Subtonic Storm Review - The Rumble of Innovation

Introduction

For the uninitiated, the Storm started as a project by Toranku of Head-Fi fame, and it’s been years in the making. I heard one of the final prototypes more than a year ago at CanJam Singapore 2022; at the time, I placed it directly to the top of my personal ranking list which (at the time of this article’s publication) sits at 400+ IEMs.

A move like that places a lot of expectations on an IEM, not to mention on me, to back it up. But due to high demand and a lack of a tour unit, I haven’t even been able to hear a production version. In fact, my recent trip to Singapore for vacation was the first opportunity I’ve had to listen to it - in over a year - at Zeppelin and Co, the audio cafe! Thankfully, I've also been able to get a couple more listening sessions in at CanJam SoCal 2023. 

Diving into the paper specifications, the Storm is a 7BA/2EST configuration that comes in at $5200 USD for the launch edition (now sold out, by the way). Let’s unpack this. Once upon a time, $5200 USD would have been unheard of for an IEM; however, IEM prices have skyrocketed in the last couple of years making the Storm - at least by its price - just another very expensive flagship IEM. Let’s take a closer listen at what actually sets it apart from the pack.

In the interest of full disclosure, I consider myself a friend of the Subtonic crew and I’ve hung out with them in the past. But I believe it would be a disservice not to cover this IEM given the significance I believe it holds for the flagship market.

Source & Drivability

All critical listening was done off of my iPhone 13 Mini with the Apple dongle, Questyle M15, and a Hiby R6 Pro II with lossless files. The stock Mira cable and silicone tips were used. I had no issue hitting my usual listening volume of ~70dB on either device. If you would like to learn more about my listening methodology, then I would encourage you to check out this page.

The Tangibles

The Storm feels surprisingly substantial in the hand because the shell is composed of Grade 5 titanium. This is one of my favorite materials for its incredible properties; it’s hypoallergenic, has a high strength-to-weight ratio, and is extremely rust-resistant. The Storm’s faceplate is further supplemented with golden enamel and a cloud-like engraving. Taken together, it’s clear that Subtonic has spared no expenses when it comes to the Storm’s construction. Additionally, although the Storm’s shell is quite large, the nozzle itself is fairly small and the shell contours nicely to the outside of the ear. I had no issues wearing it for a couple hours.

In terms of accessories, I didn’t have the full retail packaging on-hand, but I got to handle the cable and the case. The Mira cable is not my favorite in terms of ergonomics (I find it less pliable than I’d like); however, there’s no mistaking it for being a quality piece of hardware. I had similar reservations about the Storm’s Todah leather case based on pictures I’d seen. But actually holding it in the hand is another story. It feels incredibly high quality; the leather is thick and beefy.

Sound Analysis

I’ll preface this section with the rest of my trip through Japan and South Korea where I had the opportunity to visit stores such as E-Earphone and Scheherazade that had no shortage of high-end earphones. Yet, I don’t recall being truly impressed by a single one of them. Flying into Singapore, then, it was basically my last chance to be impressed and I was anxious to see if my impression of the Storm from a year ago would hold up. Confirmation bias be damned, the Storm did not disappoint.

The measurement below was taken off an IEC-711 coupler. It should only be considered accurate up until ~8kHz as there is a resonance peak. If you'd like to compare the Storm to hundreds of other IEMs I have measured, then please see here. Special thanks to 'tamtrum' for letting me listen to his unit and measure it. 

Listeners often like to make a distinction between BA and DD bass (the latter being more desirable for its natural timbre). Over the last couple years, though, I’ve heard IEMs that use BA drivers for bass that have slowly challenged this notion. The Storm epitomizes this sentiment: I would not hesitate to attest that its bass response is superior to most DDs - even some of the best - that I have heard.

It doesn’t sound quite like a DD if you’re looking for a natural response; however, when it comes to qualities like slam and control, the Storm indisputably makes its mark. This is crucial given that many IEMs that use BAs for bass will nail control but still sound quite plasticky. Not so with Storm; successive hits are superbly delineated with a sharp leading edge and a fair amount of bloom behind them due to the strong emphasis on sub-bass.

Moving upwards, the midrange of the Storm is one of the most neutral that I have heard. The lower-midrange is dead-flat from 200Hz to 1kHz, then is followed by a 3kHz notch for the pinna compensation at about ~8dB and then a gentle slope moving into 4kHz. My personal preferences for the pinna region are a little earlier; however, even I recognize the ~2kHz notch as more so adding ‘color’ than it being ‘neutral’. The best word to describe Storm’s midrange is simply transparent with an even sense of weight between male and female vocals.

The Storm’s treble is nearly perfect, and it illustrates a lot of the cutting-edge technology that Subtonic has packed into their magnum opus. Looking at the frequency response, you’ll see a series of peaks from 5-15kHz. While many armchair enthusiasts might be quick to pan this (and believe a smoother response is ideal), there’s a strong argument for these peaks.

