Accutone Studio S2

Overview

Flagship IEM model of the new Accutone higher line. Featuring a hybrid dual setup of a 10mm dynamic and a single Knowles BA (WBFK). With a fixed over-ear design in a strong red color and standard detachable MMCX cables. Powerful and warm sound in a slight dark tonality with smooth midrange and more laid back treble combined with a strong bass response. At the higher $300 price tag it may be very lacking in accessories set, though the sound tuning is quite nice.

Specifications

• Speaker: 10mm Dynamic driver & Single Balanced Armature (Knowles WBFK)
• Sensitivity: 118 dB
• Impedance: 32Ω
• Weight: 5.1g
• Cable: 1.2m
• Plug: 3.5mm

Price: U$D 339.

The Studio S2 arrives in a very similar package as the Gemini HD, easy to unpack with everything snugly arranged inside. The accessory set includes one pair of small/short dual flange silicone tips which are already installed on the earpieces and two extra single silicone tips in small and large size. There is no medium sized tips, but there is a pair Comply Foam tips in medium size. There is also a small carrying case. The accessory selection is really lacking, which I already complained about on the Gemini HD, but and this higher $300 price tag it is quite unforgivable.

Design

Overall build quality on the Studio S2 is decent. The earpieces are made entirely of plastic material and do look thick and sturdy enough. They are composed of two separated parts well attached together. The all translucent red color theme is cool, though for some can be too flashy, but it possible to see the entire inner setup inside with the large 10mm dynamic driver just in the center of the shells and the small BA unit closer to the nozzle. At the tip, there is a mesh filter (similar to what was found on the Hifiman IEM models in case there is need to replace them).

The earpieces have a strict over-ear design, and when looking at them, well, there are too obvious similarities with the old Aursonics (now Fender) in-ear monitor line. They are on the large side with a long body structure that may be quite challenging for small to medium size ears, however, the well shaped form factor lets them sit fixed on the outer ear part with just the smaller nozzle reaching the ear canal. They are comfortable and do provide a good level of isolation too, however the included silicone tips proved to be useless missing the medium size pair or being the dual tips just too small.

The cable connection utilizes a standard MMCX type. The included cable has a normal connection to the MMCX socket, and of course proper care should be taken when detaching it. It simply consists of three twisted strands on lower half from the angled 3.5mm plug to the y-split and then two strands for each side. The cable has a memory wire that act as earguides and hold the earpieces in place.

Sound Impressions

Main IEMs used for comparison: Dunu DN-2002, Falcon-C, Lear Kaleido, GR07 Bass, iBasso IT03, Brainwavz B400.

Overall, the Studio S2 could be described as having a mid-centered sound that arrives from the BA unit with a very dominant low end response on the mid-bass region, and then a present, well leveled, but more laid-back treble performance.
The bass is truly powerful, very rich with full body and plenty of impact. The weight is towards the mid-bass part which is the most noticeable frequency on the whole sound. Sub-bass is also very present, but just not as forward as the mid or upper bass, though it has plenty of rumble, good depth and fair extension and dynamics. Speed and resolution is about average; not that is sounds slow, but not fast as to match the BA driver inside. Quality-wise, well, the bass is not very tight and can get out of control sometimes. Not a total basshead IEM, but should classify very close to that category.
In terms of pure quantities, the S2 reminds of the Dunu DN-2000, though not as large and extended or controlled, and more intrusive at the lower midrange. The Lear Kaleido has a more similar bass presentation, though the S2 sounds wider if with less balance in sub and mid-bass.

The midrange has the typical characteristics of the single Knowles BA driver. Technically, the whole midrange is a bit forward, accurate and rich, with a nice texture and decent layering. However, it is the dynamic driver with the super extra energy that tends to overshadow the lower mids and keeps much more forward, especially when raising the volume a bit. EQ does work very well here, taking down the extra bass bloat for a cleaner midrange. The S2 gives good priority and fairly sweet texture to the voices, if a bit preferring the female singers as they are less affected by the low end.

There is not too much brightness on the upper mids, and remain usually smooth, and maybe with just hint of grain (but not harshness or sibilance). Treble too, is smooth with still enough energy but not too much sparkle; enough to give the necessary weight and texture to instruments when needed, never trying to stand out and more shy than the midrange. Can be considered a bit safe or too soft, rolling off at the top. Not too surprising with the type and tuning of the single balanced armature driver, matching the warm and laid back signature.
Stage dimensions are not large, though thanks the powerful dynamic driver the S2 shows decent depth and big headstage. Air and separation are limited too against more balanced sets, though the tuning on the S2 is quite fun to listen. Moreover, the WBFK doesn’t reveal too much micro detail compared to a TWFK based hybrid, but it is more comfortable with lower quality files.

