BLON BL-03 Review: The (In)Famous “Giant Slayer”

Updated: Nov 19, 2020

Pros: Great Imaging and Timbre, Unbeatable price to performance ratio, Fun and musical

Cons: Fit (shape and eartips), Uncomfortable Cable, Bass may be too much for some

Driver setup: Single 10mm Carbon Diaphragm Driver

Price: $20 (USD)


Disclaimer: This review is done of my own accord and I purchased this set at full price from Aliexpress.

The BLON BL-03 has a single dynamic driver configuration, with a 10mm Carbon Diaphragm. If you haven’t yet heard about these, it’s time you did. At a current retail price of SGD$27 to $30, this is one of the budget kings of chi-fi. The BL-03 comes in either gunmetal or mirror silver finish and you, with and without a mic on the 2-pin removable cable to suit your needs.

In today’s review, we will be looking at whether this set deserves every bit of the hype and praise that it has been showered upon. I think the problem with many reviews today is that many are coming into this pair having very high expectations for this set, so I will try to be as objective as I can, reviewing and writing my honest opinions for a $30 pair of earphones.

Packaging and Accessories (Score: 5/10)

Right off the bat, the packaging sure leaves an impression already, my boy OPPOTY out here. Really basic packaging, but I don’t think it’s anything to complain about.

Opening it up, it comes with a twisted rubbery black cable with a few silicone tips and a drawstring pouch with the logo hideously stamped on it. Apparently, depending on which batch your set is from, you may get a different pouch, I’ve seen some people get a felt pouch with theirs. Either way, I don’t think I would be using it anyway, so a nice inclusion regardless.

The silicone tips feel iffy in the hand and even worse in the ear. Even for a $30-dollar set, these feel kinda poor. Hence, you may need to add the cost of your third party tips to get the most out of your BLONs.

Build quality and Fit (Score: 6.5/10)

I’ll first be commenting on the quality of the cable. To be honest, I’m not a fan of it but at this price point, I’m just thankful that it is easily replaceable. I’ve equipped my own 2-pin cable and I’ve not looked back since. Cable has a somewhat dodgy y-split and a pair of unhelpful and oddly shaped preformed ear hooks.

Build quality of the earpieces themselves is stellar. I’ve never seen such a sturdy build for an IEM in this price range. The finish on both the mirror and gun-metal finishes is almost flawless and feels nice, smooth and sturdy in the hand. Definitely not some cheap sprayed on finish. The earbuds themselves do have some weight to them as well.

Lastly, on the fit, this is where it may cause quite a divide in opinions and hence the score. I’m giving it an above-average score since I personally do not have a problem with the fit, but this earphone doesn’t have the most universal shape. Ultimately, whether it is a good fit for you will vary for different people but what I can say is that changing the tips to something more comfortable will definitely help in achieving a good seal and bringing the best out of these.

Sound (Score: 7.5/10)

Moving on to the most anticipated section – the sound.

Frequency graph of the BLON BL-03

I tested extensively with following equipment and tracks and did not find an external amp necessary to drive this earphone but using your favourite go-to setup will sure help you enjoy this best.

Sources used

  • Fiio Q1 MkII
  • Shanling M3s

Cable used

  • TRN T2 2-pin 2.5mm balanced cable

Albums used

  • Carpenters – Gold: Greatest Hits
  • Green Day – American Idiot
  • George Ezra – Staying at Tamara’s
  • The Lion King: Original Broadway Cast Recording

Bass (Score: 8/10)

Love it or hate it. Few sets at this price point can truly say that they have got that Bass with a capital B well done. I wouldn’t declare that its everyone’s cup of tea as it is boosted quite significantly. I do admit that in some tracks it can get a little overwhelming, but when it calls for it, few do it better than the BL-03s. The tonality of the bass is also where this set shines. It has both quality and quantity. Listening to “Shotgun” by George Ezra, the sub-bass rumbles authoritatively without bleeding into the mids or overpowering his vocals. The bassline on Lion King’s Broadway Recording of “I Just Can’t Wait to be King” was something I’ve never heard before on any other earphones. It has such great separation and rumble that I had to listen to the whole song just to appreciate it.

