Audeze Euclid IEM Review

My First Planar Magnetic IEM Experience

Here's some geometry for you:

The whole of the Audeze Euclid IEM is greater than the sum of its very amazing parts.

I know, you weren't looking for math here. But surely you remember that Euclid was the father of modern geometry, and, well, Audeze named its newest earphone after the Greek mathematician.

Euclid wasn't any old mathematician, and the Euclid isn't any old in-ear monitor. It's a closed-back, single planar magnetic driver IEM that boasts the highest dynamic range of any in-ear in its size category. Now, I'm a big fan of planar magnetic headphones. Their excellent bass, detail retrieval, and smooth, relaxed sound had me hooked pretty much from the get-go. But I hadn't yet tried any planar IEMs, and was very eager to see if they would captivate my ears in the same way.

At $1,299, the Euclid's price competes with some full-size Audeze headphones. But the Euclid has the advantage of being portable and easy to drive. I love Audeze headphones, with the LCD-X being among my favorites, but they're a tad heavy and aren't exactly ideal for extended wear.


  • Wide soundstage
  • Instrument separation
  • Detail
  • Comfort


  • Price
  • May be bass-lite for some

Materials, Quality & Comfort

It's "plane" to see that this is a really comfortable IEM. (Sorry, little geometry humor there.) The ear pieces are not small, but their shape really worked for my ears, providing a snug fit. The 5mm ear port and the contoured design make for excellent ergonomics.

The ear pieces are precision-milled from solid aluminum and have a matte black finish. The faceplates are carbon fiber and feature a cool holographic design with a raised "A." The black with gold accents make for a look that is both elegant and cool. And you know what? It's sexy, too.

The black braided cable is 3.5mm and unbalanced with gold-plated MMCX connectors. Bluetooth and 4.4mm balanced cables are available as options. The cable routes behind the ear, so there's no need for ear hooks. I found it very easy to remove the ear pieces from the cable, but they felt completely secure when attached.


"Euclid's 18mm planar magnetic drivers incorporate Audeze's patented Fazor™ waveguides to eliminate the phasing and distortion typical of most closed-back dynamic in-ears. The efficient single driver design also includes our patented Fluxor™ magnets and Uniforce™ voice coils to further reduce distortion, improve sensitivity, and create superior coherency across the entire frequency spectrum." -Audeze

What the Fazor waveguide does is eliminate the phasing and distortion typical of closed-back in-ears. Imagine dropping a pebble in a pond. A series of waves will result, which radiate outward in a circle. Now imagine you drop two pebbles.


When those waves collide, they become distorted. When this happens in audio, it's called wave interference. Audeze's Fazor technology combats this. Think of Fazors like guides for sound, maneuvering the sound waves out of the drivers in an even and smooth way without interfering with each other. Each Fazor element is placed just outside the magnets that drive the diaphragm, allowing the sound waves out in a more even and parallel direction, reducing interference and diffraction, or scattering of sound waves.

Fluxor magnets and Uniforce voice coils also help to reduce distortion. In addition, they improve sensitivity and create superior cohesion across the entire frequency spectrum.

Euclid is engineered for an incredible 105 dB/mW efficiency and a max SPL well over 120dB, which Audeze claims gives it the highest dynamic range of any in-ear in its size category. Of course, as any responsible audio company should, Audeze cautions against listening at volumes higher than 85dB, lest you damage your hearing.

Sound Impressions

There is a sense of width and depth that had me turning my head at times because I perceived certain sounds to be coming from within the room vs. my music. This can actually be startling, but I think it speaks to the amazing soundstage of the Euclid.

Review setup: Tested with 1) Matrix Audio Element X headphone amp/DAC/music streamer and 2) Astell&Kern A&ultima SP1000 DAP music player.

In a way, the Euclid sounded as I expected it would. In quite another way, it sounded nothing like I expected. Let me explain.

I expected a planar magnetic sound: natural, musical, relaxed, and detailed. Those terms definitely describe the Euclid. The bass response was lighter than I was expecting. But what it may have lacked in raw power and rumble it made up for in tightness, articulation, and refinement. Overall, though, I feel that the Euclid is a more mid- and high-centric IEM.

But the Euclid has a soundstage that I simply didn't expect on an IEM, much less a closed-back one. There is a sense of width and depth that had me turning my head at times because I perceived certain sounds to be coming from within the room vs. my music. This can actually be startling, but I think it speaks to the amazing soundstage of the Euclid. This happened, for example, in "Julius," where I literally turned around because I mistook female backing vocals for a conversation happening behind me! Also on that track, which sounded light and quick, the horns had a lot of presence in the mix, and they absolutely shined.

