THE PLUS:
-energic and Vividly balanced V shape
-fast attack and control
-good technicalities
-good imaging
-fast punchy bass
-decent resolution
-impressive treble speed
-smallest planar IEM ever
-good accessories
THE MINUS:
-shouty and too agressive at high volume
-source capricious
-boomy bass that lack definition
-unbalanced treble that can distract
-prompt to sibilance even at low volume
-rough sometime harsh treble
-intimate spatiality lacking wideness and deepness
-fuzzy bright timbre with saturated grainy texture
-typical lack of brilliance and sparkle from planar driver
-blurry noisy sustain and definition edge

TONALITY: 7.2/10
TECHNICALITIES: 8/10
CONSTRUCTION: 8.2/10
SOUND VALUE: 7.2/10
INTRO
AKOUSTYX is an American start-up manufacturer based in San Jose, California with their assembly line in Nashville, Tennessee NOT in China….which is something I truly admire nowadays where even big brands do not tend to care to assemble their product in their own country mostly to higher their benefit, not to lower the price of their final products. This fact tends to make the final product less rushed in production, which at the end can result in more trustable craftsmanship and quality check.
Behind their company, they have a team of musicians and audiophiles, which serve them to achieve acoustic qualities that will please as much musician searching for reference monitor sound than audiophile searching for musical reference sound.
Today I will review their latest release, the S6, which is an ultra small planar IEM using a 6.2mm double sided magnet planar driver patented by Akoustyx themself.
Priced 175$, the S6 promise a ”studio reference tuning” that put emphasis on clarity.
Let see if this planar IEM can stand out of ver competitive sub-200$ market in this review.
CONSTRUCTION & PACKAGING

UNBOXING experience is a very rewarding one. The presentation is minimalist, but you are spoil by lot of accessories in the box. I’m often underwhelmed by the protective case included with earphones, not this time because we have a superb neoprene padded carrying case that has 2 pouch with a zip so you can bring an extra cable with the R-220. It’s really a well-crafted carrying case that I will use daily.
As well, you have good amount of ear tips including their own-designed customization kit ear tips, silicone ear tips and a pair of memory foams ear tips. The cable include is titannium kevlar coated OFC and feel very sturdy. Quality is OK, but ear hook choice is questionnable.

CONSTRUCTION is simple yet well made. S6 use the exact same IEM housing than the R-210-220 with black color instead of blue. It’s supremely small, and a unique look that looks like a mix of Etymotic and Final Audio F iem. Material of housing is a mix of aluminum alloy and polycarbonate plastic. Sturdy and classy looking iem that promises long durability.

DESIGN is nice and comfy, it’s so small that it will fit any size of ears. As well, you can both wear it over-ear or cable down. It must be noted that if you wear it cable down, cable will create microphonic. As well, with ear hook, over-ear design is less comfortable than with a soft flexible cable without ear hook. But, and this is an important BUT, if you use the earlock tips, the ear hook problem is partly solved as the fit will be very secure. Earlocks tips cancel any unwanted movement, but I don’t think it is very comfortable. In fact, I prefer using another cable and wear the R-220 cable down.
ISOLATION is impressive and it really acts like noise ears plug when used with memory foam tips. As well, sound leakage is inexistant, which is a big plus.
SOUND IMPRESSIONS