Worth mentioning that the Studio S2 is not picky at all, just plays well with any source and doesn’t ask for a better cable to sound best. On the other hand, eartips are too critical with the S2 to get a best balance out of it.

Accutone Studio S2 Review: Articulation Through Simplicity
Accutone is a consumer-electronics company based in China that specializes in building earphones. They’ve had some pretty solid offerings that met the market well in the past and they’re back again to woo the audiophile market with their new lineup: the Studio series. But are their efforts worthwhile? Or is this a failed attempt to breach an already saturated market?

You can find the S2 available for sale, here, for $340.

About My Preferences: Heads up, I’m a person! As such, these words are my opinion, and they are tinged by my personal preferences. While I try to mitigate this as much as possible during my review process, I’d be lying if I said my biases are completely erased. So for you, my readers, keep this in mind:

• My ideal sound signature would be an extended sub-bass with a leveled, but textured, mid-bass.
• I have a mild treble sensitivity.

Source: The S2 was powered like so:

HTC U11 -> USB-C adapter -> earphones

or

Hidizs AP100 3.5mm out -> FiiO A5 3.5mm out -> earphones

or

HiFiMAN SuperMini -> earphones

or

PC optical out -> HiFiMe SPDIF 9018 Sabre DAC 3.5mm out -> earphones

All music was served as MP3 @320Kbps or as FLAC.

Tech Specs

• Impedance: 32 Ω
• Frequency Response: 20–16,000Hz (-3dB) 8–20,000Hz
• Sound Pressure Level: 100dB SPL/0.128V |118dB @1V, 1kHz
• THD: <1% (1kHz, 0.178V)
• Cable Length: 1.2m Oxygen-Free Cable (OFC)
• Weight: 5.1g (Without Cable)

Sound Signature
Sonic Overview:

The S2 features a gently U-shaped sound signature. The midrange is rather linear with a small bump to the vocal range around 1–2KHz. Treble is boosted past the mildly recessed midrange by with a peak at roughly 5KHz. The bass is present in quantity and solid in quality. Mid-bass is pretty much on par with the lower-midrange with only a small increase in emphasis past it. Sub-bass is well extended and is slightly less emphasized than the mid-bass.

Treble: Songs used: In One Ear, Midnight City, Outlands, Satisfy, Little One

The Studio S2 seeks to implement a more “pro” sound signature than its cheaper sibling, the S1. In doing so, the S2 acquired a U-shaped sound signature with a boosted treble. The BA-driver that Accutone chose to use with the S2 is competent. There’s no tricks here, just plain old articulation and a natural timbre. Quick, but not artificial-sounding, attack and decay lend the S2’s treble a precise feeling and its highly resolving disposition works hard to justify its price tag.

The S2 managed to pick up all of my “test” details for the entire duration of In One Ear with ease. Of the 10 or so Accutone IEMs I’ve tested, this is only the third to catch more than half of them, and the first to catch all of them. But you know, for $340, it better be that good.

The treble is also quite smooth. There’s no graininess or unseemly peeks, allowing you to focus more on your music and less on the vessel producing it. This smoothness combined with the treble’s sonic resilience allows it to induce some phenomenal instrumental separation and airiness. Spatial cues are consequently well defined.

Midrange: Songs used: Flagpole Sitta, Jacked Up, I Am The Highway, Dreams, Too Close, Little Black Submarines

The mids are linear, with some small QOL improvements that bring a nice energy to the S2’s sound signature. A mild boost to the lower mids adds weight to guitars, drums, and the vocals, while a small spike in the 1–2KHz range adds clarity and separation to the vocals.

The timbre of the midrange is natural. There’s no distortion or weird disconnects in the sound from the crossover, and instrumental separation is really good, even compared to other IEMs at this price-point. Electric guitars sound really good through the S2, though. Electric crunch is super satisfying, and I often get lost in the solos of my rock playlist while using the S2.

Vocals are above average in terms of intelligibility. The S2 doesn’t have a preference for either male or female vocals, and they are both weighted quite well.

Bass: Songs used: Moth, Gold Dust, In For The Kill (Skream Remix), War Pigs (Celldweller Remix)

The S2’s low end is mid-bass-centric. It’s blended very well with the midrange and isn’t emphasized much past it. This, combined with the bass’s good control, deep extension, and solidity, prevents it from overwhelming the midrange and bloating up songs.

The chugs of a bass and guitars in drop-C tuning are deep and powerful on the S2, providing much-needed weight to genres like metal. The S2 has some mid-bass impact in its low end, and while it isn’t huge in quantity, it is precise and naturally toned.

Electronic genres that typically benefit from lots of impact and rumble are enjoyable on through the S2, in spite of its comparatively lean bass response. Drops are weighty in Gold Dust, and enjoyably chaotic on War Pigs. And while I didn’t get lots of rumble out of In For The Kill, the bass-line was very well articulated. It never bottomed out or felt too shallow. The S2 adopts a “hear not feel” policy for its lower-register it seems.

