I recently received the Fir Audio VxV IEMs and while this is the first Fir Audio product that I have reviewed, there is something very familiar about them. Fir Audio is a relatively recent start-up, but it comes from a family with a long history in audio and brings a lot of experience to the game.
The Belonozhko family founded 64 Audio a few years back and Bogdan held many roles within 64 Audio before leaving to start this new venture. His partner, Daniel Lifflander, was an engineer at 64 Audio before joining Bogdan in forming Fir Audio in 2018. Together, the two partners bring nearly 3 decades of experience in the personal audio market to the table and they know what they’re doing.
Fir Audio’s initial products were a line of earphone maintenance products aimed at keeping in-ear monitors clean and dry and ready for use. These include cases that dry and clean in-ears either for a single person or a whole band, vacuums for cleaning residue out of the nozzles, and cable testers to make sure everything is working properly before your next gig. After successfully getting those products to market, Fir turned its attention to making their own in-ear monitors and the M Series debuted in 2019.
The M Series has models ranging from two to five drivers and sport innovations like the RCX connector that is arguably an improved MMCX connector that addresses some of the shortcomings of the original design.
Their flagship M5 is a hybrid model with a dynamic driver for bass, 3 balanced armatures handling the midrange and lower treble, and an electret driver (This is referred to in their marketing materials as electrostatic but is more correctly called an electret) handling the upper frequency range.
The M5 has a startlingly low impedance of 6.8 ohms that has been the subject of some debate among audiophiles, but when paired with an appropriate source there is no denying that the M5 deserves a spot in the flagship ranks of top tier IEMs. Not the easiest IEM to drive but those who love it consider it one of the best available.
The problem with the M5 like most flagships is that it costs $2,800 — which is a lot more than most people can stomach. Sure, diehard audiophiles will shell out that much as will professional musicians who see the M5 as a tool rather than a luxury item, but even combining those two market segments nets a fairly small number of sales opportunities. $2,800 buys a lot of quality headphones in 2021.
The Fir Audio VxV IEMs sport a lot of trickle-down technology from the M Series in a much more price conscious package; I will stop short at calling them affordable at $999.00 because that places them out of reach of most people. It’s almost hard to believe that headphones have advanced this far in less than a decade and one can spend over $5,000 on a pair right now; something that seemed rather ludicrous to even suggest to anyone within the headphone space in 2010.
The inner shells are aluminum with a Delrin faceplate that helps reduce weight and cost and is less resonant than many other shell materials. Fir also adds the ATOM air transfer module (seen in front of the cable connection point) to help improve comfort by equalizing pressure and to help prevent driver flex.
Internally, the shell uses the same direct aperture technology used in the M Series to eliminate the need for sound bores. Drivers are a dynamic driver for bass, a pair of balanced armatures for the midrange, a single armature for the lower treble, and a single armature for high frequencies. It’s not the same as the M5 but the similarities are very apparent.
Having spent almost 3 weeks listening to the Fir Audio VxV IEMs, I can say that I think Fir has succeeded in bringing the price tag for a reference quality IEM down below $1,000 and that has significance for the category in a big way.
Some people rolled their eyes when the Audeze Euclid IEMs were introduced in 2020 for $1,300 but those who prefer to spend that kind of money on IEMs saw it as a challenge to brands like Sennheiser, 64 Audio, Noble, Campfire Audio, and others to raise the performance of their products to that level.
Bass has good authority with some slam and rumble when called upon but it doesn’t dominate the sound at times that it shouldn’t. Bass texture is also quite good which is a stumbling block for a lot of IEMs; they get the quantity right, but the quality tends to suffer.
The quality of the bass response is quite good with above average detail, speed, and ample decay that gives the Fir Audio VxV IEMs a very natural and pleasing tonal balance.
You’d be forgiven for thinking this was a balanced armature handling the bass duties as it sounds a lot more like some of the best BA models than it does a lot of the lesser dynamic models in its presentation and impact.
Tracks like Vintage Trouble’s “Knock Me Out” can sound thick and almost soupy on lesser IEMs, but the Fir VxV sounds quick, tight, and very dynamic.
The Fir VxV manages to deliver just enough slam and texture to remind you that it is a dynamic design but I’m not sure how those who prefer a very bass heavy IEM will react to it. If you’re all about “shake, rattle, and roll” inside your skull — the Fir VxV are probably not for you.
The midrange has a a slight emphasis on both ends which gives male vocals a bit of weight and body and brings female vocals a bit forward in the mix. This is a fun IEM for vocal performances with groups like Pentatonix really showing off what the VxV can do. Strings also have a pleasing tonal balance with enough energy to sound natural but not enough to cross over the line and become harsh or strident.
The treble follows a similar pattern with enough energy, but not too much. The top end has ample detail allowing snare rattles to have a nice crisp attack, and cymbals have enough energy to avoid the tinny sound they often have on some IEMs.
Thankfully, the treble stays very even throughout the range with no big jumps or dips. This allows the Fir Audio VxV to avoid the listening fatigue that usually accompanies IEMs with a lot of excess treble energy in the 7 to 9kHz range and makes them a more polite listening experience in comparison to many others at the price point.
The VxV does roll-off a little sooner than something like the Legend X or M5 with most of its energy below 10kHz. There is enough air and sparkle to not feel a need for more range but compared to something like the M5, you will notice a difference.
I actually prefer the tuning of the Fir VxV in this regard as it is much more comfortable for extended listening. If you’re looking for an IEM with seemingly endless extension in the treble, the VxV will sound too restrained but I would take less in this case rather than more considering the tonal balance of many DAPs and portable headphone amplifiers.
I dislike talking about the soundstage of IEMs as most offer something that can sound quite artificial; the soundstage is often very wide but lacking in depth.
The soundstage on the VxV isn’t huge, but it is well proportioned with no one dimension dominating the landscape.
What really helps the Fir Audio VxV IEMs is that it has reference quality instrument separation and imaging, and while soundstage dimensions may not be markedly larger than most of its competitors, it makes better use of the stage as movements are precise and one can pinpoint specific instruments in space. There is no crossover or smearing in that regard and it sounds far more realistic.
I tried all my usual tracks that cause lesser models to compress and get thick without any luck; the Fir Audio VxV was one of the best that I’ve heard in that regard if you put a lot of value in imaging and instrument separation.
The Fir Audio VxV IEMs tick off a lot of boxes. They are very made made and comfortable to wear. Those who feel reluctant to spend thousands of dollars on a reference quality IEM need to give these a real shot as they offer performance on par with some of the best from Jerry Harvey, Empire Ears, and 64 Audio — at a price well below what the aforementioned brands are charging for comparable models.
People often ask me where I think the law of diminishing returns kicks in in regard to IEMs; a category with dozens of very capable products used by discerning listeners and musicians.
Right above the Fir Audio VxV IEMs. Very highly recommended.
For more information: Fir Audio VxV (5×5) IEMs