Today’s review is about the Aune AC55 that are open-back headphones with a classic on-the-ear wearing style but also pack many modern innovations as we are going to find later on.
The Aune AC55 was kindly provided free of charge in exchange for an honest review. I didn’t receive monetary or any other kind of compensation and I don’t use affiliate links.
The price of the Aune AC55 is $219 and you can buy them directly from Aune Audio. Customers within the EU can order them from here.
Aune Audio
Aune Audio is an established brand from Wuhan, China that specializes in designing desktop and portable audio equipment. Their extensive catalogue includes earphones, headphones and various portable USB DACs, as well as desktop DACs and headphone amplifiers. Their products have received numerous press awards and are genuinely admired by the audiophile community.
You can further explore the brand and discover Aune’s lineup by reading past reviews.
Aune AC55
The Aune AC55 a reference open-back headphone with an on-ear wearing style, but instead of a headband it employs a clip-on mechanism that wraps around the ear. This design combines the airy and spacious presentation of open-back headphones with the lightweight feel and portability of ear-clip earphones.
Aune is not the first brand to inherit this design, various other models with the same wearing style exist, like the Koss KSC75 or the Audio Technica ATH-EQ300M. However Aune has gone a step further, trying to overcome the inherent limitations of clip-on headphones, like the early bass roll-off, and unlock their full potential.
Aune Audio also makes another clip-on wearing headphone, the AC45 that is more affordable and slightly differently tuned than the flagship AC55.
Aune AC55 – Technical Overview
The AC55 is equipped with a 40mm W-shaped composite diaphragm made from bio-fiber materials, a design that offers around 70% greater effective vibrating surface compared to similar models. The diaphragm structure combines the natural characteristics of bio-fiber with an additional thermally stabilized layer that improves stiffness and control.
A custom ultra-elastic long-excursion surround system, fully unleashes the diaphragm’s displacement potential and is the secret weapon of the AC55 that allows it to produce powerful and energetic bass that extends deep into the sub-bass.
The headphone also incorporates a high-dynamic symmetric motor system, optimized for its long-excursion structure, providing ample room for the voice coil movement. Even at high SPL recordings, it ensures precise diaphragm control and low distortion.
Design and Build Quality
The Aune AC55 has a vintage inspired design that reminds of professional studio gear. Black colored ear cups and outer grills with bronze decorative metal parts, like the horizontal bar that carries the model and brand names. A simple, yet attractive design with a strong personality and pleasing aesthetics.
The ear cups of the AC55 don’t connect together with a headband. Instead they are equipped with semi-memory alloy hooks that wrap around the ear of the user. Each hook is attached to an elongated housing that also integrates the cable plug at its opposite end.
The overall diameter of each ear cup is around 55.5mm and this is the effective area that rests upon the user’s ear. They are equipped with user-replaceable and skin-friendly foam pads that are quite dense but not too thick.
Wearing Experience and Isolation
Wearing the Aune AC55 is simple and easy, just wrap the hooks around the ears and let the cups rest using their own weight. Don’t push them against the ears, just let them hang, and make sure to gently bend the clips until you achieve a stable and secure fit. The clips have the right size to accommodate both large and small ears.
The cups don’t feel loose when you move the head but they are not suitable for running or other activities, not because they are going to fall from the ears, but because every strong movement severely alters the frequency response and especially the bass.
Each ear cup weighs around 35g, not that much, and the weight distribution is even across the ear. The cups don’t feel heavy or exert annoying pressure against the ear, they are exceptionally comfortable and start to sweat only after a couple of hours of continuous use.
The AC55 is an excellent solution for people that don’t like the size and weight of regular headphones but also dislike using earphones. It should also be noted that while most on-ear headphones with a headband usually exert pressure and irritate the ear tragus after a while, this never happens with the AC55.
The only practical disadvantage of using the Aune AC55 is that it offers zero passive noise attenuation, it is much worse in this regard than open back headphones. It also leaks quite a lot, so it is best used in quiet environments when sitting alone.
Stock Cable and Accessories
To keep size and footprint as small as possible, Aune smartly decided to design the AC55 with a 2-pin, rather than 2.5mm or 3.5mm, plug system. Each ear cup is equipped with a flush 2-pin female plug where the cable attaches just as it happens with most earphones.
The 1.25m long cable is made from oxygen-free copper conductors in a four branch Litz braided structure. It is a high quality, modular cable with bronze hardware parts that match the appearance of the ear cups, and comes equipped with both 4.4mm and 3.5mm plugs. It looks durable, it is soft and easy to handle without much microphonic noise and its weight is low so it doesn’t pull the ear cups downwards.
Except for the cable, the package also includes a shirt clip and handy storage pouch but not a hard carrying case.
Sensitivity and Associated Equipment
The Aune AC55 a 30Ω nominal impedance with 112dB of sensitivity so it is an easy load and not picky about source noise. It can be driven by various portable USB DAC/amps, like the Aune Yuki but further testing revealed that it also scales surprisingly well and benefits from higher quality sources up to a certain point. For most part of this review, I have used the FiiO M21 and iBasso DX260 digital audio players.