What I do not really like about the bass is that on some tracks it may seem like the boost skews the overall presentation of the song. For example, in Green Day’s “Give Me Novacaine” the bass guitars can be a little overpowering and unnatural.

Mids (Score: 7/10)

The upper-mids can seem a little laid back due to the emphasis in the bass and lower-mids. On certain tracks such as in Martin Frost’s rendition of Clarinet Concerto in A: Allegro, it left me wishing more from the violins. I just found them a little too polite than I would have liked. However, the presentation of the clarinet’s tone is accurate and very pleasant, owing to a more solid lower-mids performance.

I really like the presentation of male vocals on the BL-03. Again in “Shotgun”, I feel like George Ezra’s voice really stood out and had a very nice tonality. Instrumental separation on many tracks was very well done too, it really just makes music so much more enjoyable. No, the BL-03 isn’t exactly what you would call a studio monitor or a detail beast, but musical and fun? Yes.

Treble (Score: 7/10)

What impresses me most about the treble is that it holds up decently well. The treble isn’t boosted and is still relatively polite. But it has a pretty nice presence and there’s a certain je ne sais quoi that just makes me fall in love with it. The decay is really natural and as you can see from the graph, there is significant detail being preserved in the treble without rolling off too soon and it really shows in the music. In Green Day’s “Boulevard of Broken Dreams”, many budget sets would struggle with the presentation of the cymbals and Hi-Hats and can get a little “mushy”. It sounds quite enjoyable on the BL-03.

Imaging, Timbre, Soundstage

Imaging and timbre on the BL-03 is superb. These 2 are where this set really performs and on these 2 grounds alone, I can safely recommend this set to anyone. It may not be everyone’s favourite set of earphones but I’m sure no one can deny that it is a brilliant performer at its price range.


In short, the BLON BL-03 has no business sounding this good at its price. I am in love with my set and it is something that I will keep for a long time. If you’re a fan of the Harman curve tuning, this is a rec. The thickness of the sound is somewhat reminiscent of the Sennheiser HD650s. However, this is not to say I am making the claim that the BL-03s are THE HD650s for IEMs. They are not completely without their flaws such as its fit and it also will not win any awards for detail retrieval. The timbre and overall tonality are however very pleasing, and this has to do with the way the mids and treble are in no way poorly done despite the boosted bass region. Bass heads should definitely be adding this to their collection. To put it simply, the flaws it has are not dealbreakers, but just limit it from being compared to set in higher price ranges (i.e. >$200).


BLON BL-03 vs Shure SE215 Special Edition (SGD$130)

The BLON BL-03 in some way reminds me of the Shure SE215 in some way, although they are at 2 different price points, which speaks really well for the BLON BL-03 actually. The only place where I would rank the Shures over the BLONs is in terms of fit since the Shures have an almost unbeatable and proven universal design. Both earphones have a sort of fun tuning and boosted bass, but I would find that the imaging on the BLONs is more accurate and immersive and the treble extension is much better on the BLONs as well.

BLON BL-03 vs Moondrop KXXS (SGD$240)

The Moondrop KXXS (Review Here)

It’s not exactly fair to compare these 2 earphones side by side but I just wanted to point out some similarities they have. They have some similarities in the tuning, and they both do the bass really well, although I have to give it to the KXXS as it is overall more controlled than the BLONs. You can check out my review for the KXXS for more information on that. But I somehow see the BLONs as a little brother to these, and for a fraction of the price, you can get an “expensive-sounding” tuning. The KXXS overall is like a more polished BLONs, with better detail retrieval and controlled bass. This is a real-life example of the law of diminishing marginal returns in the case of 2 superb earphones.

Conclusion (Overall Score: 8.5/10)

I think I have said too many times throughout this review that these are “excellent at its price bracket” but I can’t emphasize this any less. These are excellent regardless and I am duly impressed. These have very pleasing timbre and immersive imaging. It also has a non-fatiguing sound signature, so much that I can sit and listen to these at my desk for hours on end. This is not to say this set is flawless. It may have too much of a good thing sometimes, with its boosted bass, it may overly skew the presentation of music on some tracks and not all may be a fan of the copious bass.

Overall Grade: B+


Click HERE for our grading list for earphones

Leave a Comment

Your email address will not be published. Required fields are marked *