Muxicbox Steranko 40

Muxicbox was founded in 2023 with the aim of offering high-quality IEMs at affordable prices. The first two models were the Steranko Gold and the Steranko Platinum. The new flagship Steranko 40 was first introduced at Can Jam 2025 in Hong Kong. With this model, the aim is to produce nothing less than the best IEM in the world! Its exceptional tribrid configuration with a total of 40 drivers is set to redefine the listening experience for audiophiles and musicians alike.

The production of a single Steranko 40 is so complex that it takes a total of 20 days. The highest quality materials are used, which are assembled with great precision. The shell is custom-made from synthetic resin and polished by hand. This dedication to craftsmanship underlines Muxicbox's commitment to delivering a product that is outstanding in terms of both workmanship and sound. Attention has been paid not only to the IEM itself, but also to the entire packaging and unboxing experience. In addition, the specially manufactured “Golden Voice cable” was used to further optimize the sound quality. This is a 10-core, oil-impregnated cable consisting of 99.99% pure gold strands. This cable is absolutely amazing!

Now we come to the driver configuration, which really makes you click your tongue. Firstly, there are 8 EST drivers for the ultra-high frequency range. I don't know of any other IEM that uses so many EST drivers. The other TOTL IEMs usually use 4 EST drivers here. For the bass range, 2 coaxial drivers are used, which are known for their ability to produce very deep and powerful bass. A further 10 BA drivers are also used. 4 BA drivers for the mids. 4 BA drivers for the upper midrange and lower treble and 2 BA drivers for the high frequencies. Muxicbox uses only the very best Knowles and Sonion drivers for each Steranko 40, which are meticulously selected beforehand. More on how the whole thing sounds in the end product later. First of all, I would like to talk a little more about the unboxing experience.



The Steranko 40 package as a whole is a pure delight. You just have to say that. The storage box is covered in elegant blue leather. On the top is a black card engraved with the model and the globally unique serial number. The label “Craftet By Hand” is also included. Yes, here you can see how much craftsmanship has gone into the overall product. This is one of the best unboxing experiences I have had in the IEM market. For the price of 3250 USD you can expect a lot and you won't be disappointed. That much is for sure! When you open the storage box for the first time, you immediately see the incredibly good-looking faceplates of the Steranko 40 and a golden music box that you can wind up on the underside of the box. I've never seen this before on an IEM product. I think it's a great idea. The company credo “Groove On The Go” is immortalized in an enclosed small booklet. It contains the detailed specification and technical background to the Steranko 40 and explains that the primary aim during development was to ensure that this IEM plays at the very highest level and masters every genre. At the end of the booklet there are 40 selected songs (including lyrics), which were also used in the development of the Steranko 40. These include global hits such as Yesterday by the Beatles and Bohemian Rhapsody by Queen.

Underneath the booklet is the connection cable and what a cable it is! In my reviewer history, I have never seen a better finished and better looking cable than this “Golden Voice cable”. Absolutely amazing, both in terms of design and sound. Of course, I also tried another after-market cable. More on that later. The cable itself is very thick, but still very soft and the weight is still within the tolerable range. Of course, it is not as light as a normal 4 core cable. But it is also a 10 core cable and in terms of sound it gets the absolute maximum out of the Steranko 40! The massive plugs and splitters just look great. The scope of delivery also includes a metal card with a printed serial number that is designed to match the card on the top of the storage box. Two different types of silicone pads in different sizes are also included. The whole thing has an absolute boutique character.



The IEMs themselves are relatively light despite the number of 20 drivers per side, as the housing is made of lightweight synthetic resin. The transparent underside was specially chosen to show the ingenious inner workings. There's really nothing to hide here. The faceplate looks insanely good with shimmering blue colors and the imprint of the golden company logo. Blue is my favorite color, by the way, and I think the design of the box and the IEM is absolutely stunning. The Steranko 40 is also very comfortable to wear thanks to its ergonomic shape and relatively low weight. The slightly smaller APX SE is a little more comfortable, but the Steranko 40 is still relatively compact despite having 20 drivers on each side. It is still a long way from an EE Raven with its huge dimensions.



