What an entry into the IEM market. I don't think I would be exaggerating if I say that here we have a piece that is going to be compared to IEMs well beyond its price point.

Before I begin with a review though, some things to know where I come from:
Sennheiser HD598s, Moondrop Blessing 2, & Thieaudio Monarch MK3 have been my listening buddies in the last ten years; the Monarch being the latest. To pair with them I've used the Jcally AP98 DAC/Amp & Sony NX707 walkman.
I can listen to any kind of music as long as I like it, but my library mostly consists of instrumentals, which I listen to through Apple Music.

What brought on the need to shop for an IEM? Primarily because I wanted to listen to my songs through a different tuning. My Blessing 2 ran out of commission a while back, and I wanted a bit of change from the MK3s. Funnily enough, I ended up picking something thats actually not too different signature wise from the MK3, but after listening to them once, there was no way I couldn't pick them up.

So lets get into the meat of the matter: the sound.
Tansio Mirai X comes with a U shaped default tuning, but you can change this with the three tuning switches provided, which affect the low, mid, and high frequency bands.
The Audio Store was amazing as usual, and provided me with a plethora of options to test which included - ISN Neo 3, ISN Neo 5, Penon Dome, Penon Quattro, Penon Turbo, & Symphonium Meteor, all of which range from a level lower priced to a level higher priced than TSMR X. I might add my comparisons to all these pieces (and my own MK3s) wherever it feels pertinent.

The bass:
This has some of the most gorgeously tuned bass I've heard in a long time. For some people, it just might be on the limit of bassy side (I am myself not a basshead and in some songs it does feel borderline to me), but the quality will more than make up for it. Some of the drums, lower tone strings, and tabla (especially the strokes of the dagga) I've heard through this have left me amazed. Only the Penon Quattro with its 4 DDs could maybe offer more detail, but there is another reason why TSMR X will still feel like it has better bass (which I'll mention later).
Playing with the tuning switches over here and using the 100 mode will get you more bass, but doesn't affect the quality. Go for this if you are a basshead. If you think the bass is too much, go for 003 mode. I'm using the default 020.

The mids:
Compared to the bass, the mids are not as forward even in the 020 mode which is the balanced tuning. Especially with vocals, you might feel that they are slightly being pushed back, but in my opinion, this is because the instrument presentation feels much more forward. The strings here are very nicely heard, and although it might feel like it could have had better resolution, overall you will not be disappointed. Out of the pieces I had a chance to listen to, these were still close to the best, with the cheaper ISN Neo 5 also being surprisingly quite good for mids, the Penon Turbo doing well, and the Symphonium Meteor being the clear winner here.

The treble:
You will find this to be fun. There is enough detail here to put them above many IEMs in and around this price range. Instruments like cymbals, maracas, tambourines, and chimes can be perfectly heard, and the sound in general is not overly sharp. Of all the IEMs I tested, I would safely put these the best for treble (although I will mention that Penon Quattro sound very interesting here as well).

The mindblowing:
Up till now, you might not have understood why I've been so overboard with positivity about these IEMs. So the bass and treble is good, but the mids are only decent. Why would that alone make them phenomenal? The Xenns Mangird Top would probably be equally good (or even better) sound quality wise. That my dear friends, is because this IEM brings something into the equation that I've not expected any IEM to bring. Soundstage.

The soundstage:
Till now, I've never really rated IEMs on this. After listening to open cans like HD598s (and some very good ones like HD600, HD650, Sundara, Ananda courtesy TAS), I know that I can't expect IEMs to deliver that effect to me. But boy does this come close. I've never expected to hear acoustic reverberations in an IEM. Maybe it is the custom film retarding driver with the detachable design that does this, I'm not sure. It gives you the most rich acoustic feeling you will have ever heard even among IEMs way beyond this price. My Monarch MK3 which is nearly 3 times costlier cannot do some of the things that TSMR X does! It was especially so good for my playlist, which I mentioned earlier is mostly instrumental. Some of the guitar notes, the tabla, the cymbals I hear on this are just out of the world.

And this last bit is what makes the TSMR X punch way, way above its price point and make it worth getting IMO.