The Sirius has a well-balanced signature with a mid-centric focus. A hint of warmth that adds an emotional touch to the music, without overdoing it. The instrument positioning is slightly close to the listener, with the vocals placed a bit further behind. Because of the proximal front line positioning spanning along the width, the stage has a bit of a ‘front row’ effect where you’re close to the music. The instrument size is well proportioned within the stage; neither thick nor thin – just exactly right, which gives a nice sense of spaciousness. The stage is wide and has good height, creating an overall large screen. In my initial impressions with the Cowon Plenue S I found that the Sirius lacked some depth, but this is source dependent as the Lotoo Paw Gold provides more depth and air, at the cost of some of its width. On the other hand, the Sirius’ tonality comes across as more natural with the warmer Plenue S, mainly due to a more prominent and brighter upper midrange with the Paw Gold.
The bass is fairly neutral, with a slight emphasis on mid- over sub-bass and an overall warm tone. The sub-bass is a pure delight. I spend most of my time listening to multi-BA drivers, so the gorgeous ‘thump’ of a dynamic driver is refreshing. That texture and decay; it’s with good reason people say a BA can never deliver that same type of quality. Kick drums sound magnificent, very realistic due to that decay. Not to mention bassy electronic music – possibly with the bass amped up a bit. I believe the proper audiophile terminology for this would be ‘awesome’. The mid-bass is well-controlled, although there is a tradeoff for speed compared to faster BA drivers. Overall the bass is punchy, textured with a natural decay, and I rate it highly.
The Sirius has a beautiful and sweet midrange, alongside the nicely textured bass. Slightly forward, but mostly balanced and refined, a tuning I liked from the go. The midrange is warm and smooth, with a natural timbre for vocals and instruments. In accordance with its mid-bass it has a slight lower midrange fill, giving the Sirius the right amount of note thickness without overdoing it. The midrange emphasis is on the upper midrange; guitars have good bite and vocals are clearly articulated, though not as deep or dense as a truly midforward iem as the S-EM6 or Zeus-XIV that have an emphasis on the center midrange. This gives the Sirius an excellent sense of balance, as vocals are neither particularly forward nor distant. The upper midrange peak is followed by a dip around 4-5 khz which adds some fullness to the presentation, adding to the overall smoothness rather than artificially brightening the midrange. Its midrange resolution is good within its price tier.
The treble takes a slight step back in the presentation, giving the Sirius a smooth and more mid-centric signature. A lower treble dip is followed by a peak around 7 kHz; a common tuning in many iems. It’s a necessity to add some clarity, especially in a mid-centric signature that might get too stuffy otherwise (we’ve seen this recently in the Primacy). The peak gives an iem a more ‘hi-fi’ sound, although there is a tradeoff for tonal naturalness at higher volumes. With a treble rolloff around 10 KHz, the Sirius performs according to the iem average. The treble is foremost smooth and non-fatiguing, and tends to stay on the safe side of sibilance. Overall, I’m a bigger fan of the bass and midrange; the treble is there doing its thing, but lacks that final bit of precision. This isn’t a treble that will bother anyone, but it doesn’t excite me much either.