FiR Audio VxV

General Information

FIR VxV Specification
1x Dynamic Driver
2x Mid-driver Balanced Armature
1x High-driver Balanced Armature
1x Ultra-high Driver Balanced Armature
MMCX connectors
2.5mm TRRS balanced connector
Chassis: Hybrid 6000 aluminum and DuPont ® engineering plastic.

Latest reviews


1000+ Head-Fier
Long Live the Bunny - King of Treble!
Pros: Top-tier Treble
Excellent mids
Excellent soundstage/Imaging/Instrument Separation
Good quality bass
Durable Build
Nice cable
Cons: Lacking bass QUANTITY, but not quality
2.5mm balanced cable with MMCX connectors
Packaging is minimalist, which can be a plus or minus
VxV Front.jpg

Original Logo Small.png


Up for review today is the FiR Audio VxV (pronounced Five by Five). FiR Audio has been hitting it out of the park lately with their universal IEMs. Previously, the Belonoshko brother worked at 64 Audio designing and manufacturing IEMs for that lauded brand. They brought their knowledge to FiR Audio and began producing fantastic IEMs in both universal and custom formats for both musicians and audiophiles. Mine are a used set, so they’ve been fully burned in before I got them.

Normal FiR Audio IEMs come with the ATOM venting/tuning system and a bunch of other cool technology, but the VxV is really designed to be a more simple everyday carry IEM. As such, there are no fancy faceplates or gold coloring, or the kinetic bass port you’ll find on their higher-end models. What you do get is 5 drivers, 1x 6mm DD for the lows, 2x BA mid-drivers, 1x BA high-driver, and 1x BA Ultra-high driver per ear. The focus here is the best possible sound without the advanced tech of the M series or frontier series at a more approachable price – and spoiler alert, they pull it off. On with the review!

VxV Accessories.jpg

Accessories/Earpads/Eartips (7/10):

The stock box is really minimalist, just a small regular cardboard box with the FiR VxV Bunny logo on it. It’s very plain compared to IEMs like the Elysium and Mezzo LE. Inside the box is a really nice package though, with a black leather case with everything inside it. There is normally a 3.5mm cable included, though you can get a balanced 2.5mm balanced cable if you like, and 5 pairs of ear tips. The tips come with one set of foamies, a set of double-flanged, and 3 sets of silicone. They should fit just about any preference, but I personally used the Spinfit W1s since I know they give me a good fit and good isolation/sound quality. The case also includes cleaning materials.

Oh, and you get awesome bunny stickers including an astronaut bunny with a FiR flag. I have to give a bonus point for the best stickers I’ve seen come with an audio-related product. So yes, it doesn’t come with a lot, but this is also their “budget” offering, so it comes with everything you need, and nothing you don’t. It’s just as nice as the kit that comes with the more expensive Fibae 5, but it doesn’t really hit the amount of stuff that comes with the $80 TRUTHEAR HEXA. So, if you really need more ear tips, you can just buy your own set, Final, AZLA, and Spinfit make nice ones. Still, it’s nicer than the kit that comes with the Fibae 5, which is the bare minimum anything near $1k should come with, and approaching the JH Audio ROX kit. 7/10 points here. As always, I'm using my Spinfit W1 tips since they're the best I've found (You can buy them here if you want a set:

Cable (8/10):

The cable that comes with the VxV is better quality than a lot of cables I’ve seen come with IEMs costing 2-3x as much. The biggest downside here is that it comes with a 3.5mm stock (mine is the 2.5mm), oh, and MMCX instead of 2-pin. So, if you’re looking for a 4.4mm balanced, which at this point is the gold standard of balanced cable connections, you’ll have to find one from an aftermarket company because there’s not even an option for a 4.4mm from FiR. Additionally, if you have an extra 4.4mm laying around, it likely won’t fit the MMCX connectors unless you’re a Campfire Audio fan. Luckily, you can grab a pretty nice Zonie cable from Linsoul off Amazon for only $20. Or, if you want, FiR will build you an 8-strand one for around $325.

If for some reason your DAP or DAC/amp actually has a 2.5mm balanced port, you can get your included cable terminated in that connector. Or, you can use an adapter, which is what I had to do since mine came with the 2.5mm cable. I had to add a 2" adapter to use the 2.5mm cable since I've only ever owned one DAP with a 2.5mm port. The problems with 2.5mm will still exist though, compatibility, and durability – the 2.5mm are super easy to break since they’re so thin. The cable itself is silver-plated copper, and it’s a 2-strand instead of a 4 or 8-strand. The cable is soft and lightweight and one of the nicest stock cables I’ve seen in this price range, previous connector issues aside. Personally, I really like MMCX - it doesn’t have a lot of the issues that 2-pin has. It is harder to find though, and some people hate it for some reason, so if that’s you, avoid FiR and Campfire products I guess (you’ll be missing out).

