Watermelon Boi

100+ Head-Fier
NXEars Basso: The way to excitement
Pros: "NXEars style" done more exciting and familiarly
-Neat and meaty low-mids, fast and crisp highs
-Low ear/sound pressure by AGL technology
-Penetrates with deep & bold thickness
Cons: Mild speak on upper the mids may be bothering for treble-sensitive users
-Not ideal for those who seek a flat or BA-ish sound
NXEars Basso Review: The way to excitement

Numbers of new brands are flooding in but we know as a fact that most of them are from China. Not to mean that is a bad thing, of course, but I have been willing to see some new faces from other countries as well - which is why I would like to introduce a new IEM brand from elsewhere called NXEars. Founded in California, USA, NXEars is created by a former Knowles engineer as well as the NuForce founder. Even if your curiosity sensitivity got dull after encountering multiple new brands, NXEars is especially worth the attention as the products show one-of-a-kind characteristics when it comes to the sound. Their first wave of products includes 3 IEMs with different price ranges - Opera, Basso, and Sonata. In this review, we will be dealing with their premium mid-range model, Basso. Let us now take a closer look at its sound signature along with some comparisons.


Basso comes in a white box with a clean, simplistic design. Basic information and specs about the products are described on the rear and the sides. Once unboxed it reveals the earphone and related accessories. Other than the earpieces, it comes with a stock 3.5mm cable, a leather storage case, 4 pairs of silicone eartips, 2 pairs of foam tips, a metal bag clip, a shirt clip, a cleaning tool, and some paperwork. The included shirt clip has a typical form factor which is quite tricky to install it on the cable due to its small lips. The case is durable, light, and large enough to store extra accessories or another set of earphones.

Earpieces - The techs (1/2)

Basso utilizes 3-way 4 Knowles balanced armature drivers per side that are applied with NXEars' unique tuning methods. The core technology of NXEars IEMs is Aperiodic Ground Loading (AGL) which a patent-pending structure that restores the balance of natural pressure that occurs in the ear canal. You would be familiar with ear pressures that build up as you insert the IEM into the ears. Although building a higher ear pressure usually makes the sound more dynamic and intense, it is not so desirable in forming a natural tone and, most importantly, your health. Since that, companies started to look for solutions to relieve ear pressure without killing the dynamics and isolation an in-ear provides, though not many are out there, yet. A good example would be the APEX technology that 64 Audio uses. In that sense, NXEars' AGL technology is very welcoming news as we are served with another good option for hearing protection.

Another feature from Basso is their 'Linear Phase Crossover' where it corrects the irregular phasing that occurs from multi-driver setups. This happens mainly happens due to two reasons - different bandwidth and driver position. Bass travels slower while the treble travels faster. Plus, multiple BA drivers that are all placed in different positions are tied together, causing extra differences in tube length. These features lead to different arrival times to the nozzle, causing sound cancellation and phase irregularity. Therefore, appropriately setting up the crossover and distancing the drivers according to their travel time would solve such issues. JH Audio's FreqPhase technology is another excellent example.

Earpieces - The techs (2/2) / Design

However, I would like to highlight that both techs (AGL and Linear Phase Crossover) applied for NXEars IEMs are fundamentally different from others that were mentioned. The concept varies, though they all sure have the same goal. Thanks to these two technologies, Opera retains dynamics and isolation while eliminating the ear pressure, thus having a more natural timbre throughout the range. Applying both these technologies makes a chain reaction and form a unique headroom that expands wide and spatial, as NXEars describes that the sound would feel like an "over-the-ear headphones". That sure is one of the key topics that I would be dealing with at the impressions section and more analysis of the sound will follow at the later part of the review.

The earpieces are 3D-built with mildly transparent, dark navy bio-resin cavity. The faceplate is topped with real copper plates that in fact influences the sound by serving as a "foundation" for the bass to have solid grooves or bass lines. The red "n." logo that represents NXEars is placed at the center of the faceplate. Fitting is very comfortable and hassle-free, having no edges that would potentially bother me nor does the ear pressure builds up once inserted to the ears. The earpieces are detachable and terminated to standard MMCX connection.

The nozzle length is about T400, making it compatible with most aftermarket eartips out there. Speaking of eartips, Basso is highly sensitive to eartip pairings and I would strongly suggest trying to match Basso with eartips that have narrow bores (Acoustune AET08, etc). Using eartips with wider bores (Spiral Dots, Sedna Earfits, etc.) would cause Basso to lose tightness and rigidity, making the sound rather mushy. However, in particular, I would also refrain from using FAD E-Types as I found them to be intensifying the sibilance quite easily, despite the great depth that they provide. The stock grey eartips work out just fine, though I suggest trying others and would advise doing enough tip-rolling before you conclude your impressions.


