OK, I get it. I finally understand the hype.

Pros: Amazing mids
Great highs
Good fit for me
Modular cable
Good quality bass
Great price/performance
Nice metallic faceplate

Cons: Tougher to drive than some full-size headphones – I was still able to do it with no issues on my gear
Heavy, microphonic cable with mediocre ear fit – get the Kinnera Leyding
Needs slightly more low end
Fit for some people, I had no issues – these are big

Overview:

OK, I get it. I finally understand the hype. I have different tastes from Crinnacle (he prefers neutral, I prefer fun), but when he put the $1000 Thieaudio Monarch Mk2 (MMk2) IEMs as his #1 product over $4-5k IEMs, I took notice, along with a lot of other people. Somehow, I picked up quite a few other IEMs before these, despite wanting a pair. The 64 Audio u12t (u12t,) for instance, another highly lauded set of IEMs – which were quite excellent and sat at the top of my IEM tier list until the MMk2 came along. I also tried out the UM MEST Mk2 (MEST), which some people love, but while I found the bass to be among the best, the highs were painfully sharp for me. I traded the MEST for the MMk2 and I am very happy with the Monarch. So, if you’re thinking about these, have big enough ears, are ok buying new tips and a cable, and you don’t feel like reading my review, go buy a pair.

Update 13 Jan ’23: I got the Kinera Leyding cable from Amazon and it is the cable these should have come with from the Thieaudio. It’s not microphonic, flexible, still modular, doesn’t get tangly, matches the color scheme, and opens up the bass and sub-bass more on the Monarch Mk2. It was only $70 too. So, with $20 Spinfit tips, and a $70 cable…you can get the perfect set of $1089 IEMs. It’s just a shame the MMk2 doesn’t come with better accessories from the factory. I’m updating my score to a 5 from a 4.5 because these are truly the best IEMs at this price range, and maybe any price – that deserves a 5 for now despite Thieaudio’s best efforts to cheap out on accessories. I will update this score if I find anything better.

Build Quality/Comfort:

Honestly? I always thought the face plate on these were pretty ugly in photos, but in person they are REALLY nice – it’s a sort of copper/silver/rock look. The face plates have a lot of depth and they change as you move them around in the light. The fit is an issue for a lot of people and after seeing the driver opening, I definitely see why. It’s huge – 6mm, and I’m a little amazed it fit in my ears at all. Since mine was used, it didn’t come with both stock small tips, so I installed some small Spinfit tips designed for this size driver opening. They worked great and I had no issues with the fit.

The cable is a really cool design with interchangeable amp-ends so the IEMs will work with 4.4mm, 3.5mm, and 2.5mm. That’s kind of where the awesomeness for the cable ends as it’s tangly, and is wrapped in microphonic paracord. The ear hooks don’t fit all that well either and can take some adjusting to get a good fit – it’s better than the Symphonium Meteor cable (terrible,) but worse than the u12t cable. Lots of people recommend an aftermarket cable, but I find the stock cable acceptable. I did get a Kinera Leyding cable anyway since I listen to a lot of IEMs and it has the connector swap without the paracord. Overall, the build quality of everything is excellent, it’s just the design that needs some work.

Sound Quality:

Well, if you didn’t get scared away by the fit or the cable, then you’re here for the sound right? Well, you’re in luck, because the MMk2 sounds really, really good. A quick run-down up front before we get into breaking down specific songs. These are a mids-forward headphone with slightly boosted bass and well-controlled and detailed treble. What does that mean? It means that there is a decent amount of good quality bass, more than the u12t, but not as much as the MEST – the MMk2 are not basshead headphones, the MEST are thanks to their bone conductor tech. Also, there is less sub-bass from the MMk2 than the MEST, but the overall bass presentation is still good. They do have some of the best mids I’ve ever heard though, better than the u12t, much better than the MEST. Vocals and instruments sound amazingly clear and exactly like they were meant to. The highs are also great, with no sharpness or sibilance – something that the u12t can match, but the MEST is terrible at.

