Erebus is a way-under-the-radar (in the West at least) TOTL IEM, with an overall performance paralleling or besting many other legends such as Traillii and more. Here are some of my impressions about this fantastic IEM, excerpted from my Head-Fi review of Erebus:
It has a premium build. The Erebus shell feels like a small piece of polished marble. The plate design is not super attractive, and I never would have chosen this on looks alone. Erebus has a more comfortable than any other IEM I have tried except Fei Wan. I could have Erebus in all day and barely notice.
Erebus has a relatively relaxed sound, but it has some verve, scales extremely well, works with just about any type of music, for any mood I brought to it.
It features a largely uncolored, very slightly warm, reference-ish sound (its bass strength and upper mids energy keep it from being what I imagine truly reference style to be).
At first it does not sound really special, rather just very good, but with more extended listening, the full scope of how impressive and top-shelf Erebus is becomes clear.
Erebus features a balanced W shaped sound. All parts of the FR are distinct and still coherent, unlike some other W shaped IEMs like Rn6 that to me sounded slightly less coherent.
Erebus’ sub bass has punch and snap, and is articulate and tactile.
There is a medium amount of mid bass that comes up to lower mids just enough to bring them a bit forward and add depth and a little warmth. No muddiness across the spectrum.
Erebus’ mids provide just the right amount for vocals and acoustic instruments to assert their space well and not be left behind, as can be the case with Loki in particular. Erebus’ mids are neutral-ish but still have excellent texture. To go beyond the set of four in these impressions, and going from memory, I find Erebus' mids not to be as warm and romantic as Trailli's. I find its mids however to be as detailed and similar-charactered as Mentor's.
The upper mids can be energetic at times, though not peaky and generally not fatiguing. This quality lends urgency to many vocals, which 90% of the time is welcome. Still, I would prefer it was dialed down. At points the danger zone is approached, but never fully entered into thankfully.
Erebus has fantastic treble, not dry but rather neutral to slightly sweet, loads of air with just the right sparkle, softened crispness, medium extension, zero sibilance, not at all fatiguing. Very close to Annihilator 23’s class-leading treble, I would say 95% of it, just lacking a very slight bit of the superior transient snap that Anni possesses.
Erebus provides a largely neutral sound, slightly warm with minimal color. It presents music how was intended perhaps (as overused an expression as that is).
Superb technicals, right up there with the very best as an entire presentation.
Excellent layering and separation of instruments, better than the other three, in spite of their excellence. Superior imaging as well.
Compares to other staging class leaders like Fei Wan, Traillii, and Mentor, which has massive 360 holographic staging, more than Erebus.
Dynamics are solid but Fei Wan is a dynamics monster, and Erebus isn't quite at that level. It is on par with Anni and Loki's dynamics performance.
Excellent detailed transients, particularly acoustic and brass instruments. Overall top-shelf resolution, as well as speed and dynamics.
Maybe the best part of Erebus’ performance is with vocal-focused music. Up and down vocal ranges, it scales so well, so many Wow moments. All across the vocal spectrum, I hear excellence of pacing, timbre, intonation, detail.
Best music genres for Erebus: All of them! (or at least all the genres I listen to). Jazz and bass vocal sound superb. Classic rock, modern rock, pop, dance pop: all excellent. I suspect classical would sound terrific, though I don’t listen to it. Live music sounds fantastic, spacious, holographic, dynamic.
Erebus is a bit of a slow burn as far as recognizing its amazing qualities. After a handful of listening sessions of "this is good but not great" and allowing Erebus to burn in, it became very evident what a special IEM this is. Erebus rewards patience, but not too much is required.
I can find only a few flaws for my preferences. One would be the plate design, not a big deal for me but still it is not attractive. The lack of recessed 2-pin connector ports is not great. It is expensive at $4700US retail. The other nitpick is the energy in the upper mids, which if they were slightly reduced would make this the IEM I could quit the hobby with. Even still, it very well could be if that sad day were ever to come.
Hopefully more people will get to hear Erebus. It is first-rate and should be in the conversation when we all debate which are the TOTL of TOTLs in the IEM world.