Thieaudio Monarch MKIII

The THIEAUDIO Monarch MKIII is the much-anticipated successor to the, predictably named, rankings-topping Monarch MKII. Introduced at the same price ($999) as its predecessor, the new MKIII model features a different driver configuration, a subtle retuning, a slight shift in technicalities, and includes an upgraded modular cable system (with 2.5mm, 3.5mm and 4.4mm connectors) and new custom face-plate design options.

Technical Specifications

  • TYPE: In-Ear Monitors
  • DRIVERS: Sonion EST, Knowles DWFK 31785 (x2), Sonio 28UAP (x1), IMPACT2 (2 x 10mm Composite DD)
  • CROSSOVER: 4-Way Passive Crossover with 4 Sound Bores
  • SENSITIVITY: 99dB @ 1kHz (+/- 1dB)
  • IMPEDANCE: 20 ohms
  • CABLE DETAILS: 1.2 meter 22AWG 6N OCC Silver-Plated and Graphene Silver-Plated Cable
  • CABLE CONNECTORS: 2-pin 0.78mm
  • CABLE TERMINATION: Modular Termination with 2.5mm,3.5mm,4.4mm Interchangeable plugs

What’s In The Box?

  • THIEAUDIO Monarch MKIII In-Ear Monitors
  • 22AWG 6N OCC Silver-Plated and Graphene Silver-Plated Cable With Modular System
  • 3 Pairs of Silicone Ear-tips
  • 3 Pairs of Foam Ear-tips
  • Carrying Case

Power/Drive Requirements

THIEAUDIO Monarch MKIII - Power Requirements

The THIEAUDIO Monarch MKIII is available from at $999 for the “default” design, and with custom face-plate designs starting at $1,099.

I did not see a dedicated Monarch MKIII thread, excepting @Fc-Construct’s MKII vs. MKIII comparison/review. If this is better as part of that thread, feel free to move it.


Thanks for starting this thread @Torq. I think the MkIII flew a bit under the radar because it’s seen as mostly a sidegrade to the MkII with a shift in tuning towards more midbass heft and upper treble zing. And it’s that upper treble zing is something a few people are cautious about. Personally, I prefer the MkIII but think the MkII is one of the safest recommendations at $1,000 along with the 64 Audio U4s. But if you’re after sheer resolution, I haven’t heard anything that beats the MkIII at $1,000. Even at double or triple the price, it still holds its ground in that one specific technical parameter IMO.


That was certainly the impression I got.

For me, it was exactly what made it appealing over the MkII. I wanted something as close as possible to the technical performance of my Empire Ears Odin, but with a bit more bass/sub-bass presence (but not as much as Raven or Legend) and a bit more top-end energy (my ears aren’t getting any younger).

That was partly just for a more “fun” or less “neutral” tuning, but also because there are times (or more accurately, places) I don’t want to carry a $3,300 IEM around.

I saw had restocked a few days ago (specifically I wanted the A5 “Disco” model), and Taron was kind enough to expedite an order for me, so I’ve had them for a few days now.

I’ll write more, and more coherently, as I can … but for now, I’d say they’re fantastic.

Tuning aside, they surprisingly close to the technical performance of my Odin. I was expecting them to be good … but was still surprised at how close they come.

For some reason, the Monarch MkIII is more comfortable than the Odin … which seems odd as I think the nozzle on the MkIII is larger (I’ll have to get out the calipers to check). But, they sit in my ears better and I’m less aware they are there after 5 minutes, and 2 hours, than is the case with the EE pair.

I’d been using an IE600 in this role.

They’re not a million miles away in terms of tonal profile (some bass emphasis, slightly spicy treble), and are super comfortable and very listenable, but the Monarch MkIII jacks the technical abilities up significantly, and pretty much across the board vs. the Sennheisers (and I prefer the IE600 to the IE900 here).

A few non-audio things I appreciate … the packaging … tasteful, simple, inexpensive. Enough to protect them, without going over the top on unnecessary fanciness. Basically the way 64 Audio does it (or, at least, did it when I bought my original tia Fourté).

Not that I don’t appreciate a nicely packaged product. But there’s a tradeoff, especially around the $1,000 and under spot, where it doesn’t make as much sense. And no IEM, to date, has gotten close to the presentation/packaging of the AAW Canary … which was really nicely done.

The modular cable is nice, as well. While I use 4.4mm output on my DAP or my W4, from my laptop or iPhone it’s a 3.5mm connector, and from a Bluetooth DAC/Amp usually 2.5mm so it covers all bases.

Anyway, more specifics on the sound as I get time … but very impressed and engrossed so far … especially listening via the N30LE.