Build Quality/Comfort (9/10):

The build quality on these is really good. The chassis itself is aluminum while the faceplate surround makes me think of glow-in-the-dark roller blade plastic – no clue why, but sadly they don’t glow (missed opportunity FiR). The inner part of the faceplate feels a little like a tough sticker, and while I love the logo, the black part scratches easily with tiny, almost imperceptible scratches. You can only see them if you angle them in the light a certain way, but I’d be remiss not to mention it. Overall, these feel like really durable IEMs and I would feel OK tossing them into a bag and using them as their intended EDC IEM. I don’t think there are any other IEMs in this price range with this sound quality I can say that about – not the Fibae 5, and certainly not the Monarch Mk2.

The comfort of the VxV is extremely good since they are lightweight and tiny IEMs. They remind me of the Symphonium Meteor with their size and shape. I can wear these all day long with no issues. They will sit inside your outer ear with no issues, and while they won’t sit just inside your inner ear like the Final A5000, the nozzles are long enough to get a good seal. After wearing TOTL IEMs like the Ronin and Mentor, these are a nice change – they’re about the same size as the Fibae 5 (F5), though the F5 has longer nozzles. 9/10 points - 1 point off for the weird, hard-to-see scratches on the faceplate.


Check out the frequency response graph below. I’m comparing these to the Custom Art Fibae 5 since I have both on hand and they’re very close in price. Obviously, the Fibae 5 are going to be your IEM if you want bass – that’s just not what the VxV is shooting for and it’s apparent when listening to EDM. The mids on these two are surprisingly close – almost identical – believe me, that’s a good thing. Lastly, while both appear to have pretty close highs, I’ll take the tuning of the VxV over the Fibae 5 for Highs quality any day since the F5 has some of the BEST highs I’ve heard on any IEM, let alone one in this price bracket. That said, the sibilance and sharpness on the VxV come as a trade-off to those detailed and pronounced highs.

VxV F5.png

I am powering these off of my HiBy RS8 on Medium gain through Tidal Hi-Fi with MQA enabled. They are easy to drive and I’m using about 20-30/100 volume through a balanced 4.4mm connection.

Lows (15/20):

I’m starting off with the Mid-bass/Sub-bass test I’m using David Guetta’s “I’m Good (Blue).” The VxV starts off with some punchy bass and the clapping in the background is quite highlighted as well. The sub-bass windup is almost imperceptible and the sub-bass itself is present, but not mind-blowing. It’s a very muted sub-bass. These are very neutral-sounding IEMs and the mids are very forward and present (which I like, but it’s not great for a bass test.) 5/10 points.

Up next is Demon Hunter’s “I Am A Stone,” which I use to test whether the bass is too strong and overwhelms the mids as that is just as important as how strong/good the bass is. Well, if the bass on the previous song is just average, then this song must score really well, right? Actually, yes. There’s still a present bass instrument in the background and it doesn’t overwhelm the excellent mids at all. This is about as good as this song can get. 10/10 points

Mids (18/20):

Weaving The Fate’s “The Fall” is my test song for clean/dirty guitars and vocals with background instruments to see how clearly the vocals can be heard. The clean intro guitars sound great with excellent detail and separation. The dirt guitars also sound good with no blurring of the lines between the guitars and the other instruments. The vocals come in very clear and forward which pushes the guitars to the back a little. The high-hats can be clearly heard as well, and while this is not the highs section, it’s worth mentioning – along with a tad bit of sibilance I don’t normally get from this song. But, as this is not a highs test song, the VxV still ears a 5/6 on this.

Staind’s “Something to Remind You” has clean electric guitars and wonderful vocals – this song tests vocal quality and background noise. The intro guitar comes in quite clearly and with excellent musicality. Truly, the VxV is a mids monster – and I’m expecting great things from the highs detail as well. The vocals here are about as good as you can get in this price range, and only a step down from MUCH higher priced products. Yes, you can hear the fingers on the guitar strings on this song, do the detail is excellent as is the layering. 6/7 points.

To test classical instruments in the mids, I’m using The Piano Guys' “Code Name Vivaldi.” For headphones that don’t have a lot of sub-bass presence, the mid-bass and low-mids can still show up impressively as evidenced by this song. There is a ton of body on the lower instruments and the mids of course come in very clearly with the piano leading the show. The mid-strings also excel here. It is really rare for headphones to do so well on all 3 mids songs, especially under $1k. 7/7 points.

Highs (12/20):

To test sibilance on headphones I use Panic! At The Disco’s “High Hopes. While I am expecting great things from the VxV on the next two songs, the fact that I heard sibilance on my mids test songs don’t bode well for this song. Yeah, it’s extremely sibilant – one of the worst I’ve ever heard – there’s always a trade-off, but it should mean the next song gets full points. 1/6 points.

Dream Theater’s “The Alien,” is the highs test song I use to see if the cymbals/high-hats/snare drum can be clearly heard and distinguished from the rest of the music (also good for instrument separation.) As expected, the highs on this song are excellent and easily some of the best I’ve heard. The cymbals come in very clearly and if that’s something you’re looking for, you’ll LOVE the VxV. You can even hear the cowbell in the background, which is very hard to hear on most IEMs. 7/7 points!

