THIEAUDIO Monarch MKIII Headphones Review

The THIEAUDIO Monarch MK3 are premium IEMs. The buds' bodies are made from premium resin. We tested the stock colorway version, which is mostly black apart from a swirly white pattern and some colorful, glittery highlights on the outer face of each bud. The THIEAUDIO brand name is printed on each bud in pale grey lettering. You can also order the buds with custom colors and faceplates directly from THIEAUDIO.

The contoured buds are designed to sit securely in each concha, supported by a copper-colored cable that wraps over your ears. Text on the inside of each bud helps you distinguish between the left and right one. They come with three sets of translucent white silicone ear tips and three sets of black foam tips that are color-coded by size.

The THIEAUDIO Monarch MK3 have a decently comfortable fit. They come with small, medium, and large tips in both silicone and foam, so most people will have enough variety to find a fit and seal that works for them. However, if you've smaller ears, you might find that even the smallest tips are a bit painful. The outer part of the buds nuzzle easily and securely into your concha and distribute their own weight well. That said, they're quite heavy for IEMs, which may cause you some pain, and their heavy cable can create discomfort by pulling down on the buds.

The THIEAUDIO Monarch MK3 are very portable, like most in-ears. Still, it's worth noting that they're a bit heavier than many other IEMs.

The THIEAUDIO Monarch MK3 come with a zip-up hard-shell case to store the buds and their accessories. The case is covered in a sturdy-feeling, thick fabric, and it'll do a good job protecting the buds from everyday damage like drops. That said, it doesn't have an IP certification, so be careful not to pack the case next to anything that might leak liquid. The case is lined with softer material so that the buds don't get scratched. There's also a pouch on the inside, which helps keep the accessories organized, and an elastic band secures the buds in place.

The THIEAUDIO Monarch MK3 have a very good build quality. The bodies of the buds themselves are made from a high-quality resin that feels very robust, and the metal tips covering the speakers have a premium feel. Like many IEMs, the pins that connect the cable to the buds are very small and could get bent if not handled with care. Finally, the sturdy build quality of these headphones comes at the cost of added weight. The cable is heavy, and the buds weigh twice that of competitors like the MOONDROP Blessing 3.

These IEMs have a good, stable fit. They are designed to fit comfortably in your concha, and their cable then hooks over your ears, which helps keep them in place. Even heavy headbanging to your favorite Haken tune won't dislodge these from your ears. However, their cable is quite heavy, and if you move around a lot, the weight of it could cause them to become dislodged, breaking their seal with your ears. You'll also want to take care not to snag the cable on anything.

• THIEAUDIO Monarch MKIII headphones
• Detachable cable (47 in/1.2 m)
• 3x adapters (1/16 in/2.5 mm balanced, 1/8 in/3.5 mm single, and 11/64 in/4.4 mm balanced)
• 3x pairs of foam tips (S, M, L)
• 3x pairs of silicone tips (S, M, L)
• Hard-shell carrying case
• Microfiber rag

The THIEAUDIO Monarch MK3 have a well-balanced sound profile that is generally flat in the bass- and mid-ranges, before rolling off slightly in the treble range. That roll-off lends these IEMs a slightly warm, bass-heavy tonality, but they're never boomy or muddy. Kick drums feel thumpy, and the slight boost in the mid-bass ensures basslines have enough punch to cut through busy mixes. A peak in the low-treble can make vocals sound just a touch harsh at times, especially relative to the generally recessed treble range, but the overall sonic signature is more smooth than piercing.

The Monarch MK3 have outstanding frequency response consistency. In fact, they're among the best we've tested. Once you get a good fit and seal, these buds will deliver consistent audio with every wear.

The Monarch MK3 have superb bass accuracy. Their low- and mid-bass regions are practically razor-flat, with just a touch of boost in each to keep kick drums feeling thumpy and engaging. The high-bass is also fantastically well-balanced, with a slightly smaller boost that ensures basslines never become overly boomy. In songs like Bitter Melon by Cola, each note of the prominent melodic bassline is clear, and individual pitches don't jump out of the mix unnaturally.

The Monarch MK3 have fantastic mid-range accuracy. The low-mids are virtually flat, but there's a small dip in the mid-mids that can make instruments feel a touch distant. The high-mids are superb: vocals in songs like Send My Love (To Your New Lover) by Adele sound clear and detailed without being harsh.

The Monarch MK3 have very good treble accuracy. If you like a warmer sound, these are a good choice because the entire treble range is de-emphasized. A dip in the low-treble means that sounds such as fingers plucking on nylon guitar strings lose a little detail and articulation. The entire mid-treble region is recessed which can make cymbals sound dull and sibilants like S and T a little lispy.

The Monarch MK3 have excellent peaks and dips performance, meaning they do an amazing job of following their own sound profile. A little boost between the mid- and high-bass regions adds a touch of warmth to basslines. A dip in the mid-mids and a peak across the high-mids and low treble means instruments can sound a touch distant or overly loud depending on their harmonic content. Finally, a big narrow peak in the low-treble and a couple of small dips in the mid-treble mean vocals can sound either a bit harsh or dull, depending on the pitch of the singer.

The Monarch MK3 have outstanding imaging, and although we've only tested one product by the manufacturer, these results suggest superb quality control and ergonomics. Our unit's drivers are well-matched in group delay, amplitude, frequency, and phase response, so objects like voices are accurately placed in the stereo field, and the soundstage doesn't feel unnaturally tilted to the left or right. There's a small peak in the mid-range phase response, but it's not audible. Keep in mind that imaging varies between units, so these results are valid only for our unit.

These IEMs have a bad passive soundstage performance, but that's to be expected from IEMs. Their in-ear design means audio can't interact with your outer ear like it can when you wear over-ears, meaning that they don't lend a sense of distance and width to the passive soundstage. Audio feels as though it's coming from inside your head and not two speakers in a room.

These IEMs have good weighted harmonic distortion performance. Most frequencies fall within good limits. Even the broad peak from the mid-mid to mid-treble won't be audible to most listeners. Overall, these IEMs reproduce audio purely and cleanly.

These are the settings used to test these headphones. Our results are only valid when used in this configuration.

These headphones have great full-range noise isolation, which they accomplish purely via passive isolation. Since they don't have ANC, they don't do a great job of blocking out bass-range sounds like the rumble of a bus engine. However, they do a very good job of isolating you from mid-range sounds like chatty coworkers and excel at blocking out trebly sounds like fan whine.

These IEMs do a decent job of blocking out everyday sounds. They won't isolate you from the low-pitched rumble of a plane engine or a passing bus, but they'll greatly reduce the ambient sounds of an office, from your colleague's voice call to A/C whine. You also won't hear much in the way of pedestrian chit-chat when out on the street.

The leakage performance is remarkable. Even if you listen at loud volumes, audio that does escape is concentrated in the low- and mid-bass regions and will sound muffled to anyone nearby. Feel free to blast your favorite Sunn O))) tunes without fear of bothering people around you.

These IEMS come with a 47-in/1.2-m detachable cable. The smaller two-pin connectors plug into the buds, and the four-pin connector plugs into one of three adaptors: 1/16 in (2.5 mm) balanced, 1/8 in (3.5 mm) single, or 11/64 in (4.4 mm) balanced. You don't need a dedicated amp to drive these.

These buds don't have a built-in microphone, so if you connect them to your PC, you'll only receive audio.

You can plug these into your PlayStation controller's AUX port, but they can only receive audio as they don't have a microphone.

You can receive audio from your Xbox by plugging these into an AUX port. They don't have a mic, so you'll need to add one if you plan to chat while you game.