Audeze Euclid review: Raising the bar for planar IEMs

Audeze is one of the most recognizable names in enthusiast audio, with the brand's planar-based headphones offering exquisite clarity and imaging. The manufacturer is aiming to bring that expertise to portable audio with the introduction of the Euclid, its first closed-back in-ear monitors (IEMs) with planar drivers. The IEMs are named after one of the greatest Greek mathematicians of all time; Euclid's pivotal treatise laid the foundation for geometry and general mathematics.

Audeze is aiming to set a similar standard for IEMs with the Euclid, and they definitely have a lot to offer. The IEMs feature custom 18mm planar drivers, a unique design that includes carbon fiber, and all the accessories you could ask for. Retailing for $1,299, they're clearly aimed at enthusiasts looking to get the best out of portable audio, so let's find out what you're getting here, and if they're as good as Audeze claims. 

Audeze Euclid: Pricing and availability

Audeze launched the Euclid in February 2021, and the IEMs are available in all regions where the brand has an official presence. They retail for $1,299 in the U.S., and you can get your hands on the IEMs at Amazon and other audio retailers. 

Audeze offers a standard one-year warranty on the parts, and three years for the drivers. They're available in a single color option. 

Audeze Euclid: Design and comfort

Audeze likes to make a statement with its products, and it's no different with the Euclid. These IEMs have a striking design that is unmistakably premium; the shells are made out of aluminum, have a good heft to them, and feature a matte finish. The gold band running around the diameter of the shell adds a nice contrast to the design.

The face plate is interesting in its own right thanks to a splash of carbon fiber. The Audeze logo is ensconced within the face plate, and like the rest of the design, it is also made out of metal. As you'd imagine from IEMs that retail for $1,299, the build quality is absolutely exquisite. Each earbud comes in at 7.5g, and while that's on the heavier side, the weight is balanced very well and I never felt like the IEMs were uncomfortable even during extended use.

The Euclid have a unique design owing to the large 18mm planar driver, with the shell being larger than most IEMs I used thus far. The large size means it protrudes from the ear — like the best wireless earbuds — but you get a snug fit thanks to the contoured design. The nozzle doesn't extend too much from the shell, and the design means the IEMs have to twist and lock into position inside the ear canal.

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You'll find a lot of accessories bundled with the Euclid, including Comply memory foam ear tips alongside silicone ear tips by Audeze and SpinFit, a mesh carrying bag, and a hard-shell case that's ideal for portability. Audeze includes a standard 3.5mm cable in the box along with a balanced 4.4mm cable.

Because the Euclid are larger than most IEMs, they may not fit as securely if you have small ears. I didn't have any issues in this area, and the way they sit on the outer ear isn't too different to that of the Galaxy Buds 2 Pro or other wireless earbuds that have a battery.

I found the medium-sized SpinFit option to be the most comfortable for my ears, and that's what I went with as standard. The IEMs have standard MMCX connectors, and Audeze's bundled 3.5mm and 4.4mm braided cables are of a good quality.

Audeze Euclid: Sound quality

Audeze tunes its products to deliver a neutral sound signature, and that's no different with the Euclid. The large 18mm planar drivers produce a detailed and airy sound that's fantastic, and I'll get to the nuances of it below. But first, what makes the Euclid stand out from every other IEM I used is the soundstage: they sound incredibly wide and open, and I found having to constantly remind myself that these are closed-back IEMs. Good job, Audeze.

I listened to an eclectic mix of genres in the two months I used the Euclid, and in every situation, the IEMs produced a wide and inviting sound that was thoroughly enjoyable. The dynamism and stereo imaging is the biggest differentiator for these IEMs, and I'm not exaggerating when I say that the soundstage is among the best of any planar-based IEM to date.

With a sensitivity of 105dB/1mW, the Euclid can be easily driven by just about any DAC. I tested the IEMs with a variety of sources including Fiio's excellent K9 Pro, M11S audio player, and the KA3 portable DAC, but a bulk of the listening was over the K9 Pro.

Bass is tight and detailed, with a good extension for sub-bass frequencies. There's not too much in the way of exuberance, but you get excellent definition and body, and the sound is highly engaging. There's plenty of speed too, a characteristic of all planar drivers. The low-end isn't overbearing, but you'll find that it has good depth and detail. On the whole, the Euclid does a brilliant job nailing the technical details; it doesn't have an aggressively bass-heavy sound profile, instead delivering a more nuanced low-end that's an utter joy.

Coming to the mids, the Euclid have great tonality, timbre, and detail retrieval, with an airiness to the sound that's key to the wide soundstage. There's excellent instrument separation — noticeable in orchestral pieces that include wind instruments — and vocals shine through with good energy and presence. This is definitely where the IEMs come into their own.

Treble has good extension, clarity, and airiness, and it is never harsh or overly congested. There's a sparkle to the sound that accentuates the pluck of a guitar string or the clash of a cymbal, but it isn't overbearing in the least. There's no sibilance to the vocals, and the overall balance is spot-on.  

The biggest takeaway here is the soundstage; Audeze has somehow managed to deliver an incredibly wide and detailed sound from closed-back IEMs, and that's a testament to its tuning efforts.

Audeze Euclid: The competition

You won't find many alternatives if you're looking for high-end planar IEMs, with most of the choices in this category aimed at the sub-$500 market. If you're in the market for high-end IEMs, you should take a look at ThieAudio's $999 Monarch MKII. They use an array of drivers to deliver a powerful sound, and while I haven't tested the IEMs yet, there is a lot to like here. 

The $1,500 Sennheiser IE900 also gets a lot right, delivering a wonderful sound combined with a design that's comfortable even with extended use. 

Audeze Euclid: Should you buy it?

You should buy this if:

• You want IEMs with exquisite sound and tonality
• You need high-end planar drivers with a wide soundstage
• You're looking for IEMs that deliver a neutral sound and great stereo imaging

You shouldn't buy this if:

• You have small ears
• You're looking to maximize value

With the Euclid, Audeze has shown that it can deliver a closed-back IEM that has the same warm and inviting sound as its over-ear headphones, and that's a significant achievement in and of itself. The IEMs are technically proficient, delivering excellent tonality across a variety of genres. The design is unabashedly premium, and the bold styling makes a statement. The build quality is among the best of any IEMs I've used to date, and you get an exhaustive list of accessories in the box.

But with the likes of Fiio and other Chinese brands delivering great-sounding IEMs for under $500, Audeze had to do something truly meaningful to justify the $1,299 asking price. Thankfully, it managed to do just that — the soundstage on offer combined with the excellent tuning makes the Euclid one of the best closed-back IEMs around. You're not just paying for the brand name here; these IEMs sound absolutely phenomenal in just about any situation.