Basso comes with a silver-plated OFC stock cable. The 8-braided wires are well-braided without any loosen part along with being soft, light, and non-microphonic. The end termination is done with a TRS 3.5mm plug. There are blue and red rings at the tip of the MMCX connectors, making it easier to recognize the L/R earpieces. An option is available for Basso to pay an extra charge to upgrade to a Mono-crystal 6N copper cable, yet I actually found the original silver-plated one to be working out better with Basso.

Sound impression - Nature of the sound

A lot of elements from Basso resembles its upper flagship model, Opera, but with some noticeable difference. Please be aware that the following sound impressions may show a fair amount of similarity with the ones from the Opera review, therefore I will be quoting sentences/paragraphs used for Opera as well as make comparisons as I proceed with this review. If you are yet to read the NXEars Opera review, I suggest doing so before you proceed further.

Along with that, I must mention that Basso is very dependent eartips it is "extremely" crucial to set it up with the right eartips and installation depth. After pairing it with a variety of eartips, it appears that Basso works well with those casual narrow silicone tips (yet excluding FAD E-Type such as Acoustune AET08 or basically the stock tips. For the depth, the eartips should not be installed too close to the nozzles and needs to be installed more to the edge which causes a deeper insertion. Achieving a long-enough nozzle length and deep insertion would create the proper sound from Basso - if not the bass would feel rather light with the upper ends getting hotter and spikey.

Sound impression - Staging

This time, the order of my impressions will be a little different as the sound philosophy is different from our casual earphones. Let us first consider how a casual earphone would rather sound like - it would be whispering close to your ears, creating a headroom where you are the one in the center of the field. It is basically having you to be the cast of the music. Though in the case of Basso, its headroom would form a decently-sized, mild concave curvature right behind you - looking like a shape of ")", where a standing half-sphere would be containing you - by having you fully covered in all directions except the front which is opened.

While mids feel to be fairly close to you, lows and highs would reach out frontward and forward, as if creating a floor and roof for the headroom. Comprehensively, the impression would be closer to having you to be the audience of the music - creating a snug, relaxed environment that embraces you. The size of Basso's unique headroom is relatively smaller than from Opera, but at the same time, Basso's presentation would likely sound more familiar or less drastic, since it possesses more elements of a normal sound stage. The same goes for the snugness - lesser effect, but also more familiar.

Sound impression - Lows / Mids (1/2)

Lows dive quick and deep, thoroughly filling the lower ends of the headroom packed with density. Basso shows a bold ultra-low presence with much thickness, giving a full and sturdy body to the bass. While ultra lows are well-caught with vividness, it delivers subtle and thick vibrations that do not cloud up the atmosphere. While achieving the tightness, the bass strikes are mildly polished to have smooth edges and surfaces, making it feel organic to the touch. Throughout the range, lows show consistent, highly stable, and large bass grooves that stay refined at the bottom end, building a steady establishment for the sound.

Compared to Opera, Basso produces a bit more sub-bass quantity with denser bass grooves, plus being slightly more energetic when delivering the slams. At the end of the day, Basso's bass would scale large and immersive as a basshead IEM would while the actual bass quantity is closer to a slightly v-shaped IEM, where the bass is roughly 30% more emphasized from flat. Although keep in mind that Basso still has that stiff bass-thick, depth-thick environment (you know what it is if you have heard a basshead IEM before), so it would not be an empty-clear environment on the lower end but a serious, weighty one.

While mids would feel recessed at first, shortly you will notice that the way how its recession is made is different - feeling to be the position that is only pushed back rather than becoming weaker in presence. Normally when a muffled feeling is present on the mids, there are high chances for the bass to eat the vocals and killing off the details. Interestingly enough, that is not the case here. For Basso, it is more due to its "standing half sphere" (that I previously mentioned as a metaphor), therefore the vocals are not really shadowed as lows do not flood into the vocals but to mildly create a speaker-like environment.

