Acoustune RS ONE

General Information


The RS ONE, the first product in the series of Acoustune's new monitor line, is the brand's first stage monitor earphone that combines high durability and monitoring performance. Hi-Fidelity In-Ear-Monitors. This is a standard monitoring earphone designed with an emphasis on robustness and monitoring, which is important as a stage monitor, utilizing the acoustic technology cultivated in the HS series and the knowledge cultivated in the 3D custom fit shell of ST1000 and ST300.

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Headphoneus Supremus
Pros: -balanced V shape that feel like bassy neutral
-bright airy tonality
-fast attack speed
-edgy and snappy treble
-good vocal presence
-impressive bass performance
-hint of sparkle and brilliance
-open soundstage
-very good for jazz and rock
-good sound value
Cons: -agressive tonality
-average bass separation
-not cleanest resolution
-average micro details
-thin mid range
-not the most natural timbre
-scooped sustain-release
-poor imaging
-not mmcx or 2pin connector

TONALITY: 7.8/10

Acoustune is a well know japanese earphones company that produce mostly high end single dynamic earphones. Their secret for good sound is due to tuning experience as well as dynamic driver technology used like their famous myrinx diaphragm use in their HS flagship serie.
The IEM i will review today is the RS ONE, the most affordable Acoustune IEM using a myrinx driver.

Myrinx EL Dynamic Driver info:
  • Myrinx units have always been an important part of Acoustune's earphones, and the different generations of the HS series have always witnessed the growth of Myrinx units, and for the new RS ONE series, the team has developed the new Myrinx EL dynamic unit especially for this purpose. Made of medical polymer resin, it is lightweight, very strong and has low wear and tear characteristics, which greatly improves performance with low distortion and higher acoustic performance.
The Acoustune RS One is priced 150$ (but can be find for 100$ too) and is thinked to be a monitor stage performance IEM. Let see in this review if the sound quality ir produce is competitive enough for it's price range.

Disclaimer: This is a loan unit from a friend. I have zero incitative to do this review apart pure passion.


Since these are loaner unit, I can't comment on accessories or packaging, just plain construction which at first sight is underwhelming and feel very cheap. Yet, in term of durability and comfort it is very good. Quality of plastic is thick and feel solid, it's soft and light and rounded shape of housing permit a long time listening comfort. Isolation is averae tough, which question for monitor purpose. The mesh seem prompt to collect dust too.
My biggest qualm about those are the use of proprietary cable, the pentaconn, which is very similar to MMCX but less prompt to unwanted swivle. Yet, it mean that you need to pay tremendous amount of money to have a balanced cable (between 150-400$) from Acoustune. I suggest you to look at Ali express cheaper alternative, so you don't get rip off. You can find OEM pentaconn cable for 30$ there.
All in all, nothing impressive construction wise but durability seem good. The included cable is kevlar reinforced, so it's bullet proof for those living in dangerous neighborhood.


Balanced bright V shape with thumpy boosted bass, fowards vocal presence and vivid treble that add sens of openess and crispness to the tonality. We can call these technical sounding basshead IEM, well, near bass head because mids aren't very recessed, and the fast bass response avoid muddyness and doesnt have out of control boost.

Acoustune consider these monitor IEM, but this doesn't mean its neutral at all, it mean stage musician like vocalist and bass player will not struggle to hear themself in the mix, yet if your a drummer or acoustic piano player, the RS One will not have enough lean and fully resolve mid range. In fact, as a pass time music producer, i would never use these for monitoring my tracks. In that regard, Seeaudio Yume 1, Kinera Idun Golden and Hisenior T2 are all better due to cleaner imaging and better layering.

The bass is quite phenomenal with these, it offer a fast slam with fast resonance and sens of immediacy in it's attack, both sub and mid bass are equally boosted and this make separation between kick and bass line a bit glued togheter, which can magnify sens of impact with the disadvantage of veiled definition sharpness. Separation with mid range isn't the cleaness, some resonance embrace lower mid but in an organic way, it doesn't darken nor warm the tonality. Toms have scooped resonance too. Cello sound a bit dry-bright lacking natural vibrancy and lower mids fullness.
Its more on the boomy than flexible dynamic side but the excited speed make it very enjoyable for anything beat heavy like electronic, rap, pop, and even rock. All in all, great bass performance tough a bit dry and not the most meaty-juicy in body and timbre.

