Thieaudio Monarch MKIV | Flagship Tribrid Universal IEMs

I’m coming from an Oracle MK3 and I can definitely tell you that the Monarch MK4 is an upgrade in almost every aspect.

In short, the Monarch MK4’s trebles sound very similar to the Oracle MK3’s, but with more air and space. Stereo imaging and soundstage are pretty spot on for an IEM and it’s excellent for playing FPS games too, like COD, Valorant, Battlefield, CSGO, Overwatch, etc.. Most of the time, everything sounds like in your skull, but if you focus on listening critically, then the soundstage sounds like coming from the outside, as if you’re listening to a pair of speakers. The mids sound right on the money. Both male and female voices sound natural, and none sound like they’re too far at the back or right at your face as if they’re trying to seduce you. The Monarch MK4’s mids sound more refined than the Oracle MK3’s, there’s no roughness. Finally, the bass, dual DDs will slam hard and fast, even in the Standard mode, and nothing sounds muddy, slow, or bloated. The Monarch MK4 will probably make you wanna bounce to the beats. The Oracle MK3 doesn’t and can’t do this. In Rumble mode, everything sounds like watching a blockbuster in a Dolby Cinema theater from an AMC.

Regarding the price, it’s very expensive and there are diminishing returns here too. But if you’re on a mission of getting yourself out of the rabbit hole of the IEM world, then I sincerely hope that the Monarch MK4 is your true answer. It competes competently against other flagships that cost double, if not triple, the price. Probably only the ultra end or money-no-object IEMs can beat the Monarch MK4.

I've spent some years chasing an all-rounder with a more organic leaning sound while still being quite technical in nature. I'm stopping my search with these. I've owned the Volur, EXT II, Trifecta, Kublai Khan, the Mefisto, and others.

The Monarch Mark IV really just do everything right, while being very good at it all. The bass switch is a game changer. It's easy to change on the go while they're still in your ear. If you decide to switch from electronic beat driven music to say indie rock, just reach up and change the bass response. It's quite impressive.

Across the spectrum these IEM really sing. The bass is impactful, with an extra special rumble with the switch on. Vocal sounds beautiful and present, and the treble is detailed yet not fatiguing.

They fit my ears well, though after a few hours session I do start to feel their presence as they are rather large, but it's not bad.

Sonically these are amazing. The only thing a little wacky about them is the cable does not match the IEM color wise. But this is about sound and that's not enough to ding them any star.

Buy these with confidence.

a little bit/gets uncomfortable after a few hours, but sounds amazing and i love the bass boost switch! also, bloomaudio is great in terms of packaging

The Thieaudio Monarch MKIV has earned a permanent spot as my daily driver. It’s one of those IEMs that just works with almost anything in my library — from jazz and acoustic to EDM with heavy drops. The balance is spot on, and when I want more low-end impact, it delivers with clean, controlled bass that never muddies the mids.

Vocals sound natural and clear, and the treble has enough sparkle to bring out detail without ever getting harsh. The soundstage feels open and well-layered, giving music a real sense of space without overdoing it. It’s the kind of tuning that keeps you coming back because it simply makes music enjoyable.

Build quality is excellent. The shells feel solid and well-finished, and the aluminum case is one of the nicest I’ve used — sturdy, good-looking, and actually practical. The stock cable is just as good, with a comfortable feel and no annoying tangles.

For me, the Monarch MKIV hits that sweet spot of versatility, great sound, and premium build. It’s not a “special occasion” IEM — it’s the one I reach for every day because I know it’ll make whatever I’m listening to sound its best.

I loved the Monarch 3 but they were a little lacking in bass to me. Not by a lot, but enough to not be the set for me.

The Monarch Mark IV definitely solves that problem. I do also find the shells lighter and a better fit. While they do stick out a bit, and are on the large side, they feel better in my ears than the previous version. The b build quality is excellent, and the shells are gorgeous. I find the cable to be fine comfort wise, but the color is completely a mismatch with the actual IEM. If that's something you think about, keep it in mind. It wouldn't be a deal breaker for me, but I did use another cable with them. These do benefit from a balanced termination If you like higher volumes as they do need some power to shine up there.

Sound quality wise these are excellent across the spectrum. My goal is to find a warm and organic leaning set with a nice timbre, which still retains excellent technical performance. I find these fit that description to a t. Sometimes I do wish the mids were a slight bit more forward but it's rare. The bass switch is actually very functional and easy. You can simply reach up to your ears while you are listening and easily flick the switch. For example I was walking my dog and my playlist switched from beat driven music to some indie rock. I simply paused for a couple of seconds and turned the rumble off. Most switch implementations I've seen require you to remove the set from your ears and sometimes even have to use a small little tool. This implementation is much better.

If you have a varied music collection that works with this kind of sound signature, these are the all-rounders you want. These are not as specialist IEM, these are a throw anything at them, and you'll know it's going to sound good. If you want a specialist IEM for say acoustic music or just vocals, you could get a specialist set. If you're like me who listens to all kinds of different music from beat driven to classic Rock to jazz to electronic to indie rock, and
more, this is the set for you.

Highly recommended.