Michelle McLaughlin’s “Across The Burren” is another of my favorite highs/sharpness test songs as it can easily sound painful on some headphones. Based on the two previous songs, this one can either come in really good or really sharp, it could go either way at this point. My guess is sharpness – and my guess is right. There is some definite sharpness, but it’s not too bad – the VxV controls it better than I was expecting – putting it just above the headphones I’ve tested with sharpness. 4/7.

Soundstage/Instrument Separation/Imaging (9/10):

I use MGMT’s “Time to Pretend” to test soundstage, instrument separation, and imaging. The separation on these is fantastic and so is the imaging and resolution. Once again, I am amazed at how these perform in this price range – they certainly give the Monarch Mk2 a run for their money. The soundstage is surprisingly large as well, not TOTL level, but better than just about anything else in the $1k price range I’ve heard.

The VxV are much easier to drive than the F5. I find the soundstage to be slightly larger on the F5, but the detail drops back a little bit and the mids are slightly more recessed on the F5. The Fibae 5 are not bass-shy like the VxV, and there’s almost too much bass on the Fibae, with some unwanted distortion. The sub-bass is also far more powerful on the F5, so if that’s your thing, get the F5 instead. If you want extremely detailed mids with a forward presence, grab the VxV. Additionally, if you want to hear every cymbal strike, the VxV is the IEM for you – some of the best detail and quality I’ve heard on highs, even up to the $3k bracket. Yes, there is a sibilance/sharpness tradeoff, which the F5 tames a bit, but the F5 still has both without the detail the VxV has.

In the end, it comes down to your preference between these two. If you can’t live without sub-bass, get the F5. If you can’t live without excellent highs and great imaging/instrument separation, get the VxV. The VxV is my best IEM under $1k while the Fibae 5 is my best IEM under $1,500. Do with that what you will.

VxV Stickers.jpg


The VxV are a massive surprise for me. They don’t quite hit that sub-bass itch that I’d like to hear (get the XE6 or Fibae 5 for that), but the mids are fantastic and the highs are top-tier, other than the inherent sibilance that pronounced highs bring with them. The VxV are easily my current recommendation under $1k for a mids-focused IEM with excellent highs, good detail, good separation, and an impressive soundstage. Everyone talks about the Frontier series from FiR, but really, for normal people who don’t want to spend $3k on an IEM, this is really the pinnacle as long as you can handle the missing sub-bass. Long live the BUNNY!

Headphone Scoring (v3):
Accessories / Earpads / Eartips (10 pts):
Cable (10 pts):
Build Quality/ Design / Comfort (10 pts):
Lows (20 pts):
Mids (20 pts):
Highs (20 pts):
Soundstage / Instrument Separation / Imaging (10 pts):
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DJ Core
DJ Core
Love this tubeless technology and have narrowed it down to 64 Audio U4s, VXV, and symphonic audio "Meteor". Love the natural sound of this tech but don't want to sell my liver to get one lol.

Please advise on which one to get. Meteor could save me $400 + I do like some decent bass but not too much.
The VxV is the best of those most likely, I haven't heard the U4s though. The Meteor will be the cheapest, but it's pretty hot or miss.
Very nice read :) PW Audio no 10 mmcx also works. Cable upgrade which doesn’t break the bank (slight soundstage increase stands out).


Headphoneus Supremus
Down The Rabbit-hole With The Jack-Rabbit Of All Trades
Pros: Great balanced warm-neutral tonality, pretty all-rounder tuning.
Good technicalities.
Very coherent for a hybrid.
Textured bass which is well controlled.
Comfortable and light, solid build.
Good isolation.
Cons: Somewhat limited accessories/packaging at this pricing.
Semi-proprietary MMCX connectors.
Slight BA timbre.
Shell 2.jpg


I would like to thank Kenneth from Project Perfection for loaning this FiR Audio VxV unit. The IEM will be returned after this review. The VxV can be gotten here!

Project Perfection is a Singaporean audio company that distributes some storied brands like Lotoo, Final Audio, DITA, Stax and FiR Audio.

FiR Audio was founded in 2018 by two brothers, Bogdan and Alex Belonozhko and their friend Daniel Lifflander. Between them, they have over 20 years of experience from working previously at 64 Audio.

Shell 3.jpg

FiR Audio's mascot is that of a rabbit named Firry!


This FiR Audio VxV is a pretty competent 5-driver hybrid IEM that does most areas well, and has few weaknesses in the tuning. The warm-neutral signature is quite balanced to handle most music genres. In fact, I see the VxV as a jack-rabbit of all trades, and most folk should find something to like about it, perhaps other than die-hard bassheads and trebleheads.

  • Driver configuration: Hybrid: 1x Dynamic Driver, 2x Mid-driver Balanced Armature, 1x High-driver Balanced Armature, 1x Ultra-high Driver Balanced Armature
  • Frequency response: 20 Hz – 20000Hz
  • Impedance: 16 Ohms
  • Sensitivity: no specs available online
  • Cable: MMCX, 2.5mm TRRS balanced connector
  • $999 USD
As per its namesake, the VxV contain 5 drivers for each side.


External Package.jpg

The packaging is rather austere, coming in a small white cardboard box. BTW the Firry rabbit stuff toy is not included!!!

