Today, I’m reviewing the BLON BL03 II IEMs. The BL03 II is the second-generation version of the extremely popular BL03 from several years ago. It features an upgraded 10mm dual-chamber dynamic driver and is priced at 32 USD.
Disclaimer: This sample was provided by Linsoul in exchange for an honest review. All observations and opinions here are my own, based on my experience with the product.
BLON BL03 II
Specifications
Frequency Response: 20Hz – 20kHz
Sensitivity: 116dB
Impedance: 32Ω
Connector: 0.78mm/2-Pin
Cable Length: 1.2m Silver-Plated Cable
Driver Unit: 10mm Dual-Chamber Dynamic Driver
In the Box
- BLON BL03 II IEMs
- Detachable 0.78mm 2-pin cable
- 6x pairs of silicone eartips
- Canvas carry pouch

Design
The BLON BL03 II boasts the same shell shape as the original model but it’s now made from a precision-molded zinc alloy. The new material has a matte black finish and feels more premium in the hand compared to the old polished aluminium model. Moreover, the new shells are resistant to fingerprints and scratches.
The BLON BL-03’s iconic design and commercial success understandably make its shell a desirable choice for subsequent models. However, the original faced criticism regarding its short nozzles and potentially problematic fit. Disappointingly, these issues remain unaddressed, meaning comfort may still be a concern for some users. Personally, I found two effective solutions: replacing the stock cable, whose pre-formed ear hooks tended to rotate the IEMs and disrupt the fit, and switching to my Penon Liqueur (XL) eartips. These modifications resolved the fit issues for me but your mileage may vary.

Sound
Gear used for testing includes the FiiO KA17, iBasso DX180 and SMSL RAW-DAC1. The BL03 II is an efficient IEM and doesn’t have any special power requirements, so you can use it with any audio source.
The BLON BL03 II has a balanced sound signature with a fairly even spread between the bass, midrange and treble. There’s a focus on the midrange and vocals which are presented slightly forward in the mix. This is a very different beast compared to the original BL03 but I’ll cover that in a later section.

Bass
The BLON BL03 II presents a bass response that’s subtly elevated above neutral, offering a satisfying low-end presence without becoming overwhelming. It’s a well-controlled bass that exhibits a decent amount of texture; this means it reproduces the subtle variations and nuances within the bass frequencies, preventing it from sounding like a single, droning note or a blurred mess.
The bass is evenly distributed between sub-bass and mid-bass, providing a balanced mix that’s neither too forward nor hollow. While the BL03 II can generate enjoyable rumble, it stops short of basshead levels. The mid-bass strikes a good balance between tightness and weight, combining control with engaging impact. This bass tuning leaves ample space for the midrange to breathe, ensuring clarity and preventing any unwanted masking.
Midrange
The midrange of the BLON BL-03 II presents a mostly neutral tone and note weight. Vocals and midrange instruments are reasonably forward, ensuring they don’t get lost in the mix. The midrange is fairly spacious, avoiding any sense of congestion or crowding.
Clarity is good, allowing individual instruments and vocal nuances to shine through. Overall, the BL03 II offers a pretty impressive tonal quality in the midrange, especially considering its budget-friendly price point.
Treble
The treble tuning is interesting here and it seems like it’s been catered to counter criticisms about the original BL03 and its soundstage dimensions. The lower treble is lifted to add some vibrance and presence to vocals before it starts tapering off. Then, there’s a peak in the upper treble at around 12-13kHz to preserve and heighten the upper harmonics and air.
The BL03 II increases its soundstage dimensions and detail retrieval with the improved treble extension. Thankfully, it does so without introducing sharpness or sibilance to the presentation. However, this ‘enhanced’ treble performance may come at the cost of the original’s naturalness.
Soundstage & Technicalities
BL03 II presents its sound in an average-sized soundstage. It’s wider than the original model’s stage (which I’m sure is exactly what the engineers were going for) and also has a good sense of depth. The detail retrieval is good and the BL03 II can pick up some of the micro-details that other IEMs miss. Instrument separation is good but it deteriorates during complex passages and as a result, the overall resolution is fairly ordinary.
Comparisons
BLON BL03

Ah, the original BLON BL03—the IEM that catapulted BLON into the hearts (and ears) of budget audio enthusiasts worldwide. Its shiny, polished shells are surprisingly resilient, resisting fingerprints and scratches remarkably well. Mine still looks—and sounds—fantastic after five years of use.
The BL03 shares a similar bass curve with its successor, the BL03 II, but with a touch less (approximately 2dB) quantity. The BL03 II edges out the original in sub-bass extension, providing a deeper rumble.
In the midrange, the core presentation is similar, but the original BL03 is slightly more restrained in the upper mids and lower treble. This difference results in a less pronounced V-shaped sound signature compared to the BL03 II. The BL03 presents a more forward midrange, while the BL03 II emphasizes the upper mids, giving vocals a touch more presence and clarity.
The contrast in the upper frequencies leads to distinct differences in the treble. The BL03 II delivers a brighter and more detailed presentation, but at the cost of potential harshness or sibilance, particularly with already bright recordings. The original BL03 offers a smoother, more forgiving treble, though it sacrifices some airiness and micro-detail retrieval.
Overall, the original BL03 offers a more balanced and cohesive sound signature, prioritizing a natural midrange and a less emphasized treble. This results in a relaxed and easy-going listening experience, though it might not be as exciting or detail-oriented as the BL03 II, depending on individual preferences.

Verdict
The BLON BL03 II has some significant improvements compared to the original model. It has better sub-bass extension, vocal clarity and detail. Furthermore, the new shell material looks and feels classy and the stock cable is objectively better (though I’m not a fan).
On its own, the BL03 II is on par with other current IEMs in its price range, even if it doesn’t stand out from the crowd. It has better technicalities compared to the original BL03 but the original’s charm is still compelling. I’m grateful to have both and I’m grateful to see BLON is still delivering quality IEMs for us to enjoy.