Here are some of my general impressions from the day. Fortunately, I took a bunch of notes as I listened. Unfortunately, I forgot to take a single damn picture of the gear I auditioned.
Subtonic Storm
To start, I heard these as close to IEM neutral. In other words, lifted sub-bass, but otherwise following a similar curve to the Harman target for over-ears. I find this low-end lift helps increase the heft that would otherwise be lacking from such physical small drivers, especially BAs. That said, the vocals are rendered a little bit lower in the mix, giving these a slight v-shape to the sound signature. The bass I found to have a bit too much emphasis for my taste, but I tend to prefer ruler-flat planar-style bass, so that's not a fault with the earphones. Likewise, in comparison to my own ears' reference, these had a certain roundness to the bass because of the sub-bass rumble and more extended upper bass. In the upper mids/lower treble region, I found that guitars were nicey bitey, and only occasionally too aggressive. Treble was extended and even, but slightly too tame for me. Still, treble had no flaws. Technicals were a bit of a mixed bag. The dynamic range was excellent, giving notes an intense feel to them without being overly done. No fatigue, just energy. The soundstage, while great for an IEM, still left something to be desired compared to headphones. However, I feel like even decent soundstage in an IEM is a feat and appreciated the effort. Layering was excellent, but I found these still suffered from what I, perhaps wrongly, call crossover effect. In other words, when it comes to sounds divided by the crossovers between different clusters of drivers, the layering is very clear and instruments stand quite separate from each other. However, when the sound is such that individual driver clusters have to resolve that detail, they cannot render those details quite as cleanly. This creates a little bit of incoherence in the sound as the resolution seems to vary depending on the music. Not a big deal, and something I've noticed in many IEMs. Anyway, individual resolution was very good. On my "Hey" test, it scored 85%. Overall, these are outstanding IEMs, the best I've yet heard. But, they aren't my favorite and ones that I can, thankfully, live without.
Thieaudio Monarch MkII
These were decidedly a step down in technical ability, but I actually liked the tuning of these the best. Very coherent and slight v sound that suits all-round listening quite well. They had round, boomy bass, but it was pleasant. Very tubey and musical sound to them, in the sense that they tended to have a lot of heft and body to the sound, while suffering a little from a lack of clarity during busier moments. This one also sounded a bit v-shaped, but that might just be me. I heard some hollowness in the mids along with some blurring there and overly accentuated bass. For their price, very tempting, and they struck me as a bit of a refinement on the Dunu SA6, which is one of my daily drivers.
Elysian Annihilator 2021
Definite V shaped sound signature on this one. Bass was startling impactful and punchy, but very aggressive. The treble is quite extended and present, with some real zip to it. Just pushing the envelope into too hot or too sharp at times. I am pretty tolerant of that though, so it wasn't much of a distractor. Some unevenness was evident in the treble, with cymbal strikes occasionally souding too blunted and too shimmering. The mids were recessed but the great layering and very good resolution kept the mids from being washed out. I feel like that's an important but forgotten feature in too many V-shaped sigs. Mids that are low in the mix are fine as long as they are still resolved well. These do that well. That said, this isn't the most natural sound and certainly not an all-rounder. For electronic music, it's killer, but lots of music sounds kind of off-kilter. At MSRP, frankly kind of tempting.
Hisenior Febos
These were fine. Basically a myriad of small issues that detracted from the listening experience, but overall not bad bad. Bass was too bloomy and blurred, bleeding into the low mids more than I like. Couple that with the polite bass and these were just too dark for me. The mids had a slight cave-iness to them that sounds like a big dropout in some key frequency. Resolution is middling, while imaging and layering were fairly good. EQ helped, but it seems like dialing these in just right would take some real effort. That said, I am more impressed now that I've discovered these go for around $200. I don't think that's a bad value, but I didn't like these much.
Harmonicdyne Zeos Eris
I auditioned these with no introduction and then guessed their price, so I suppose that means they're pretty good for the money. That said, I did not like them. This is a strikingly \-shaped sound, but manage not to do the bass especially well. Boomy, bloated, wooly, and the word that came to mind first, puffy bass. Resolution was fairly weak and the vocals had an odd tsk quality to them. Vocals sounded simultaneously distant and overamped and overly contrasty. Cymbals were zappy, which is to say, rolled off but with an aggressive peak. They reminded me of the TH900, but with all the bad qualities accentuated and the good qualities nerfed. That's a hard pass from me.
Focal Utopia
I've heard these a few times on various gear and I'm always impressed. However, this time I heard them on my tube amp and Allanmarcus's 300b tube amp, and they were as close to perfectly tuned as I think any headphone can get. Clean, clear, fast, resolving, and impactful, but I think the key word for their sound is beautiful. My own Clear shares these characteristics to a lesser degree, but the step up with the Utopia is noticeable. These definitely go on my shortlist of headphones to consider buying. Honestly, my only reluctance is due to the warranty/customer service side of Focal. Well, that and the fact that I also listened to...
ZMF Caldera
I've got lots of notes on these because I tried them with solid state with and without EQ and with my tube amp, but really, the bottom line is that these belong on tubes and on tubes they are glorious. My first page of notes is riddled with quibbles that I scribbled as I fiddled with the swivel of the gimbal. On solid state, I couldn't get past the impression that these just don't sound like planars. They aren't as fast or resolving or clean as the Audezes I love. They also seemed to have a high contrast sound to them that washed out some details and sounded occasionally too aggressive. The vocals had slight but off-puting chirpy quality to them. And so on. However, once I put them on tubes, all that changed. They still don't have the Audeze sound, but what they do offer is the ZMF dynamic driver sound with more resolution. The tubes evened out the issues with the mids, widened the soundstage, and gave them an incredible heft to the sound that other planars invariably lack. The complete opposite of a HiFiMan planar. With tubes, they were much more in line with the Verite in spirit, if not in sound. Aside from being too warm for my taste, the Caldera on tubes is pretty fantastic. Having discovered that, these also go on my shortlist. I still prefer the Utopia overall, but these would be a better edition to my collection.