Other than the IEM, these are included:

- 3 pairs of silicone tips (S/M/L)
- 1 pair of double flanged silicone tips
- 1 pair of foam tips
- Cable

- Cleaning brush
- Leather hardcase
- 3 x Firry rabbit stickers

Accessories FiR.jpg

The cable is made of silver-plated copper. This cable is very well braided and pliant, with no microphonics. It only comes in a 2.5 mm termination, so those that use 3.5 mm or 4.4 mm sources may need an aftermarket adapter (which isn't included). There is a chin cinch to secure fit during usage.

Cable FiR.jpg

Sadly, this cable features a semi-proprietary MMCX design, where there is a shroud over the left/right termination of the cable, and it may hence not be usable with other standard MMCX IEMs. If aftermarket MMCX cables are used, they can still pair with the VxV housing, but there will be a bit of a metal sheath that will be exposed. Nothing deal-breaking, as sound can still be generated, just that it may be a bit of an eye-sore as such.

While I'm generally not a fan of MMCX (they seem to deteriorate faster than 2-pin connectors with repeated cable changes), the MMCX quality on the VxV seems very robust. The cables snap off easily and back on without much force needed on the MMCX connectors.

The leather hard case is very elegant, with the inner layer lined by a velvety material.

Everything is pretty usable out of the box, I don't think you will need to source for aftermarket accessories for the VxV (other than the aforementioned adapters for non 2.5 mm sources). Only thing is at this pricing, the provided accessories are not exactly class-leading, but well, accessories maketh not an IEM, and I would be more interested in the sound, as we will read on below.

For the purposes of this review, the stock silicone tips and cable were used.


The VxV is tear-drop shaped, and is extremely light and ergonomic, with no discomfort with prolonged usage. It is advertised to be made of hybrid 6000 aluminum and DuPont engineering plastic, which does explain the very light yet solid build.

I didn’t find any driver flex during usage; the VxV sports a unique ATOM pressure venting system, with the vents placed near the MMCX female connector region, rather than the traditional location on the shell housing. This in theory lessens listener fatigue and pressure, in addition to reducing the likelihood of driver flex.

Shell 4.jpg

The right earpiece showcases Firry (FiR Audio's rabbit mascot), while the left earpiece is emblazoned with FiR Audio's logo.


Isolation is good (especially with the foam or double flanged tips), this set is quite usable in noisy or outdoor environments. Perhaps it can even be used as a stage monitor in view of the good isolation levels.


I tested the VxV with:
- Khadas Tone Board -> Schiit Asgard 3 amp
- Khadas Tone Board -> Topping L30 amp
- Sony Walkman NW A-55 DAP (Walkman One WM1Z Plus v2 Mod)
- Sony Walkman NW A-55 DAP (Walkman One Neutral Mod)
- E1DA DAC/AMP dongle
- Colorfly CDA M1 DAC/AMP dongle
- IKKO Zerda ITM01 dongle
- Tempotec Sonata HD Pro dongle (BHD firmware)
- Smartphone

The VxV is pretty easy to drive from lower powered gear, but scales with amplification.


The FiR Audio VxV is a warm-neutral IEM with rather good tonal balance. This makes it quite all-rounder for most music genres. Perhaps only die-hard bassheads and trebleheads may dislike this tuning as there are slight roll-offs at both extremes.

For a hybrid, the VxV is very coherent, and there aren't any awkward troughs and peaks that are audible.

Fir Audio VxV.jpg

Graph of the VxV via IEC711 compliant coupler. The 8 kHz area is a coupler artefact peak.

Bass on the VxV is north of neutral, but not at bona fide basshead levels. It is mid-bass focused with a slight sub-bass roll-off, though sub-bass still extends quite well. Bass quality is controlled and tight, with minimal mid-bass bleed, and the bass has good texturing and speed. Of note, the VxV kept up with the bass movements in Sting's Englishman In New York, which is my test track for bass speed and texturing; some IEMs with a slower bass may have smearing during the bass solo movements mid-track.

Midrange on the VxV is quite full-bodied at the lower mids. Upper mids are slightly boosted, but with a less than 10 dB pinna gain, this set is not shouty in the upper mids. Vocals are hence forward without being fatiguing.

Treble is moderately extended, there is good clarity and micro-details. Lower treble is boosted around the 5 kHz regions, but upper treble has a slight roll-off, hence the VxV lacks the air and sparkle that die-hard trebleheads would yearn for. There are occasions of sibilance, but by and large, treble sensitive folk should be quite at home with the tuning.


Technical aspects are pretty solid on the VxV, with good micro-details, imaging and instrument separation on tap. Soundstage is above average, it is not the tallest, but has good depth and width. Layering is no slouch and music never sounded compressed on the VxV even with tracks with complex movements.

Timbre is acceptable considering there are BAs inside. There is a slight tinge of BA timbre for acoustic instruments, but nothing really deal-breaking.


Campfire Andromeda 2020

The VxV has a deeper sub-bass extension, thicker note weight and a better soundstage than the Andromeda 2020. Timbre is slightly better on the VxV too.

