FiR Audio Electron 12

Overall rating: 4/5

Aesthetic:
- Build Quality: 4.5/5
- Design: 5/5
- Accessories: 3/5
Sound Rating:
- Timbre: 3.5/5
- Bass: 4/5
- Midrange: 4.5/5
- Treble: 4/5
- Technicalities: 4/5

DISCLAIMER
- This is a review unit sent by Fir Audio US in exchange for a review session. Regardless, all opinions remain original ideas, thus there is zero influence from any 3rd party or external opinions.
- No EQ or filter presets were used during the entire review period.
- Sound evaluations are kept neutral and does not include 3rd party accessories (ie; eartips, cable, reversible mods).
- Burn-in was done for 100 hours prior to review.

Introduction:
Fir Audio is a renowned audio company that has established since 2018 by Bogdan Belonozhko, and has offered many necessary and unique accessories for all IEM owners. They are the experts in manufacturing and custom made nearly thousands of IEMs, and their proprietary acoustic technology like the RCX connector, Tubeless high-driver, Tubeless shell design, and Atom-X modules defined the new age of in-ear monitors technology. I have no doubts of their high reputation in the high-end audiophile market and I am sure whoever is interested will want to know how good is their new Electron series, Fir Audio E12.



Unboxing and accessories:
Fir Audio comes with a compact box, covered with a white sleeve that has the E12 image printed at the front. Once we get to remove the sleeve, the box will reveal and it is black with gold accent logos and art.
What is inside the box?
- Fir Audio E12
- Genuine leather protective round case
- Fir Audio genuine sticker art
- 3x Foam tips (S/M/L)
- 3x Whirlwind tips (S/M/L)
- Pure silver core cable with OFC shielding
- Cleaning tool
- Suction plunger



Design and build quality:
Fir Audio E12 is light to hold and premium looking, and the design enhanced with a matte touch finish. It has implemented the SwapX technology that has the ability to swap the faceplate design. The faceplates are highly customizable and attached by magnets so it can be removed easily by using their included suction plunge. There are some ready-made face plates for you to purchase on their official website, but Fir provided custom artwork option for people to unleash their creativity.

While the SwapX technology being one of their party tricks, it also has Rigid Tech built in for user to replace the 2pin connector socket easily. Fir Audio has researched long enough to ensure the IEM has enough longevity, thus increase its capability to be repaired which I think everyone will appreciate.

Another proprietary tech that the E12 equipped is the ATOM (Air Transferring Open Module) being highlighted as to reduce pressure built inside the IEM, to achieve results such as bigger soundstage and reduce listening fatigue. So far, I have never felt tired listening to it for a few hours easily per day, which is a promising feature coming from them.

The fit is okay for my small ears. However, my friend will say the otherwise. He complained that it is hard to get good seal maybe because of the shallow nozzle. So, this maybe one’s deal breaker if cannot achieve the best fit.

Talking about the nozzle, it has no mesh within the nozzle as the drivers sit far away from the nozzle for easy cleaning. It feels weird at first glance like something is missing, but I got used to it later.



Technical Specifications:
Drivers: Single 12mm Electro-Dynamic Driver with Tactile Bass
Frequency Response: 20-20kHz
Impedance: 16 ohms
Isolation: -17db
Cable: Pure silver, Oxygen-free, copper shielded Clear Cable with Gold-plated balanced 4.4mm Termination

Purchase link (Unaffiliated):
https://www.firaudio.com/designer?product=e12

Drivability:
Fir E12 is surprisingly easy to drive. It does not require a lot of sheer power and it scales well with amplification. The bass becomes bouncier and soundstage is a bit more expansive when it is drive properly off a desktop DAC AMP.

My music (don’t judge me xD) :
- Yoasobi - idol (24bit/96khz)
- Joji Nectar Album (24bit/96 kHz)
- Kamado Tanjiro no Uta (16bit/44.1 kHz)
- ReoNa - Human, Alive, Seimeisen, till the end (24/96 khz)
- Taylor Swift - We are never ever getting back together (DSD 5644kbps/ 2.8MHz)
- Radwimps - Suzume (24bit/96 kHz)
- Ado – Unravel (16bit/44.1 kHz)
- And whole album of Kessoku Band
- G.E.M – GLORIA (24bit/96 kHz)
- Martin Garrix – In the Name of Love (24bit/44.1kHz)
- Calvin Harris – Motion album (MQA via Tidal)
- Avicii – Stories album (MQA via Tidal)
- Taylor Swift “1989” album (24bit/48 kHZ)

Source used:
- Acmee SoundMagic 4X pair with Android phone
- Aune Yuki plugged into iPad Air
- Aune S9C Pro plugged into PC
- Fiio KA17 plugged into PC
- Topping A0300 plugged into PC
- Astell & Kern SR25 Dap

Sonic Impression:
The E12 is sporting a 12mm single dynamic driver, aided by its solid chassis as an acoustic chamber to transfer the sound into ear canal, resulting it to sound airy and vocals have certain transparency. The overall sound signature of Fir E12 is a mild V-shape, and it has its own charms that stands out from its competition.

Bass:
Fir Audio E12 is a sub-bass focused IEM, as it has fair amount of rumble and reverberation thanks to its acoustic conduction technology. The sub-bass has deep extension but it will not fracture your head with its quantity. The sub-bass is prominent, with good texture and weight that you can feel it resonates in your head.
On the other hand, the mid-bass of E12 is allowed to make spaces and give some percussion attacks. The sub-bass sometimes will be a bit overwhelming, resulting the mid-bass to sound not as fun in congested tracks. Bassheads rejoice as this may be the closest IEM that has tight and high-fidelity bass but let loose for rock and metal music.

