A Larger, But Soft Planar

Ratings

Pros

• It sounds wide, broad, clear, transparent and doesn’t feel forced to gain detail or brightness.
• It’s undoubtedly one of the smoothest, most balanced, natural, pleasant, melodious and musical planars I have ever tried.
• The larger driver doesn’t lose any of the good characteristics of the planars: great bass capability, with a technical level on a par with the most expensive planars. Very good layering, speed, separation, precision, resolution and expressiveness of detail in a pleasant way.
• The cable has four strands, is quite soft and flexible.
• Despite the size they are quite comfortable.
• Very good value for money.

Cons

• It’s not as technical or as analytical as other more expensive planars.
• Bass response is more neutral, it doesn’t have as much power, body, physicality and punch as others.
• Kiwi Ears still doesn’t offer a balanced cable option.
• Perhaps the capsules are too bulky for some.

Purchase Link

https://kiwiears.com/products/kiwi-ears-aether

Link to the Store

https://kiwiears.com/

Introduction

Kiwi Ears, in its unstoppable process of launching new products, now presents one of the planar IEMS with one of the largest transducers of this type on the market. This is the Kiwi Ears Aether, with a 15.3mm driver. It has multi-layer N52 neodymium magnets that offer reduced output power and distortion. Its studio-grade sound provides clean sub-bass response, flat mids and a natural treble peak for clear, balanced audio. With improved ventilation and a wide soundstage design, the Aether recreates the immersive experience of open-back headphones, ideal for professionals and audiophiles.
The Aether’s planar magnetic transducer excels in speed, responsiveness, imaging and soundstage, delivering precision and clarity. Tonal integrity was a primary goal in the Aether’s design, ensuring a natural and accurate sound signature. The bass delivers a deep, subwoofer-like punch, and a smooth transition from the mids to the lows adds warmth to the overall body of the sound. The midrange (300 to 800 Hz) is carefully tuned for monitor-like accuracy, ensuring a faithful representation of vocals and instruments. The treble has been precisely tuned to match the tonal perception of the human ear, providing a clear and natural treble response. The result is a balanced and immersive listening experience, true to the essence of each track.
The Aether’s 15.3mm planar transducer, combined with a newly designed chamber and advanced ventilation, delivers a listening experience similar to that of open headphones or high-quality stereo systems. This design not only improves resolution, but also provides a wider, more accurate soundstage and enhanced imaging, allowing for an incredibly immersive listening experience. The result is a clear, airy and realistic sound that captures the essence of planar magnetic transducers and delivers a truly spacious and dynamic audio experience.
As usual, the Aether have a 0.78mm 2-pin connector and a 3.5mm gold-plated plug, as well as the brand’s classic packaging for this price range.
Aside from all the brand talk, let’s see all these details expanded in this review, as well as the sound that this new model from Kiwi Ears can bring to the table.

Specifications

• Driver Type: 15.3mm magnetic planar with multi-layer N52 neodymium magnets.
• Frequency Response: 20Hz-20kHz.
• Sensitivity: 105dB SPL/mW (at 1kHz).
• Impedance: 14Ω (at 1kHz).
• Jack Connector: 3.5mm SE gold-plated.
• Capsule Connection Type: 2Pin 0.78mm.
• Starting Price: $169.99.

Packaging

Of course, the Kiwi Ears Aether come in the classic Kiwi Ears box, measuring 164x113x54mm. On the main side is a large, life-like photo of the capsules on a pink background with a vertical gradient upwards. Below is a black strip with the brand name, model and description on the left side, while on the right side there is a QR code that redirects to the website. In the top right corner is the brand logo and the model description. The model name is in very large pink font on the lower black stripe. On the back, at the top, are the logos of the certifications that the product complies with. The brand logo and description are repeated. The brand name and importers’ contact details are shown below. The specifications are on one side and are not too extensive. On the other side is a description of the product. Once the cardboard is removed, a brushed metallic coloured cardboard box with the brand logo in the centre is visible. After lifting the lid, the inside is the same: a flap is repeated to protect the product. Underneath, the rest of the layers are of the same type. At the top left, you can see the capsules embedded in a white foam mould. Underneath is another box containing the silicone tips, while in the right half is the larger box containing the zipped case. The complete contents are as follows:

• The two Kiwi Ears Aether capsules.
• A user manual.
• A warranty card.
• One warranty certificate.
• Three pairs of grey silicone tips with red core, sizes SxMxL.
• Three pairs of black silicone tips, sizes SxMxL.
• Three pairs of white silicone tips, sizes SxMxL.
• One black four-stranded cable, 2Pin 0.78mm interface and 3.5mm SE plug with plastic protector.
• A black leatherette zipped case with white brand logo.
• A velcro strip for winding up the cable.