In essence, it’s common for studio monitors to measure with slight jaggedness in the treble. And when peaks are kept in quick succession and in a careful, ever-so-slightly declining trajectory like on the Storm, treble is able to strike a balance between traditionally opposing characteristics: incredibly vibrant, yet non-fatiguing. This is exactly how I hear treble on the Storm.

Of course, I did say nearly perfect, and where Storm falters is in extension past ~16kHz. The majority of listeners can disregard this issue. But if you have younger ears, or have been fortunate to protect your hearing, then be aware that Storm’s treble could be just a hair more extended. Comparatively, full-size studio monitors will exhibit this extension. I mostly perceive this as ‘zings’ benefitting from more space around them.

Technical Performance

In the past, I’ve shied away from ‘scalability’, the idea of a transducer’s sound quality benefitting from additional power. I’ve rarely found additional power to yield better results especially with IEMs. Differences between sources are often just that too: differences, and not necessarily for the better.

The Storm might be considered a rare exception even if it’s not night and day running Storm off the Apple dongle versus a dedicated DAP like the Hiby R6 Pro II. It still sounds fantastic either way. But the difference is noticeable enough for me that, if you’re already spending this much money on an IEM for the best sound quality, I think you should consider using a dedicated source. Subtle differences in technical performance that I usually hear between sources just seem more exaggerated using Storm.

In any event, the standout is unquestionably the Storm’s sense of dynamics. By this, I refer to a transducer’s ability to convey gradations in track volume and between individual instruments. The Storm sounds animated and explosive; on a more granular level, subtle shifts in the impact of kick drums and percussive hits pop from the backdrop of the track. More than once while listening to Storm, I’ve picked up recording artifacts in a track that I wouldn’t have known were otherwise present.

Some of this can no doubt be attributed to the way the Storm’s frequency response has been meticulously crafted. The midrange is perfectly balanced, and slightly pulled back in the pinna notch, which facilitates listening at higher volumes. However, higher volume listening is often difficult to sustain with other IEMs due to narrow peaks in the treble region. This isn’t the case with the Storm as I discussed above. Similar to high-end speakers which measure flat, one can listen quite loudly on the Storm without noticeable fatigue; collectively, these factors contribute to an increased sense of dynamic contrast.

In a similar vein, there are many ways to achieve perceived detail. The most detailed IEMs often make use of unconventional peaks and dips that pull attention to sounds that we aren’t used to hearing. The Storm straddles this line; in general, it actually has a fairly conventional frequency response profile. Everything in the mix comes across as balanced and audible. However, zooming in, its treble response is unique due to the deliberate series of peaks. I believe these peaks ‘catch’ onto the trailing ends of transients and enhance the overall sense of detail. The bottom line is that the Storm is easily a top contender when it comes to a sense of resolution and micro-detail.

The ideas of coherency and timbre have become increasingly important as manufacturers have begun mixing and matching driver types. Drivers such as ESTs and BAs have led to breakthroughs in technical performance - often via increased treble extension. However, they have also come at the price of poorly executed crossovers between the differing drivers, leading to odd timbre and a lack of coherency.

This isn’t the case when I hear the Storm. It is dead coherent with a consistent timbre from top-to-bottom. Transients are wrapped-up incredibly cleanly, yet without the weightless or plucked quality that characterizes some electrostatic and planar headphones. They also sound rigid with a good amount of weight behind them that defies other BA/EST examples that I have heard in the past. In essence, its transients sound close to what I'd expect to hear on my pair of Genelec G Two monitors.

In terms of imaging performance, this is where there is a clear distinction between full-size monitors and an IEM. The staging of the Storm is certainly above average for an IEM, and it's like clockwork honing in on the placement of individual instruments in the mix. But ultimately, the Storm lacks impactful center imaging - the sense of a “third” speaker coming projecting from the center like with a speaker setup.

The Bottom Line

At face value, the Storm is not worth $5200 USD and no sane person would purchase it. And you definitely shouldn't purchase it if you're someone who enjoys colored sound.

But here are the caveats. One, if you’re an audiophile, you’re probably already no stranger to poor financial literacy. Then two, let's consider context. There are a lot of other IEMs that have broken into this price range in the past couple years; think of examples like the Aroma Audio Jewel, Oriolus Traillii, and Unique Melody Red Halo. Not only do some of these IEMs utilize standard acrylic builds versus the Storm’s titanium shell, but they also don’t come close to touching the Storm’s sonic prowess.

So what’s the bottom line? The Storm is an IEM that almost perfectly encapsulates the reference tonality that you'd hear on full-size speakers. If that's your jam, there's no substitute that does it better than the Storm. But even outside of that context, at least in my opinion and by the metrics I index for, I believe the Storm sets the current bar for the world's best IEM. Again, I'm not saying it's worth $5200...but if you want the best, you know where to look.