I don't know much BLON, but my first impression of their motto that is "Belief - Let music burn - Oppoty - Never give up" when buying the BL-03 made me think whether they are joking or their English is that bad (No offense by the way, but still). Needless to say, the BL-03 was also one of the hype in the chifi community around the end of summer 2019 and due to how frequently people have been talking about it, it has definitely got my attention.

Before going into the post, if you are new, please read this before having any comments regarding my writing or point of view


  • Price: 40$
  • Drivers: 1 DD

This unit was purchased from Linsoul. The review will use the microphone version of the earphone.

Note: At the time I am writing this, there has been multiple reports of the BL-03 sample variance, I am aware of this and also did find another sample but I will still use the earphone I purchased for this review.

Build and Accessories:

The BLON BL-03 packaging
  • 3 pairs of round-shaped silicon tips (S/M/L)
  • 2 pairs of cone-shaped silicon tips
  • Soft pouch
  • Unbalanced 3.5mm 2-pin cable
  • The IEM itself

Right off the bat, the cable of the BLON BL-03 is the worst item of the package, it doesn't have good texture and the whole cable looks like someone just used some cheap plastic and turned it into an IEM cable - In short, it is cheaply made. The pouch on the other hand, is one of my favorite of the whole package: It is soft and nice to touch, and I find myself using it a lot although I didn't use it to store the IEM as a hard pouch is more to my liking.

The BL-03 build is metal and has a strange droplet-like shape, some also can say it is literally an IEM in earbud shape. Surprisingly, despite complaints about the fit, the BLON BL-03 with the cone-shaped tips seals well in my ear out of the box and I find myself comfortably wearing it for a long period of time. However, I asked my friend to try the BL-03 and he found himself rearranging the IEM every 15 minutes until he decided to do some tip rolling. The problem about the BL-03 fit has also been pointed out by multiple reviewers so take my caution about the fit more than any other IEMs as it seem to be the biggest issue for a lot of people.


Measurement and Signature:

BLON BL-03 frequency response - Sample 1
BLON BL-03 frequency response - Sample 2

Measurements are done on a steel coupler with dynamic microphone, while the result seem to be close to an IEC-711 coupler, there is noticeable roll off in the bass region and frequencies higher than 2kHz is also expected to have 2 - 3dB roll off.

My measurements are also raw and uncompensated, hence flat in graph is not flat in real life.

The BL-03 features a V-shaped sound signature that can be seen from the elevated bass and upper mid-range/treble. At this time of my writing, there are 2 versions of the BL-03 that exists, one has a V-shaped sound signature, the other is more of a U-shaped one. Of course, this measurement isn't from a IEC-711 coupler and 2 sample is a joke by itself but I think both Crinacle and Antdroid measurements can proof what I am saying here.

The bass of the BL-03 smear a little bit into the mid-range which makes it slightly warm. Frequencies started to raise upon reaching 1kHz and then peak at about 2.1kHz. There is a peak at about 9kHz as well but this might be due to insertion of the IEM into the coupler.

Subjective opinion:

Some people have told me that the BL-03 has a "relaxed" sound and I can agree with them to some extent. Bass has rumble and is also boomy, the mid-bass can be a little bit bloat to some people but honestly, I don't really mind. The mid on the BL-03 is a little bit laid back and throughout my listening experience, there is no indication that the earphone is outright aggressive even with dense genre such as Speedcore. Its tuning in my opinion can be called "inoffensive" and can rival other earphones that are worth 100-200$.

That being said, while the tuning of the BL-03 is something I can appreciate, there is still some problem with it: For some people, it can be the mid-bass bloat like what I said above but to me, it is actually the treble. While the BLON BL-03 is not a dark IEM, its treble is somewhat dull which makes plucked string instruments lose a bit of their edge. It also sounds a little bit congested due to its long dull, mushy attack. The BL-03 struggle to shine on music genres like Instrumental, Orchestra and even on busy tracks as well.


Although my experience with the BLON BL-03 was a little bit underwhelming, because of the price tag that is 40$, the BLON BL-03 received my solid recommendation due to its tuning. Despite its technical flaws, it can work well with a lot of mainstream genres like Pop, EDM,... and for people who are on a budget, that is already fine.