Mid range is where i'm not a fan of the RS One, and that even if vocal presence is very good and permit both male and female singer to have enough loudness and not feel recessed. What mids are lacking is note weight and dynamic rendering, timbre is thin and a bit overly focus on texture details, making vocal sometime uneven in timbre, too thin and even prompt to slight sibilance. This is the issue here, timbre isn't natural nor lush nor warm, its bright, dry and tend to magnify texture details we never want to listen too in first place,as if the mic is too near the lips and low harmonic are taken off vocal or instrument. Violin have upper mids bite that is beneficial for attack articulation, but always feel a bit higher in pitch, cello can in fact sound like violin too, again lacking these low fundamental. So, i don't think RS1 is for mids lover, nor warm or lush timbre lover nor acoustic instrument lover, its for those that favor technical and bright mid range with upper mids push.

Treble while not perfect in balance it's the part that impress me the most with RS1, it's the kind of highs that everything: snap, crunch and sparkle. It's open sounding and doesn't lack air as well. To have highs like these under 100$ is somekind of miracle by it's own. It's very fast and well controlled in attack, with minimal splashyness even at very high volume and with busy track like ''Skink'' from Elephant9. While i was complaining about violin lacking bit of body, their attack is super precise and well resolved which add excitment to staccato, allegro or lively symphony, where their a mix of strings being plucked and bowed in high range, the result can be incredibly captivating. This is the same for rock or metal music, or jazz rock, the treble abrasive bite and speedy transient is truely excellent and avoid muddy compressed layering by adding instrument separation space. Again, i test RS1 with ultra difficult experimental track, now from John Zorn ''Chaos Magik'' album, ''Egregore'' track is invade with rythm change and electric guitar experiement as well as fast toms and percussions, everything is well layered and while cymbals crash can go jsut a hint hot, and never bleed on other instrument, RS1 keep the crazy fast pace and deal with synths and guitars like a champ, just mind blowing! But not everything is perfect, this treble can be agressive and even fatiguing, and it's crunchyness doesn't benefit all instrument as well as decay can cut short in natural resonance, so while snappy, its not fully controlled and i would have like more air and extension on top for cleaner brilliance and sparkle.

Technical performance are very good for the asking price and among the best in sub-100$ offering, its both muscular in dynamic and fast in transient, sure, this speed isn't perfectly timed end game way, yet, the crunchy edge can really be spectacular for fast rock track or drum rolling. I feel harmonic distortion is a bit high with this myrinx driver, especially at higher volume, this stole clean silence between instrument which is a drawback imo. Transparency too isn't the best, another sign of noise. While resolution is good, it's not an iem that will reveal higher number of micro details, since it tend to focus it's capacity around 8khz section, so the surprising details we often discover pass 10khz arent boosted nor reveal if we try to dig into it's slightly foggy imaging.

Soundstage feel out our head but isn't widest, tallest or deepest, it have a compressed intimate stereo feel to it, with more recessed center stage tha add sens of deepnest but can't be explore further, so not the deepest but holographic sounding enough.

Imaging is where i was disapoint from an IEM that target stage musician, it's very average and not crisp and clean enough, layering is to close to each other while instrument separation lack air, as well, bass can feel in front of everything sometime so it's not what i would call accurate nor precise instrument placement, here, we enjoy a macro-resolution presentation without precise spatial positioning.



Olina is more neutral, cleaner and with higher resolution. Bass is less boosted and more about mid bass texture and punch, it's better define for kick drum attack and have better separation from mids. In other word, its less boomy, and resonance is more natural too, attack seem faster as well. Mids are fuller sounding, richer in details and better layered as well as more open sounding, making vocal overly compress in center stage with RS1 and less fowards for wide range of instrument, piano is fuller restitute with Olina and have more note weight and natural decay, violin and cello and well, all acoustic instrument sound more realist with Olina and less about forced presence with treble boost but sometime overly softed in edge. So, RS1 is notably brighter and more V shape as expected, the treble is less smooth and balanced than Olina, have more edgy and snappy attack as well as air on top. Soundstage is wider and deeper with the RS1 but imaging is notably inferior, especially in layering transparency.

All in all, technical performance is superior with the Olina and tonal balance is smoother, but less dynamic and fun than RS1.


Aria is cleaner, smoother and more U shape. Bass of RS1 hit harder and have more mid bass boost and presence. Mids are more recessed and brighter with the RS1, it feel more stocked in center stage while Aria feel more open and wider in soundlayer, vocal have more presence and less upper mids boost in sibilance zone. Mids are cleaner, with higher details, better separation as well as better transparency with the Aria, but overall dynamic is leaner too. Treble is notably more refined with the Aria, but darker in texture and bit as well as not as snappy and energic as the RS1, so while cleaner and hint more sparkly and refined, Aria highs can feel too lean and not enough edgy, especially in rock music where electric guitar will sound more crunchy with RS1. Soundstage and imaging is superior with Aria, layering benefit from transparency and more neutral tonality.