Sound impression - Mids (2/2) / Highs

Mids are a mixture of mellow and crispness. Taking a mild step-forward, Upper mids would show a quick shine up in emphasis and brightness. However, this does not particularly cause the sound to be fatiguing as the transition is not too intense or drastic. It gives more of a small poke rather than a piercing, leaving it manageable - though for those who are sibilance/treble-sensitive may still find this bothering. This is the main reason why I have stated the importance of eartip selection and its depth - the sibilance difference will be day and night depending on what eartips and how deep you install them into the nozzles. Compared to Opera, Basso possesses less of this "unique tuning effect" (NXEar's unique headroom I have been quoting) and sounds slightly less spatial and immersive. Yet again, this also results in Basso to form a headroom that sounds closer to our usual IEMs along with vocals being placed more frontward.

Highs are snappy and very crisp where it delivers a vividly crunchy bite. As highs beautifully articulate fine strings of details with delightful strikes that hit right to the core of the music, they stand slightly forwarded than the mids but not by a big margin. The tone is pure and transparent with a mildly cool tone, carrying a fair amount of air. Unlike Basso's upper mids where around the sibilance area could rather risky with the hotness, trebles would not get fatiguing or hot by no means. The treble instruments and details would boldly and clearly make their presence without breaking the harmony, yet their intensity is well controlled and stabled. Thanks to that, Basso's slight edginess on the upper mids are quickly cooled down once entered the treble area, making its sound as a whole to still be easily enjoyable.

To once again compare with Opera for the trebles, Basso shows its advantage in terms of clarity, closeness, and quantity, yet Opera possesses more details as well as carefully and calmly articulated than Basso does. However, this is only the case once spoken subjectively - the gap is not too big after all. Basso's trebles provide a lot more dynamics and liveliness, and most importantly, the fun. The strikes are done clear and refreshingly, hitting the head dense and fast. Opera shows distinctive superiority in spatial impression and massiveness but Basso would put up with a good and strong defense with its energetic nature and higher-transparency. Separation is on point and would precisely locate each instrument in the right position.


-Oriveti OH500- *review coming soon

The bass from OH500 focuses on giving a smooth and mildly fluffy texture while Basso goes for a different direction, which is to have the bass rock-solid and snappy. But of course, Basso's still have enough meat and body to the lows - it is just that they are tighter and lesser in reverbs. The situation goes on similarly once we move onto the mids. The following applies throughout their sound, but especially on mids, OH500 has moist textures with round edges that give a comfy, cozy environment. However, this does not get the details dull or degraded. Basso is overall drier when it comes to moistness but tuned in with better accuracy in phasing. It is also more revealing and blatant in texture details, therefore more dependent on sources and eartips. Obvious enough, Basso is tensed up with more of a BA-ish texture and atmosphere going on that leads to faster and agile reaction speed while OH500 sets its base characteristics on the dynamic driver, being relatively relaxed and easy-going.

-Dunu DK-3001 Pro-

DK-3001 Pro is flatter in the spatial aspect as well as a bit in its dynamics. Mids are relatively closer to the ears with a brighter atmosphere going on. The tone is relatively more delicate as it stays neutral in 'moistness' - making the sound feel neither dry nor damp. It also takes the lead in terms of stability by keeping the upper mids more leveled and better controlling the sibilances while Basso shows a mild peak on the upper mids. However, Basso immediately makes a comeback with its superiority by showing thicker vividness, depth, and density in vocals. Lows on Basso also scale a bit larger with more dynamics and depth. The tone is damper and darker, having extra depth and forcefulness in creating its atmosphere. The general advantage of DK-3001 Pro is its reference-like nature that has adequate dynamics, clean and neat presentation, and a gently airy, residue-free background. Though this could also be comprehended that the dynamics or the impact might marginally come short to your taste - or just too gentle. In contrast, Basso thoroughly pours in dynamics and liveliness to the music, however without overdoing or getting excessive in its intensity.


Let us say Opera is a well-tamed big dog - then Basso is more of a high-spirited, sanguine underboss that could match against its superior, Opera, depending on different fields. While being the middle child of the product family makes itself vulnerable as it is, Basso overcame such bias well and easily. Basso pursues NXEar's unique staging style but does not go as far as Opera did, making it more casual and suitable for wider coverage on personal tastes. Plus, it embraces a livelier, fun-based tuning that would go along better with modern music. On a personal note as I conclude this review, I have been finding that Basso's overall sound signature quite resembles Empire Ears Legend X. There sure would be no surprises for Legend X to be holding the higher ground when it comes to comparing absolute performance, but considering Basso's affordable price, quality, and highly attractive characteristics, I would say Basso already made a market for itself, even just by that. If you want to enjoy your music 'NXEar's style' with more fun and orthodoxy, Basso is the very way to go!