Listening to the S6 was a real roller coaster ride, let say it sure doesn’t let you indifferent for the better and the worst. These are bright energic V shape where the bass is all about fast bright punch and upper mids and treble is most boosted part, so, you can feel these are neutral when their no bass then when it hit, it hit hard and overall very foward and immediate musicality hit you like a wall.
I can’t listen to those at high volume, and Akoustyx underline to me that the ultra small 6.2mm planar driver is sensitive to loudness and will indeed create harmonic distortion at too high volume. So, are these the kind of IEM that are overboosted in clarity so we can perceive high resolution at low volume? I do think so and I do think it’s a very risky approach to tuning too, since pinna gain is intensely boosted here and do create upper mids issue that can’t be overseen even at lowest volume.
And depending of your psychacoustic awereness, resolution will perhaps feel scooped in sound info, overly colored, confirming again this isn’t neutral IEM at all but unapogically intense and sharp sounding. Sure not boring, the Akoustyx are planar on amphetamine, impatient to rock your sock off.
The result can be highly engaging for simple rock or folk track or dangerously over excited when it come to busy jazz fusion or classical symphony track.
The bass is all about urgent loud punch and boosted presence texture, depending of bass line and kick drum instrument, it can go from wow to What. With a track like ‘,Magic Arrow” from Timber Timbre, we are in wow territory since the kick isn’t hitting hard in the track, it’s well texture and define with good weight and the electric bass line is superbly articulated but doesn’t dig low, wich benefit S6 limitation. So, this is the type of bass that doesnt lack bite, not weight, but is limited in linear rumble so for big beat with heavy boom it can go into What territory. Why? Because bass is overly boosted for a planar and when bass is loud in a track, it will be multiply in boomy way with euphonic sustain that affect proper roundness. This can be distractive and tend to make mid range even more recessed, some veil and bleed can happen, stoling instrument separation air. We are in quantity affect quality here, and we have a sub bass roll off too that is replace by boom resonance that darken low end when it occur. But again, I underline that bass line can be fastly redered in presence and definition when they have texture and the attack speed can be mind blowing with an album like ”Not tight” from Domi & JD beck, where the drum is fast and punchy, well define and have good layering with the bass line that is more about high pitch play. Things begin to go wrong with heavy trap track like ”Broken Clocks” from SZA which is all about unclean foggy big sub boom and overly sharp percussion, with lost in dark female vocal. Bipolar low end that lack versatility, elasticity and flexibility.
Mid range is most recessed part of the spectrum and can get crumpled between bass and treble quite intensely. Let say these Akoustyx aren’t for piano lover, an instrument that blossom in mid range, here it’s barely hearable sometime, for ex, in chamber orchestra violin will overshadow with their bright presence the warm and dark piano note that lack definitio and attack edge and feel 1km more distant than other high pitch instrument. Even with calm jazz track like ”Air” from Dieter Ilg ”B-A-C-H” album, the piano seem more distant than both bass and percussion, bass is all about texture bite, not very bodied and extended while percussions is super sharp, strangely, piano sound clean and well resolve but lack note weight and loudness amplitude, so this confirm that busier is the track, darker is the mid range. Then upper mid range came to the rescue and brighten what it can, which is mostly texture and presence of mids instrument, we have extra lower mids meat too that will favor some male vocal or female vocal, but the mix of low harmonic and boosted texture presence can lead to very wonky vocal too, as well as problematic sibilance and shoutyness. Yes, the Akoustyx are wild and imprevisible and certainly not for mids, tone, timbre and vocal lover in general. For natural timbre, better go with Tangzu Zetian Wu.
Treble head rejoice! Your in for a treat with the treble centric S6, but it’s not for fainth of hearth even if it’s not spikiest treble have ever heard from lower to upper treble. Before 10khz everything is boosted, energic, bright in texture and sharp in edge. While this is problematic for some vocal and can make violin sound amplify by an electric guitar amp, it can be rewarding for solo drum percussions due to lighting fast attack speed. Yes, this micro planar driver sure is in a rush to impress us with it’s fierce transient speed and wow effect can occur for non sensitive listener. This is abrasive treble that favor presence and texture saturation, it have crunchy attack with short bright sustain, it’s not the cleanest nor snappiest treble, and it lack sparkle and air as well as brilliance and and surely full extension up to 20khz. Yet, the abrasive texture add a sens of urgency to the music by puting fowards percussions and micro details part, it add extra dimension to an overall compressed spatiality. Snare can sometime be hot and hit quite hard, but even if a hint raspy by time, the percussions timing is vividly presented and hook our attention, sometime in mind blowing way when mid range instruments aren’t the focus of music. But don’t expect end game refinement here, as well as full clear extension, clavichord and harp sound dry and scooped in resonance amplitude with the Akoustyx, this mean acoustic guitar too lack sparkle and natural decay.
Their not alot to say about the soundstage, apart that it’s average since whole sound presentation is rather fowards and in your face. So, it’s an intimate listen, and it do feel stock in your head since widenes and tallness is lacking as well as overall sens of openess. We have some deepness, but it’s limited too.
Yet, the imaging is surprisingly decent within this space limit, this is surely due to fast transient speed that permit sound layer to be extracted from each other. So, while their not alot of space between instrument in X axis, fast separation in Y axis permit precise positioning enough.
COMPARISONS

VS TANGZU ZETIAN WU (1x 14.2mm planar-140$)
First thing that hit me is how more open and wide is spatiality, deeper too, more holographic with wider instrument and mids instruments presence. As well, the Wu is notably warmer, smoother and better balanced, it sound more musical and laid back than more fowards sounding bright and agressive S6. Then the vocal, both male and female are fuller, lusher more wide open and natural in timbre, overall mids are less recessed, better rounded and less thin bright than S6. Bass is chunkier too, more rumbly and well define in body, its less textured tough, and the punch is slower, thicker and warmer in separation. Then the treble, well, let say S6 have both lower and mid treble notably more boosted and less cohesively and organically balanced than the WU, it’s sharper and edgier in definition too, percussions being more fowards with the S6. S6 treble si faster in attack, less blurry in edge, snappier and more detailed and even more brilliant and airy than the WU, which is dark on top, have less thin highs but poorer overall resolution even if the macro presentation is more realist and richer in sounds layers density. Spatiality is wider and taller with the WU, a bit deeper, tunnel like way, with S6. For imaging, the S6 is superior even if more compressed in presentation, while instrument have more space between them with the WU, this space isn’t clean a make sirupy the layering as well, while S6 isn’t most realist in positioning, since the percussions can feel on front stage for ex and center instrument from mid range will be recessed irrealisticaly, the separation is sharper and cleaner and permit better static instrument pin point than the WU.
All in all, the S6 is more agressive and technical sounding, less well balanced and more artificial sounding than the tonaly superior Zetian Wu.
VS TINHIFI PANDA (1x Planar-120$)
Simply put the Panda is a better balanced and less excited V shape S6. While bright, it’s smoother and not as boosted in upper mids. The bass is less boosted but have punchy well textured mid bass punch still, sub bass is a bit thicker and fuller extended with the Panda too. Mids are thicker, smoother and more natural, not as boosted in texture too. Treble is bit dryer, smoother, fuller, less fast and snappy, bit more blurry in definition edge. Spatiality is again more wide open and now deeper too, more holographic. Imaging is on par or superior due to more transparent layering.
All in all, Panda is both technicaly and tonaly better than S6.
CONCLUSION
The Akoustyx S6 are surprising planar IEM that deliver an energic and engaging bright and punchy musicality.
It merit an applause for being the smallest planar IEM on the market.
In term of sound value, it enter a very competitive market since chifi have release tremendous amount of good planar earphones in 2022 and the Akoustyx came late in the game with a sound quality that lack a bit of refinement and tonal balance versatility.
While not plain bad, the S6 is still an agressive sounding IEM that will not be appropriate for treble sensitive listener as well as those that seek natural timbre and full tonality.
I think this IEM is aimed for those searching ultra small and portable earphones that deliver impressively detailed sound at low volume, and for this purpose, it’s valuable.
Half-recommended!