Packaging / Unboxing

Build
Construction Quality


The S2 is built from plastic and makes use of an ergonomically styled shell. The faceplate is affixed to the rest of the shell via a combination of friction and a single screw. The faceplate features a vent and reflective Accutone logo.

Embedded in the shells are (now standardized) MMCX connectors. They are sturdy and well supported by the shell, but they do allow for rotation pretty freely.

On top of the nozzle’s are black metal filters. They do a good job protecting the driver from any debris that may try to get past them. On the inner face of the shell is a beveled “Studio” sub-logo. It’s pretty stylish and doesn’t affect ergonomics, so I’m glad Accutone included it for a little extra flair.

Accutone chose to go with a simple plastic braided cable. It does its job admirably, holding no body, and conducting no noticeable microphonics. The MMCX housing, 3.5mm jack housing, and Y-splitter are all made of a matte plastic that is thick and durable. There is ample stress relief on all the critical points along the cable. The stock cable does not come with inline controls, though it is very easy to find a replacement that does should that be important to you.

Comfort

The Studio S2 is exceedingly comfortable. I have no complaints about it at all, and would highly recommend it to anyone with larger ears. Those with smaller ears may find a way to use the S2 via the foam eartips, though there’s no guarantee given the size of the shells.

I had no problems with comfort while wearing the Studio S2 for extended periods of time, though I wouldn’t recommend laying down in it as that did produce discomfort for me.

Accessories

Inside the box you’ll find:

• 1x semi-hard carrying case
• 1x pair of foam eartips
• 3x silicone eartips
• 1x micro-fiber cleaning cloth

The Studio S2 is decently well-equipped, but needs a bolstered selection of eartips, given its price.

Furthermore, as is with every single other case made by Accutone, the case in the box is far too small. While the Studio S1 definitely does fit, the case should be 30–50% larger to avoid having to tightly coil the included cable and avoid compressing the Comply tips that were (thankfully) included in the box. At $340, I should not need to go out and buy another case for my IEM.

Comparisons
2: Heir Audio 4S ($400)

The Heir Audio 4S and the Accutone Studio S2 are fairly close in presentation, with some core differences. The S2 has a warmer lower-midrange with an accentuated mid-bass while the 4S has a more linear midrange with a slightly raised mid-bass. The S2’s lower treble is also less notable than the 4S’s, giving the 4S a much brighter overall sound signature. The S2 has a more relaxed stance though, owing much to it’s more natural decay speeds for the lower-midrange and bass. The 4S produces a somewhat more detailed midrange and treble, but sacrifices some texturing and solidity in the bass. And in order to accomplish its level of precision, the 4S has to move into attack and decay speeds that are a little too quick for my tastes. The S2 feels much more natural to my ear in those terms.

3: Audio Genetic AG2 ($430)

The AG2 and S2 have vastly different sound signatures. While the S2 is V-shaped with a mellow bass signature, the AG2 is mid-forwards with a slender bass and accentuated upper-mids. The S2’s overall presentation is much more “smooth” than the AG2’s, but that costs a small amount of texture in the treble and midrange. And while the AG2 has a more articulate lower-midrange, it misses out on the realistic character that the S2’s lower-register carries. The S2 has more mid-bass impact and sub-bass rumble, making it the clear-cut choice for listeners of electronic music, or bassheads in general. Listeners who prefer a more detail-driven midrange will prefer the AG2. The two are neck and neck in terms of detail retrieval though, with the AG2 edging the S2 out in the lower midrange by oh so little.

Summary
The S2 is a really fun IEM. While it won’t be your next pair of reference monitors, it does a good job being a slightly more “pro” version of its cheaper sibling, the S1. A natural sound signature, good amounts of detail retrieval, and a solid build make it a good choice for anyone who wants an IEM with the same base characteristics as a V-shaped IEM but has more precision and midrange presence.

As always, happy listening!

Firstly I would like to thank Accutone for sending me this sample to review; these have had well over 100hrs of burn-in before reviewing.

*disclaimer: This sample was provided for the purpose of writing a review, no incentive was given to write a favourable review. All opinions expressed are my own subjective findings.

Gear Used: Audio Opus #2 / iBasso DX200 > S2 (Comply tips)
HP Laptop > JDS Labs OL DAC > O2 Amp > S2



Tech Specs:
1 x 10mm dynamic driver + 1 x Knowles balanced armature driver
MMCX cable
https://www.audio.accutone.com/studio-s2
MSRP: $339.00

Packaging, Build quality and Accessories:
The S2 comes in a nice little card box that has a plastic outer sleeve that has a picture of the monitors on it. Once you remove this sleeve you can fold open a magnetic flap and see the IEM’s through a plastic window, with the accessories below. The box is sleek and small, and looks very good, and if more than fitting for the price. The IEM’s are held in a foam insert, with the cable held in a compartment underneath this. Overall neat and professional looking packaging from Accutone.