My biggest bugbear with the Andromeda 2020 is that it is very fussy with sources (due to the low impedance and rules of eights), and it also hisses with sources with a poor noise floor. The VxV on the other hand, is much more source agnostic, and not as troublesome to pair sources with. That in itself makes the VxV less finicky between these two SummitFI sets.

Sony IER-M9

The venerable M9 comes with a much better assortment of accessories.

Accessories aside, the M9 is also tuned neutralish-warm, but even so, it is slightly less bright in the lower treble than the VxV, and more laid back overall. In technical performance, the M9 is better in soundstage, layering, imaging, instrument separation.

The M9 is harder to drive though.

Earsonics Onyx

The Earsonics Onyx has a much heavier and larger shell, this can be fatiguing in terms of comfort.

The Onxy is more V-shaped with a bigger bass. The bass on the Onyx is unfortunately not as textured and bleeds into the mid-bass. The Onyx is also darker in the treble and has worse resolution, imaging, soundstage and micro-details than the FiR Audio VxV.

Mangird Xenns Up

The Xenns Up comes with a bigger spread of accessories and has a bigger sub-bass than the VxV. The Xenns Up are more basshead and also darker in the treble.

In technicalities, the Xenns Up is slightly poorer in imaging, micro-details, clarity, instrument separation than the VxV.


This FiR Audio VxV is a pretty competent 5-driver hybrid IEM that does most areas well, and has few weaknesses in the tuning. The warm-neutral signature is quite balanced to handle most music genres. In fact, I see the VxV as a jack-rabbit of all trades, and most folk should find something to like about it, perhaps other than die-hard bassheads and trebleheads.


My nitpicks for the VxV have to do with the packaging and semi-proprietary MMCX connectors, plus a slight BA timbre.

The VxV would be a good all-rounder and jack-rabbit of all trades TOTL model for those that are keen to sample something in SummitFI rabbit-hole. I quite enjoyed my time with the VxV and am sad to return this loaner unit. In fact, I very much look forward to what other rabbits FiR Audio can pull out of the hat (no pun intended), and watch with anticipation for their future releases!
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Dobrescu George

Reviewer: AudiophileHeaven
Fir Audio VxV IEMs - Flagship IEM Hits Luckiest Notes
Pros: + Natural, Smooth sound
+ Ergonomic Fit
+ Superb build quality
+ Great fit with most tips, no aggressive tip rolling necessary
+ Neat Aesthetics / Logo
+ Detachable, high-end cable
+ Balanced connector
Cons: - Smallest package every, very simplistic
- 2.5mm rather than 4.4mm cable
- MMCX connectors instead of 2-Pin
Fir Audio VxV IEMs - Flagship IEM Hits Luckiest Notes


Fir Audio VxV or 5x5 is a high-end IEM priced at 999 USD, and with five drivers per ear, a full bodied presentation and a special ATOM pressure venting system. Given their price point, they will be compared with Campfire Ara (1300 USD), Unique Melody MEST MKii (1500 USD), Audeze Euclid (1300 USD), iBasso IT07 (900 USD), and Lime Ears Aether R (1400 USD). I will also be including pairings with iBasso DX240 running AMP8 MK2 Module (950 USD), Dethonray DTR1+ Prelude DAP (1000 USD), and Astell & Kern SE180 (1500 USD).


Fir Audio is a company from the USA, focused on creating both Custom and Universal In-ear Monitors or IEMs. The IEM we are reviewing today, 5x5 or VxV, is available in both Custom and Universal variants, and it features some of the company's best technologies, including 5 drivers for each ear. A bug thanks today goes to Project Perfection PTE LTD from Singapore, who are the sellers of VxV in Singapore, and one of the most important distributors of those IEMs. They are also official distributors for Dita Audio, and if you read my review of Fealty and Fidelity, you probably know that both made it to Audiophile-Heaven's Hall Of Fame, so it will be interesting to see whether Fir Audio VxV will do as well.


It should be noted that I have absolutely no affiliation with Fir Audio, I am not receiving any incentive for this review or to sweeten things out. I'd like to thank Project Perfection PTE LTD for providing the sample for this review. Every opinion expressed is mine and I stand by it. The purpose of this review is to help those interested in Fir Audio VxV Universal IEMs find their next music companion.


First things first, let's get the packaging out of the way:




The package of VxV is the smallest, most compact I've seen for an IEM at this date, and they barely have a package, coming in a very tiny cardboard box, where you can find the carrying case, inside of which you will find VxV, their cable, and a selection of tips, plus a cleaning tool. The presentation is made to be space effective, and this is actually something possible, because it helps save our planet and create less waste compared to less efficient solutions.



  • 1x Dynamic Driver
  • 2x Mid-driver Balanced Armature
  • 1x High-driver Balanced Armature
  • 1x Ultra-high Driver Balanced Armature
  • MMCX connectors
  • 2.5mm TRRS balanced connector -or-
  • 3.5mm TRS 3-pole connector
  • Chassis: Hybrid 6000 aluminum and DuPont ® engineering plastic.
  • 16 ohm
  • 20-20Khz

Build Quality/Aesthetics/Fit/Comfort

Technically speaking, 5 x 5 or V x V is an interesting IEM with dive drivers per each ear, and with a very fair purpose in mind - to sound good with everyday music and everything that is played through them. The company names this the EDC or Every Day Carry, and they tout the VxV as having a welcoming sound. The physical build of VxV is excellent, and they are made of solid Hybrid 6000 Aluminum and DuPont Engineering Plastic.


