Kiwi Ears Aether - A Fine Planar with a Troublesome Peak

3.5⭐️

+ Fun, engaging, and well balanced V-shaped tuning 

+ Snappy, elastic planar bass with decent extension 

+ Clean and clear midrange with nice vocal and instrument timbre

+ Treble energy, sparkle, and air

+ Technically proficient with a touch of musicality

- Does a lot good but nothing really standout 

- 8kHz peak can be quite bothersome for me

- Not the most engaging or exciting tuning

- Lackluster accessories

- Larger nozzle and shell size could cause fit issues for some

thaslaya's star rating system:

☆☆☆☆☆ - Fantastic!

☆☆☆☆ - Recommended

☆☆☆ - There are buyers but not for me

☆☆ - Can't see the appeal

☆ - Product is a failure

Disclaimer: 

This product was loaned to me for review by a friend. I receive no compensation and all thoughts and opinions are my own. A big thank you to Jaytiss for the opportunity!

Non-affiliate link for those interested:

https://www.linsoul.com/products/kiwi-ears-aether?srsltid=AfmBOoo6HS003nEYy6Nm0c4HUDPAiJulhHhlqqHFPqx8k-NCrNhRaIpV

Gear used: 

●Samsung Galaxy s25 Ultra

●HiBy R1/R3 II

●Various DAC/amps

Source:

●Listening was done using Amazon Music HD/Ultra HD and local FLAC files.

Introduction: 

Kiwi Ears has been a staple of the budget and mid-fi IEM tiers for the last two years, with popular releases like the Orchestra Lite, Cadenza, and the Quintet, among others. The Aether is one of their latest products and it sports a single 15.3mm planar driver. Although it is their latest single planar driver IEM, it is not their first. That distinction belongs to the Melody, which received mostly favorable reviews upon its release. The Aether is a bit more expensive tbough, coming in with a price tag of $169, and it boasts athough, planar driver as well. Let's break down this newest Kiwi Ears IEM and see how it fares against some of today's competition.

Build, fit, ergonomics:

As this was a loan, I did not receive the retail box so I can't speak to the unboxing experience, but if you've ever purchased a set of Kiwi Ears IEMs, the Aether's accessories will look very familiar. It essentially comes with the same case, cable, and tips as many of their other sets. To be honest, the inclusions are pretty underwhelming, and I think it's time that Kiwi Ears steps up their accessory game to match some of their competition like DUNU and Letshuoer, who usually offer more tips, better cables, and better cases. The Aether's shell is made of black resin with a metal frame around the faceplate, which features the Kiwi Ears logo and a slightly sparkly design. I'm not the biggest fan of the aesthetic choices that Kiwi Ears made here, but taste is subjective and I'm sure some will be drawn to the design. The shells are definitely on the chunkier side and the nozzle is somewhat large too, measuring 6.4mm at the widest part where there's a lip to help hold tips. The insertion depth is a little more than average but they fit just fine for me; however, I can see fit issues arising for those with smaller ears. There is a line of three small vent holes located just in front of the flat 2-pin connection on the shells. While the black cable is nothing to write home about, it is a little bit thicker than other Kiwi Ears cables that I've seen. I chose to substitute it out for the XINHS S89 cable. I did not recieve the stock tips so I chose to use the Penon Liqueurs, which gave me a good fit and seal. The branded, black zipper case is also just the typical affair. Its a little on the small side but easily pocketable.

Sound impressions:

I'd describe the Aether's overall tuning as slightly W-shaped but still well-balanced. It has a healthy bass response, some midrange emphasis, and a decently extended treble with a good amount of sparkle. The note weight is maybe just a hair on the thick side of average, which is to my liking. The Aether isn't a particularly hard set to drive and can get to loud volumes with just a simple dongle; however, most planar IEMs do perform better with more power and headroom. The detail retrieval is not the best in its price bracket, but it is still decent. The soundstage has good width but perhaps sounds a bit flat. It could use more depth, to my ear, but overall it does not sound cramped or claustrophobic. The timbre is good, and there is no glaring planar sheen to speak of, but it is also not the most natural and organic I have heard. The accurate and precise imaging is a strong component of the technical performance, along with the dynamics, separation, and layering. The Aether never gets bogged down in complicated tracks, and the tuning remains strong despite the volume level. Overall, I wouldn't say the Aether is class-leading in terms of technicalities, but it is more than serviceable, especially at this price point.

For better or worse, the Aether is somewhat source-sensitive, and finding the right synergy can make all the difference. I found a few good pairings among the DAC/amps I own that suit my preferences. The FiiO RR11 has a more analog sound signature that helps keep any treble peaks to a minimum. The Questyle M18i is very dynamic and helps bring out bass resolution and sub-bass extension, but it might also exacerbate treble peaks. For my listening impressions, I chose to use the EPZ TP35 with the slow roll-off, low-latency filter, as it helped preserve the overall tuning while slightly curbing the treble peak.