There is no doubt that this is the brand’s classic packaging. It is slightly larger and the brushed silver colour of all the inner boxes makes it look more spectacular and eye-catching. The case and silicone tips are the same as the previous Airoso model, but the cable is superior, with a thicker and completely black wire. Undoubtedly, it is a mixture of the KE4 cable and the classic Airoso model, which retains the thickness and quality of the latter, and the black colour of the former. As for the zippered case, Kiwi Ears has got the size right, as it is taller and sufficient to hold the bulky capsules of the Aether.

Construction and Design

Aether capsules are relatively large and bulky. They are constructed of black resin and have an outer face composed of a metallic ladder rim surrounding a plate that has a horizontal flowing pattern of metallic glitter and traces of other colours, such as green, red or blue. In the centre is the brand’s logo embossed internally in a shiny silver colour. The capsules are thick and the external shape is of an almost flat face (actually, there are two planes, one short and one slightly larger) and an incomplete semicircle underneath. Next to the connection interface, which consists of a rectangular piece of translucent plastic fully integrated and smooth into the capsule, there are three holes. The inner side is rounded, completely smooth, with no protrusions on the edge. There is only one other hole in the centre. The mouthpieces are metallic, silver-plated, consisting of a base, a central cylinder of smaller diameter (5.35mm) and a larger crown (6.5mm). The total length is 3.5mm. It is worth noting the very light weight, as well as the voluminous size of the mouthpieces.
The cable has four black intertwined strands, relatively thick, but very flexible and not stiff. The plug sleeve is a simple cylinder but depressed in the centre. The cable outlet is made of black rubber with a double step. The splitter piece is very similar but half the size, with bevelled edges and a more pronounced depressed centre. The pin is a black hard plastic sphere with a through hole. It performs the adjustment function very well as it does not slip easily. The sleeve of the 2Pin 0.78mm gold-plated connectors are two cylinders with a bezel at the cable exit and two slotted rings next to this end. The pins are mounted on translucent hard plastic rectangular bases, red for the right channel, transparent for the left. There is a blue dot on one of the short sides to indicate polarity. The cable on this side has over-ear guides. The plug has a translucent soft plastic protective sleeve. The cable comes with a plain black velcro strap that cannot be attached to the cable.
I’m very struck by the thickness of the capsule and its volume. It keeps the classic Kiwi Ears look with that black resin construction, but the stepped metal bezel on the edge of the outer face stands out, as well as the horizontal and silver fluid panel, which gives it a very distinguished and more attractive look than the rest of the brand’s models, adding even more value to this special model that has a large 15.3mm planar driver.

Adjustment and Ergonomics

Despite their size, volume and thickness, the capsules are very light. Of course, they take up the entire pinna and stick out of my ears due to their thickness, but their rounded and smooth inner side makes them comfortable. The biggest problem is the size. In the long run, after a few hours, they can exert a slight pressure on the side walls of my pinna, which causes some fatigue and discomfort.
On the other hand, the fit is very good and there is hardly any rotation. It is very easy to find a good combination of silicone tips to get the best seal, a high level of isolation and the best fit for the best sound. As usual, I have achieved the best results with my large homemade foam-filled silicone tips. The insertion is shallow, as the capsule and mouthpieces are not very long. On the other hand, I find it difficult to achieve a medium insertion.
Finally, it is worth noting that the guides on the ear are not annoying thanks to their curve and also to the lightness of the cable.