Midrange:
The midrange is not thin at all, but clean and effortless despite being slightly recessed in overall tuning. The lower mids are impressive, being highlighted most of the time as it sounds very natural, full-bodied and musical. Kanye west sound has the oomph and masculine charm in his Carnival album.
The midrange is enhanced by the lower range, allowing the lower mids to be audibly natural and accurate while being clean and well separated. Instruments sound natural and clean with a dark background. Which is beneficial for congested tracks like J-rock.

Upper mids are tamed and controlled, as the bass has balanced out to avoid tendency of being sibilant. Despite being less transparent, it does not sound dull as female vocals are presented slightly forward and still sound clean and delicate.

The timbre is slightly metallic as it intended to sound more Hi-Fi than being analogue-ish. Some people may not find it enjoyable, but not in my case.

Treble:
The treble is snappy and has enough bite to allow fast attacks. It may not be emphasized as the other frequency ranges but it can capture adequate notes like cymbals. The upper treble has fast roll off to make spaces for midrange and bass to perform the tricks, resulting for a smooth and less offensive treble response. This may ease some ear fatigue in the process and promotes longer listening session.

Soundstage and Technicalities:
The soundstage of E12 ranges from average to slightly intimate, as the midrange is like in-your-face kind of tuning to separate between background and main vocals. Overall, the soundstage has wide horizontal width but average depth.

The technicalities prowess of it is very promising, which is deserved to be a Summit-Fi. Good dynamics, micro-details and imaging. However, separation takes a toll as the soundstage does not feel holographic to render its background. Orchestra music maybe is not its thing, I guess.



Comparison:

Acoustune HX2000MX Mk2
It is one of the most renowned Japanese boutique brands to date, and still releasing exotic bangers. One of their most remarkable products will be the HX2000MX Mk2 with 1DD setup, that has a modular chamber design. To summarize both sound tuning, the HX2000MX Mk2 has leaner bass and vocals compared to the Fir Audio E12.

Bass:
The bass of HX2000MX Mk2 is not underwhelming but not as weighted as the E12, however the mid bass has a good texture and presence which is more immersive than E12 which has lesser fun bass.

Midrange:
E12 has warmer vocals but HX2000MX Mk2 has better vocals clarity. The Acoustune has better transients as well but it is more prone to sibilant, which E12 has no issue with it. The V shape tuning of HX2000MX Mk2 made the vocals to be slightly recessed, which may reduce the tendency of sibilance by a bit. Instruments has more punch and attacks with HX2000MX Mk2 with the good presence of mid-bass, to enhance the listening experience.

Treble:
Treble is more audible with HX2000MX Mk2, which allows more treble bite and airiness into female vocals tracks or pop genre tracks. Whereas the E12 has tamer and controlled treble to make sure it is suitable for treble sensitive people, but to reduce transparency and airiness in return.

Technicalities:
Soundstage of both is quite similar, but all the real comparisons lie within the technical prowess. Separation and detail retrieval of E12 is better than what Acoustune has offered, but HX2000MX Mk2 edges with layering and presence. It is quite unique to see how 1DD can be tuned so different consider they have different material of body and acoustic technology.

Dita Audio Perpetua
My best IEM, no words to say. Worriless fit and smooth tuning makes it my solid endgame since last year. So does this 1DD IEM still stands compared with the brand-new Fir Audio E12?

Bass:
Perpetua is more analogue-ish and reacts like a subwoofer, rich and full bodied with that slower speed than E12. While Perpetua giving tribute to the past, E12 is looking forwards to the future with that tight and addicting bass which punches on every beats you listened. Mid-bass is better with the E12 though, which can provide more percussions listening that can benefits drummers and rock/metal genre tracks.

Midrange:
Super pleasing with the Dita’s, not so much with E12. The Perpetua has rich and creamy vocals with no glaring and hot at all, but E12 is no slouch either. However, the forwarded vocal presentation plus the slightly metallic timbre are making it slightly fatiguing after some hours of listening. Instrument sounded natural and pleasing with Perpetua while the E12 is much cleaner in the background. Both offers different approach of sound so pick your poison.

Treble:
The Perpetua has better treble response for sure, which allows the vocals to have some airiness and plenty of cymbal’s crash. E12 is more mature with the treble response and it did not react too much with the high hats and all, but it has better treble clarity which will not mushed especially with highly congested tracks.

Technicalities:
Soundstage of Perpetua is what made me buying this set. It is vivid and the rhythms wrapped around my head like a sphere. If you do not like holographical staging, then it is fine you have your taste. Talking about the technical chops, the separation, layering, dynamics of the Perpetua is better but detail clarity and micro-detail nuances are not on par with the E12 offered, at least according to my test tracks.

Conclusion:

Fir Audio E12 is well executed as a high fidelity and pure EDM and rock music beast with good number of bass that being tight and impactful, alongside good vocal presentation and tonality. Priced at $1799, this may be unobtainable for budget-conscious people. But if the price tag is not a concern, I will recommend this to you, fellow bass enthusiast.

