FiR Audio M5: five triumphal chords

Do you know what the secret of a musical piece, which both true connoisseurs and professional critics will call genius? The plays, where the composer, as if a wizard, sends the listener to a wonderful world of trembling consonants and constellations from notes, spend along minor canyons and major peaks, and at the end, during the sound of final, triumphal chords, leaves alone with the flowing euphoria.

However, the magicians from the American company FIR Audio, it seems, know such a magical recipe. Recently, they released a line of in-ear monitors: M2, M3, M4 and M5. I was fortunate enough to be acquainted with the last, five-driver model. If you express your feelings briefly, these are masterpiece CIEM. However, I will talk about this in detail in the review, but for now a few words about FIR Audio.

A year ago, I introduced you to their vacuum cleaners (FIR VAC) designed to care for in-ear monitors. After that, the guys developed some more useful devices for testing CIEM / IEM, as well as very remarkable cables for in-ear monitors.

Well, now we meet - FIR Audio M5!


Text by Alexey Kashirskey aka Hans Barbarossa


5 drivers (1-ESTAT, 1-BA High, 1BA High-Mid, 1-BA Mid, 1-DD Low)

Impedance: 6, 8 Ohm

Frequency response: 10 Hz – 20 kHz

Replaceable modules: Atom-X

Tubeless Shell design technology

Removable cable "Scorpion Wire": - 1,2м / 1,6м, RCX connectors, jack-3,5мм


Order of custom in-ear monitors

FIR Audio in-ear monitors can be ordered both in universal (IEM) and custom (CIEM) versions. I was lucky to get the second option.



The procedure for ordering individual IEM is quite simple. You need to go to, register, go to the Designer menu, select the model of interest, its design (design, connectors, and cable length) and pay for the purchase. Then you turn to the center of hearing, take your ear-impressions and send them to the manufacturer. After that, look forward to the arrival of your exclusive earphones.


Appearance kit and ergonomics

FIR M5 arrived to me in a silver tin round jar-snuffbox with a screw-off lid. On top is a white sticker with the name of the happy owner of the CIEM and the brand logo in the form of perky protruding rabbit ears.





Inside, this elegant tin can is completely glued with soft foam rubberized material for maximum protection of the CIEM during transport. In addition to the M5, we find a cool cable there, two (black and gold) replaceable atom-X modules, and another, gray module, is already installed in the CIEM, a brush for caring for sound pipes and a leather strap for fixing the wire in a twisted state.




The 26x8 Awg twisted black cable is made of oxygen-free silver-plated copper and has the spectacular name of “Scorpion Wire”. It has twice as many individual cores, compared to standard IEM wires. Due to this, the resistance is reduced by half, which allows the earphones to sound exactly as intended by the manufacturer, without unpleasant impurities and frequency response distortions.

Scorpio is a lightweight, flexible and extremely elastic cable. It has no memory effect and is pleasant tactile. When ordering, I selected new connectors from FIR Audio - RCX and an angled jack of 3.5 mm, similar to Oyaide.




The M5s are large, but fairly lightweight and comfortable. Landing is supposed to be exclusively behind the ear.

When choosing the design of my CIEM, I settled on a black shell and a faceplate with a "Web" pattern. The result was a direct illustration from a Gothic novel: it’s like an old mirror completely covered by a web, on which letters appear: the silver logo “FIR” on the left earphone and the name of the model “M5” on the right. This whole “mystical story” is varnished and polished to perfection.


The shell itself is made flawlessly, it clearly repeats the shape of my auricle and ear canal. The sound guide is neatly covered with a metal mesh, which eliminates the ingress of dust and dirt.

Well, performance, materials, and ease of use - everything is on the highest level here!

However, this part of the review is just an aperitif. If after it your audiophile appetite has played out, now you can go to the main dish.

Sound impressions

Before listening directly, you need to dwell on the technical features of the model. Five drivers are located inside each earphone: one DD dynamic is responsible for low frequencies, one BA for the middle, second BA for the upper middle, and the third BA, together with one electrostatic, are responsible for the correct reproduction of the high-frequency register.

The M5, as well as all other models of in-ear monitors from FIR, is built on the principle of "Tubeless Design". This is the company's patented technology, which means that the design does not use acoustic tubes, as well as separate cameras for drivers. In such solutions, the most accurate calculation is necessary for the correct location of all components inside the earphone shell, otherwise re-reflections and resonances cannot be avoided. Well, when it comes to the use of replaceable modules, the task becomes even more complicated. The way the developers dealt with it in this case definitely deserves applause.


However, let us talk more about this a bit later, but for now, we will deal with replaceable modules. The Atom-X is a metal cylinder valve acting as an acoustic filter for fine-tuning the sound of CIEM. It also pits the air plug that forms between the earpiece and the eardrum. Thus, the pressure exerted on the eardrum is reduced, and our hearing is not exposed to any risks.

The Atom-X modules, as you already know, vary in color: gray - neutral, black adds low frequencies, well, and gold - the most bass.


Listening on the equipment: MyST DAC 1866OCU V.2, Lotoo paw Gold, QLS QA-361, iBasso DX220 (AMP9), iFI xDSD, iFI xCAN, and iFI micro iDSD Black Lable


The M5 played at the highest level with all the devices, the handwriting changed slightly depending on the source, giving the M5 its unique shade. Best of all, the FIR M5 played with my powerful stationary MyST DAC 1866OCU V.2. This, I tell you, is inimitable. Bravo, berry nice, berrysimo! Tasty and lucid! Do not be surprised, I’m chewing blueberries in the course of the play, which is why such berry-juicy puns, ha-ha.