All in all, RS1 is more fun, bright, bassy and vivid in dynamic but not as mature, clean and technical sounding as Aria, which offer higher sound value resolution-clarity wise, smooth way.

VS HZsound Hearth Mirror (1DD-50$)

HZ is more crisp neutral to vivid W shape, with more mids and treble sharpness. Bass is cleaner, notably less boosted and faster in attack, kick drum are more punchy and textured and sub bass extend in a leaner way, it offer less slam and rumble. Mids a crisper, cleaner and more detailed and transparent, they are less recessed too and a hint more organic and liquid, less grainy than RS1. Treble is faster in attack and more controlled too, it dig higher level of micro details but feel a bit scooped in texture so again like Aria electric guitar will sound fuller with RS1 that offer less thin highs so snare will sound ticher rounder for ex. HZ have more air on top, more extended highs. Soundstage is similar in wideness but deeper with HZ. Imaging is notably superior, both in clean positioning and layering articulation.

All in all, when I say RS1 is among best technical performance, i might be overly enthusiast, this is why i need to wake up with this incredible HZ Mirror which is without a doubt superior in all aspect of technical performance for half the price of RS1. But hey, it's not as fun and RS1 is sure better than the HZsound Mirror Pro!

The Acoustune RS1 are very capable earphone with an energic and immersive musicality. They offer a very competitive sound performance that is everything but boring. They offer fast slam, great mids presence and snappy treble that never good muddy even very fast demanding track. These are great IEM choice for rock and jazz, but do well with most music genre apart perhaps classical music.
While i would not suggest those for people that enjoy warm, lush, thick or smooth sounding musicality, i do think the Acoustune RS1 are excellent entry level IEM with versatile enough bright tonality.


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New Head-Fier
Acoustune RS ONE -"The Master of Notes and the Gateway to Resolution"
Pros: -Bass has very good texture and definition
-vocals have very good presence, timbre, and realism
-the resolution is excellent for this price
-Instrument separation is insanely good for this price point
-Sibilance free
Cons: -midbass presence might be too much for some
-sound stage might be a bit narrow for some
-treble air might be lacking for some
-No cable rolling option
I bought the RS ONE as a late Christmas present for myself. Although Acoustune is one of my target endgame brands, I will try my very best to be transparent as possible, citing the PROS and CONS of this set. I am not yet very experienced in reviewing, but I see myself improving from time to time in relaying what I hear. Looking back at my first review post, I am happy that I can write this much now, and I thank the community for that. I may have different views when it comes to interpreting music, because each of us has a different sound reference. My cons might be a pro to you, and my pros might be a con for me. This is a subjective hobby after all.

Months ago, I was looking for an IEM for a good playback of Babymetal tracks. Some people have suggested Acoustune and some other brands like NFAudio, etc. I somehow managed to audition some of those brands and immediately fell in love with how Acoustune sounds. The driver is fast and powerful. It was able to replay how a proper “djent” would sound. Djent usually requires at least 7 strings guitar for those drop tunings. Some would even go for 8 or 9 strings lol.

Another thing I was looking for an IEM is its ability to layer and separate instruments. It was particularly important for me because I sometimes want to breakdown a track. I am not by any means an active musician, but I can play the guitars and drums. I am assuming that some of us here play instruments, I guess. When we have heard much of our favorite tracks, we would sometimes listen for notes, chord progression, techniques etc.

My “audiophile” ears want to listen to how music is presented, but sometimes my “music enthusiast” ears would want to listen to how that music is created.

I saw a video on youtube about how musicians and audiophiles hear music, and he said “Musicians don’t really need fidelity to process information”
And quoted from a commenter “music lovers use systems to listen to music, audiophiles use music to listen to their systems”.

For me personally, it really boils down to our music library. Don’t get me wrong, I love a well-balanced tuning or harmanish for that matter. But sometimes I find it lacking in the 60-250hz where the fundamental notes are. Also the 250-500hz is a very delicate zone because it is where the lower harmonics and bass presence are. This is the reason why stage monitors like shures or Sennheiser’s have a bump in that region. Similarly, I can see how KZ and other Chi-Fi follow this mid-bass bump in their IEMS, only that, their drivers are not able to keep up and it usually results to a bloat and muddied up mids.



-The build is pretty robust. It is made of high-quality polycarbonate, that is heat, shock and sweat resistant. You don’t even need to worry if you drop them accidentally. The fit is very secure and comfortable. Combined with how light weight they are, I sometimes don’t realize I am wearing an iem haha.


