Mell comes only in universal clear shell design, using a medical grade material from Germany. The shape of the shell is very compact, probably one of the smallest 10BA driver shells I have seen in a while. For 10BAs, the shell design ergonomics is excellent, and it has a very comfortable fit. Thanks to a transparent thick wall of the shell, you can also appreciate the full and clear visibility of every driver, internal wiring, and crossover components.
The “Oriolus” marking on the inner side of the shell, above the serial number, is color coded with red on the Right side and blue on the Left side. Faceplate panel is made from a titanium alloy with an etched Oriolus name. While CIEM design option is not available, meaning that you can’t customize these, I still find Mell to have an elegant look and a very compact design. The only thing, nozzle is on a wider side (about 6.5mm), not an issue in my case since I got wide ear canal opening (and use the largest eartips), but it could be an issue for those with a narrow earcanal.
Inside the shell, there are 10 Balanced Armature drivers per side, a mix of Knowles and SONION BAs. What’s interesting, the design has a 3-way crossover, with 4 highs, 4 mids, and 2 lows, but the nozzle has 4 bores, 3 smaller ones and one large one. I can clearly see two BA pairs going to one bore opening, and other three BA pairs going to their individual bore openings. Regardless of how drivers are partitioned and connected to sound tubes going to bore openings in the nozzle, what counts the most is how the sound mixes together in your earcanal when it leaves the nozzle, and I will cover that in the next section of the review.
I analyzed Mell sound performance across different sources while playing a variety of test tracks, such as Agnes Obel “The curse”, Sandro Cavazza “So much better” (Avicii remix), C-Bool “Never go away”, Ed Sheeran “Shape of you”, Galantis “Hunter”, Iggy Azalea “Black widow”, Indila “Boite en argent”, Robin Schultz “Oh child”, David Elias “Vision of her”, and Michael Jackson “Dirty Diana”. Also, Mell went through about 100hrs of burn in before I started analyzing it, just playing tracks in the loop, though I didn’t notice any significant changes in sound.
Mell is a neutrally tuned IEM. But when i say “neutral”, I don’t mean neutral “flat” like, for example, UERR. Instead, it has more of neutral-balanced signature where nothing is overemphasized, and everything is perfectly balanced. Mell has a neutral signature with an even natural tonal balance of a transparent effortless layered sound across the entire spectrum. While you can hear a deeper sub-bass extension and maybe a little extra sparkle in treble, there is hardly any coloring of the sound, it’s very transparent and has an excellent retrieval of details even without a need to sound analytical.
Another very interesting observation is how coherent all the drivers sound. It feels like a continuous transitional flow from low end, through mids, and into treble. Certainly, a neutral signature without too much of extra emphasis on any parts of the FR helps in creating the coherency. But nevertheless, it does feel like one coherent driver.
The sound is well layered with a clear separation between the layers, where every instrument and vocals are easy to distinguish, nothing ever gets congested or veiled. And as I mentioned already, the sound is very transparent (not colored at all).
Soundstage has a large expansion, both width and depth, taking an oval shape with not too much of out of your head depth, but still with the sound having a little bit of holographic spacing. I don’t mean it like 3D holographic, but rather more like an oval shape holographic. With such expansion and sound layering, there are no issues with accuracy of the instruments and vocals positioning within a space. To my ears, the imaging is convincing and natural, the way how you would see/hear instruments with performers on stage.
In more details, bass has a pretty good sub-bass extension, goes deep with a nice textured rumble, not too much elevation, but you need to be sure to select a pair of eartips that gives you the best seal; this could make-or-break the bass extension here. Mid-bass has a nice punch, not overly aggressive, but also not exactly neutral-flat either. It’s not the fastest or the tighter mid-bass, has a more natural attack and decay, perhaps a little slower than other BAs but not quite as slow as dynamic drivers. Overall bass is well controlled, layered, natural, having a performance somewhere between BA and DD.
Mids are neutral, especially in lower mids where you shouldn’t expect a thicker or a leaner body, and I think that’s also contributes to coherency of tuning and how smoothly bass transitions into mids without any extreme separation. Upper mids are neutral, natural, but still very detailed. In many cases, a combination of neutral and natural can smooth the sound too much, making it more laid back, taking away some clarity. Here you have a combination with a balance of many different peaks in upper mids and lower treble (2k, 3.5k, 12k, even a little 7k bump) when you sweep the FR, also confirmed when I measured with Veritas. The mix of all these peaks yields a smooth natural tonality with an excellent retrieval of details.
Treble is well controlled while still maintaining a natural clarity and sparkle, thanks to a balance between small bump around 7k and peak around 12k. Treble does sound natural to my ears. I think what’s important here is not only the frequency, but also the quantity of the peaks, creating a more balanced tonality when tuned properly. Also, the airiness is OK, but the treble doesn’t extend too far and starts to roll off after 12k, which adds more to a natural tonality of this IEM.