ACOUSTUNE RS ONE Review: Very capable bright bassy Monitor IEM

-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

 -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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