-The driver is a 9.2mm “myrinx EL” drivers. There is a membrane that coats the human eardrum and Acoustune uses a synthetic medical grade material to mimic that membrane. It is said to be super soft yet very durable. As a result, there is a very low distortion, making the sound clear yet full sounding at the same time. Imagine the clearness of a BA + the fullness of a DD. That’s how they sound like.



-The cable is a newly developed ARM011 and uses a rather rare pentacon connector. It is more stable than MMCX. But it is said to offer better sound quality because it has more surface contact than the traditional 2 pin. The cable is made of high purity litz and is braided with a said to be” Kevlar-bullet proof” something. And honestly? It does feel one! Haha. The quality of the cable really feels good to touch and can stand a chance with heavy use.

It also comes with AET07 tips in SML size and one pair of foam AET02 tips. They seal pretty well and I didn’t have any problems with them dislodging.


-Okay so here we are.
Again, it all depends on our library, and this set may not be tuned like the recent harman trend. For my ears, they are warm U shaped, with a bit rolled off treble air and has mid-bass presence. I cannot say they are bloated by any means because they do not bleed anywhere. Like seriously, it is ridiculous that there is so much bass presence, but it sounds separate from the rest of the spectrum. Even the vocals have enough presence and realism. Transients, driver speed, RESOLUTION, LAYERING and SEPARATION of instruments are very very good for this price point. The stage has this 3D effect, and every sound is well defined. It is so damn good in technicalities. It sounds like each instrument has their own speaker hahaha.

What I mean by this is, when you follow a bass line, you can clearly hear it and the rest of the instruments are blurred. When you switch to listening to the cymbal attacks, the rest of instruments does not interfere. When you focus on the rhythm of the guitar, you only hear that. When you listen to vocals, well you can hear them perfectly fine. And this is only done in ONE DRIVER! Hahahaha. This is really crazy.


❌midbass presence might be too much for some. Especially if you are used to flat, neutral or balanced tuning. But they are very tip dependent and the sound changes when changing different tips. There is a hole near the nozzle and that might be the reason why the sound changes when tip-rolling.

❌sound stage might be a bit narrow for some and when compared to similarly priced IEMS like the Final A4000 and Sennheiser IE 100 PRO. The reason might be the lack of treble air. In comparison, the Sennheiser ie100 pro has a very wide stage with good treble air and extension but can be very bright and fatiguing even in short listening sessions.

❌No cable rolling option. It is a new pentacon model and for now, it is impossible to cable roll this one. Even if you want to try older models of Acoustune cables, they are so expensive.

❌treble air might be lacking for some. They are not by any means lacking in that area. They actually have very good resolution in cymbal strikes, but I can see how other people might want more air from them.


♥️Bass has very good texture and definition. It extends deep and has so much authority that it might be your boss’s boss LOL (Headphonesty et al.) Djents sound so so so satisfying with them. Babymetal, Slipknot, Suicide silence, etc sounds really really good. You hear those heavy low riffs that you are forced to just bow your head and headbang using your hips. Lifting your head up just feels wrong. Yes that’s how commanding they are hahaha..

♥️Kick drums are also very easy to catch. Listening to Babymetal's track "Arkadia", blast beats are felt pounding in your ears and never overwhelming to cloud over the spectrum

♥️Bass notes are very easy to follow as well. You want to catch Davie504 basslines? This is for you. Haha.

♥️Although they are a bit U-shaped, mids don’t come that recessed. They have enough presence and contains a lot of details and harmonics.
-Listening to Goo Goo dolls' track “Name”, guitars sound very full and complete, with very good timbre.

♥️vocals have very good presence, timbre, and realism. -Listening to Oliva Rodrigo’s “traitor” gave me goosebumps. Also, from the track “Halaga” by Parokya ni Edgar, Chito sounded really intimate, and I felt like I was listening to him in a room.

-I am pleasantly surprised how the vocals can pierce thru instruments even with the bass presence. In Black pink’s track “Ice cream”, vocals sounded untouched even with those bass drops.

♥️treble may be a bit rolled off, but it doesn’t mean they are less detailed. Again, treble is very detailed and contains upper harmonics in guitars. Cymbals have very good resolution, and you can spot which are hit even on fast metal tracks. The advantage for this roll-off is that it can be less fatiguing in long listening sessions.

♥️the resolution is excellent for this price, and they are transparently warm. I may have made up my own description, but that is how I can really describe them! Hahaha. I did not realize that warm and transparent can go together, but hell they do. Believe it or not, but the heart mirrors would sound muffled when I switch to them, and the RS One is not even bright to begin with. That is how resolving they are.

