Thanks @Eke for your ASG-2 loaner, here are my (very brief) impressions:
I've had these IEMs for about a week now, but sadly found only time to listen to them for about 15 hours. I used a SGS3 and a Fiio X3 as sources with very similar results.
Bass: As many have said before, these are potential bass monsters. Only once did I try to open the ports a bit (very carefully so, 'cause the screws on this unit look already worn out), but quickly returned to the minimum setting. Even with closed ports, mid-bass is slightly too much for my taste and ever-present, at least in quiet surroundings. Outside, on the go, bass tends to get partially masked by ambient noise and I feel the minimum setting is pretty well-suited for that. While bass quantity is a bit much, its quality is actually very good, with fast transients and nice texture, I just wished there was more emphasis on deep bass and less so on mid/upper bass. From what I've been gathering, there's already a product update in the works to optimize the bass tuning in that regard.
Mids: These are the star of the show in my book, very clear, detailed and refined. Granted, there's a little bit too much warmth from excessive mid/upper bass, but it doesn't get problematic unless I pump up the volume well beyond my usual loudness level. There's a pleasant natural feel about how vocals are rendered which I rarely get with BA-based phones, maybe because of the "special" type of BA used (that Eke mentioned in his review), or due to the BA and DD drivers working in unison, idk. Anyway, I'd go out on a limb and say these are among the most likeable mids I've heard, at least for most part of the frequency range.
Highs: Speaking of which, transition from upper mids into highs is where things get much less enjoyable, because that's where the phones pull back with a vengeance. While even high female soprano vocals still show enough presence, cymbals suddenly appear ruthlessly smothered and lifeless to these aging ears. Perhaps presbycusis plays a role in that perception, and I'm known to like it lively "up there", but suffice to say I was instantly reminded of how Tyll wondered whether the tweeters were even working on these. That said, they (the tweeters) are indeed ok, 'cause amazingly enough the ASG-2s have pretty good air on top, which shows that they regain presence higher up in the treble range. When I say amazingly, it's because every other phone I've heard so far that rendered cymbals so politely (think SE530, SM3) continued to roll off higher up and as a consequence lacked air on top.
Bottom line: these are definitely stage monitors imo, and they make no secret of it. At that, I'd think they're pretty competent, since their midrange has excellent presence and quality. Bass is tight and nicely textured and offers more than sufficient punch in reserve to counter the masking effect in noisy surroundings, while highs are decidedly pulled back to minimize the risk of long-term listening fatigue.
However, since I'm no stage performer and prefer a less specialist sound signature, I must confess the ASG-2s are not quite my cup of tea. Don't get me wrong, I think these phones are very good on a technical level, and shotgunshane's EQ settings bring them much closer to a balanced sound signature, but strictly judging them from a home listener's point of view and from a flat source, these aren't quite at eye level with something like the 1plus2 in my book.
Nevertheless, they definitely sound "analogue" enough to pass them on to Gintaras with a clear conscience, so that's what I'm going to do tomorrow.
