Burn in required!
Out of the box, these concerned me. They had great highs, if not a little etched, very recessed mids, muted bass and booming sub bass. I listened to them for about 45 minutes, questioned my choice and left them to play for about 20 hours until I had time to return to them the next day. After that amount of time, they sounded completely different. The treble had relaxed, offering just as much detail but in a very pleasant and smoother, more dimensional manner. The mids were far more clear, even if a touch recessed due to their tuning. Bass had definitely tightened up and evened out. The bass and sub bass were most noticeable and perhaps the DD breaking in for a few hours is all this thing needed to even right out into something special.
I tested them on an Audioquest Cobalt, Cayin N3Pro and iFi Pro iDSD. All work very well. They are pretty efficient (not as efficient as a single DD) and I could probably run them off my phone, but with a DAP and Dragonfly I haven't bothered to try. With either Roon or UAPP on Android as a source, all combinations sounded great with the Cayin N3Pro actually being my favourite for most occasions. I can tune the sound with tube UL, Triode or solid state. I mostly listen now in UL mode, although Triode does bring the mids forward a bit more, which is nice for smaller scale jazz or guitar based music.
Overall, I would say the soundstage is average but with great instrument separation and imaging that can add great depth. The sub bass lift really helps modern and live recordings with a sense of space. Combined with the amount of separation, excellent imagining and depth of sound (and sub bass) they are a really enjoyable listen.
The only downside to these is the bass shelf being in the upper bass as well and lower mid range. It's great tuning most of the time, actually. But some songs you're used to may sound a little thin or lacking body. The good news, for me, is that it still interesting to hear my whole collect of music through this lens. Most of the time it's a preferred tuning that reveals dimension, depth and detail to great recordings.
If you mirror a lot of the genres people tend to reference here, you will likely enjoy these and perhaps love them.
Edit Although, I still feel soundstage is average (it's an IEM), I can say that depth and layering are better than I initially thought after burn in. This quality alone I feel makes them great for gaming and generally has more "wow" moments for me listening late at night. Which is what I hoped for, and have never got out of an IEM.
https://www.linsoul.com/collections/thieaudio/products/thieaudio-monarch