Introduction to the Fir Audio E12 Review​

The first time I came across Fir Audio was a few years ago – before I started reviewing gear – when I was looking for some cheapo wired in-ears, frustrated with faulty TWS solutions I had the misfortune of coming across. Of course, I watched some videos and read some reviews by my favorite reviewers out there, and while consuming some of their content, I stumbled across the venerable Fir M5s – back then I thought to myself: “2799 USD?! Who would pay that much for IEMs?!”. Ahh, old days. Now, a few years and a few pairs of IEMs later, experience has taught me, that I would be that crazy person. Dear kids, this is why you shouldn’t expect to get wiser as you get older…
While not my first encounter with Fir Audio, the first time I got to test their stuff for a longer time (about a month or two I believe) was when Paweł lent me Fir Audio’s Krypton 5 so I could make a video about them. That occurrence was crucial in shaping my taste in IEMs, as the Kr5 remains in my top 5 favorite IEMs of all time to this day. I was hugely impressed by Fir’s attention to detail and innovation-oriented approach – Kinetic Bass blew me away with the amount of fun I had while having a listen. The build quality left absolutely nothing to be desired, and it kinda felt like a small Bentley in your ears – that’s how impressed I was by the overall product quality displayed by the Kr5.
Before I received my pair of Fir Audio E12 to do the review, I decided to take a look at some promo materials to become familiar with what the pair was going to offer. You know, do some homework. One thing I came across was a video in which none other than Bogdan Belonozhko, the founder of Fir Audio, talks about how he’s never been so excited about a product release in his 13-year-long career. That, of course, got me excited as well. Being familiar with Fir Audio’s way of handling new solutions and technological advancements, I knew this would be something special.
After all, that’s the same way I felt about the Kinetic Bass feature on the Kr5. And I was surprised to learn that the flashiest and most marketable new feature under Fir Audio’s belt had to do with… aesthetics! Boy, I couldn’t wait to test the all-new SwapX tech out.
On another note, at the beginning of February, I took a trip to the north of Italy, to ski in the mountains of San Pellegrino. Of course, I took my e12 with me, as I need at least ONE good pair of IEMs wherever I go. One day, after receiving the overwhelmingly positive news – I’ve passed the last exam of that semester – I sat down on the patio in a small hotel in Moena, set my Balmoral Anejo XO Petit Robusto alight, plugged the e12 into my trusty old Luxury & Precision W2 and began the listening session while watching the sunset in a delightful orange and purple spectacle, melting over the serene mountains of San Pellegrino. I gazed upon the mountains right as the saxophone started its small rant in “Quarto de Hotel” by Hareton Salvanini. My soul started floating.
And just like that, I created a core memory using one of Fir’s creations. I’ll remember that moment until a social worker hits me with a “Sure you did grandpa, sure you did…” at a nursing home once I get very old. It was a great trip, even though I haven’t stumbled upon wild Gladiator Cables in the woods of northern Italy. I assure you, I’ve tried.

Packaging​

I was stoked to unbox those and give them a listen, but even despite my utmost excitement, I took some time to appreciate the unboxing experience. Once you remove the white sleeve with colorful e12 on it, you’re presented with a black box with a golden Fir Audio logo and some ornaments. it’s simple, yet elegant and classy. Seeing how many IEMs nowadays, no matter the budget, come with those pesky anime girls on the package, I can’t help but appreciate Fir Audio’s tasteful unboxing experience.
Inside the box, there’s an insert with the IEMs and a cable embedded into the foam. However, that wasn’t the only thing that caught my eye when opening the box. Somewhere inside was a FIR AUDIO SPACE FORCE patch! I love that addition, I haven’t experienced any other manufacturer doing that with their products. that’s genius – you can now WEAR Fir Audio merchandise! Wait…
Another important gadget in the box is of course the case for your IEMs. It’s a round, black leather case, with another foam insert inside – this time it houses your tips, silicone, and foam, as well as some tools – a cleaning tool and a silicone plunger-like device intended for use with the SwapX technology, which I’ll gladly talk about later on. The case can fit all your accessories while also being able to house your IEMs, which is great. I believe this type of case is a usual solution for Fir Audio – if you’ve handled their IEMs before, you’ll know what I’m talking about.
It’s not as sturdy of an option as Craft Ears’ legendary pelican case (I don’t think they can be beaten at this point when it comes to rigidity) but it’s more eye-pleasing, and it’s still a very convenient and safe option. Not once have I feared the case opening by itself or my IEMs being damaged in transit while traveling to Italy. Overall – props to Fir Audio for finding a great balance between IEM safety and sleek design.

Build, Comfort and Tech​

The build quality is not dissimilar to higher-end Fir Audio products – the aluminum shells are lightweight and well-fitted, inspiring confidence in the product and making a great first impression on a new user. I, having dealt with Fir’s build quality before, wasn’t surprised by the state of the craftsmanship displayed on the Fir e12, and it’s one of those instances where it’s pleasant not to be surprised. I haven’t heard of an instance where Fir Audio would disappoint with its build, and e12 is no standout. In terms of looks, the design is pretty straightforward, with no inscriptions or multi-color multi-material action going on, apart from the faceplates of course.
It’s just a well-made solid aluminum shell, clean and simple. The nozzles are quite long though, at least longer than those found on the Svanar. Bear that in mind. The quality feel is not exclusive to the IEMs themselves, however, since the included cable is also of amazing build, I feel like it is an improvement over what we got to see paired with the Kr5. The materials listed on the product page at Fir’s website declare that the 8-braid cable is made of pure oxygen-free silver, with copper shielding.
Usually, I find myself inclined to immediately make an upgrade when it comes to stock cables (I guess that’s just what Hifiman got me used to…), but this time I felt no such need, and I’m 100% happy with the current cable situation at Fir audio. The one I received with my e12 features a 4.4mm plug, with 2-pin connectors of course.
A feature of the Electron series that highlights both the company’s desire for innovation and the amazing build quality is the all-new SwapX solution. It allows you to swap your e12’s faceplates easily, all thanks to the use of magnets. Being presented with this solution initially was the first time I felt so excited about magnets, in a somewhat similar fashion to Jesse Pinkman in that one Breaking Bad episode with the garbage dump. Making use of said solution is very easy too, thanks to the inclusion of the aforementioned plunger-like device. You just stick it on the faceplate and pull it out of the IEM.
With the pair of reviewed Fir Audio e12, I have also received an extra pair of faceplates with a design differing from the stock ones, all packed into a small transparent case, doubling down on the unboxing experience. At first, I was quite skeptical about how this solution would work, longevity-wise. Won’t the faceplates come loose with extended use?
Won’t they fall out of my IEMs? Over time, however, I have rid myself of all those concerns, as SwapX proved to be a simple and effective solution, scoring a whopping 11/10 on aesthetics in my book. It turns the reviewed Fir Audio e12 from a cool-looking piece of headgear into a conversation piece, receiving several intrigued “Huh?” and “What?” from my friends, with just as many “That’s so cool!” sprinkled in.
If you know my reviews, you’ll know how high I usually put functionality on my priorities list – I’m glad to say I’m very impressed by Fir’s ingenuity. There’s another reason why I think this solution is genius – if you’re anything like me, you would have trouble deciding on which faceplates to pick, or, god forbid, what custom IEM design you should go with. Well, now it’s way easier to make a decision since you can swap the faceplates to your heart’s content. Now you just have to decide which faceplates to get. Oops…