For the sound test, I used the new iBasso DX340 and the combination with the iBasso D16 DAC and the Korg-based PB5 tube amp. The DX320 MAX TI is also used. The Steranko 40 (hereafter simply referred to as the S40) is really very easy to drive and the lowest gain level is completely sufficient for all devices to achieve very high volumes. In the past, I always thought that the use of many EST drivers also required more power. But the S40 proves me wrong. The APX SE needs noticeably more power to drive the same level. In this review, I also compare the S40 with the APX SE. I can already say that both are technically on the same wavelength. This is the first IEM ever to come close to the level of an APX SE, which is quite something. You should give the S40 30-50 hours of break-in time, because the bass range, which is a little thick at first, becomes more impulsive over time and ends up playing completely detached.



The S40 is tonally a neutral/warm tuned IEM with slightly boosted bass and a very smooth treble range. While the APX SE delivers a little more low bass, the S40 has warmer and even fuller mids. Both have a very natural and coherent timbre.

The most outstanding feature of the S40 is its very analog sounding mids, which give every sound element a noticeable foundation. This reminds me of the Trifecta, which also offers such a full and analog sound. In terms of tuning, however, the two cannot be compared at all. While the S40 follows the path of a more neutral IEM, the frequency response of the Trifecta is very specific and euphoric, which doesn't necessarily work with every recording. The S40 is definitely the better all-rounder. This brings us to one of the most outstanding features of the S40 and that is the mid-range. Voices in particular, whether female or male, come across so realistically with the S40 that you feel like you're there live. The plucking of a guitar string and acoustic instruments in general gives the S40 such a fullness and a body with texture that otherwise only a Trifecta can do.

If I've already said that the most outstanding feature is the mids, then everything else is only good to very good? Far from it! Now let's move on to the treble range. Please note. Best treble range on the IEM market! And yet I wanted to make the mids stand out even more. I hope this gives you an idea of the high level of the S40's highs and mids! These 8 EST drivers present macro and micro details from the hip as if it were the most normal thing in the world. I hear details that are reproduced so clearly and naturally. Many other TOTL IEMs don't present details in such a relaxed and fluffy way. And the S40 achieves this with a frequency response that is not boosted in the treble, but is exceptionally smooth! So smooth, in fact, that I can drive listening levels that quickly degenerate into shrillness with other IEMs. This is not at all the case with the S40. Even an AME Raven or Gaia with 4 EST drivers have an incredibly good treble range. But they simply don't reach the level of the S40. Here, 8 EST drivers are not just a marketing gimmick, but show technically that it can be even better.

The bass range with its two coaxial drivers provides plenty of punch and slam when the recording requires it and goes right down to the lowest registers. In terms of quality, it performs at the very highest level and is only just beaten by an APX SE, which for me is still in a class of its own in the IEM market in terms of bass that no other IEM I know of can match. Fortunately, the S40 doesn't show any weakness at all in the bass range and I have to use an APX SE as a comparison, which then has a slight advantage. With the help of the planar magnetic driver, it offers even more low bass and plays slightly faster. However, all the other IEMs in my portfolio are inferior to the S40 in the bass range. In summary, the S40 has a gigantic mid and treble range and a superb bass range.

What about the soundstage? Thanks to its technical refinements, it separates out sound elements as if with a surgical knife, making the localization of individual elements child's play, just like an APX SE does. Compared to the APX SE, the stage appears somewhat wider. The latter has even more depth imaging. Thanks to this brute separation and its technical capabilities, the image appears 3D-like, as if it is all around you, and after a few minutes you are immersed in the recording every time. The S40 is also an IEM that invites you to listen for hours on end, as it offers such a gripping and captivating sound image. You just want to listen to one more song and then another and another and so on. The APX SE also captivates me again and again. It's the separation and the bass that catch my attention. With the S40, it's the fullness and the analog character of each sound element. If you were to name two counterparts in the world of full-size headphones, it would be the LCD-4 for the S40 and the Susvara OG for the APX SE. Now we come to the sound impression on the various DAPs and chains.

