Letshuoer S12 Pro Review


Today we review the Letshuoer S12 Pro, the planar driver IEM from the Chinese brand. A model available for $159.


Disclaimer: the Letshuoer was sent to us free of charge by the brand, in exchange for our honest opinion.

About Letshuoer 

Founded in 2016 under the leadership of Danny To and Jeff Wong, Letshuoer is one of those IEM brands whose name I’ve heard before, but never really paid much attention to. Fortunately, the brand didn’t wait for me and managed to grow year after year, thanks to an ever evolving range of in-ear monitors.

Behind the (strange) name, two senior engineer: Danny To, ex engineer for Panasonic and sales director of a multinational technology company, and Jeff Wong, ex-head of Dah Chong Hong Group and Department director of ZhongSheng Group. Big heads, frustrated not to get their ideal sound, who decided to open up a company and create their own products – you know the drill. 

A process that led to many successful ventures, like Meze, FiiO or even JDS Labs, all led by engineers in search of the “perfect sound”. And so, when Letshuoer asked us if we were keen to try their S12 Pro – an updated version of the S12, their magnetic planar IEM – I jumped in.

Should you get one ? That’s what we’ll discover today.


Design & Build Quality


As usual with chi-fi products, build quality is inversely proportional to their price : for less than $150, this is a very potent IEM. Even with low-budget in-ears like this one, the brands seemed to put the same attention they give on higher end devices, as FiiO did with their FD series for example – even if, to be fair, the FiiO feels even more premium .

Entirely made of aluminum, the Letshuoer S12 Pro is a revamp of the brand’s previous planar IEM, the… S12. A visual upgrade mostly as both share the same CNC-milled case, but the Pro model now comes with a deep blue finish, for a more premium look. It wouldn’t dare to say that they are bad-looking, but compared to products from BGVP, or even the latest FiiO FD11, the end-result is kinda… conservative. 

There are a few quirks here and there though, like the gem-like 2-pin socket, contrasting with the rounded shape of the main chassis, or the silver-toned dirt-grill protection – located inside the nozzle. 

The only drawback I could spot would be its relatively light weight, but some might see that as an advantage. We’ll see once we wear them !


Build Quality

Unsurprisingly, build quality is top-notch, and if the Letshuoer S12 Pro is one of the most affordable planar, they don’t feel like a cheap knock-off, far from it. There are no steps, no cracks, no bruises, just one smooth surface all over the shell – with a small line between the two parts of the main body.

Made of brushed aluminum, that body shall easily withstand the test of time, even in harsh conditions like the bottom of a backpack. Mine were used and abused daily for the past week, stuffed in the bottom of my bag with a computer, an iPad and a Steam Deck, without a care in the world, and remained pristine up to this day.

One word about the stock cable: I love it. Made of monocrystalline copper, and four 98-strand cores weaved together, the cable displays a delightful black/white twisted pattern.. Not only is it detachable, it also sports a swappable termination that allows you to switch between 3.5mm, 4.4mm and 2.5mm outputs. Sure, that’s something that we’ve already seen on FiiO or Shanling IEMs, but the S12 Pro feels even more ergonomic in that regard, thanks to the lack of lock system – I can never get FiiO’s one right on the first try.

The only drawback here, for me, would be the 2-pin socket, which I still find less practical than the MMCX one, but apart from that it’s almost perfect.



In the ears

Comfort-wise, the Letshuoer S12 Pro surprised me, in a very good way. 

Once fitted with the right tips (I use the medium grey silicon tips) the comfort is top-notch. The semi-custom shell has been polished and mastered by many brands now, and Letshuoer is clearly one of them. I was afraid the nozzle would be too thick with a tip, but that’s not the case, and even over time

The rounded shape perfectly filled my ears, and when paired with the right tips, the S12 Pro gave me a very nice experience. To be fair, they aren’t as cozy as a semi-custom fit could be, but I’d still rate them a solid 8 out of 10 in this aspect and I’d place them above all the other models I’ve reviewed this year


With a solid shell, good tips and an ear-filling design, the Letshuoer S12 Pro were excellent noise-blockers – which was to be expected. On my daily commute, they perfectly dampened the noise coming from the train, and the subway. Same at the office: once plugged in, the ears completely cut me off from my colleagues, when music played.

So, time to check the specs!



For the nitpickers and nerdy ones here, I’m giving the specs and technical sheets. For all the others, you can just go to the next page to see how the Letshuoer S12 Pro performs.

14.8mm Planar Driver + Balanced Chassis Design

The Letshuoer S12 Pro maintains the same custom 14.8mm planar driver found in its predecessor, the S12. This large-diaphragm driver is designed specifically for this IEM, providing detailed sound retrieval, punchy bass, and clear trebles. With a high sensitivity of 102db, the S12 Pro can be easily driven to volume, whether it’s connected to a cell phone or dongle DACs, ensuring optimal sound performance with most source/amps.

The design of the Letshuoer S12 Pro’s chassis is a continuation of its predecessor. Multiple vent holes on both sides effectively alleviate negative pressure build-up within the ear canal, protecting your hearing. The independent rear acoustic chamber design ensures more consistent channel matching. In terms of sound performance, the structural design of the front and rear acoustic chambers effectively discharges pressure inside the chassis, resulting in a more natural sound.



Inside the box

The Letshuoer S12 Pro comes with a good bundle, reminiscent of its chi-fi origins. In the box, you get:

  • the S12 Pro

  • an OCC silver/coper cable, with 2.5mm / 3.5mm / 4.4mm termination

  • 3 sets of eartips (standard / Foam / standard)

  • a protective case made of pleather – and a surprisingly nice one moreover

  • an user manual and a small catalog

A good bundle with everything you shall need on a daily basis. Big bonus point for the set of three termination plugs and, that’s rare enough, the mini catalog that allows you to check (almost) everything the brand has to offer.

Additional accessories

There is only one thing you could get for your Letshuoer S12 Pro: a good source like a DAC/AMP or a DAP, I’d suggest something small and simple like the KA5, iBasso’s DC04 Pro or ddHiFi TC44C. 

Personally, I hooked up the new TC44Pro – review incoming – and the end result was dang impressive!


Full specs

  • Model: Letshuoer S12 Pro

  • Type: IEM

  • Drivers: proprietary 14.8mm planar driver

  • Socket: 2-pin 0.78mm

  • Cable: OCC copper/silver braided

  • Shell: CNC-milled aluminum, anodised and brushed

  • Frequency Response: 20Hz- 20kHz

  • Sensitivity: 102dB

  • Impedance: 16 ohms

  • Sound Isolation (up to): 27dB

  • Cable length: 125cm

  • Weight: 10g per ear

  • Price: $159

The review continues on Page two, after the click HERE or by using the jump below.

Page 1: About the brand, design, layout

Page 2: Sound performances

4/5 - (29 votes)

A nerdy guy with a passion for audio and gadgets, he likes to combine his DAC and his swiss knife. Even after more than 10 years of experience, Nanotechnos still collects all gear he gets, even his first MPMAN MP3 player. He likes spreadsheets, technical specs and all this amazing(ly boring) numbers. But most of all, he loves music: electro, classical, dubstep, Debussy : the daily playlist.

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