The technological advancements don’t end there, however. Each time a new line of products is presented by Fir Audio, it seems to carry a number of new solutions with it. To me, the most interesting of the bunch is Tactile Bass. Basically, it’s supposed to make use of the entire shell to reproduce the bass response in your Fir e12. And tactile it is indeed, but I’ll take on the subject again once we reach the “bass” section of the review. Another piece of tech that’s proprietary to Fir Audio’s IEMs is ATOM Venting – short for Air Transferring Open Module – making its return after being featured once again, last time on Radon 6, and on the Frontier series before that.
The module’s main role is pressure relief, which is supposed to help with expanding the soundstage, as well as reducing listening fatigue. I’ll mention the soundstage later on, but listening fatigue is indeed non-existent in Fir e12, perhaps partially thanks to the venting system, and partially due to a natural sound signature perfect for prolonged, easy listening. A less flamboyant, yet equally as important, is the focus on serviceability. That seems to be one of the focal points behind the way the e12 is constructed, its purpose being to shorten the repair time as much as possible.
That feature seems to be supposed to cater more towards professional users than avid audiophiles such as yours truly, as it is crucial to have your equipment working before a show or a set. And though I wouldn’t be able to shake the feeling of something being missing if something happened to my e12, my livelihood would surely not be at stake.
The comfort of those is great. One of the main reasons why, for me, personally, is the insertion depth. While something like Craft Ears Omnium threads the line between quite deep and uncomfortable for me, Fir Audio e12 has the perfect insertion depth – deep enough for noise isolation to not be an issue, yet still not deep enough to cause me discomfort. If your preferences are similar to mine, and both of us appreciate a more shallow insertion on an IEM, reviewed Fir Audio e12 is a great match. Another major contributor to alleviation of listening fatigue is of course the tip selection.
Fir Audio includes a range of sizes of both silicone and foam tips, so variety is pretty good there. Whenever I test IEMs, I try to make the experience as relatable to the user as possible, so instead of finding an exotic ear tip that not all people use, I chose to do the testing using the stock tips provided. The size that suited me the best was the medium size of the foam variety. For reference, I use the M size of Final Audio Type E, and the tested Fir Audio e12’s foams fit me just right – I didn’t even need to squeeze the foams before insertion, yet they still managed to provide a fun, yet clear sound. When pairing your e12 with your favorite kind of tips, please keep in mind that the nozzle may end up being quite long in your experience, as it is surely longer than that on something like the Svanar.

Sound of the reviewed Fir Audio E12​

Fir Audio’s focus on comfort and ease of listening in the case of the reviewed e12 does not end with the ATOM Venting technology. That kind of approach is evident in the sound as well. The e12 focuses on a laid-back, slightly warm, and bassy approach to sound, without leaving technical aspects like detail and dynamics behind.
While it does not provide the most open and snappy presentation achievable, it is no slouch when it comes to a satisfyingly high technical level of reproduction, all served with a not-so-little side of fun and engagement. Overall, the sound of the Fir e12 solidifies the impression that it is a device geared for comfort first and foremost – you can sense it when you try out the SwapX function, when you fit them in your ear, and finally – when your first listening session comes to life.
Another aspect that is worth a discourse is the debate about whether heightened driver count enhances the listening experience. Softears Twilight, Hifiman Svanar, and finally, the e12, show that that statement is not necessarily true, while doing so at different price points. I feel like the potential of a single dynamic driver is utilized very well here – the Fir Audio e12 presents a kind of sound that doesn’t make me question whether or not a few additional balanced armatures or an electrostatic driver or two would make the listening session more enjoyable.
I have taken the reviewed Fir Audio e12 as it is, and I have enjoyed it, without ever asking myself what should be changed. If you’ve read my review this far, you already know that when it comes to technology, the e12 is already impressive. No need to complicate things by increasing the driver count.

BASS
The bass of tested Fir Audio e12 is probably the most in-your-face and fun aspect of the sound that these have to offer. The tactility of the bass, combined with its ability to reach the lowest registries is exactly as advertised on the “Tactile Bass” section of the product page. The most notable example was the last time I listened to the e12, and “Mr. Rager” by the one and only Kid Cudi came on. I was reading through some homework with the e12 in my ears, and the depth of the bass that these IEMs have reached during the very low bass note concluding the first minute of the song scared me for a second. It’s like the Fir Audio e12 makes the listener use more than 2 of their ears – the rumble is so strong, it feels like it’s penetrating your skull all the way to the inner ear.
Apart from the capability of low, texturous, nearly tectonic sub-bass, the low registries shine with their punch and dynamics. One thing to keep in mind though – the presentation is not razor sharp like it was with Omnium and Svanar. This time, however, we are presented with a bass response that, once again, seems geared towards easy listening – it is softer than the aforementioned models. Yet, it doesn’t lack a visceral punch or high-performing texture. One of the more aggressive tracks in my roster is “Satan” by Raydar. I don’t think it’s possible to do justice to those thunderous bass hits and low synths without a very capable bass response, and the e12 does very well in that regard.
Another thing about the bass – it seems to me that another one of its strengths lies within its versatility. Indeed, it’s very strong, but it comes to their advantage 99% of the time. If one day you decide that it’s time for something more relaxing than a track that could be another one of Hotline Miami’s staple soundtrack pieces, Fir e12 won’t disappoint you either. Dire Straits’ beautiful “Brothers in Arms” song is a great example of how a quite bassy Fir e12 can still provide a tasteful reproduction of the lowest registries, without the whole spectacle falling apart, even in a more serene, cogitative piece of music.


