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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


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


HiFiMAN SuperMini -> earphones


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


Construction Quality

The S2 is built from plastic and makes use of an ergonomically styled shell. The face-plate is affixed to the rest of the shell via a combination of friction and a single screw. The face-plate 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.


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.


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.


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.


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!



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