I've been listening to the Tansio Mirai TSMR-X for about two months now. I bought them from Penon for $400 USD. I wanted to answer the question: what can IEMs offer in the same price-class as my much-loved Hifiman Ananda headphones. Spoiler: while I had just been mildly interested in IEMs before, I'm now convinced they can offer exceptional value-for-money in hifi and my savings for new headphones will eventually go towards upgrading to even better IEMs.
The TSMR-X have dual 8mm dynamic drivers (isobaric) for the low-end, four BAs for mids (Knowles) and highs (Sonion), and a tuned vent like 64audio's APEX modules. The vent contributes to the tuning and prevents pressure build-up in the ear canal. They're quite efficient at 103 dB/mW and 10 ohms. I found them easy to drive from most sources, though the bass really shines with a bit more power (Quedelix 5k is enough, iPod 5.5 gen leaves a bit to be desired; both Chord Mojo and VE RA2FE+Prime DAC sounded great). Three tuning switches allow meaningful adjustments of the bass shelf, to better suit different preferences or genres. I've landed on 011, which is between the "bass" 100 and "balanced" 010 setting, but I use 010 a fair bit also.
The sound is V-shaped with impactful bass and great clarity in the highs. My only gripe with this tuning is that male vocals can sound a bit recessed. However it's a worthwhile tradeoff for a really satisfying bass reproduction and great detail/technicalities; it offers nice separation in space as well. The V-shaped sound signature also works great for lower-volume listening (most of my listening), maintaining that nice physicality in the bass. The tuning is well suited to pop music and instrumental works. Really though, I've been happy with it for my whole library across a wide variety of genres.
The build quality is solid, with translucent shells that look better in person than in the photos. The nozzles are slightly shorter and wider than my previous Letshuoer S12s, making tip selection a bit tricky. I found soft wide bored tips like Moondrop Springtips and TRI Clarion worked well. Once fitted, they're light and comfortable with a medium shell size.
Since getting them, my Hifiman Ananda headphones have gotten very little listening time. I find the TSMR-X match or exceed them in technicalities, while offering a much more satisfying bass experience that makes it hard to go back to the full sized planar headphones. Of course, full-sized open back headphones still have their advantages, but the convenience and sound quality of the TSMR-X has convinced me to dive into the IEM space for the foreseeable future.