MIDS
The best thing about the mids when it comes to the Fir e12 is how natural, smooth, and seemingly effortless the presentation is. One of the first tracks that comes to mind is the immortal classic – “Stumblin’ in” as performed by Chris Norman and Suzi Quatro. I won’t get tired of this song, no matter how many terrible house remixes of it I come across while the radio is on.
The tandem of the higher-pitched female voice of Suzi, and Chris’ lower, more raspy vocals, together with a dash of strings make for a layered sequence that requires some amazing separation from the Fir Audio e12’s electro-dynamic driver. And that’s exactly what the reviewed IEM provides – the presentation is very tidy, allowing each part of the song’s arrangement to shine on its own. All in a natural, lush, and realistic way, without even the slightest hint of artificiality in the mix.
“Without You”, a ballad originally released by Badfinger, dubbed by Paul McCartney as “the killer song of all time”, has its dramatic qualities especially heightened with Harry Nilsson’s haunting performance. The best thing about listening to it on Fir Audio e12 is how, despite being a quite bassy IEM without a special focus on the high registries, it reproduces the highest notes of Nilsson’s vocals in a beautiful, realistic fashion.
Some might be inclined to believe that when it comes to mids in a bassy headphone or an IEM, the lower part of the midrange would be the one to look out for, with the upper mids being behind, even lacking in some cases. That kind of an issue doesn’t exist within reviewed Fir Audio e12’s performance. It’s capable of reproducing great midrange no matter its nuances, period. That also confirms how well-controlled the bass is – the level of control amidst its quantity and scale is impressive and doesn’t take away from other frequencies.

TREBLE
The treble in Fir Audio e12’s sound signature seems to be the least prominent aspect of the sound, however, it’s quite evident that Fir Audio decided to leave no loose ends when tuning the IEMs, as it is still on a high level of technical performance. The tuning of the highest registries is far from an afterthought, highlighted by musical pieces with prominent hi-hats and cymbals. Take “For Whom The Bell Tolls” by Metallica for example. The cymbals and hi-hats work almost like a metronome for the menacing guitars and thundering kick-drums, and despite not showing the treble much emphasis, Fir Audio e12 reproduces them with the right amount of authority for them to not get lost among the bassy background.
That’s exactly when the treble’s dynamics shine the most, and let the listener know that a high level of technical performance is not limited to the punchy bass – Fir e12 is consistent with its high performance from the lowest to the highest registries. Another great example occurs when listening to something fast-paced, like “Keep Your Eyes Peeled” by ULTRA SUNN. A lack of a decisive treble performance would keep this song’s potential at bay. Sure would be a shame, because it’s a good one.
If you want to experience how the Fir Audio e12 deals with something like high-pitched violins, look no further than Henry Mancini’s “Theme from Love Story”. When the violins all come together for an enthralling, almost overwhelming performance, with the highest notes on full display, you will come to notice that there is a complete lack of harshness in the treble. It’s a pretty challenging piece of music – reproducing it without a hint of harshness is not something that every IEM can do. The e12 can, though. It’s a great example of how the lesser emphasis on the treble may present itself as an advantage in certain situations when the violins and vocals strike the eardrum the hardest.

SOUNDSTAGE
The soundstage of Fir e12 doesn’t present itself as the most spacious – while the overall scale of the sounds is quite amazing, the width of the stage won’t knock you out of your shoes. The limited space is utilized to the fullest, however. Fir e12 takes the given real estate and uses it to highlight aspects of sound such as realistic imaging, a decent amount of air, and a huge scale. As I’m writing this section of the review, a live performance of “Land of Confusion” by Genesis is playing.
The applause of the fans is very clearly separated from the instruments, which, thanks to their realistic presentation, can easily be discerned on the stage. Here’s where the scale comes into play as well – Phil Collins’ voice seems huge and powerful, grabbing the whole performance by the collar and establishing his position.
There are situations, however, where the low notes are so immersive that the separation loses some of its proficiency. Whether you like that or not is up to you, but I feel like it does some kinds of music more justice than a huge, separated presentation would. Here’s a positive example – if you like listening to your electronic music live, a Boiler Room performance for example, the realism of the imaging and the stage makes for a fun listening experience – like you’re thrown into the middle of the crowd, while simultaneously being right next to the speaker. However, if you’re into something orchestral that requires some huge staging with the clearest separation and air – you may want to consider turning that Boiler Room back on.

Comparisons​

HiFiMAN Svanar


This comparison seems fair to me, as both Svanar and Fir Audio e12 seem like quite a similar duo in many aspects – both are around two thousand dollars, both entail a single dynamic driver, hell, even the materials used are not dissimilar.
Overall, as a product, I must admit that I like the product presentation and the overall package more on the e12. It provides higher-quality accessories, offers a very clever and efficient customization option, and the cable is miles ahead of that provided by Hifiman Svanar’s package. Comfort-wise, they trade blows – some will prefer the sculpted shape of the Svanar, and some will find themselves fond of e12’s simple and universal shape. Both have a pretty shallow insertion, which I love.
How about the sound? That’s the aspect where the differences are the most evident. Starting with the bass, both present a cutting-edge level of dynamics and extension, and don’t even get me started on that texture. Which one you like more in that regard will mostly depend on your preference for bass presentation. If you’re more inclined towards snappy and fast bass hits as heard on Hifiman’s latest flagship in-ear, go with that. If, however, you enjoy a softer, more relaxed, yet not at all less powerful low registries, e12 won’t disappoint.
In terms of mids, I find the Svanar to be slightly warmer and more musical, with the Fir Audio e12 balancing the mids with the rest of the frequencies very well. The e12 creates a coherent and balanced picture, not without its magic and musicality, however, the Svanar allows the mids to shine a slight bit more, perhaps due to its overall presentation feeling a bit brighter, with a slightly lesser focus on the bass. Both midrange presentations can be labeled as natural, realistic, and lush. Moreover, both contenders show a certain level of versatility in their presentation – the mids are pleasant no matter the musical circumstance.
When it comes to the treble, both models are very dynamic and detailed, overall presenting a very high technical level. In terms of the presentation, the Svanar seems, as mentioned before, brighter to my ears. The e12 however seems to aim for something else – the higher registries are wonderfully balanced, cooperating with the rest of the sound signature like clockwork. Like Bonnie and Clyde. Davis and Coltrane. PB & J. You get the point… The treble is not too airy and bright, but it’s smooth, dynamic, and very detailed. It lends itself to an overall sound presentation that is cohesive, without anything seemingly out of place, or unnecessarily accentuated.
As you know by now, the soundstage of the Fir e12, while not exactly congested, is a bit less spacious than the one found on the Svanar. The versatility and overall capabilities of Svanar’s grandiose staging are most welcome no matter the genre, but it doesn’t make the e12 seem like you’re listening to music in a coffin. Both contenders present a high level of separation paired with imaging capabilities that just make their sound signatures make sense.
Overall, both are excellent picks, trading blows in many aspects of the sound, both as listening devices, and overall, as products. If you’re forced to pick between the two, then I hope you know what you like – otherwise, the choice may not be easy for you.