Fir Audio is actually one of those big guys who develop new technology and implement new ways of creating IEMs rather than just repeating and purchasing just the drivers from the producers, and they implemented the DAA Sound Reactor technology inside of 5 x 5 as well. They also implemented the ATOM pressure system, and the Tactile Bass Technology in 5x5. The company promises that VxV is made in small batches, to ensure the highest of quality controls, and as someone who just purchased and had to return multiple TVs due to poor quality control, I really appreciate that we can have those nice things as audiophiles, good quality control, and good build quality for our products.

The Dynamic driver takes care of the bass, with two mid Balanced Armatures, One High Balanced Armature, and One Ultra High Balanced Armature. The cable for today's sample is the balanced version, with a 2.5mm connector, and Fir Audio has an alternative that is single ended, with a 3.5mm connector.

The ATOM Venting system is basically a pressure relief system that helps equalize the pressure between the ear canal, the IEM driver and outside pressure, to reduce listener fatigue and reduce hearing loss from wearing IEMs. I can say that it works well, and there is ventilation flex or driver flex with VxV.


The Tactile Bass Technology is the kind of tech that helps conduct the low notes through the entire IEM shell, using it as a Transducer, having a unique coupling between the IEM shell and the Bass Dynamic Driver. This is borrowed from the flagship M-Series from Fir Audio. We also have the DAA Sound Reactor technology inside of VxV, which is basically a special way of arranging the drivers in a tubeless configuration, with the dynamic driver pushed to be in physical contact with the IEM chassis / shell.

Subjectively, VxV is comfortable, has no round edges, and it is the kind of IEM I can see myself using for many hours in a row without wearing fatigue. The ultra low impedance of 16 OHMs tends to leave the VxV prone to some hissing, especially if you're connecting them to noisier sources like FiiO M11, or Hiby R6, but things are super ok with Lotoo PAW6000, and Astell & Kern SE180. With no driver flex, no microphonic noise, and an excellent comfort, VxV is the kind of IEM that makes wearing IEMs a pleasure, and I can fully recommend them for both their comfort and construction quality.


Even with quiet music playing, it is impossible to hear my girlfriend screaming at me from 2 meters away, as we're both working, so VxV is great at passive noise isolation. It also has very little leakage, and most people won't hear what you're listening to. Sadly I wasn't able to test the latest cables I had in for review, as the MMCX connectors mean no 2-Pin cables, but I may want to look into some high end cables for VxV.

Sound Quality

Fir Audio VxV is the kind of IEM that sounds great with all sources, as long as they don't have a high output impedance, but for the sonics part of today's review, I've been using VxV with high-end sources, in hopes to find the best performance possible for VxV and to give them the best chance I could. The main pairings I went for are with Astell & Kern SE180, iBasso DX300, and Lotoo PAW6000, but also with portable DAC/AMPs such as Palab M1 Mini, Cyrus One Cast, and unique music players such as Dethonray DTR1+. I also allowed a burn-in time of about 100 hours for VxV, which I do for all IEMs, so that burn-in believers and non believers can both be at peace, VxV having had its chance to shine and change their signature as much as they're likely to do. One thing that I noticed is that if you're using the balanced cable variant, you're likely to experience a good overall sound, and you won't need to upgrade the cable, but if you went for the single ended variant, and your music player / source has balanced outputs, you're best upgrading your cables, VxV getting more energetic and engaging with cables like Effect Audio EVO 1 and Plussound Copper+.


The overall tuning of VxV can be described as perfectly natural, sweet, well separated, with a full, deep and natural bass, natural tonality, with beautiful female voicing, as well as natural, deep and smooth male voicing. VxV is unique because it really manages to feel the most transparent, all while sounding deep and natural, smooth and impactful. Most transparent sounding IEMs and Headphones tend to be brighter, and have less bass quantity, as well as sub bass, where the bottom extension of VxV is superb. In fact, they also have a superb treble extension, and a lot of air, enough so that if you're listening to brighter tuned EDM and Dubstep, you will hear all the sparkles and the micro details presented there with no misses.

The bass of VxV is deep, rounded and full, with excellent reach as low as 20 Hz, and a lot of energy for the entire bass body. VxV is excellent at present music with good impact, deep and full, with no cutout on the substance for instruments, and a delightful, lush tuning for all instruments. The best part of their sonic presentation is the way the bass can keep up with any song, but won't become too quick or dry even if the song is slow, so Jazz and Classical has all the elementary building blocks in the lows for instruments to sound correct and accurate, while EDM, Dubstep and Metal music sounds quick, delivers outstanding impact and everything just seems to sound natural. The company tried to make an IEM that sounds as natural as it is humanly possible, and this is exactly what they managed to do with VxV, the low end having just the right parameters to sound spot on. The slower and smoother the original music is, so the more it leans towards Jazz and Slow Pop, the more satisfying and sweeter VxV sounds, as it provides the kind of Chugg impact for Deathcore, leaving natural trails after bass notes in Metal music. This natural decay is perfect if you're looking for impact and explosion, but can feel like the note decay is long if you enjoy Infant Annihilator on a daily basis.