The build quality is very good, the housings are a 2-piece plastic design screwed together, and they feel lightweight but also durable. The plastics feel good, on the end of the nozzle there is a lip to keep the tips on tight. The one thing that worries me is the paper wax filter; this comes off easily and could do with having some better glue hold it in place. The MMCX connectors are tight and providing you don’t change cables all the time they should last. The cable itself is soft and rubbery, with good relief on all ends, and they have a short section of mouldable memory wire, one thing missing from the cable is a cinch.

Accessory wise you get a fairly standard semi-hard clamshell case, a soft velvet pouch, a set of M size comply T-200 tips and S, M and L single flange silicone tips. This isn’t a huge amount of accessories, but they include the essentials.



Comfort, Isolation and Driver flex:
With comply tips these fit nice and tight, and also fairly deep but they still stick out of my ears at a funny angle, this is due to the angle of the nozzle. Once inserted they are comfortable to wear, and the cable is ergonomic. If it weren’t for the odd angle of the nozzle these would look a lot sleeker in use.

With Comply tips they isolate fairly well, they are vented so there is a certain amount of outside noise that leaks in and they do not isolate anywhere near as well as a fully sealed unit, but they are fine for most general usage.

Driver flex for me was only an issue when using silicone tips, and it was fairly bad, so I recommend sticking with Comply foam tips.



Sound:
Split into the usual categories with a conclusion at the end. The below is written using Comply tips which I found tames the slightly exuberant treble, but also makes the lows a bit fuller.

Lows: With the dynamic driver taking care of the lows these are very dynamic and have a v-shaped sound signature with boosted bass and treble. The lows extend deep with ease, and are also very full and punchy. They do dominate the sound a little and slightly overshadow the lower mids. Saying that, the lows are fairly well controlled and can keep up with most genres, their ability to articulate bass guitars is very impressive. If you enjoy EDM these also work well really bringing out the impact and fun bass in tracks.

Mids: The mids are pushed back a little in the mix lacking in bite and aggression, they fall short a little if you want a more neutral midrange. There is still a good amount of detail in the midrange, and separation and air are very good. Female vocals sound a little better due to a bit more clarity in the upper midrange, and they are not as recessed as male vocals. If the bass was toned down a little it would let the midrange shine through a little better, as the detail and tonality is there. EQ can really help these.

Highs: The highs are nice and sparkly, and with Comply tips never too harsh or bright. They have the right amount of presence, cymbals crash with power and the highs extend with ease without becoming splashy. The highs are well defined and I wouldn’t really change anything here, but some may find the highs borderline bright. The thing about the highs is that they sound real, like when you go to see live music they are right there and audible but well separated from the rest of the sound.

Soundstage is wider than average with excellent layering, but the bass does make the overall sound full rather than airy. Instrument separation is good overall, but again the fullness down low does make the sound quite thick overall.



EQ really goes miles on these, due to not really needing to boost signals you don’t run into issues of distortion. I found around a -8dB cut at 32Hz, -6 at 63Hz, -4 at 125Hz and -2 at 250Hz brings the bass under control and allows vocal to shine through.
Once EQ’d you get superb detail retrieval in the midrange. This also means that for most tastes you can tune how much bass you want without ever having to boost it, as it is there in stock form.

Cables:
iBasso CB13: The CB13 is a very soft and ergonomic cable, that fits the S2 very well and also compliments the sound in my opinion. Without EQ the lows are still full but they are much tighter suffering from slightly less bloat; however they are still a little overwhelming. The midrange is not quite as full, and it is still recessed, but there is a little extra air and detail. The highs are surprisingly not piercing and are actually toned down a little. This cable tightens up the sound a little, and widens the soundstage without making them sound thin or piercing.



Comparison:
Vs Clear Tune VS2:
These 2 monitors are tuned very differently, with the VS2 having a more neutral and slightly mid forward sound that focuses on air and detail. The VS2 does not extend as low, or as high, but does have a much better balance across the spectrum. The Accutone S2 is all about fun, with its bouncy V shaped sound signature that lacks presence in the midrange.

Conclusion: The Accutone S2 is not a reference monitor, it is a fun and engaging IEM that sounds best when used with comply tips to tone down the slightly over the top treble. The build quality is good, the fit is comfortable but they look a little odd in my small ears. The S2 are undeniably fun, and those who enjoy a V shaped sound signature will really enjoy these, they lack a little control and refinement but do have very good detail retrieval.

Sound Perfection Rating: 7/10 (full and fun but a little uncontrolled at times)