Fir Audio E12 – summary​

Fir Audio did it again – it’s not the first time that we have been presented with a fun product, entailing new technologies and solutions, all geared to enhance user experience. And not in a gimmicky way either – they bring real improvements to the table, solidifying Fir Audio’s name as one of the leaders in terms of innovation and variety. Everything about Fir Audio e12 lets you know you’re dealing with a premium product, whether it’s the unboxing, handling the IEMs, or making use of included accessories.

The inclusion of something equally as simple as it is brilliant – the SwapX technology – has truly swayed me and made a lasting great first impression. It makes me wonder what’s next for Fir Audio and their future models, and what’s in store for us, audiophiles, in terms of customization of our products, at least when it comes to things we can uninvasively alter at home – like the faceplates, thanks to the SwapX technology.
Fir Audio e12 is another great proof of how you don’t need a multitude of drivers to make a great sounding in-ear. Its single dynamic driver handles all kinds of music with grace, presenting them in a more or less appropriate, yet always fun manner. The sound signature may leave something to be desired for lovers of the most spacious sound, or a leaner bass reproduction, however, enthusiasts of heightened quantities of bass with a more intimate yet grand presentation will be overjoyed to test this one out. Whichever of these categories you identify with, I encourage you to give this one a try.

Recommended!

Big thanks to Fir Audio for providing us with the E12 for this review. I wasn’t paid or asked to say anything good or bad about this product, all of the above is just my personal, unbiased opinion.

MatAudiophiles

FIR Audio E12​

FIR Audio E12
INSTAGRAM: LINK

Prelude:
Today a large parcel from the USA landed on my desk. As you can guess, inside there is a very unusual and extremely interesting product in terms of design. This is something FIR AUDIO has already accustomed us to. It’s truly amazing how confident brands defend themselves despite high prices thanks to technology and product quality. Undoubtedly, FIR Audio is one of these brands. When it comes to products of this brand, so far I have only heard about them among other audiophiles. Fortunately, today I can tell you my observations about E12. These headphones are so unique that a book could be written about the technology used and developed by FIR Audio. The E12 model has a single 12mm electro-dynamic transducer and for the first time we can replace the faceplates ourselves. For my review unit, I received panels called mars, the price of which is approximately USD 129. Thus, I could personally check the operation of the replaceable panels. I’ll tell you now that this technology works phenomenally and at the same time allows very simple access to the inside of the headphones in an emergency situation. The headphones cost USD 1,799 and are rather one of the cheapest products of the FIR Audio brand. The manufacturer promises “extra bass”, so let’s check what it is like in practice!


Unboxing:
Fir Audio E12 are headphones that remind me of my first steps in audio, it was many years ago when form was as important as content. For the price of USD 1,799 we get a large cardboard box that is really well packed. Additionally, we get a lot of cool accessories. After unpacking, apart from the headphones themselves, we also have three sets of spiral tips and three pairs of foams. Then we get a rubber tool for changing the front panels along with a beautiful screw-on case made of real leather. The set includes a beautiful thermal patch and a coaxial cable made of eight strands of pure monocrystalline silver with copper insulation. This cable itself is literally a steal when it comes to value for money. In headphones of this price class, it is not often that the market value of the cable from the set is several hundred dollars. The stock cable is terminated with a 4.4mm plug and a 0.78mm plug on the headphone side. The E12s themselves are made of CNC-machined metal housings, and although they are slightly larger, they fit very comfortably in the ears, providing excellent isolation and comfort. The only thing I missed was some sort of mask at the end of the nozzle to prevent anything from getting in there. However, a device for cleaning the headphones is included, so I think that this type of nozzle ending is an element of tuning. The nozzles are made of metal and finished with solid rings that prevent the tips from slipping. Therefore, when it comes to the quality of workmanship, it is phenomenal and absolutely exemplary, all of which makes E12 really solid headphones that will last for years.

Sound:
Let’s go a bit further, i.e. to the sound sensations. In general, FIR Audio E12 are headphones that clearly show how underestimated the 1DD configuration is. What the engineers did in the E12 model is an amazing phenomenon. These headphones sound like a high-end multi-driver setup, not a single driver.