●Lows - The slightly elevated bass response is probably my favorite aspect of the Aether's tuning. It is more sub-bass focused, but the mid-bass presence is good too. The extension is not the end-all-be-all but can definitely dig low when called upon. The bass has a nice elasticity and snappy character, and the texture is clean, but I think it could be more resolving. The impact and slam are decent, if not a little staccato and punctuated. The attack and decay are on the quicker side and can sound slightly unnatural to those used to a traditional dynamic driver bass response. The rumble and reverberation are good, but again, they are a bit on the shorter side due to the characteristics of planar drivers. There is no bleed into the midrange to my ear. Overall, the bass of the Aether is pretty well done, but it still falls short compared to DD bass for me.

●Mids - I have a bit of a love/hate relationship with the Aether's midrange. While vocals are generally well-accentuated, I typically enjoy a slightly more forward presentation. There is just not quite enough emphasis in the upper midrange to let them reach their full potential. The mids could use a bit more energy around 3 kHz to help highlight vocals and instruments in this range. Going by the graph, the pinna gain should have an earlier rise, which would help lend more weight to male vocals, as they aren't quite as forward as their female counterparts. The lower midrange could also use more weight to showcase lower-registered instruments like the cello. I also find the entire midrange generally lacking some emotional depth, and it's hard to make an emotional connection. Overall, the mids are good, and while guitars in particular sound quite detailed, the entirety of the midrange could be better for my tastes.

●Highs - The Aether's bass is quite nice, and the midrange is decent, but the treble is where I have the most trouble. It's not inherently bad or anything, but there is some peakiness around 8 kHz that I'm sensitive to. This leads to some harshness and sibilance on certain vocal notes like "s" and "sh," and can be wince-inducing on sibilant-prone tracks. The treble has a certain incisiveness consistent with many other planar IEMs I have heard. To it's credit, there is good extension and air without sounding too ethereal, and cymbals are particularly well done. They are crisp and correct without sounding splashy or metallic. Snares and claps also have a crisp texture and a nice snap. Overall, the treble is energetic and fun, and I do not have much issue with it except for that pesky 8 kHz peak, which really does put a damper on the entire experience for me.

Comparisons: Credit to Jaytiss and Audio Amigo for the graphs. 

●Letshuoer S12 2024 ($200) - This one is a matchup of single planar drivers. The S12 has the far superior unboxing experience and overall accessory package. It includes a better modular cable, sturdier case, and better tip selection. The S12 has a smaller shell and a shorter nozzle. The Aether fits me a bit better due to the nozzle length and angle. Design is always subjective but I personally really like the black and rose gold combination of the S12. These two graph pretty similarly and have well-balanced V-shaped tunings. While both have a decent bass shelf with a focus on sub-bass, the S12 is overall a bit bassier, with deeper extension, more fullness, and more mid-bass impact. Both have some characteristics of planar bass response (speed and resolution), but the S12 has a longer lasting reverberation that goes a long way towards sounding more natural for my preferences. In the midrange, the Aether positions vocals a bit closer to the ear and they sound a little thinner compared to the S12. However, instruments have a more natural balance and timbre on the Aether, while the S12 adds a noticeable amount of noteweight and warmth to the midrange that some may not prefer. The treble on the Aether is a little airier and more incisive especially with claps, snares, and "s" and "sh" sounds. The S12 doesn't have quite the same airiness up top but it has a smoother presentation and a sense of energy and sparkle that hits my ear better. In the technicalities, the Aether has more depth in the soundstage and slightly better imaging and dynamics. The S12 has a wider soundstage with more space between instruments, better separation and layering, and a slight edge in detail retrieval. Overall, the Aether is admirable, but the S12 2024 has a certain combination of warmth, bass, and detail that just grabs me, and it remains my favorite planar IEM to date.