The midrange of VxV is also a full and deep experience, with excellent layering and a natural soundstage, in both width and depth. I am willing to go as far as saying that VxV presents music very holographic, sphere-like, with sounds coming from literally any area and angle, within a natural boundary around the listener. VxV is the kind of IEM that will showcase female voices as well as male voices, having the right amount of smoothness and fluidity to give artists like Mori Calliope, Jill Tracy and even Pop singers like Kesha a sweet and fun tuning, pleasing for listening. VxV is also capable of properly rendering screams and complicated voices such as those of John Mess from Dance Gavin Dance, or Alesana and Asking Alexandria. Something you won't see me saying often, but VxV has a really pleasing presentation for dialogue as well, as the natural presentation doesn't recess the midrange much, so you hear a really natural voicing, which can make movie watching and gaming with VxV considerably more pleasing than I expected them to be. You could call VxV one of the most musical IEMs created to date and tell no lie there.

The treble of VxV is actually fun to hear, because you'd imagine them being too smooth or rolled off, at least when you hear "natural presentation" but that ain't the case at all, and they provide a really nice resolution, micro and macro detail, as their sound is very focused and sparkly. They have a good extension as high as about 16kHz-17kHz, having a natural amount of treble, as well as a natural texture and treble presentation. This means that you're unlikely to be bothered by the treble or fatigued by it, but you'll notice sparkles in songs where the artist intended the highs to be easily audible. All in all, VxV is fun, engaging and plenty enjoyable, being the kind of IEM that you can easily listen to on an everyday basis without ever growing bored or growing tired of. I can't emphasize this enough, but if it is refreshing to see and hear an IEM done for pure enjoyment, without a particular focus on a coloration, and made to be enjoyable in all possible scenarios, VxV being the cup of tea you'd enjoy both with your fancy friends, best friend, and alone, truly a versatile master of all.



Fir Audio VxV vs iBasso IT07 (999 USD vs 900 USD) - We also have a good comparison with IT07, an IEM that's made to be as clean, clear and detailed as possible, with the least compromise. iBasso is a master of live and alive tunings, and they generally manage to make interesting music players, but their IEMS always had a specific tuning, that's light, clean and slightly ethereal (AM05 and IT04 being good examples for it). IT07 is much bolder, heavier sounding, with a really natural tuning, and it is similar in many ways to VxV, including comfort, but I found VxV to have slightly higher resolution, focusing slightly more on detail, and also managing to reproduce certain male voices, like deep baritones, slightly more accurate compared to how they would sound in real life. I also found VxV to be more credible when it comes to its soundstage, although to be fair both IT07 and VxV have a similar stage, and a similar instrument separation to begin with. IT07 can be thicker, and also slightly more hot in the treble, which can mean a more engaging sound, where we know from the sound quality part of the review that VxV is as natural and as comfortably sounding as it is possible, all while having the highest amount of details possible.

Fir Audio VxV vs Lime Ears Aether R (999 USD vs 1400 USD) - Aether R is the kind of IEM you start listening to, and never stop. This is a characteristic I found true about VxV as well, and you're likely to insert both in your ears and forget how time flies, because both are tuned for enjoyment, and both are comfortable. I found VxV to be slightly smaller and more ergonomic than Aether R, but it doesn't have any switches and ways to tune it, like Aether R has. I also found VxV to be more natural in the midrange, with a more natural bass and treble, where Aether R has certain colorations to its sound, as I presented in my full written review of it. Most listeners will find that VxV sounds excellent out of the box, with their default cable, and with pretty much all sources, where Aether R is slightly more dependent on good tips, a good source, an upgraded cable, and requires more time to get adjusted to. Somehow, Fir Audio managed to really achieve their promised perfectly natural sound with their VxV and this is truly a sight to behold for a music lover who always notices all the minor imperfections in the midrange of all IEMs. Aether R will have a slightly bolder bottom end, a slightly less upper midrange enhancement, and slightly less treble extension, where VxV will have a sound that you can really call natural and transparent.

Fir Audio VxV vs Audeze Euclid (999 USD vs 1300 USD) - Euclid is an IEM that many love, but it is a very neutral and fair IEM, it will present music exactly as it was recorded, mistakes and bad parts included. VxV is the perfect alternative, because both IEMs have excellent build quality, and similar comfort, with Euclid actually being slightly larger. The overall sonics are very different, with Euclid being extremely neutral, clean, clear and crisp, with a very resolute and honest sound that will highlight every single little detail and nuance in music, while VxV is much more natural, considerably less fatiguing and less bright, smoother and generally presents music closer to a real life tonality, where the neutrality of Euclid implies that it is a bit brighter. They are both source dependent, but you could get away with a lower quality music player with VxV, and a FiiO M11 PRO could do just fine, while with Euclid, they reveal the source quality as well, so music players such as iBasso DX300, DX240, Astell & Kern SE180 and Astell&Kern SP2000T are much better sources for Euclid, increasing the initial cost for the best performance. VxV is also slightly more beginner friendly, and more user graphic friendly, compared to Euclid that has a serious and high-end approach.