NXEars Opera: In-ear 'Headphone'

NXEars Sonata (coming soon)

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Thanks to NXEars for providing Basso in exchange for an honest impression/feedback.
I am not affiliated with NXEars and none of my words were modded or asked to be changed.


Reviewer for The Headphone List
ryanjsoo's Reviews
Pros: Excellent fit and finish, Punchy extended bass
Cons: Bright middle-treble may not suit some
Introduction –

NXEars is a new audio manufacturer from the USA that was spearheaded by former Knowles employee Casey Ng whose notable work includes the NuForce NE, HEM and Primo line-ups in addition to the new Erato TWS earphones. NuForce is most fond to me for their Primo 8 quad driver earphone which made a lot of noise for its phase-coherent crossover that ensured all drivers were time-aligned; you can read more about it in RinChoi’s excellent analysis here. NXEars takes this design to the next level, aiming for a sound more akin to an over-ear headphone or speaker over an in-ear.


This has been achieved with numerous technological innovations with the addition of AGL (aperiodic ground loading) which mitigates the pressurization often used to achieve sub-bass extension in IEMs and standing wave resonances within the ear canal. Their line-up consists of 3-models, all utilising Knowles BA drivers. In for listening today is the 4-driver Basso coming in at $499 USD. Read more about the line-up and technology behind NXEars here.

Sound –

The Basso has a distinctly brighter sound, opening up the top-end and imbuing a pleasing amount of air and headroom. Meanwhile, its bass is more linear than the flagship Opera, deeper reaching and with more accurate timbre. It doesn’t possess quite the same magic but provides its own unique voicing that caters towards a different audience.


NXEars mention that the Basso is utilising two of Knowles’ largest BA woofer drivers alongside heavy copper faceplates that I’m assuming serve to decrease resonances. And indeed, the Basso provides more sub-bass extension than the Opera in addition to a more mid-bass centric tuning that makes it more orthodox in its presentation. Lows are slightly warm, pleasantly full and smoothly textured. Decay is slower than the Opera but it still retains that a typical BA response, being controlled and quickly decaying nonetheless. The combination of increased extension and a slight increase in note weight creates a perceptibly more dynamic low-end which is somewhat reaffirmed by its slightly slower but also more natural decay. The transition to the midrange is more linear on the Basso as its upper-bass is less present, while vocals are more laid-back, creating a roughly U-shaped sound overall. However, as opposed to competitors, the Basso is a highly coherent U with bolstered lower-midrange body; it isn’t vivid or clarity boosted in the slightest.


As the upper-bass isn’t overly warm nor the low-end too emphasized, the midrange is similarly devoid of muffle or congestion. The centre midrange is relatively flat with a natural 3KHz bump which helps to redeem a natural image after which the earphones have a substantial 4KHz trough. As such, mids are very dense and smooth in addition to being full-bodied. In turn, there isn’t a lot of vocal definition or layering and they clearly lack the extension and clarity of the Opera. Up top is where they falter most. The Basso is a clear step down technically from the Opera, as can be expected. However, its lower-treble is smoothed to the extent that detail presence is largely diminished even if raw detail retrieval upon scrutiny is ample. The superlative imaging and layering performance of the Opera is vaguely apparent, however, due to a sizable middle-treble emphasis, the Basso tends to glare over foreground instruments and micro-details higher up. As the background is bright and the Basso lacks the extension to project immersive dimension or resolve fine background details, it suffers from a less involving soundstage and foreground presentation that can comes across as detail deficient.

Early Verdict –

NXEars’ latest earphones are easily the most intriguing that have come into my hands for review in a long while. The Basso takes the most “normie” approach with its sound tuning to my ears, only with a polarising middle-treble peak and reduced bass/midrange separation.

It is designed for live stage monitoring and mainstream genres like pop and EDM that require more high-end energy. The earphones is still evidently very purposeful in its tuning and a standout mention goes to NXEars’ proprietary innovations; it’s clear that these earphones have been the source of much deliberation for Casey. The 3D printed housings are also gorgeous and have delightful ergonomics to my ears. This experience is made especially enticing by pricing as Casey’s ties with Knowles grant him access to the best supply chains. The Basso sports a $499 USD price tag, thereby undercutting most of the competition when compared driver for driver. The NXEars range deserves a listen and you might just find that one deserves your hard-earned cash too.

Thanks for reading! If you enjoyed my review, please see my website for more just like it!
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