Listening evaluation
The Impressive Low-End
I am sure that the first question that springs to the reader’s mind is “does the AC55 has bass?” Well, the short answer is yes, not only does it has remarkably extended and full sounding bass but it is also of high quality and without any audible distortion. You may doubt what you have just read until you listen by yourself and become a believer.
The bass is really present and it doesn’t start to roll off until about 50Hz but even then, the AC55 can actually produce audible sub-bass without sounding too anemic or as lacking in solid foundation. It is not worse in this regard than a lot of full sized open-back headphones of the past, like the venerable Sennheiser HD650. The AC55 can even handle modern electronic music, as long as you have realistic expectations and don’t ask for rumbling or chest thumping bass.
Not surprisingly, the audible low-end extension can vary a little depending on the shape of the outer ear. The drivers must sit as close to the ear canal as possible and establish some kind of a “seal”, otherwise the bass will sound less extended and not as powerful.
From 50Hz and upwards, the low-end is neutrally tuned up right to the mid-range. Thankfully, Aune has not bloated or emphasized the mid-bass too much in order to compensate for the lack of sub-bass, so what we have is reference tuned bass with admirable tonal precision. All low pitched instruments are reproduced with good realism, making the Aune AC55 ideal for listening to classical and acoustic music.
Technical Performance
The technical performance is far better than expected. The bass is fast, tight and controlled with very good timing and enough natural reverb despite the lack of an enclosing chamber. I would have expected it to be mostly lean and dry but it is not. It actually has sufficient weight and is not that lacking in elasticity while it is surprisingly powerful and dynamic for an on-ear headphone. It is also clean and defined, even during complex tracks where it retains satisfactory composure and tempo.
In summary, Aune Audio has successfully engineered a clip-on headphone that overcomes the typical limitations of this design when it comes to the low-end performance, allowing the AC55 to deliver genuinely deep and powerful bass.
Mids and Highs
The same reference oriented tuning style also carries on to the higher frequencies where the AC55 goes with a tonally balanced mid-range and an energetic yet controlled treble.
The mids can sound rich, organic and expressive with the right source, the timbre is realistic and tonal precision is almost excellent. There is a touch of upper mid-range emphasis that favors some overtones but it won’t make the music shrill or fatiguing, except with some recordings or sources that already emphasize this region. The AC55 is an enjoyable and engaging headphone that plays well with all kinds of music, while it also retains good levels of clarity and definition.
The treble is not the most resolving or refined but it can still extract plenty of information, while it is sparkling and brilliant without sounding aggressive or edgy. Aune had to go with a more conservative tuning, given the relatively shy sub-bass response of the AC55, otherwise they could have ended with a bright and unevenly tuned headphone. People that crave for emphasized treble and the best possible resolution may find the AC55 falling short for their taste but the rest are going to appreciate the smooth and relaxed high frequencies. The timbre is mostly natural and enjoyable without much metallic or artificial artifacts and without thinning out the higher pitched instruments.
Head-Stage
The head-stage is exceptionally wide but also somewhat strange and let me explain why. It is open and spacious, even more than some famous open-back headphones, with excellent lateral positioning but it somehow fails to establish a solid center image and is also somewhat lacking in depth. It is like the left and right sides don’t meet to blend at the center, thus creating some kind of a small void. Still, the AC55 can easily handle large scale music, never sounding congested, while it easily adapts when the ensemble is more intimate.
In the End
With the AC55, Aune Audio has managed to create a clip-on headphone that overcomes many of the sonic limitations traditionally associated with this form factor, narrowing the gap not only with conventional on-ear headphones but even with full-sized ones.
The AC55 has unbelievably extended and technical bass for a clip-on headphone, while it goes with a reference-balanced tuning, making it able to handle all kinds of music and satisfy both the casual and the critical listeners alike.
The Aune AC55 is the perfect solution for people that don’t like full sized headphones but also hate stuffing earphones in their ears. And the best part is that this is the first time that they can actually appreciate the comfort of clip-on headphones without sonic compromises.
Copyright – 2026.
Authored by Petros Laskis for Ichos Reviews. All content is original and copyrighted. Republishing full reviews or substantial portions without written permission is prohibited. Excerpts up to 100 words are allowed with a direct link.
+ Outstanding bass extension and performance for a clip-on
+ Tonal precision and realistic timbre
+ Balanced mids and smooth treble
+ Full bodied and weighty textures
+ Loves all kinds of music
+ Easy to drive and scales well
+ Compact sized, relatively lightweight and comfortable
+ Doesn't exert annoying pressure like conventional on-ears
+ High quality modular and detachable cable
+ Well made and beautiful looking
+ Price and value
- Limited sub-bass extension in comparison with earphones/headphones
- A little hollow soundstage
- Not suitable for commuting or exercise
- Sound leakage and zero passive noise attenuation
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