Sound

Profile

If there is one defining characteristic of IEMS with planar transducers, it is that their frequency response can be very similar to each other. In this case there are no major differences and the profile of the Kiwi Ears Aether is a classic tiny w, somewhat softer in the sub-bass than in other models. As I say, the sub-bass is not as emphasised and, up to about 12 kHz, the FR moves between a 10 dB band, where the peaks of that W are at 20 Hz, 2 kHz and 8 kHz, offering a relatively balanced profile. From 12 kHz onwards, there is that typical drop in the air region, which can be more or less wide depending on the model. This tuning is very similar to that of the early Letshuoer S12, the latest 7Hz Timeless II (with Flat Gold mouthpieces) or the not so recent NiceHCK F1 Pro. In this respect, there are not many surprises.
Another area where the Aether does excel is in soundstage size; it seems that both capsule and driver size matter in extending that quality.
Finally, it is worth noting that, like most planar IEMS, they require a certain level of power to bring out their true potential.

Bass

What the Aether FRs demonstrate is that the bass is not as powerful as the competition. This is also evident in the first note of my test list: there is not as energetic a punch, its punch is quite dry, but generates less impact; the volume and physicality of the bass is more limited and not even as dark as in other models. In the classic very low frequency pure tone test, the 20 Hz LFO is perceived as a very controlled, low negative undulatory vibration, with a slight sensory and audible capability. The energy level is not very high and the result is quite realistic, but with limited darkness. On the 25, 30 and 40 Hz LFOs, this remaining wave character is noticeable, while the result becomes more audible, naturally, gaining slightly in power and physical sensation of energy. The behaviour is quite good for a planar that has a more technical level and is less powerful and physical. It shows that its way of proceeding is not so dark, although it still seems quite natural to me, with that lower energy aspect, but more resolute in terms of efficiency, speed, control, resolution and very low decay. In this way, the base hits are very dry, fast and with hardly any decay; the level of elasticity is low and hardly feels rubbery, which makes it lose some sense of volume and realism. However, for other ears, these qualities will be more appreciated, as they imply a higher technical quality. For my part, I miss it being darker, deeper, more voluminous and energetic.
In the dirty, complex and unfiltered bass test, the technical level of the Aether’s bass is evident: they hardly suffer at all in the most complex passages and are able to recreate them with full control performance. The Aether’s are very well adjusted to the dirtiest bass lines, reproducing them with a very high level of precision and resolution. No bass note is left unrepresented and no note is left out of the script. Even the most complex passages feel totally controlled, as they are generated in a very musical and efficient way, recreating the dirtiest lines beautifully, maintaining a distance between the layers and stratifying the planes in a distanced, precise and resolute manner. Undoubtedly, the Aether’s technical bass capability is very high and is ideal for those looking for planars with a more controlled bass impact, where special qualities prevail over other physical abilities such as energy level, volume, space occupied, sense of depth and level of darkness.

Mids

The mids are characterised by a higher energy top end that seeks that level of transparency and clarity in a natural or forced, but always controlled, way. The first half of the mids have good presence, but their notes are relatively thin. The base is lighter and the sense of body and physicality is neutral. This moves the Aether away from a high level of density that sets it apart from other planar IEMS. However, the sense of distance and amplitude is increased. By reducing the physicality, the sound is not perceived as homogeneous and dense, but more free and expansive. The separation between notes is clearer and the sense of clarity and transparency is more pronounced.
The male vocals have a very good presence and proximity to the listener, but do not have a completely solid, strong and physical base, but are somewhat lighter and lacking the full power to make them more noticeable. The result is a balance between physicality and nuance, something that becomes quite noticeable when it comes to the overall summation of this first half. Surprisingly, although the female vocals have a more prominent and closer presence, they are not dense based either, but maintain that balance between body and detail, as well as an obvious clarity. The result is vocals with a slight hint of warmth, which are well balanced to sound natural, pleasant and smooth, because the expansion of brightness is well controlled from 2 kHz to the first highs. In this way, sibilance levels are adequately nuanced.
On the instrumental side, the sense of density that planars usually have is limited in favour of a more expansive, clear and transparent feel. The impression of separation prevails, but the overall foundation remains somewhat light. Thus, the lower-based instruments lack a bit of foundation and the higher ones lack a bit more drive and bite. Nevertheless, they all have very good presence and naturalness, and also achieve a good level of detail, nuance and ornamental richness in a realistic and unforced manner.