♥️Instrument separation is insanely good for this price point. Man, I have a never-ending list of timestamps to relay this.
-The intro of the track “brighter” by Parmore has this guitar riff, te dedeng deng, tededeng deng, and then all instruments play around 7 seconds, oh my can I clearly track everything from the bass guitar, kick drum, rhythm, and lead guitar. It sounds like every instrument have their own speaker and you can easily follow chords, tabs, notes, drum patterns easily.

♥️Note retrieval is excellent. Polyphia’s track “GOAT”, at around 2:08, there seems to be kind of trumpet sound playing note patterns in the background, and they sound very clear even with all those instruments playing in front.

♥️I don’t know if this a PRO, but it is transparent on how the track is mastered. So you will either love your favorite tracks more, or you will despise how they are mastered ahaha. It will show you how instruments are positioned and how much gain they gave in each instrument. Crazy.. haha.. -Rivermaya’s track “214” has some cymbals gains that are pretty inconsistent, sometimes its far, sometimes its near lol.. Of course, you can hear that in other IEMS too, but it is just more pronounced in Acoustune RS ONE

♥️Detail retrieval is also commendable. Thanks to the very good layering, separation, and stage depth, getting details is a breeze.

♥️Soundstage may be narrow but has a very good depth and height, giving you a 3D effect stage. Vocals are in the center, bass in front, guitars on the sides, high hats on top/further away, and further to the sides are vocal harmonies and some extra synths.

♥️Sibilance free. Like really. Non-existent


-I mainly listened using my Shanling M3X. I also used dongles like jcally JM20, VE OHD, JA21, JM04 pro, and they are very transparent in whatever source you feed them. They may exhibit the flaws of your source and may also reinforce the good qualities.

They are also very responsive to tip rolling. I noticed that there is hole just below the nozzle. I am not sure if that is a vent, but it seems like it. It kind of works like how the bass of BQEYZ autumn can change depending on the magnet filter. I have not heard the autumn but I certainly hear a difference of the bass amount when I tip roll RS ONE.


❗Stock AET07- Bass texture, open mids, airy highs

❗Sony Hybrid foams- Less overall bass, forward mids, more air in treble

❗Spinfit CP100- less lighter on the midbass, retains the mids, boosts treble

❗Final type E- Tighter bass, a bit forward mids, a tad lower treble

❗Stock AET02 foams- almost linear bass, forward mids and treble

There are more generic tips I rolled, so experiment to your liking. For me I ended up using Spinfit CP100


-They are marketed as monitors, so these are basically good for stage use. Monitors should really have good instrument separation or else it will be difficult to hear click tracks especially in loudness wars haha. The mid-bass presence also helps a lot with note tracking from bass guitars and kick drums.


-Not at all. I have not seen the graph of this, but this can also be good for music listening.

What sets RS ONE set apart from other monitors like Sennheiser ie100pro and shure215 is that it seems to have a pinna gain for vocal presence. Most monitors skip the pinna and just go straight for treble details, making them sound overly bright or too warm, and they are not really good for music indulgence. Acoustune RS ONE is both good for music listening and for professional use.


-It played my library pretty well, from Metal, rock, reggae, alternative, KPOP, JPOP, Original Pinoy Music, EDM etc. I guess it is safe to say that the Acoustune RS ONE is an all-rounder. Just be mindful of that mid-bass presence and treble roll-off. But for me personally? I don’t really mind because they are so worth my money.

Acoustune RS ONE is the perfect definition of an In-Ear-Monitor, be it for professional use or for music indulgence. It may not be a perfectly tuned IEM relative to the current trend, but Acoustune did a hell of a great job on hitting two birds in ONE stone.

my unboxing and comparison here:

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Thanks for the impressions, well written! I do want to point out the it seems like the RS ONE is using the RECESSED pentaconn ear which makes it even more obscure for cable rolling. The normal pentaconn ear plug is flush with the body but the recessed version has only been previously seen with newer Sennheiser IEMs (IE400 Pro, etc.)

I would say about 1/3 of the bespoke IEM cable makers offer that connector nowadays...or you can go with Effect Audio's ConX swappable connectors to cable roll for days.

(I DIY my own cables so I am fairly familiar with cable terminations.)
wow thanks for the information! I do feel that they shine with more power even if they are fairly easy to drive. They just dont distort even on higher volumes. Ill try to find the cables you suggested, but if they are expensive, I guess my option is to find cable DIYers.. :)
Dust by Monday
Wow! Using the same connector as Sennheiser's Pro line? Nice!


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