I own both the Andromeda and the Xelento. I flip-flop on which one I prefer, recently using the xelento more often. To be honest, both are excellent. Really more just a personal preference on sound signature than anything else. Technical performance in detail retrieval, speed, dynamics, imaging, and sound stage all solid. The Andromeda definitely does win in terms of absolute width of sound stage, but everything else is very competitive. The major sound signature differences is simply the xelento has weightier bass while the andromeda has an airier and lighter presentation in relative comparison against each other. They actually both have excellent tight and solid bass and articulate smooth treble. The andromeda's bass is not as visceral but still does have great sub-bass extension. The Xelento has deep sub-bass extension with more weight to its bass notes and a bit of extra punchiness in the midbass compared to the Andromeda. Neither headphone sounds "full" in the sense that neither has an upper bass or lower midrange boost. The Xelento's sound signature is "relatively fuller" than the Andromeda. Neither of these headphone really sounds "intimate" or "lush" or "rich" in the sense that Audeze headphones or some more "tuned-by-ear-type" JH or Noble IEMs sound. They are both more of the analytical and/or clinical and/or neutral-orientated sound signature, but can be "warm" if the source material calls for it. That is actually a great strength of both these IEMs, the lower frequencies do not get in the way of the other frequencies, but can reach deep and hit hard if called for. In relative comparison, the Xelento is more intimate and laid-back than the Andromeda, but the Xelento is not likely to be described that way when compared to most other IEMs (besides IEMs more treble-centric than the Andromeda). Regarding treble response, the differences in the regions of emphasis between the two IEMs lead to distinctive flavors of their presentation. The Andromeda has a bit more energetic, sharper, airy treble with more upper treble emphasis. The Andromeda has more bite, edgier sound, and is more prone to sibilance and/or piericingness. However, the Andromeda's treble generally strikes the right balance and I've only noticed treble issues a few times. On the other hand, the xelento has a smoother sounding treble while still providing a good sense of crispness and definition. The xelento never loses that clean edge to notes and picks up the micro-detail, but does not get as piercing or as sharp as the andromeda, so I can see some perceived dullness in the xelento's treble response in direct relative comparison to the andromeda. The xelento is also not as airy as the andromeda as the andromeda has a bit of extra emphasis in that highest registrar. The xelento does have overall good treble extension and nice sense of air to wind instruments. If listening critically, there were a few tracks where I picked up sound signature issues with the Andromedas regarding its treble presentation being a bit unnatural or slightly too glaring/sibilant, whereas the Xelento is more forgiving. They kind of straddle what is acceptable for me, the Andromeda's treble tuning is as sharp and piercing as I feel like I would want without being too excessive, while the Xelento's treble tuning is as smooth as I feel like it can be without losing out on the crispness and well-defined edge to notes. I feel like the Andromeda is for those who don't mind pushing the boundary with their treble tuning and would prefer to have that extra bite or last breath of air to their notes, while the Xelento are for those who want great articulate treble detail but also has the philosophy of "do no harm" aka "do not want piercing treble or sibilance unless obviously present in the source material." If picking between these two IEMs, I think first question is: if relatively neutral-orientated sound signature, what would make you happier: "weightier bass" vs "airier treble"? Second question is: would you prefer the songs with "too dull" treble presentation to be a bit more edgy and high energy (aka Andromeda) or would you prefer the "too sharp" treble presentation of certain songs to be smoother (aka Xelento)? To me, the sound stage difference isn't that significant of a factor after owning both IEMs for a few months. I do think that HD800/HD800S fans would naturally lean more towards the Andromeda as I see many many similarities between those two headphones. It is harder for me to come up with a flagship open IEM analog to the Xelento. The Xelento does remind me quite a bit of the HE-1K with that overall smoothness and weighty bass presentation, but I no longer have those headphones on hand for direct comparisons. The xelento's weighty bass is not like Audeze bass where the sound signature turns a bit darker and/or rich. There are some similarities with the Xelento and the Utopia, more than the Andromeda with the Utopia (primarily due to the Utopia's weightier bass and 'relatively smaller sound stage' when compared to other