Treble

The upper area follows the usual trend of recent planars to control the energy level. However, it does not manage to do so throughout the whole range, as some sparkle escapes, which can be slightly critical at times. Starting from a fairly controlled transition between the mids and early treble, the impression of brightness is not very high, but has a certain nuance and smoothness. It is certainly not sharp, incisive or crunchy, but chooses to be more effective and slightly pleasant to optimise long listens. I don’t detect too much planar brightness, nor is it a cold range. The extension up to the air zone is quite good, and the near homogeneity of the presence up to that point makes the treble expressive, clear, articulate, well-defined, resolute and precise. But it is also true that they lack a certain sense of air and a more vivid sparkle that would make them more dynamic, fun and far removed from the treble heads’ preferences. However, the upper range has enough prominence on its own and maintains the natural support of the rest of the range with its harmonic extension and precise speed.

Soundstage, Separation

Perhaps one of the strengths of the Aether. The combination of a large capsule and a planar, which is also larger than the competition’s, creates a very wide and almost enveloping soundstage. The most prominent axis is the horizontal one, which extends beyond my ears. On the other hand, depth and height are quite good, but not quite up to the same level. The expansive sensation is noticeable, but these are not ethereal or volatile IEMS, so the gaseous sensation is limited. Nor are they dense or overly homogeneous, but rather more relaxed, smooth, separate and transparent. Given these qualities, the macro detail is quite obvious and is never shown in the foreground. In this respect, the nuances are clear, but natural and pleasant, without being forced. The very good level of stratification and layering makes it possible to discern micro-detail from the background, although it is not an analytical or incisive presentation that executes this in an obvious way. If you pay attention, they do appear, which demonstrates the technical skill of the set, but is not its strongest point.
The positioning of the elements is precise, if somewhat relaxed; it is never diffuse, but neither is it overly marked, and maintains that sense of naturalness and gentle musicality amplified by the level of transparency, clarity and separation.

