iFi audio iDSD Diablo-X

Disclaimer:

Ifi has kindly asked me if I would be interested in reviewing their new Diablo-X with Soranik's MEMS-2 in-ear monitors. Since I have good relationship with iFi and I am always interested in new technologies, I agreed even though I am more into full size headphones as opposed to IEMs.

This is a review of how the Diablo-X and the Soranik IEMs work together with an emphasis on the new xMEM circuitry. Apart from this special circuitry, there is no change in the Diablo-X compared to the original Diablo which I already reviewed in 2021.

What is this new technology?

This new technology is called MEM, which stands for micro-electromechanical systems. These are microscopic mechanical and electrical moving parts combined in one package. The technology has been used in some speakers in the last few years, but it is so new to personal audio, that only two companies have created IEMs with MEM technology so far: Soranik and Singularity. These drivers are tiny and made of silicon, with a similar manufacturing process used in making semiconductor devices like a CPU chip in a computer or smartphone.


MEM drivers

The advantage of these microscopic silicon diaphragms is an ultra-fast mechanical response: 150x faster than your usual dynamic driver and 30x faster than balanced armature drivers. MEM drivers are also extremely durable, very lightweight and super efficient. There is no passive crossover between channels at all, which completely eliminates phase issues and provides practically zero (!) level of harmonic distortion. These silicon components are capable of reproducing 80kHz (!). This sounds intriguing, doesn't it?


MEM driver next to BA driver

The Diablo-X:

The Diablo-X is an updated version of the popular iDSD Diablo which was released in early 2021. The only difference between the two units is the xMEMS circuitry in the Diablo-X. Since this technology is extremely efficient, xMEM IEMs cannot be used on regular DAPs and amplifiers. The Diablo-X is the first device on the market that has a special circuitry built for xMEM IEMs. Apart from this, there is no difference between the older red Diablo and the new black version. For this reason I won't even go into details regarding the Diablo's performance, since I already reviewed that unit back in March 2021. If you are not interested in using xMEM IEMs, there is no reason for buying the Diablo-X over the original Diablo. This beautiful and powerful little red brick is now available for £699 at most retailers, discounted from the original £999. The new Diablo-X retails for £1099.



The 'Eco' mode for extremely sensitive IEMs on the previous Diablo was replaced by the new xMEM circuitry in the Diablo-X. It is still possible to listen to highly sensitive traditional IEMs on the Diablo-X, you just need to use the little iEmatch wire included in the package. The number of accessories provided with the Diablo-X is exceptional. I counted seven cables and three adapters for pretty much any usage scenario you can imagine.

As of today only two IEMs exist on the market with this new technology. One is the 'Oni' made by a company called Singularity in California, it is just fitting that they are based in the silicon valley. Their Oni xMEM IEM retails for $1500. The other company is Soranik, they are based in Vietnam and their MEMS-2 IEM retails for $1200. Both companies are planning to release other models in the future at different price points, as well as their own devices to use these IEMs with. Today we are mainly going to have a look at Soranik's in-ears paired with the Diablo-X.



Soranik MEMS-2:

Build, comfort:

While build feels decent, I was expecting a little more for $1200. The shells of the IEMs are nice and comfortable, but there is only a very basic set of three simple ear tips included in the package. The eartips are thin, they deform easily and I was struggling to find a good seal with them. In my experience aftermarket eartips are a must with the MEMS-2, but the issue is ear tips affect sound significantly. I tried some thicker, more comfortable ear tips but the sound became dark and muffled. Eventually I did find good seal with the medium sized factory eartips, but it took me some time to find the right angle, and moving around also became restricted in order to keep the seal. I hope Soranik will improve their ear tip selection in the future. The cable feels a bit plasticy, not quite what I would expect on a $1200 IEM.



Soranik uses two drivers in each shell, developed by the two different companies that currently manufacture these micro silicone drivers. One comes from XMEMS, the other one from USOUND. Soranik says, by the combination of the two different drivers they were able to achieve the desired sound. They found Usound's module to provide a richer midrange with better depth, while according to them, xMEM's module sounds wider. In comparison Singularity's Oni uses two modules per earpiece from xMEM. I have not heard the Oni, so I am unable to compare.



Sound:

Technicalities

The purpose of xMEM IEMs is to provide a new sonic experience, mostly by improving technicalities compared to traditional dynamic or balanced armature drivers. The incredible specs suggest a fast and clean sound, on a level that was unheard before. If we forget the enthusiastic marketing texts published with every new product, we are still left with something very new and indeed unique. It is true that the xMEM drivers have incredible speed, very good detail retrieval and clarity. I cannot say these IEMs immediately blew my socks off, but listening to them and then going back to conventional planar or dynamic drivers did reveal how special these tiny silicon pieces are. Everything else felt sluggish in comparison, even top of the line planar headphones. The piezoelectric speed is truly special.

