tuning for $28, something that has little difficulty with slower songs. Anyone arguing for the BL-03’s excellent technicalities is in an uphill battle. I never expected the BL-03 to get a high rating on this list, just a fair one. And this is fair.

    1. I agree with you completely. This was a fair and accurate review. The BL-03 has a good tuning and decent technicalities and is a great value.

  4. This review, to me and only me, shows you should show graphs but not do reviews. Your ears are not good enough to review, but you do good graphs. Try learning to get familiar with an IEM, to get mindfulness and increase your power of concentration and noticing. Your left brain is good at graphs, but your right brain is seriously challenged. On the one hand you help people and on the other hand do a disservice all at the same time.

    1. It’s a review, it’s just his opinion (as he’s stated probably a hundred times now including this very article) and plenty of people agree with him. If you feel he does the community such a disservice, why don’t you make some YouTube videos so you can rant and rave about the unfairness of critical reviews and the flavor of the week and insist everyone go out and buy a product with obvious quality control and fit issues with no criticism and no concern for others’ wallets?

    2. Why? This review seems completely accurate to me. Maybe it’s your brain that has issues. Or maybe you’re being blinded by fanboyism. His review was fair. The BL-03 is a good value due to its great tonality and decent technical attributes, but his overall ranking seems pretty accurate.

  5. BLON stands for
    Building the Legend Of Nobles (which makes more sense than Belief Letmusicburn Oppoty Nevergiveup)
    as what the paperworks inside the box said

  6. I found stock to lack shimmer with too.much bass and too little control… I upgraded the cable to a balanced and tips to foam and the shimmer (upper treble impact) has improved and the phones sound a lot clearer but the bass is still too much. Even with my Fiio x7 which isn’t a bass monster!

    I do however enjoy the overall, slightly relaxed if not very warm sound, but I do crave more detail (kz as16) and I crave more extension with less bass. Especially less bass bleed!

  7. Thoughts about its driver flex? Bought 2 units, both have driver flex despite the vent. I used foam tips to solve this but reduced the sparkle which is already expected.

    1. bggar is a very honest reviewer/youtuber, but sometimes I think he’s confusing and seems to put himself in some sort of high ground in the community. Yeah, it’s a good IEM but it’s never going to beat the 100+$ IEMs he’s putting below this.

  8. Your graphs are so useful to me. Your reviews reflect the crazy amount of IEMs you go through though. Maybe reviews are best left to others with better musical perception. Too much.

  9. My BLONs are different from each other. One has the flat 400-1000khz line and one looks just like the graphs you’ve measured. So one is a true BLON and the other is a dirty BLON 😉

    Seriously though I really like this set, hence why I bought a second. It replaced my KZ AS10. It’s a great set that I can do yard work, exercise, ect with. Use comply foam tips and it really fits well. Definitely not as good as my Fearless or ER2XR however it’s a very nice fun signature that I can listen to for a long while. When I am active this is a good set to have around. Not so much for the critical listen but put in some Tycho and it’s got some really great bass.

  10. I’m not hidng behind anything. Not an imaginary Spanish connection or someone who thinks you have even more hearing problems than I do. Weird how I morph between being Spanish and someone else. Your overreliance on graphs has numbed your true ability to hear spontaneously. You are like a false guide spurred on by ‘Hubris’. Stick to infomation and let others use better listening skills and concentration than you can manage. It seems you are challenged in empircal hearing. Maybe thats why you started your enterprise, self-healing. It’s got out of hand now and possessed you. Get your right brain activity vs left brain checked out. It would be fun for you.

    1. So you’re an easily offended, toxic person who hides behind the guise of Buddhism and “left brain right brain” pseudoscience to insult people you don’t agree with, and then call them mentally challenged.

      You give Buddhism a bad name. Get out of my website.

    2. Steve, you need a life. Seriously. Maybe you should proceed with your own “empirical” exploration of the “dharma” in your moniker and ponder your ironic mentioning of hubris.

  11. My Blons finally arrived. The tonality is spot on but mine is on a shrilly side and I dont experience the bass boost on mine. I guess I have the good one? As far as technicalities go, it is rather competent. This is spot on the perfect entry level piece to get to get acquainted to what actually sounds good. It is lacking in the overall resolution and slam but for sub $50 range, this is a bargain especially since I have stuff that cost $199-$300 that sounds like this. The caveats are there but really, at this price point, I’d take it.