My pick: S12 2024

● Hidizs MP143 ($130) - Here's another single planar matchup, and for this comparison, I utilized the MP143's gold filter, which graphs fairly closely to the Aether. Neither of these two has great accessories, in my opinion. Both have somewhat cheap-feeling cables, but the Aether has an actual case, whereas the MP143 includes a small carrying bag. However, the MP143 does come with three different tuning filters, which adds variety and value. The shell of the MP143 has an all-metal build compared to the mostly resin Aether. The MP143 is larger, but the Aether has a longer and thicker nozzle, and I personally prefer its fit due to the nozzle's insertion depth and angle. As for aesthetics, neither one really grabs my eye, but I would probably pick the MP143 due to its more unique shell shape and design. Now, for the sound comparisons, the Aether has a more balanced, V-shaped sound signature with more treble emphasis, while the MP143 is a bit more U-shaped. The low end of the Aether is more sub-bass focused, with a deeper reaching extension. The MP143 has more midbass focus and impact, which also adds a warm tilt to the frequency response. The Aether's bass is more characteristic of what I expect from a planar driver: decent speed, quick decay, and good resolution. To my ear, the MP143's bass is closer to that of a typical dynamic driver. By this I mean it can be a bit messy sometimes, but it also has a certain fullness and a more natural decay. The midrange is warmer and smoother on the MP143 but it sounds overall cleaner and better separated on the Aether. I prefer the vocal presentation of the MP143 because it is a bit more accentuated and forward. In the treble, the Aether definitely has more energy, air, and sparkle. The MP143 is not without its own treble energy and excitement, but it is decidedly less than the Aether, due in no small part to that 8 kHz peak I'm sure. In the technicalities, the Aether has slightly better timbre, dynamics, and detail retrieval, while the MP143 has more note weight and greater soundstage depth. The MP143 may not have the bass performance or technicalities of the Aether, but neither does it have the treble issues. Overall, the tuning of the MP143 is much more enjoyable for me, and at the end of the day, this hobby is all about enjoyment.

My pick: MP143

● NiceHCK F1 Pro ($99) - Here we have yet another single planar driver contest, and these two graph fairly closely. This matchup is also useful to gauge the difference between more budget-friendly planars and the tier above. Both sets have very similar accessories, but I'll give the nod to the F1 Pro for a slightly better case and cable. The shell size, build quality, and overall design vary quite a bit. The F1 Pro has a small, all-metal shell and a much smaller nozzle. The Aether has a mostly resin build, with a shell and nozzle size that are definitely on the larger side. The design is subjective, but I prefer the F1 Pro's blue aesthetic, although the Aether offers a better fit and seal for me. The tunings of these two are pretty similar, with the exception of the Aether's larger bass shelf and extra mid-bass, which does add some warmth. The Aether has a more boisterous bass response with deeper sub-bass extension and a slightly slower decay that sounds more natural to my ear. The F1 Pro has more of that typical speedy planar bass response, with a quick attack and decay, which is great for resolution but doesn't sound the most natural. In the midrange, the F1 Pro has better separation between the bass and lower mids. The Aether lends more weight to instruments in this range, but the F1 Pro has a better overall midrange balance to me. It also allows vocals to come forward a bit more and really shine. The graph shows a close relationship in the upper frequencies as well, and both sets have a somewhat accentuated treble that is not really my preferred style. However, the F1 Pro is noticeably brighter and sounds a bit thinner, exhibiting some splashiness on cymbals. While the Aether's 8kHz peak is quite noticeable to me, the added bass helps it sound less bright in comparison. As for the technicalities, the Aether offers better timbre (the F1 Pro has some of that classic planar "zing"), more note weight, and better dynamics. However, the F1 Pro is a very capable sub-$100 set and rivals the Aether in detail retrieval and soundstage. Ultimately, this matchup comes down to overall tuning preference and sensitivity. I do prefer the Aether's more balanced tuning and less zingy timbre, but honestly, the difference between these two is not night and day. Pairing the F1 Pro with a warmer source or utilizing EQ could be a great alternative to spending the extra money on the Aether. 

My pick: Aether

In conclusion:

The Kiwi Ears Aether is a fun and energetic planar that really impresses, but there are a few drawbacks that keep me from rating it higher. The first is the somewhat lackluster accessory package. It is not terrible for this price tier, but other companies seem to be stepping up their cable and case game, so Kiwi Ears should really re-evaluate their offerings. Next is the somewhat larger shell and nozzle. I myself have large ears, and fit is never as much of an issue for me as it might be for those with smaller ears, but it's worth noting. The third and most concerning factor for me is the 8 kHz peak in the treble. This is definitely subjective, as each individual is sensitive to different areas of the frequency response, but using EQ to bring down the 8 kHz peak by about 4 decibels did wonders for my enjoyment of this set. The peak is most apparent in pop and rock genres, but orchestral and classical genres perform well without the need for EQ. Now let's talk about what the Aether does well. The bass has nice elasticity, punch, body, and sub-bass extension, the midrange delivers an excellent vocal and instrumental presentation with a decent timbre, and the treble has a good amount of sparkle and air. Also, details and instruments in the upper frequencies are very pleasing, especially cymbals. In summation, I think the Aether could be a great choice for those looking for a balanced and fun tuning, and wanting a taste of planar performance without breaking the bank. Unfortunately, it is one I cannot really enjoy without a touch of EQ, but that doesn't keep me from recommending it to others.