Bass: This is probably the most impressive point of the E12 – I have heard many models of headphones, which is an essential element of review work. Fir Audio declares that the bass will be like from a subwoofer and I must honestly admit that in reality it is much, much better! Low tones sound like they come from a stereo system, not from in-ear headphones with a 12mm dynamic driver. The amount of energy generated by this single driver is so impressive that I can confidently call the E12 the king of the lower bands. The amount of bass at the same time is constructed in such a way that it does not completely disturb the other bands, leaving them clean and clear. It’s really like headphones with a subwoofer or a multi-driver hybrid with great musical presentation. Importantly, the overall presentation is quite smooth and is aimed at pleasant and calm listening while maintaining full listening pleasure. This is important because many products do not pay attention to the fact that most often our headphones are supposed to accompany us for many hours, providing listening pleasure, and not shining far away among the technical side of music. This is a very good move and I am personally glad that FIR decided to go for it.

Musical midrange: The midtones are slightly recessed below the bass line, but this is done in such a well-thought-out way that it does not come at the expense of the overall musical presentation. Additionally, the diameter is clear and legible. It sounds like a good quality armature, not a single dynamics unit. Although the sound will not be as dense as in the case of multi-driver designs. However, by using only one transducer, the sound becomes more coherent. The midtones are clear and very naturally reproduced, and at the same time the amount of information we hold is enormous. The details and size of the sound stage can amaze you with their grandeur. I have no doubt that the E12 are great headphones with a very pleasant diameter. Vocals sound less warm, but are still extremely natural and allow you to catch even the smallest musical details. Honestly, I really liked it.

Treble: This is another point where the FIR Audio E12 show that sometimes less is more. The high tones are perfectly extended and provide a perfect sound experience. The treble is clean and full of air. At the same time, the high tones are smooth and very pleasant. FIR Audio E12 have a huge amount of air and excellent separation of instruments. The stage in the E12 is large and presents an excellent picture of what can be achieved with in-ear headphones. Both the width and depth of the sound stage are truly impressive. The smoothness and consistency of the treble is truly world-class. I often had the feeling that I was listening to an electrostat and not an ordinary dynamic transducer, which once again proves the quality of the FIR Audio brand. Of course, this is not the grandeur of multi-driver designs, but in my opinion it is not a disadvantage, because the contoured image is more natural and coherent. However, if you are looking for greater scope, consider the larger sizes of the FIR AUDIO brand.

Control:
Generally, FIR Audio E12 are quite sensitive and effective headphones, which means that they do not require strong current to work. However, they benefit significantly from better DAC systems, which is definitely worth remembering. They also like clean sources because they have a slight tendency to pick up noise.


Equipment used in tests:
For my tests, in addition to Tidal and AppleMusic, I used my music collections. The equipment used during the tests was DAP iBasso DX170, EARMEN colibri, angel and FiiO K11 and KA17.

Comparisons with other headphones:

FIR Audio E12 VS Hifiman svanar:
Svanary are much warmer headphones with a slightly wider soundstage. Providing a more analog and intimate sound. However, Fir Audio E12 are headphones with more space and more information (I mean details). Generally, both pairs have a different character and are tuned differently. However, if someone is looking for an intimate and warm sound, the Svanry from HIFIMAN is closer to this tuning. However, if someone prefers a slightly more analytical sound with more information, the E12s are perfect. At the same time, they retain the natural warmth of the dynamic driver and offer a slightly more entertaining and smoother tuning. When it comes to comfort, it is an individual matter, some people prefer the angular shapes of SVANAR, others the flat finish of E12. However, both pairs provide very good noise isolation and a great fit in most ears. Hifiman in the Svanar model opted for a less smooth, more dynamic presentation, while FIR AUDIO in the E12 model opted for a smoother, more entertaining and easier to listen to tuning. Of course, both pairs are absolutely brilliant and it’s hard to pick a winner. The level between both headphones is absolutely top. However, the differences in tuning make both headphones feel completely different, which allows us to tailor our choice to our individual preferences.

Summary:
FIR Audio E12 are unique and unusual headphones. They made an incredible impression on me with the quality they presented. The E12’s bass is probably the best bass I’ve ever heard in in-ear headphones. Mid tones, although slightly cooler, retain a natural and engaging character. The high tones are smooth and full of information, and the amount of detail and scene are literally stunning. At a price of USD 17,999, it is a really strong and interesting proposition. Additionally, we can personalize our headphones using interchangeable front panels. The set includes a very functional and nice case made of real leather and a very good quality silver cable. All this makes the Fir Audio E12 headphones one of my favorites on the market and I highly recommend them to anyone who likes strong bass and beautiful high tones with a lively midrange. When it comes to sound insulation, it is above average and provides a very good cut-off level. The things that I particularly liked are the pressure regulation system inside the headphones, which ensures high comfort even after many hours of listening. The only thing missing was a small bag to protect the headphones from scratches in the case, but it’s really a small thing and despite my desire, I have no reason to criticize this great model of headphones, the E12 from FirAudio. That’s why I highly recommend checking out and assessing for yourself how these headphones sound. Quite honestly, no matter how hard I try, it’s hard for me to find any real flaws. However, please remember that these are headphones with strong bass. If someone doesn’t like low tones, either E12 changes their feelings, which is very likely, or they should look for something else. However, the low tones I mentioned and emphasized are not at the expense of the mid or high tones. The remaining parts of the band represent very good, high-quality sound comparable to that of a stationary handset. It is a difficult art and that is why I really admire the FIR AUDIO brand for the technologies they have developed and the quality of their products, regardless of the price. In the case of E12 it is completely justified.

The Fir Audio brand is world-renowned for its Frontier Series and the unique technologies it has introduced, such as the Kinetic Bass. IEMs such as the Radon6 or the XE6 are among the absolute elite in the current IEM market. With the E12, Fir Audio is moving away from a hybrid IEM for the first time. In this case, the number 12 in the name E12 does not mean that 12 drivers are used, but that a single 12 mm dynamic driver is used. At 1799 USD, the E12 is priced well below the Frontier Series, but offers a lot in terms of sound. I can tell you this much already.