    1. BLON BL03 in summary:
      The bundled grey tips feel like rubber and get white when stretched so in conclusion – it’s not silicone.
      Use trn silicone tips (black and tiny red bores) they offer better soundstage than foam tips, trn tips must be inserted halfway only.

      Picky of genre, not neutral, not for prolonged listen, not for gaming, 100% for monitoring.

      Most excellent for “band” genres (eguitar vocal bassist drum)
      No need to EQ for rock or alike songs (jrock punk metal).

      5k/8k bump are there so expect stage and if not – change tips, everything else in FR is smooth. FR having no harsh spike/dip means no sawtooth mid/treble. Some may find the 1-2k bump to be unsettling and piercing, Harman fatigue or shouty sopranos in general, good for male vocals or soft voice.

      “Over your face” sparkles are nonexistent. But that is due to the front veil. No “In your face” bass, EDM trap basslines are thin while female vocals are too forward.

      Soundstage feels like veiled, like there is a cardboard blocking your face but every direction around is on point – this feels like “being inside the band” instead of “being the listener of the band”. This is likely intended for monitoring and it’s what makes this IEM fun (except for that 2kHz.. female vocals/violins are fatiguing).

      1. this review is very close to my experience so far! blon-03 is my first IEM and i was astounded by the amount of detail and balance in this iem. What IEM might you suggest that has better Detail/imaging than bl03?

  12. I believe a perfect example of bass problems on the 03 can be heard on an album titled, “Blue Maqams.” On the song “Opening Day” one can hear Dave Holland’s upright bass plucks sounding bloated, unnatural and bleeding over other parts of the music. Listening to the same song on my Tin P1’s (properly powered) sounds much more natural and enjoyable with those plucks present but not overpowering.

  13. I enjoy music when I’m listening with my set using a 2.5 balanced cable and a BTR5. The balanced output gives a wide soundstage. The added power fuels the bass definition. But it’s not technical or overly distinct. The mids and highs are the same. And that evenness makes it fun to get into the overall spell of a composition. I can do something else if I want to at the same time.

  14. Final Audio has quality control issues? Genuinely curious since this is the first I’ve heard of it.

    1. Oh also unrelated to this review but the “estimated hype start” sorting in the hype monitor is wonky cause you mix words and numbers. Maybe use the quarter following the year instead? As in instead of “Mid 2019” say “2019 Q1”

    2. LOL so you took the time to read my comments, changed my name from ___ ____ to anon, deleted the last cheeky comment (fair), but didn’t bother acknowledging the other 2 comments despite being legitimate? I’m sorry but this is the funniest thing I’m dead. Wasn’t trying to make you mad I promise, just thought it would be funny to impersonate “he-who-must-not-be-named”

      1. Just slipped my mind.

        Final Audio has some QC issues, I’ve measured a few samples of each model and there are significant channel balance issues and unit variation, getting worse the lower down the chain. I’ll update the Hype Monitor when I have the time.

        1. Ah I see now looking at the graphs, channel imbalance and unit variation is definitely a valid knock. I really appreciate what you do btw! Not only the graphs but it’s nice to have a consistent voice in this space considering many of us don’t have the option to actually try many options before we buy 🙂

  15. I find them painfully fatiguing to listen to, to the point where I pull them out and use the busted old pair of Soundmagic E11 or E10 they were meant to replace.

    I suppose it’s possible I’ve got a faulty pair somehow, but I doubt it.

    It’s not that there’s too much treble or bass, it’s that the sound is ‘screechy’ and ‘noisy’, like a hissing tv set.

    I don’t know what that would equate to in technical terms, probably a waveform thats blowing out all over the place.

    Either the unit I’ve got here is defective, or you’re all nutters. Um, subjectively speaking.

  16. I just ordered a pair of BL03’s, and I really appreciate your take on them. It’s important to have some tempering voices on a much-hyped product, and it’s a shame those voices get dogpiled. I’m glad I’ll go in with my expectations tempered a bit now, they’ll be my first decent pair of IEMs and regardless of the hype I don’t think I’ll be disappointed for $30USD. Thanks for this review!

  17. I have been using these for several days. Trying different eartips and cables (stock cable is poor quality and fit).

    I noticed that BL03 received same rating here as Samsung AKG EO-IG955 (freebie with Galaxy S8, which I owned for several years). BL03 is clearly better!

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