These IEMs sound extremely nimble and immediate, the closest comparison from other technologies would be electrostatic transducers. To me the xMEM drivers are similarly fast if not faster and they also offer a 'lighter', more delicate sound familiar from electrostatic headphones. Texture is not the thickest, body is not the most substantial, their trick to captivate the listener is a super quick and clear presentation.



Bass

At this point I have to mention that the Diablo-X comes with a built in EQ (as opposed to Soranik's own energizer which offers a flat response). We know that iFi generally likes their bass, and compared to the Soranik energizer there is a 6dB bass shelf by default. This to me is actually welcomed, as in my opinion the MEMS2 definitely needs a bit of a bass boost. Perhaps not 6 dB like in the Diablo-X, but maybe 3-4 dB would be enough. On the Diablo there is no option to play with this preset EQ, you have to use your own software to do that.

Apart from good quantity, the quality of bass is also great on the Soranik/Diablo-X combo. The notes stop on a dime, the sound is very precise and quick. There is no issue with bass quantity or quality in general, but do not expect the weighty and impactful bass you might be used to from planar or dynamic drivers. Texture is ok, but it does feel a bit light. This bass impresses with speed and not with impact. Bass is only present when the recording calls for it which is a positive.

Mids

The theme is the same. Mids are speedy, light, clear, but to me they lack a bit of body and texture as if they were too 'light'. The extreme speed adds a lot to a 'lifelike' sonic sensation but on the other hand the lack of 'substance' in notes takes away from the same experience. It is a very interesting mixed bag for me: one side of this presentation is extremely appealing, the other side leaves my ears unsatisfied. This is not necessarily an objective criticism, it can well be personal taste.

Treble

IFi has also implemented a noticeable amount of treble EQ. I hear more dips and peaks on the Diablo-X than with the Soranik energizer (plugged into my Cayin HA-3A amplifier). In both cases the treble to me is quite bright. It is also a bit thin, although the extension is good. Speed again is fantastic, but the lack of body is even more apparent in the high frequencies. My ears are rather treble sensitive and I did find the treble occasionally too much, for example on some recordings from London Grammar or Aurora. The energizer's response is a lot more flat, but still bright and not free from some issues I heard on the Diablo-X combo like occasional sibilance and a thinner, sharper sound up top.

Tonality

The general tonality of the IEMs is neutral/bright. Luckily they respond very well to EQ, as I am almost certain most people would want to use EQ with them and I am saying this as someone who does not normally like to use EQ with his headphones. In its current form the XMEMS2 to me sounds a bit thin and bright despite their amazing speed and some other impressive technical aspects.



Soranik's own energizer:

Soranik approached me halfway through the review and asked if I would be able to include their prototype energizer: of course I said yes. The energizer is to be released soon and it will be included in the $1200 asking price. This in my opinion increases the value proposition a lot!
The energizer I have with me is a prototype version, the final product, which is a lot thinner, is shown on the picture from Soranik.


The prototype energizer

As I said earlier, the energizer does not use any preset EQ we find in the Diablo-X. This means the sound is less coloured, flatter and more neutral: a better starting point to implement your own EQ. If you prefer a flat response, the energizer is the way to go. If you like iFi's bolder and bassier sound, you will enjoy the Diablo-X more.

To me personally bass was preferable on the Diablo-X, mids were fairly similar. Treble perhaps sounds more even on the energizer and a bit flatter which I marginally prefer to the Diablo's somehow peakier tuning.

The energizer is a simple device only with a 4.4mm input and a 4.4mm output. You will need to use your own DAC/amp with it as opposed to the versatile Diablo-X which incorporates a DAC, amp and the xMEM circuitry all in one.


Picture from Soranik showing the final version of the energizer

Conclusion:

Even though I mostly use full size open headphones, I love to see new technologies entering our hobby. Silicon drivers, ribbons and so on are all a bit experimental, financially risky for companies. That is why I respect anyone who dares to come out with new technologies, ideas. It is great that iFi provides a bigger space for such experiments, this time collaborating with Soranik (and Singularity).



While I do find some aspects, like speed of the piezoelectric technology groundbreaking, I am not fully convinced this will take the IEM market by storm in its current form. I do miss a bit of body, weight, impact I am used to from more traditional drivers, but I feel the same way with most electrostatic headphones, so take that with a grain of salt. To my ears there is also room to improve tonality/timbre, and perhaps not just with EQ-ing.

All that said, this is a brand new and thrilling technology and I truly hope there will be developments into this direction as there is definitely a lot of potential in these miniature silicon membranes. For me, for now they offer an interesting alternative but not a substitution to similarly priced conventional IEMs and headphones. Your preference might be different, so as always, I highly recommend an audition.