flagship open, while the Andromeda definitely can be considered "TOTL even among flagships" sound stage like the HD800, though some do consider this type of sound stage to be a bit unnaturally wide). Definitely interesting to run various random comparison between different gear to see what types of attributes really standout in relative comparison. Some other non-sonic but very important points I've found with these headphones after living with them extensively to keep in mind. The Andromeda's fit is extremely user-dependent, may not be comfortable, need to play around with different earbuds if having fit issues, best way to resolve fit issues is to have large earbuds that keep the housing off your inner ear. The Andromeda is a picky with source, sound signature can vary quite a bit. The Andromeda is very sensitive, will hiss if not at the right output impedance. The Xelento's are extremely comfortable in terms of fit, housing will sit flush so you can lie on your side while wearing these IEMs with minimal discomfort. Xelento sound signature relatively stable with different output impedance as dynamic driver. This post got longer than I was planning. Hopefully helpful for those interested in this type of direct comparison with multiple other reference points. If wanting more direct comparison thoughts, here were my initial impressions after doing my first direct head-to-head testing: https://www.head-fi.org/threads/xelento-vs-andromeda-vega.868177/#post-13932872 The Andromeda does have a larger sound stage than the Xelento. Most noticeable is that Andromeda has a wider L to R separation in direct side-by-side comparison to the Xelento. basically, the andromeda has an oval soundstage with longest diameter going left-to-right, while the xelento's soundstage is a sphere with its diameter comparable to the andromeda in all the other directions except for left-to-right. Sidenote: to me, I don't personally think the difference in sound stage between those two IEMs is really that significant. Comparing the sound stage of the Hifiman re-400 vs noble velvet OR 1more tripledriver vs 1more quaddriver sounds to be a much more dramatic and larger degree of difference to my ears. I think this is because once you reach a certain degree of quality and if the headphones have relatively similar tuning goal, the perceptible differences in sound stage is not as glaring. And after saying that, the differences in sound stage when just comparing high-end IEMs is nothing like the variation you can get with comparing high-end over-ear headphones. The HD800S vs the Utopia actually have a really significant and audible difference in sound stage, which always makes me laugh a bit when someone raves about the Utopia's sound stage. All about relative comparison points I guess. Neither the Andromeda or the Xelento match the HD800S in terms of sound stage. I would say the relative difference in sound stage is smaller than the differences when comparing the AKG Q701 vs the AKG K7xx, but the degree of difference is in that range. The sound stage difference is definitely not has dramatic as the HD800S vs another open flagships. Even the difference between the HD800S vs Focal Utopia sound stage is dramatically larger in scale than the Andromeda vs the Xelento. The Andromeda does have that similar effect as the HD800S where it has a wider left-to-right field that makes you feel like the soundstage is more oval than circular. The Xelento do have really good treble detail and brightness is comparable to the Andromeda. I would say the Andromeda is "brighter." The different points of emphasis in the treble region between the Xelento and the Andromeda do give them distinct flavors. While I would categorize both IEMs as neutral-orientated tuning with very good balance throughout all frequency ranges and no overt emphasis in a specific region, I do personally feel like both the Andromeda and the Xelento have a subtle v-shape to their sound signature with the Andromeda leans a bit more on the upper treble while the Xelento leans a bit more towards the lower frequencies. Not so much that the mids are recessed, but just the way that both headphones extend far into the sub-bass and upper-treble regions. Regarding the Xelento's sound stage, easily better than the rest of my 'favorite per price point' IEMs at various categories, but I have not done direct comparisons against other flagship IEMs besides the Andromeda. Will likely get a chance next month. Yes, the Andromeda is relatively "smooth" but it depends on your comparison points. Against other high-energy treble IEMs, the Andromeda are definitely very smooth. However, the Andromeda definitely have a few peaks in the upper treble region, one particularly glaring one to my ears is at around the 9kHz region. You can definitely can feel like almost getting too piercing on certain tracks and I've definitely gotten sibilance and unnatural glare from the Andromeda on certain tracks. Usually not an issue, and often more related to the source material than anything else.