How do you find the bass quality on it? I think that was probably my biggest knock against it, sound wise. IMO both the MKII and MKIII have enough quantity but are very middling performers in bass dynamics at that price, especially when compared to something like the 64 Audio U4s.

I’ve not spent enough time with other ~$1,000 IEMs to draw “reliable” direct comparisons, at least not in terms of very specific comparisons on technical performance.

They’re discernibly (though not problematically) softer in terms of bass dynamics than the Odin, the original MEST (from memory), and even the IE600 (though it’s closer here), by which I mean those “hit” a bit harder. I didn’t really notice it with acoustic pieces, but with bass-centric electronic music I might lean towards something a bit punchier.

Otherwise I find the overall bass-quality to be very good … texture is good, its tuneful (no one-note bass issues), and there’s no fatigue from their elevated bass level (which I sometimes find a problem with other more bass-emphatic tunings).

Haven’t heard the U4, so can’t comment there.

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Really surprised there is not more commentary on these things …

I guess I’ll add some, possibly starting with re-iterating (or emphasizing) my original thoughts.

I’ve been spending a fair bit of time listening with the THIEAUDIO Monarch MKIII since snagging them. This has included multiple 100% → 0% listening sessions on the N30LE.

At this point, they’re the most comfortable universal IEM I’ve used excepting the Sennheiser IE600 (and there isn’t much in it). And with Asla SednaEarfit XELASTEC tips, the seal is perfect. It is with the Odin, as well, but there is more pressure on my inner ear with the Odin (despite the nozzles on Odin being smaller … go figure).

So … SUPER comfortable, easy to wear … moving around, drinking, even nibbling a snack doesn’t break the seal and I don’t have to faff about to GET that seal.

Tonality is damn near perfect for my IEM preferences … neutral with a useful bass-lift. And they have just enough more bass (level/quantity) vs. the Odin to be thoroughly satisfying. The Odin is still ahead on bass-quality (a hair more impact/slam/thwack to it), but that’s being a bit nit-picky (especially given the price difference).

They don’t quite have the tactility of the original MEST, but they’re tonally a lot more enjoyable. Maybe a MEST 4 if/when such a thing exists, will change that … but those will need a higher level of bass output vs. the MEST 2 and 3 to be as satisfying as the Monarch MK3 (or the original MEST).

Odin is still ahead on raw technicalities. But the differences are very small, and really only apparent in a back-to-back comparison (and hard to detect even then).

Very pleased with the Monarch MK3 … even off an iPhone USB-C->3.5mm dongle, they’re excellent, and with the W4 or the N30LE they’re amazing.

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They are a very popular IEM but I think they probably hit a demographic that is mostly discussing them in Discord / other places.

I was never really able to get to a place of enjoying the Monarch / Monarch MKII as the tuning wasn’t quite up to my preferences. I should probably give the MKIII a shot to see if it’s more my speed.

I had issues with the MKII where the nozzles were simply so big that I couldn’t use them for more than 20 minutes.

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MKIII, as with pretty much the entire current ThieAudio line, has the same 6.2 mm nozzle at the same insertion length and angle.

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I think the reason they’ve gotten a little get looked over is because quite a few people are concerned over the upper treble zing they have and thus prefer the Thieaudio Monarch MkII, which by all means is still a very respectable IEM. Also, Thieaudio has put out so many IEMs now that it’s diluted the share of voice for their own products.

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I had these for 2 weeks, they weren’t for me, too large for my outer ears. The sound signature was pleasant, it was a little bright and the bass was separated nicely from the mid/treble. Wasn’t blown away by the detail at all compared to headphones in the same price range, maybe I expected too much.

I found them a lot better sounding than the IE900’s (though less natural), but also a lot less comfortable. The eartips they came with were just plain bad, the foam ones are completely unusable, a boomy mess. Xelastics worked a lot better and brought out the clarity in the sound.

Since I sold them I’ve seen them be resold twice more, citing that they fit uncomfortably as the issue. Despite all the rave reviews online I think this is too often overlooked.

Before someone goes and tells me something about the nozzles because I always get this comment, the nozzles weren’t the issue. The outside part was too big.

I found 64 audio IEMS way more comfortable for this purpose, they’re a lot smaller

I was surprised, myself, as comparing them to the Odin nozzles the MKIII are larger - but I found the MKIII is more comfortable in my ear … which must be down to how it is sitting/insertion depth, as they Odin nozzles are clearly narrower.

But it’s one reason I generally don’t consider IEMs on the used market … the fit, both in terms of nozzle diameter and depth, as well as how the shell sits in the ear, can easily be a make-or-break thing.