Comparisons

7Hz Timeless II Flat Gold

Without a doubt, the Timeless II has become my reference model of planar IEMS. Their starting price is $229 compared to $170 for the Aether. They have an excellent presentation and a great level of accessories. Starting with their heavy, round metal case with screw-on lid, they also include three pairs of silicone tips, with a set specially designed for the occasion. The cable is a little thicker, with four strands, but somewhat stiffer. They have two detachable screw-on plugs (3.5mm SE and 4.4mm BAL). The Aether have a nice rectangular zippered case, a decent cable, but no detachable plugs or balanced option, and three sets of silicone tips with none that are very particular. I think the price difference justifies the Timeless II’s improvements over the Aether in terms of accessories and presentation.
The design is very different in the two models. While the Timeless IIs have a round, flat capsule, which is somewhat difficult to fit, the Aether has a capsule that is closer to a semi-custom shape, but more rounded, bulky, thicker and larger. There is no doubt that the design of the Timeless II is special, as well as having four pairs of mouthpieces for fine-tuning the sound. The combination of the Timeless IIs with the Flat Gold drivers generates a frequency response very similar to that of the Kiwi Ears Aether. The following sound comparison will be made with these mouthpieces.
The Aether are subtly less sensitive than the Timeless II. The Aether’s sound presentation is somewhat more relaxed, with less weight and less emphasis on bass. On the other hand, the Timeless IIs present a more powerful, more pronounced and punchier sound, offering a fuller sense of energy. Their sound is also more incisive, lacking the soft, relaxed feel of the Aether.
In the low end, the Timeless IIs demonstrate that sense of power that the Aether can’t match. The 7Hz bass is punchier, deeper, darker, more powerful and has more texture and roughness. The Aether is softer, smoother, but faster and with less decay. Aether bass has less impact on the overall sound, being less polarising and more balanced. It is not bass neutral, but those who want a lower level of bass load will get it with the Aether. However, the Timeless II’s bass will delight bass-lovers, with its more rumbling, energetic, punchy, powerful and voluminous sound.
In the very low frequency pure tone test, the behaviour of both IEMS is very similar, with an excellent physical and wave component in both models. The difference lies in the energy level, which is higher in the Timeless II. In the dirty, unfiltered bass test, the Aether’s slightly more refined smoothness and technical prowess is apparent. It’s not that the Timeless IIs are technically inferior in bass, far from it, but their greater power and texture give them a sense of power that seems harder to control, even if it never bounces. So, technically speaking, both are very good in the bass department.
In the mid-range, Timeless II continues to build on this more powerful and impactful presentation. This is especially noticeable in the male vocals, which are more present, closer, but also with a fuller base, with more body and physicality, and a more defined, incisive, marked and cleaner recreation. In the Aether, the male voices are a little more distant, wider, softer and more relaxed, but also lighter. The presence of the female voices is more similar, but the differences in impact, definition and resolution more evident in the Timeless IIs are maintained. In the rest of the midrange and with the rest of the instruments, the feeling that the Timeless IIs are very fast and generate finer, more precise, resolute, incisive and marked notes prevails. The Aether are smoother, more relaxed and musical, and more homogeneous. The character of the Timeless II is more analytical and sharper. And this is also noticeable in the treble. The Timeless IIs maintain that finesse and the feeling of more precise, resolute, thin, intense and penetrating notes. However, the Aether’s treble is not as refined as the Timeless II’s; it is softer, wider and a little more clustered, giving the impression that it is not as fast and has a slightly longer decay, with a longer lasting echo. In the Timeless IIs there is a more noticeable sense of air.
The Timeless II are more analytical and deeper, and have more height than the Aether. Their scene is more three-dimensional and spherical. They are also more volatile and ethereal. However, the horizontal extension of the Aether is very good and superior to that of the 7Hz. However, the soundstage is not as surrounding, but flatter and more frontal. Music is more vivid in the Timeless IIs, as it generates much closer detail, with notes coming closer to the listener in a very dramatic and direct way, and delivers a very shapely and analytical sound, with a great definition and sense of resolution. It feels very clean and transparent, and in the distance between notes you can appreciate darkness and silence. The Aether are more relaxed and smooth, and show detail in a more musical and cohesive way. In contrast to the Timeless IIs, it feels as if the 7Hz has that cooler, more analytical character capable of unpacking detail in depth and with more clarity.

Conclusion

Kiwi Ears has manufactured a larger planar transducer for its Aether. The size of the capsule has also been increased for this purpose. The immediate effect of this combination is something that is immediately apparent in the sound of this new model: spaciousness. The soundstage of the Kiwi Ears Aether is very wide. On the other hand, their frequency response is more homogeneous and balanced. On the one hand, they do not have such an accentuated bass, but their energy level is lower, without any loss in their technical level. On the contrary, the bass of the Aether is very tight, fast and with minimal decay. Its behaviour is at the level of the big planars, but without as much power, physicality and punch. It is a more neutral bass that many will appreciate. The midrange is characterised by smoothness, balance, a slight hint of warmth and overall musicality. The Aether’s sound moves away from the denser, more homogeneous, cohesive, wall-of-sound character of other planar models. In this way, the mids are more relaxed, less impactful and placed close to the listener, but never above or in a conspicuous plane. This makes the listening level very pleasant and suitable for long listening sessions. The high end maintains a medium level of energy that fits the overall balance of the Aether’s sound so as not to clash, but with a good level of extension and adequate sparkle to maintain the naturalness of the sound with some nuances. Thanks to the speed of the transients and the intrinsic capability of its planar driver, the Aether has a very good layering, separation, clarity and transparency to provide good micro and macro detail, calm and quiet, never obtrusive. All this makes the Aether one of the smoothest, most balanced, natural and musical planar models I have tried, without giving up the abilities that characterise drivers of this type and without falling into the darkness or excessive shading of the high end. Undoubtedly, they are a clear alternative to other planar models with a very good price.

Sources Used During the Analysis

• EarMen TR-Amp.
• iFi GO bar Kensei.
• EPZ TP50.
• Burson Audio Playmate 2.
• Aune X8 XVIII Magic DAC + OpAmp Sparkos Labs SS3602 + ifi ZEN CAN 3.
• Tempotec MARCH V.
• Tempotec V3 Blaze.