Fir Audio VxV vs Unique Melody MEST MK2 (999 USD vs 1500 USD) - Unique Melody really knows how to deliver performance and price / performance, since their 3D Terminator IEMS are some of the best selling IEMs ever created, but VxV and MEST MK2 are closer to each other, for comparisons. The general comfort is slightly better on VxV, especially as they are smaller with almost 30%, compared to MEST MK2. The fit is considerably more important on MEST MK2, and they work best with Azla Xelastec tips, where VxV are less sensitive to tip rolling (no IEM will be zero sensitive to tips type and quality, but some are really sensitive to tips quality). The overall presentation is considerably more V-Shaped on Mest MK2, where it has a fuller, more midrange forward kind of sound on VxV. I actually think this is one of those situations where I would generally grab MEST MK2 for rock and metal, but VxV is more versatile, especially when the music was not recorded very well. MEST MK2 tends to apply their sonic signature to music a bit more, where VxV tends to color sound less. MEST MK2 has more sub bass and more treble, where VxV has a fuller sound, less

Fir Audio VxV vs Campfire Ara (999 USD vs 1300 USD) - The price difference between Ara and VxV is somewhat significant by the point we review their comparison, as ara is about 40% more pricey than VxV. The comfort is great on both, and both are really nicely made, with good build quality, but the default cable on VxV is slightly better than that Campfire uses by default with their IEMS (especially as Fir Audio makes Balanced cables an option). The overall sonics are more natural on VxV, with a more versatile, fuller, and more warm presentation. Ara tends to draw more details from music, but it can end up being slightly more fatiguing, especially if you're sensitive to treble sparkle and strong top end. The bass is comparable between them, VxV has a somewhat slower bass note presentation, where Ara tends to be quicker, but has more sub bass quantity, less mid bass. VxV has a more forward midrange, with more emphasis on a perfect tonality, and fullness of voices, where Ara tends to present details more fiercely, the same way Dita Fidelity does, VxV having more of Dita Fealty DNA in their sonic presentation. The treble is stronger, more resolving and also potentially more fatiguing on Ara, where VxV goes with a really natural, clean and safe treble that's versatile and which I can enjoy regardless of how tired I am.



Fir Audio VxV + Detonray DTR1+ Prelude (999 USD vs 1000 USD) - It always seems like DTR1+ does something to IEMS, because it seems to have some kind of adaptive output impedance, always changing its signature depending on what it is being paired with. VxV is one of those IEMs that sounds really engaging, dynamic and punchy, but also really colorful with DTR1+. Somehow, they tend to be natural and well balanced with most sources, but DTR1+ brings the most sparkle, most dynamics and overall color in the sound of VxV, giving them a really detailed, clean, yet active and peppy sound.

Fir Audio VxV + Astell & Kern SE180 (999 USD vs 1500 USD) - SE180 brings a sweeter, fuller sound to VxV, making them really smooth in the treble, yet interesting and engaging. You mainly explore your main music library with SE180, but I found that this is what I prefer to do with most DAPs, as Streaming services never have all of my hipster bands, so once I got a microSD full of music, SE180 is the perfect source to drive the VxV. The background is especially silent, and SE180 is one of the most silent sources you can find on the market, plus one of the fullest, deepest and most impactful ones.

Fir Audio VxV + iBasso DX240 + AMP8MK2 (999 USD vs 950 USD) - This is one of my favorite sources, because the sound is simply sublime. iBasso really knows how to make beautiful sounds out of really normal looking players, and DX240 is one of the best examples of iBasso's finest craftwork. I like the overall dynamics, engagement and the punchiness of this pairing. The midrange in particular is slightly more colorful and sweeter than with most pairings, giving VxV a really well rounded and dynamic presentation. DX240, especially with AMP8 MK2 has one of the best dynamics you can find in a portable music player.

Value and Conclusion

The value of Fir Audio VxV is actually pretty great, and they have a pretty solid position in today's market, despite the diminutive package, and the sparse accessories they come with. The company is the kind of company that will focus considerably more on providing the actual sonic performance to back their products, rather than impressing with their package, so I'm happy to say that for their price, VxV sounds pretty good, natural, and achieve exactly the purpose that Fir Audio set for them.


The sonic performance, excellent build quality, along with Project Perfection PTE LTD from Singapore's support are so nice that I am going to add Fir Audio VxV to Audiophile-Heaven's Hall Of Fame as the best IEM to purchase if you want a really versatile take on the audiophile hobby, and something to sound beautiful regardless of the music, mastering quality, or other conditions, as VxV is invariably enjoyable with all music styles.


At the end of the day, if you're looking for one of the most versatile IEMs ever designed, with a really comfortable fit, high quality chassis and driver technology, support well by the producing company, and sporting unique tech for their sound, Fir Audio VxV is going to spend a lot of time with you, and find a place in your heart, as one of the most natural sounding IEMs ever creating.
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