Symphonium Helios Impressions
It’s becoming increasingly rare that I get excited about an IEM these days, but this is one I’ve been eager to hear - enough that I probably refreshed the DHL tracking about a hundred times throughout the day waiting for it to arrive yesterday! (And yes, DHL conveniently decided to deliver at nearly 8PM which is why these impressions are going up today). But I digress. I think it’s only proper that I lend some context about Symphonium, a brand that most readers have probably never heard of before. Symphonium is a small Singaporean brand, and the Helios is their 4BA flagship IEM. Yup, you heard me right. A humble four BA drivers, and it’s very reasonably priced at $1100 too.
In the interest of transparency, the Helios was also developed with consulting from Subtonic. Subtonic is an upcoming Singaporean audio brand; a partnership between several audio enthusiasts that includes @toranku of Head-Fi fame. I regularly converse with Toranku and would consider him a good friend and someone who inspired my style of reviewing.
I had already seen the graph of the Helios, and it wasn’t ever really a question of whether the Helios was going to be well-tuned given the individuals at the helm. Nonetheless, this can be considered neutral with bass boost; I’ll also give a quick run-through of the overall tonality as well as some possible weaknesses.
The first thing that strikes me about the Helios is its bass performance. I praised the 64A U6t for its BA bass not too long ago, but the Helios is just as much a winner in the BA bass department. This is partly due to its tuning which is concentrated almost solely in the sub-bass regions, therefore emphasizing a high degree of cleanliness. But the Helios is no less a slouch in the intangible department either. It actually slams, so much so that I wouldn’t mind putting it up there with my beloved 64A U12t. I still don’t find it quite as “organic” - the Helios’ bass texture leans more dry than the U6t and U12t, perhaps due to a lack of mid-bass - but the Helios sets the standard at a kilobuck for BA bass. Yes, I think prefer it to the Sony IER-M9’s bass (certainly at least tonally) from memory.
The midrange of the Helios continues to follow the Harman target closely throughout the lower-midrange. Despite the more gentle approach taken to the pinna compensation and the upper-midrange, then, the Helios’ note weight definitely skews slightly thin to my ears. Is this bad? Not at all, but this is where tonal preference will divide some listeners on the Helios’ tuning. Personally, I think it could use with some more warmth. I also want to say that the Helios is almost too clean for its own good here. While I don’t hear any exaggerated instances of sibilance on my usual test tracks like Girls Generation’s “Flyers” at 0:46, transients seem to have a slight edge to them that makes even very small instances of sibilance, such as on Loona’s “Voice” at 0:25 to 0:30, pop more than I’m used to. This is especially apparent when listening with the Azla Sedna tips.
My only real complaint with the tonality of the Helios would be its treble. It’s something of a double-edged sword. I cannot deny that it is wonderfully extended and mostly smooth without any egregious dips or valleys in sine sweeps. But here’s the not-so-favorable side of that sword: the treble of the Helios teeters on abrasive to my ears. I have to imagine that this abrasiveness is partly baked into excess air as, again, swapping off the Azla Sednas for the Symphonium tips mostly fixes this issue. But either way, the timbre of the Helios’s treble seems somewhat distinct from the bass response which is surprising given that this is an all-BA IEM. This applies to the midrange to a lesser extent. At times, I could even mistake the Helios for sounding more like a hybrid than it does a BA IEM.
You might see where I’m going; the Helios doesn’t sound as coherent as I’d like. As with IEMs like the Thieaudio Monarch and the Moondrop Variations, this feeling is ostensibly attributable, at least partly, to the tuning. From the Helios’ razor sharp bass shelf, slight dip to the lower-midrange, and to its excellent treble extension, it all culminates in a more segmented if not clean presentation. I have to admit that my critiques of the Helios are, to some extent, because it’s actually too damn good in one department or another. The midrange is too resolving, bringing out micro-detail I don’t want, the treble has too much air resulting in slight harshness, and the timbral inconsistency is partially because the bass is so good for a BA. I’d say these are some of the better problems to have. Your average listener probably wouldn’t pick up on the coherency issues, and the excess treble air would likely be a boon for most listeners.
It doesn’t hurt that the Helios has a strong technical foundation with little to no weaknesses in the departments I usually index for. Detail is good. I hear that faint ring to the backdrop of Taeyeon’s “I Found You” which usually only presents itself to me on my speakers. Imaging is slightly out-of-head and the Helios’s layering chops are excellent. While not as holographic as the Andro 2020, the Helios edges out the Andro 2020 in terms of positional incisiveness in A/B. And as much has I like to complain about dynamics, the Helios is certainly not compressed for macro-dynamic contrast. Transients also lean fast, and I find myself glued to BoA’s Deluxe album. Honestly? I’m hard-pressed to ask for more on the front of technicalities. You (or at least certainly I ) wouldn’t know this IEM toted a mere 4BAs if it wasn’t in the product literature.
The million dollar question is whether the Helios is top-tier material. To be blunt…nah. Not quite. It lacks that last leg of refinement, perhaps special sauce, that would place it at the top amongst greats like the 64A U12t, Empire Ears Odin, and Elysian Annihilator. But for the price of a little more than a grand, I have zero qualms giving this my stamp of approval. At least on the basis of sound quality, as the shells of the Helios are comfortable but quite large and stick out more than I’d like. But I digress. Symphonium has released a highly competitive IEM for its respective price bracket, one that is definitely worthy of kilobuck gatekeeper status in my eyes. And as far as the bias scale goes, I think the score will speak for itself.
Score: 8/10
All critical listening was done off of the 2.5mm jack of my iBasso DX300 with the stock cable and the stock tips. I found the included Azla Sednas to be a tad strident for my preferences, so I swapped to the other included Symphonium tips.