Instead of using many different drivers and complex crossover networks, there is only one dynamic driver that covers the entire frequency range. For the first time, Fir Audio is introducing SwapX technology, which makes it easy to change the faceplates yourself. Using a magnet on the faceplates and an enclosed tool (a kind of suction cup), the faceplates can be replaced in a matter of seconds. On the Fir Audio homepage, a designer is provided with which you can order prefabricated faceplates in various designs, but you can also upload your own image files. For an additional price of 149-200 USD you can create your own individual E12. A great idea in my opinion.

But it's not just the faceplates on this IEM that can be changed quickly. Fir Audio has also put a lot of thought into the longevity of the E12 and good maintainability. The entire shell can be removed with just 2 screws under the faceplate. As with the Frontier Series, the 2-pin connectors are the most stable of their kind and are specified for up to 1000 mating cycles. And let's be honest, who changes the cable every day and could theoretically do this for around 3 years? And even if the connectors break at some point, they can be replaced very easily with a set screw.





In contrast to Kinetic Bass technology, the E12 uses what is known as Tactile Bass technology. The entire IEM housing is coupled to the dynamic driver and thus acts as a secondary transducer. This results in a more intense bass experience. The bass becomes more perceptible, although the Kinetic Bass technology has the edge here. The advantage of the Tactile Bass is that no sound escapes to the outside. I can hardly hear my Radon6 in the bedroom, as my wife can also hear some of the music. This is not the case with the E12.

As in the Frontier Series, the E12 also uses the ATOM Venting System for more relaxed listening through the use of a pressure relief system. This allows you to listen for longer as it significantly reduces listener fatigue. It also enlarges the sound stage and ensures an even more natural reproduction. The ATOM module is permanently installed in the E12 and cannot be replaced, as is the case with the Radon6, for example. This eliminates the possibility of adjusting the sound in the bass range. The built-in module has an isolation of -17dB.

The build quality of the E12 is once again typically Fir superb. The very sturdy metal housing is slightly larger than that of the Radon6. Even though the faceplate is attached with magnets, it remains firmly in place at all times. You don't have to worry about it slipping or coming loose during sudden movements. This is never the case. The nozzle itself is shaped on the outside in the same way as the Radon6 and therefore helps to prevent the eartips from slipping off or shifting. In contrast to the Radon6, the E12 has a complete opening of the nozzle without a protective mesh. The dynamic driver sits a lot further away than the driver of the Radon6, making it easier to clean the nozzle with the cleaning tool supplied.

The scope of delivery includes the typical Fir patch, a letter from CEO Bogdan Belonozhko, a round leather case with cleaning brush, suction cup and two different eartips in different sizes. The cable is the same as for the Radon6. An 8-strand pure silver cable with copper shielding. Such a good cable in this price range is not very common, great! A transparent jacket is used here as opposed to the brown one on the Radon6. I like the cable of the E12 better, as it shows the full class of the cable used. The faceplates in the "Titanic" design, which can be seen in the pictures, are not included and must be purchased separately.

I use my iBasso DX320 MAX Ti for the sound test. With an impedance of 16 ohms, the E12 is very easy to drive. Even higher volumes are no problem at low gain. Of course, the included cable is a 4.4 mm termination to be able to drive the E12 symmetrically on the MAX. For the eartips, I can recommend the AZLA Clear and the SpiralDots. The latter sounds a little smoother with the E12 and the Clears a little more lively. So you can vary according to your mood.





From the very first seconds, it is clear that we are dealing with Fir Audio DNA here. I only know the very open and airy playing style from a Radon6. I think this is thanks to the ATOM venting system, which allows more air to be created between the instruments and thus ensures this airy and holographic image.

Overall, it's a V shape tuning with a good portion of bass. The bass range is clearly the highlight of the E12. It goes deeper than the Radon6 and has more presence in the low bass range than in the mid-bass range. You can literally feel the low bass rumble of the E12. The kick basses are also very hard, although I find them more noticeable on the Radon6 with the Kinetic Bass. In terms of quality, the E12 is almost on a par with the Radon6. So this large 12mm driver really packs a punch! The last time I was so impressed by a bass range was with the 64 Audio Volür, which uses two dynamic drivers in an isobaric configuration. Unlike the E12 driver, these drivers are only 9 mm in size. For me, both models are right up there with the top models such as the Radon6 and Raven when it comes to bass. The E12 really makes every bass lover happy, that's for sure.

The overall tuning of the E12 is brighter than that of the Radon6. To ensure that the bass range, which is so strong, still has a controlled effect and has enough air to breathe, the lower mids are set back a little. The upper mids, on the other hand, are slightly boosted, as is the presence range, which brings the vocals slightly forward. With this tuning, the mid-range is not quite as full as with the Radon6 but still very natural. A dynamic driver creates a different atmosphere here than a BA driver. I would consider it more analog. Not quite as strongly separated and audible as is the case with the Radon6. The fact that the mids are not quite as full-bodied as with the Radon6 has to do with the strong bass range. This would simply be too "fat" overall.

The treble is also boosted by the strong increase in the bass range in the 8Khz range in order to create enough airiness in the sound image. Fortunately, this boost doesn't make it sound too sharp or sibilant. I even tested some of my old New Wave recordings, which can be annoying with the one or other IEM that sounds too bright. However, the E12 passed this test. The overall resolution is good, but it can't keep up with a Radon6 whose EST drivers simply tease even more detail out of the recording, even with a smoother tuning of the treble. The EST drivers simply have the edge. But I wouldn't have expected it any other way.

If someone asked me whether there are other IEMs that sound very similar to the E12, I couldn't answer that question. In my opinion, the sound itself is unique in the IEM sector. Of course the E12 has some of the genes of the Radon6. Nevertheless, there is a big difference and the two complement each other very well. The E12 manages the balancing act of a very powerful bass range and yet a very balanced sound overall. I wouldn't see it as an all-rounder, but rather as a great playing partner for more modern genres such as rock, pop, metal or EDM. The slightly brighter, more energetic playing style and the bass really suit these genres. If you only play one of these genres, you should definitely give the E12 a listen.