Instrument separation is a real strong suit for the Euclid. Frenetic music is a great way to gauge this, because you either keep track of the instruments or they start to blend. In Jethro Tull's "Skating Away," there was a great sense of separation in the second part of the song, where the bass, flute, guitar, and vocals all hold their own. And at the beginning of the track, one can hear Ian Anderson whistling and making tea. There are a lot of sound treats here, from the clink of the teaspoon against the cup to Ian Anderson's breath. The Euclid did a fine job of presenting this bit with a major amount of clarity and realism. Also, strings sounded amazing here and in other tracks. I love it when guitar plucks sound three-dimensional!

On "Time," there was a wonderful sense of dimension in the opening sequence, which is a series of jarring alarms followed by a simulated heartbeat via rototoms. It was the instrumentation that really shone in this track, with David Gilmore's strong and gritty vocals taking a slight backseat.

I chose David Bowie's "Golden Years" for its strong bass opening. There was great punch here, but it wasn't deep and rumbly and it wasn't the highlight. I was more focused on pops of sound and the way the instruments complemented rather than competed with each other. There was a nice funk factor, even if it wasn't the most energetic presentation.

Switching to the SP1000, which has a more forward sound than the neutral Element X, I found that the Euclid had a more analytical presentation. The opening of "Time," for example, had an insane level of sharpness and detail, which was really cool, but the alarm clocks were almost too shrill! The tap of the drums, however, was pleasingly sharp and holographic. The guitars absolutely wailed, to the point where I almost felt like they had voices.  


  • "Golden Years" - David Bowie (Station to Station)
  • "Julius" - Phish (Hoist)
  • "Skating Away on the Thin Ice of a New Day" - Jethro Tull (War Child)
  • "Time" - Pink Floyd (Dark Side of the Moon)


Audeze Euclid vs. Meze Audio Rai Penta

The Rai Penta is a five-driver design, with two dual balanced armatures and one dynamic driver per side. The Penta has a neutral and balanced sound that to my ears has more bass impact (think power vs. articulation) and more energy than the Euclid. The Penta hits with more warmth and emotional impact in the midrange. The Euclid, on the other hand, has a more bass-light, smooth, relaxed sound. To my ear, it also has more detail and a wider soundstage.

Meze Audio Rai Penta

Audeze Euclid vs. Audeze LCD-i3

Audeze LCD-i3

This open-back planar magnetic IEM from Audeze has a similar sound to the Euclid, minus the convenience factor that a closed-back offers. The LCD-i3 has bigger drivers (30mm vs. 18mm on the Euclid), thus bigger ear pieces. The LCD-i3 uses ear hooks; the Euclid doesn't. Now, what I'm about to say is purely subjective, but then again, that's what a review is. My experience with the LCD-i3 was rare in that I truly forgot I was listening to an earphone -- or a headphone for that matter. In other words, I kept having these flashes of awareness where I "remembered" that I was listening to recorded music. It sounded so natural and spacious. I do think the LCD-i3 has a warm tilt whereas the Euclid is more neutral-sounding.

The Verdict

  • Genres: Especially good with blues, folk, acoustic rock, classical.

The Euclid is a great option for audiophiles who want a convenient, closed-back, and portable planar magnetic IEM. I really enjoyed my time with the Euclid. I love the detailed yet relaxed vibe of a planar headphone, and the Euclid did not disappoint. The Euclid has a natural and revealing sound that's neither fatiguing nor analytical. I especially enjoyed the Euclid with complex instrumental tracks and slower-paced music. There is definitely a mid-high focus, and the Euclid might be bass-light for some. I never felt like bass was lacking, but it's not the highlight. And the soundstage is amazing, instrument separation is phenomenal, and detail and clarity are top-notch.

Featured Products


What's in the Box

  • Euclid IEMs
  • MMCX Braided Cable
  • Pelican 1010 Travel Case
  • Mesh Fabric Bag
  • Assorted Ear Tips
  • Cleaning Brush
  • Cable Clip
  • Certificate of Authenticity


Audeze Euclid Planar Magnetic Closed-Back IEMs Review

Audeze Euclid Unboxing


Style: In-ear, closed-back

Transducer type: Planar Magnetic

Magnetic structure: Fluxor™ magnet array

Phase management: Fazor™

Magnet type: Neodymium N50

Diaphragm type: Ultra-thin Uniforce™

Transducer size: 18 mm

Maximum SPL: >120dB

Frequency response: 10Hz - 50kHz

THD: <0.1% @ 100 dB SPL

Sensitivity: 105 dB/1mW (at Drum Reference Point)

Impedance: 12 ohms

Max power handling: 500mW

Min recommended power: > 50mW

Wired connection: Braided MMCX

Weight: 15g/pair without cable

Sound port diameter: 5mm