With the brand new DX340 from iBasso, the S40 sounds simply fantastic. The slightly more energetic playing style of the DX340 suits it well. The slightly thinner bass range of all my chains is also no problem with the S40, as it already offers enough punch. The DX340's discrete DAC also emphasizes the very analog and full-bodied presentation of every sound element, making it an ideal partner for the IEM from Muxicbox. The PB5 is even more energetic and punchy when paired with the DX340. The entire chain of DX340 + D16 + PB5 then sounds a little warmer with slightly more low bass. A carpet of sound that you can sink into for hours. Absolutely brilliant! But the last combination exclusively on the DX320 MAX TI is my favorite. I simply love this wide stage imaging of the ROHM DACs and the S40 with its extreme scaling possibilities with the sources also expresses this directly with an even wider and more holographic imaging. In addition, the bass is more agile with a harder mid-bass punch compared to the DX340 in solo mode. The very analog and brilliant midrange of the S40 does not necessarily require a discrete DAC. The ROHM DACs also conjure up a real and breathtaking image on the S40. To summarize, however, I can say that with each of these combinations you get a sound that plays in the highest IEM league and where nothing is missing. I can't necessarily recommend a mid-range DAP such as the M15 with the S40, as it simply doesn't exhaust the S40 in terms of resolution and dynamics.

I have rarely tested the S40 with a range of different eartips. I always use the Azla Clears as a reference with the IEMs as they usually fit well in terms of comfort and leave the sound relatively unchanged. They also work wonderfully with the S40. The Divinus Velvet Wide Bore make the S40 sound a little more energetic, brighter and more open and increase the stage size slightly. It then sounds more tonally similar to the APX SE. However, I then lose some of the magic in the mids. The SpinFit W1s are somewhere between the Clears and the Wide Bore. With the Eletech Baroque, the S40 sounds a little warmer and slightly punchier than with the Clears. That's a bit too warm for me. To my surprise, the combination with the Coreir Brass is my favorite besides the Clears. I had actually bought these a long time ago, but apart from the Radon6, I didn't like them with any other IEM in the end, as there were usually also “seal” problems. However, due to the longer nozzle on the S40, the Coreir isolate without any problems. They bring the clarity of the S40 a little further forward with more airiness and a larger stage. In addition, the mid-bass range hits even harder. A great combination. Depending on the DAP and your own taste, you can use the eartips to fine-tune the sound.

As already mentioned, I also played around with other cables, such as the Grand Silver IEM cable from Lavricables. This makes the S40 sound a little more purified and open, but the magic in the mids is lost too much for me. I kept returning to the delivery cable. It just fits like a glove!

The S40 plays in the top league, so a comparison only really makes sense with the APX SE and perhaps the Kinera Imperial Loki Emerald. Apart from that, no other IEM I know of can hold a candle to it. And I have already heard many TOTL IEMs and still have many in my collection. I've already covered most of the differences between the APX SE and S40. The APX SE has a bass range that is unmatched in the IEM market. I can hardly imagine what could be done better. It is perfect. Even though the S40 has an equally brilliant bass range, it has to admit defeat to the APX SE here. In terms of stage imaging, both are on the same level, although the APX SE has the slightly deeper imaging. The S40 has the warmer and more analog mids. The APX SE plays a little brighter and therefore a little snappier and more energetic. The treble of the S40 with 8 EST drivers reveals micro details more easily than the APX SE despite the smoother imaging. Two world-class IEMs that complement each other wonderfully. The fact that the S40 is technically so close to the APX SE and even beats it in terms of resolution is a great achievement by Muxicbox for half the price!

Of all three IEMs, the Imperial Loki Emerald has a much more energetic playing style and is tonally a touch brighter. It doesn't have such a full and warm midrange and is designed for maximum separation. Its 4 EST drivers produce a very high-resolution treble range. It is not quite as smooth as that of the S40 and the S40 presents the details even more effortlessly. The bass range of the Loki Emerald is very fast and hits hard when it needs to with the use of the BCD. The APX SE and S40 have the more detailed bass range. The Loki Emerald plays the airiest of all three. Technically, it doesn't quite come close to the other two. At the moment, these three are among my top 3 IEMs!

The S40 from Muxicbox is a killer IEM and for me the best IEM 2025 so far and my new number 2 behind the APX SE! Of course, the year is still young, but in order to go one better technically, another manufacturer has to stretch itself really, really far. I'm excited to see what the year will bring. For the price of 3250 USD you get one of the best IEMs in the world. I think the price is even reasonable in view of the prices charged by the competition. Such a cable alone would probably cost around 1000-1500 USD elsewhere. By the way, Muxicbox is already working on another IEM called Steranko 52. The manufacturer himself told me that it will be difficult to top the S40 again. Among other things, the S52 will use a new type of driver to try to achieve this goal. And even more sophisticated materials. When I see the result of the S40, I am completely convinced that the outstanding team around Paul Cheung will achieve the goal and will surprise us in the future with IEMs that will really shake up the IEM market. Well done, Paul!