My chain for listening to these is a Burson Conductor 3X Performance (3XP) and a Shanling M3 Ultra (M3U.) The M3U does a fantastic job providing power and quality sound from Tidal to the MMk2 using the 4.4mm balanced connection (40/100 volume level.) The 3XP sounds similar (with a touch more soundstage) using a 6.3mm adapter, but since it’s not balanced, it required 80/100 on low gain to power these – more than my JMA XTC-Closed backs with 50mm beryllium drivers.

So, beginning with the bass heavy songs, I’m starting off with Cyberpunk 2077’s “I Really Want to Stay At Your House.” The first thing I notice is how well the vocals are presented – just an absolute masterpiece presentation of how to do vocals. They are clear, forward over the rest of music (which admittedly they should be,) with what feels like their own separate stage to perform. Everything else takes a bid of a backseat – including the bass. That’s not a bad thing, though in this song, I do prefer a bit more rumble at 3:30 when the bass comes back in – there is still plenty of bass, more than the u12t, less than the MEST – but at least it’s really good quality bass. The high-vocals here sound as good as the mids and nothing comes across as harsh or grating like they do on the MEST.

Switching to an oldie-but-a-goodie is Darude’s “Sandstorm,” where once again, there is excellent quality bass representation in the background, but it’s not quite what the MEST, or the JMA XTCs can do with bass one this song. It really takes a backseat once more to the excellent mid-synths (which are the whole point of this song really. The high-synths and cymbals in the background come across wonderfully without any harshness (a major relief after being let down by the MEST.)

David Guetta’s “I’m Good (Blue)” shows the best of this bass with good bass drum response and some decent sub-bass, but it doesn’t have that low rumble that some headphones can hit with this song. The vocals and synths, both mid and high really come across wonderfully though and the bass doesn’t drown them out, which it can do on some headphones as well.

As previously mentioned, the mids are REALLY where these IEMs shine. Vocals are amazing and guitars, pianos, and strings come across perfectly. A fantastic example of this is Staind’s “Something to Remind You.” Aaron Lewis’s voice comes across clear and strong with no missed frequencies whether he’s on mid or high notes. You can hear the waver in his voice and the guitar in the background can easily be picked out from the bass guitar. Really, these IEMs are the best mids representation I have probably ever heard besides maybe the Rosson RAD-0 (Rad-0) and JM Audio XTC-O (XTC-O.) Those are full-size open-back headphones, and yet the soundstage and presentation of the mids on these tiny IEMs are on par – crazy.

There For Tomorrow’s “Dark Purple Sky” opens with some nice bass drums and quiet guitar, both of which are nicely separated as the song slowly build into the vocals and the distorted guitar picks up and the chorus breaks out at 1:08. The mid-vocals and high-vocals once again are excellent – there’s not a ton more I can say about this, but in every song I played on these the vocals and instruments are fantastic – I just want a little more in the bass and sub-bass.

The highs are not where the music lives in most cases, but they can very quickly turn a good headphone bad with a sharp treble response (sorry MEST.) The MMk2 has no issues with treble sharpness while listening to high-pitched vocals or pianos. A great example of this is Mark Schultz’s “Letters from War.” Only listen to this song if you want some feels – the vocals and pianos come in beautifully both in the mids and the highs with no distortion or sharpness – this is a good clean song that the MMk2 is really designed for. Without getting redundant, Eminem and Beyonce’s Walk on Water illustrates once more the detail that the MMk2 is capable of portraying.

Conclusion:

These are great. I have never heard any IEMS that are as well balanced, with as clear and excellent sounding mids. They could use a touch more bass and sub-bass (bone conductor Monarch would be cool,) but that’s it (unless you’re a basshead, then look into the Symphonium Meteor or the MEST Mk2.) They could also use a better cable and ear tips included, but that would raise the price to u12t levels – and the stock stuff is fine. As mentioned in the update, buy $90 worth of accessories for these and they’re as close to perfect as you can get. These perform at the $2-3k level, but are under $1k – that’s just great. I’d take them over the u12ts because they do have better bass and I like the forward mids more than the neutrality of the u12t. If there is anything better, it likely costs several arms and legs more. So, unless you have tiny ears, grab a pair of these, I doubt you’ll regret it.

Build Quality	1​
Design	1​
Cable	0.75​
Case	1​
Ear Pads / Tips	1​
Comfort	1​
Lows	1​
Mids	1​
Highs	0.75​
Price	1​
Total:	9.5