Disclosure: I’d like to thank Linsoul for sending me the Kiwi Ears Aether for this review. All thoughts and opinions are my own, and Linsoul/Kiwi Ears had no say or input for the contents of this review.

The Kiwi Ears Aether comes to the IEM market with something that immediately sets it apart – a massive 15.3mm planar driver that stands among the largest you’ll find in any in-ear monitor. At a price of $169.99, this planar IEM is said to deliver audio quality you’d typically expect at a much higher price point.

I’ve had the Aether in my regular rotation for quite some time now, letting the online hype dissipate a bit. Throughout this review, I’ll be digging into whether having one of the largest planar drivers in an IEM actually translate into real-world sound quality. Let’s dive in to see if this affordable planar IEM can deliver where it counts.

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• Kiwi Ears Aether
• Cable with 3.5mm SE termination
• Travel case
• 3 sets of S, M, L silicone ear tips
• Manual

The included cable performs just fine for daily use. It avoids tangles reasonably well and stays in place thanks to an effective chin slider. There’s also no microphonics when moving the cable around while listening to music.

The carrying case is the same one Kiwi Ears used for the Canta planar IEM. It offers sufficient protection with its semi-hard shell construction and interior mesh pocket, but nothing particularly special. It does the job, and that’s perfectly fine. As for the ear tips, the three sets that are included are typical of Kiwi Ears IEMs, and they work just fine.

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The substantial physical presence of the Kiwi Ears Aether is immediately noticeable when you first handle them. These aren’t your typical compact IEMs, as they make a statement with their size alone. Picking them up reveals a premium construction that combines medical-grade resin shells with metal-bordered faceplates, creating an aesthetic that’s both striking and refined. The patterned faceplate looks unique and completes the understated yet classy look of the Aether.

These shells, though, are definitely on the larger side, as is the nozzle width. I’m sure this was a necessary design choice to accommodate that massive 15.3mm planar driver I noted earlier. Despite their size, though, they remain surprisingly lightweight at just 7.1 grams, which helps tremendously with long-term comfort.

Speaking of comfort, for my average-sized ears, the Aether fits comfortably without any real issues. The width of the nozzles takes some getting used to, but in the end I’ve worn them for 2-3 hour listening sessions without significant discomfort. That said, if you have smaller ears, you might find these IEMs a bit challenging to position properly due to the chonky shell size.

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At the heart of what makes the Aether different sits its massive 15.3mm planar magnetic driver. To put this in perspective, most competing planar IEMs typically use 12mm or 14mm drivers. This size difference isn’t just a marketing gimmick, though, it translates into real benefits for sound quality.

Despite housing that massive planar driver, the Aether features surprisingly accessible power requirements. With a 14-ohm impedance and 105dB sensitivity rating, it falls squarely into “easy to drive” territory. Using Apple’s USB-C dongle and even a Sony NW-A306 digital audio player, the Aether sounded great, and I detected no loss in soundstage or quality.

That said, like most planar magnetic IEMs, the Aether truly comes alive with additional power. Sources like the FiiO JM21, iFi GO Link Max, and Qudelix 5K all help unleash what these IEMs are truly capable of, adding just a bit more musicality and dynamic range.

The sound profile of the Aether strikes a careful balance between technical performance and musical enjoyment through its reference-style tuning. It has a mild W-shaped signature that maintains excellent tonal integrity. This tuning delivers a clean sub-bass response, balanced midrange, and a natural treble peak that ensures clarity without becoming fatiguing.

Bass

The Aether’s bass presentation immediately sets it apart from many other planar IEMs I’ve tested. Its sub-bass reaches remarkably deep with excellent extension, delivering a satisfying rumble when tracks call for it. Rather than overwhelming the mix, though, the bass maintains a focus on clarity and control instead of just raw impact.

What really impressed me is how the mid-bass maintains definition without bleeding into the midrange, something many IEMs struggle with. The bass response focuses more on sub-bass than mid-bass, providing just enough warmth to prevent the sound from feeling thin without muddying the overall presentation. For critical listening, the Aether resolves subtle bass cues with nearly tactile precision, letting you hear nuances in bass guitar fingering and drum textures that lesser IEMs simply gloss over.

Midrange

The midrange performance showcases excellent tonal balance throughout. Vocals possess what I’d call a “center front” presentation that remains clean and natural without becoming shrill or shouty. Male vocals have appropriate weight and body, staying detailed without feeling pushed back in the mix. Female vocals can occasionally exhibit a slight thinness, but this is minor and only noticeable on certain tracks.

Piano notes are reproduced with clarity and fade out organically, maintaining their harmonic structure. Even in complex passages with multiple overlapping instruments, the Aether maintains excellent separation, with each element occupying its distinct space in the soundstage. This separation maintains a cohesive presentation that sounds natural rather than clinically dissected.

Treble

The treble extension on the Aether provides that characteristic planar “airiness” without becoming harsh or fatiguing. Unlike many planar IEMs that push treble aggressively, the Aether maintains excellent control with just enough sparkle to reproduce cymbals and hi-hats accurately. My go-to track for testing sibilance is Reckoner by Radiohead, and this track is extremely pleasant to listen to with the Aether. If you are susceptible to brightness or sibilance, then the Aether is a great choice for you.

What’s most remarkable is how this IEM avoids the typical “planar timbre” issues, that somewhat metallic edge many planar drivers tend to exhibit. Instead, the treble remains smooth and detailed with sufficient presence to reveal nuances in recordings without ever becoming grating. The Aether’s treble seems finely tuned to harmonize with the bass and midrange, creating a natural high-frequency response that remains engaging through extended listening sessions.

Soundstage and Imaging

The soundstage for the Kiwi Ears Aether is very open, with great width and depth, and good height. The depth actually is very deep for an IEM, and it allows a sense of surround audio to it. The openness doesn’t sound artificial, and the audio is clear and layered beautifully.

Imaging is extremely solid, with all instruments being placed accurately in the mix and making it easy to identify the direction each sound is coming from.

Gaming

I really like using the Aether for gaming. In fact, for IEMs, they have become my go-to set for gaming sessions. This is for both competitive gaming and single-player immersive games. In PUBG and Call of Duty Warzone, the excellent holography and imaging allowed me to accurately hear where sounds like gunshots and footsteps are coming from. The sound profile also lends itself to being a great IEM for these types of games. Gunshot sounds aren’t too shrill, and footstep sounds don’t take over the mix.

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The Kiwi Ears Aether stands as a remarkable achievement in planar IEM design. The massive 15.3mm planar driver delivers exceptional technical performance while maintaining a natural, yet engaging sound signature that works beautifully across multiple genres.

Sound quality is undoubtedly the Aether’s greatest strength. The clean, articulate bass, precise midrange, and smooth, fatigue-free treble genuinely rival more expensive offerings. That said, potential buyers should consider their ear anatomy, as the large shells might not be suitable for everyone. Overall, though, at $169.99, the value proposition here is exceptional.

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