These CIEM can cope with any musical genres without any problems, and replaceable modules allow you to accurately add weighty sound to the sound without touching the rest of the registers. I mainly used gray atom-X, and even in it, it seems to me, bass is quite enough. But I also liked the other two options with even lower elaboration.


By the way, when ordering, you can choose M5 with a built-in gray atom-X. But we must understand that in this case it will not work in any way to finish the bass.

The sound of the M5 is massive, polished and natural, delivered in a neutral-warm manner with a darkened background, a well-designed low-frequency range, well-textured bass, a smooth, extremely rich, detailed midrange and an unusually clear and accurate high-frequency range. This is a thick, adult, thoroughbred and extremely naturalistic way of delivering sound.

M5 give out a sprawling stereo panorama, harmoniously and proportionately building a virtual space both in width and in depth. The volume is amazing, and the dynamic range is wide. 

M5 impresses with its temperament, clear articulation, good speed characteristics, high resolution and extraordinary tonal accuracy. I note a competent configuration with excellent driver matching and a complete absence of phase distortion.



The musical canvas is drawn unusually lively, embossed, with a symbiotic plexus of small and large parts of the composition, excellent transmission of contrast. It is integral, volumetric, proportionately built along all axes of sound coordinates.

However, all the above definitions cannot convey the most important thing. Inside the M5 there are clearly not only impeccably tuned drivers, but also a pinch of some magical powder. Otherwise, how else to explain the magical abilities of this model. With these CIEMs, the virtual audio images in my head came to life, grew flesh and became tangible. The virtual world turned into the real one. Now you are reading these lines and smiling incredulously, but in vain, I am not joking. The creators of the FIR M5 not only collected beautiful earphones, but also breathed life into their creation.

Okay, reluctantly set aside my lyrics; let us move on to the frequency amplitude.


The bass is precise, thick and resilient, with good control and quality texture development. It is neatly forced and clearly interacts with the mid-frequency register, complementing it with depth, a rhythmic base and an unusually lively, significant substance. The blow is powerful and biting, going deep down. The drum kit is perfected: powerful rumbles from the dancing of sticks on cymbals and drums scatter on both sides of the listener. Testing of the low-frequency register strikes with accuracy, reverberations and clearly distinguishable impact force. Wow, goosebumps are running down the back!

The mids is smooth, natural, timbrally rich and textured. Here, every musical image is endowed with a bodily basis. This is an extremely naturalistic and melodic manner, with a striking depiction of the contrast and all the details of the composition, where each instrument and every note played is in its place in space. Gracefully stringed instruments, winds and especially vocals. Here there is a light, correct, I would even say, jewelry rise in the mid-to-high junction zone, which adds to the vocal parts a pleasant charm, gloss and expressiveness. This is a well-balanced and at the same time emotional performance, where all elements of the composition are served unusually accurately, large-scale and multifaceted.

High frequencies are reproduced clearly and harmoniously. Their quantity and quality also does not cause the slightest complaints. The register is transmitted cleanly, accurately and distinctly, without sharpness and distortion. This is an unusually reliable and maximally correct manner, with good articulation, served in a light, elegant and comfortable form. Here, as in the other registers, there is agreement and harmonious interaction with the entire frequency range. Everything is beautiful and vibrant, simply amazing!


I cannot resist not to listen to my beloved Paul McCartney in the M5 brilliant So Bad.

Bass smoothly and recklessly fills the space. He waltzes himself and makes the whole composition spin around him. Its pulsation carries away measured drums. Bah, it’s Ringo Star himself following his old friend and paving the way for the rest with his lazy bit.

And here is the sparkling brilliant brute force guitar playing in the strings with windy, light, like a summer breeze, keys.

Paul McCartney's pure falsetto cuts space and time:

And if you leave, my pain will go

But that's no good to me

Girl, I love you, yes, I love you so bad...

Backing vocals scatter on both sides of the listener, going far beyond the boundaries of space and are already fading there.

The singing of violins and cello, enveloping like a languid aroma, makes you tremble with your whole body.

M5 amazingly convey the volume, texture and topography of the song. Every sound, every breath, intonation and touch of the strings are felt by the skin, and at some moment you literally sink in this moving melodic mass.

Amazing, chic, indescribable. It is something fantastic.



As for the frequencies (In the dry)

Lows - timbre-rich, with a powerful clap and a precise rolling kick. The bass is deep, embossed, gives the sound a warm and analogue hue.

Mids - even, smooth, detailed, organic, with excellent resolution. The pitch is clean and layered, with an extremely natural transmission of tones.

Highs - clean, smooth and natural. They are transmitted clearly, accurately and without any flaws.




FIR Audio M5 is an amazing CIEM model that geniuses have created, and I don't exaggerate a bit. For me personally, these in-ear monitor became an opening, a door to the bright future of portable sound. To create such a masterpiece, it is not enough to be a talented engineer; you need to have a deep understanding of the industry, an impeccable taste and a visionary gift. From an excess of feelings, to be honest, it is difficult for me to continue to talk about these earphones. Yes, you already understood everything. Today we were talking not about a good product, but about embodied audiophile's dreams and thoughts.

In addition, if someone says that dreams and thoughts are priceless, then it will be wrong. The price tag in our case is available and it, of course, is also impressive. You can order the M5 model on the official website for $ 2799. Of course, these in-ear monitors are not for everyone, but for the most notorious fans of perfect sound. To them I without the slightest hesitation recommend making every effort, but to purchase these CIEM.



Sound, design, convenience, build quality and materials.


No (if you leave the price behind the brackets).


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