The less-prominent brand BLON, a sibling to BOSSHiFi, has blown the market by surprise with this initially obscure pair of earphones, and their high demand has caught my attention.
Despite having a single dynamic driver, the BL-03 exceeded all of my expectations. I'll even say that the single-dynamic-driver budget earphones formula has been revived by these metal gems, finally. They can easily compete head-to-head with the classic TinAudio T2 (which had a second driver and were more expensive), and the less popular (but highly appraised, and more expensive) single-driver LKER i8 when it comes to sound quality. With a substantially smaller price tag, we finally have a fresh king in the dynamic-driver-only category, when considering raw sound quality alone.
Although the form factor ain't my cup of tea, there's no doubt that these earphones are built like a tank. Their durability is unquestionable. The cable is somewhat similar to TRN's braided cables, but the ear-loops are way stiffer, which makes the cable less managable when tangled and could also make it more difficult to keep the earphones in place during usage because of the higher tension strength.
The included ear tips don't look too impressive, but they actually worked quite well with these specific earphones, especially the L-size ones.
All taken into perspective, if you're ready to the possibility that some ear tip experimenting might be needed, this pair of earphones can trully fulfil all of your listening requirements, but only if you're not planning to use them mainly for electronic music, as the bass on these isn't exactly suitable for heavy bass content. But in short, highly recommended. Well done, BLON.
P.S. If you're looking for something that sounds more universal and is more comfortable to wear, check my impressions of TRN V90.
How easily you can achieve a perfect seal can vary heavily, depending on the size and shape of your ears, given the unusual shape of the housings, which probably could be more appropriate for cable-straight-down style of wear. Unless a perfect seal is achieved, the ear pieces could sometimes be pulled out slightly by the heavy tension of the pre-shaped ear-loops (which are stiffer than usual). Having stiffer ear-loops also means that the cable is much more prone to tangling in a way that untangling was harder than usual for me. I usually have to use L-size tips only when using earphones with narrow nozzles, but this one is the exception: I had to use the pre-included L-size tips to acheive the desirable seal.
Lows / Bass
The bass on these is perfect for those who prefer their bass warm but not heavy. Especially suitable for enjoying vocals to their fullest, but not exactly powerful enough to drive bouncy bass-heavy content, like EDM, dubstep, trap. Generally speaking, the bass is full-bodied (when the seal is proper), warm and fuzzy, and never overbearing. It is clean and I couldn't get it to distort at any point. With all that being said, the bass is heavily affected by the quality of seal you manage to achieve, and I find it to be a bit of a hassle.
Mids / Vocals
The highlight of these earphones are the mids. Despite being relatively upfront and "in your face", they are not too prone to sibilance and don't feel too intrusive, as long as you keep the sound balanced by maintaining a proper seal. The crispness and level of detail is definitely astonishing for a pair of single-dynamic-driver earphones. What's most important is that these mids are very precise and clean of any metallic coloring that can sometimes be noticed with BA-driven earphones, which is a huge plus to those who don't like how BAs tend to sound.
Highs / Treble
As long as you maintain a proper seal, the highs are crisp and full of detail, and don't get in your way of enjoing your music without fatigue. This is, in fact, a surprising performance, and it is very unusual for dynamic drivers to reproduce such an extended upper frequency range. Once your seal gets loosened, you'll start hearing some pierce originating from the 10kHz peak, given that your hearing is sensitive enough, so try to maintain as good seal as possible.
Normal seal (with pre-included silicone ear tips):