FiR Xenon 6 (Xe6)

There’s something about Xenon

Pros: Insane bass you can actually feel
Gorgeous IEMs – basically a piece of gold jewelry
An emotional experience the Rn6 can’t replicate
Something different from your usual $3k+ IEM
One of the best for casual listening
Good mids

Cons: Doesn’t do well with critical listening
Scores poorly when analyzed
Bass bleed like crazy into mids
Terrible cable
Non-durable finish
Packaging is consistent with a sub $1k IEM

Xe6 Side.jpg


Up for review today are the “Love It” / “Hate It” FiR Audio Xenon 6 (Xe6) which I purchased used on the Head-Fi classifieds. With these IEMs, you either love their bass or hate their bass – I’m definitely on the “Love It” side of the spectrum, but it likely comes down to what your preferences are. These are FiR Audio’s most expensive IEM currently, but not technically their Flagship IEM anymore if you count the limited-edition Radon 6 (Rn6). The Xe6 does, however, come with gold plating and a stainless steel housing instead of the Rn6’s black aluminum housing. So, again, it comes down to your preference on which you prefer (and if the Rn6 is still available).

Both the Xe6 and Rn6 have the same 6 drivers (thus the 6 in their name) with 1x 10mm Kinetic Bass Dynamic Driver, 2x OpenDriver Balanced Armature Driver for mids, 1x OpenDriver Balanced Armature Driver for high-mids, 1x OpenDriver Balanced Armature Driver for highs (with Sound Reflector), and 1x OpenDriver Electrostatic Driver for ultra-highs. There’s also a ton of cool tech on these that push the envelope of what IEMs can do. The Kinetic Bass alone is worth the price of admission with an almost open-back design for the bass driver sitting inside your ear, which really does help you feel the bass, not just hear it. It’s like being in a live concert – wubwubwubwub.

You also have the ATOM vents which prevent pressure build-up on the ears, and you can adjust the tuning slightly with them as well. Lastly, there are no sound TUBES between the drivers and the earpiece which creates a bigger soundstage. The Xe6 also has sapphire glass face plates with gold fleck and a 1-year warranty. Overall, a very cool design – certainly class-leading in tech.

Xe6 Box.jpg

Accessories/Earpads/Eartips (6/10):

It’s OK. That’s the best I can do here since it comes with almost the exact same stuff as the $999 VxV…at 3x the cost. The box sleeve and box itself are less Magic The Gathering-card-holder box (VxV) and more luxury-watch box, but it’s nothing compared to the Elysium, Trifecta, or Mezzo LE. Inside the box, all you get are several sets of ATOM modules, which are tiny, a tool to remove them, and 4 sets of meh ear tips. I just threw my trusty Spinfit W1s on instead of messing with the stock ones. You get a cool FiR Space Force iron-on patch, though I have no idea why – nothing else really screams Space Force from FiR except for their occasional Space Bunny Logo. Still, a cool patch, but something I’ll never use. Really, that’s it, the bare minimum, which was acceptable on the cheaper VxV, but is unacceptable on the $3,900 Xe6. At least include more ear tips in a separate baggy if not in the case.

Yes, the Xe6 comes with the ATOM venting modules which change the isolation the Xe6 provides. Most people feel the Black module may be the best for the Xe6 – but play around with them and you do you. The Gold module gives you the most isolation (and the most bass) while the Grey is slightly less isolation, and the Black is the least isolation. So, it makes sense why the Black module might be the favorite since it makes the Xe6 the most open back and tames some of the bass. Mine were tested below as they come from the factory – with the Grey module installed. But yes, changing the modules (which is a royal pain by the way) will change your tuning slightly and also increase outside noise – just like the 64 Audio series. 7/10 points here – you can do better FiR. 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:

Xe6 Case.jpg

Cable (3/10):

Ugh. I hate the scorpion cable. It’s actually worse than the Aroma Audio cables – which I also dislike. The scorpion cable, so called due to the shape of the ear hooks looking like a scorpion’s tail, is the most tangly and annoying cable I’ve ever used on an IEM costing almost $4k. It kinks, has memory retention, is poorly braided, has gold accents that dent or scratch easily, and it’s actually worse than the Aroma Jewel cable, though quite similar to the Aroma Thunder cable. At least it’s 4.4mm, so that’s a plus. Still, FiR learned the lesson from this one when they released the Xe6’s brother, the Rn6 with a brand new cable that is one of the BEST I’ve ever encountered on an IEM – and it’s $700 cheaper than the Xe6. So, if you’re planning on getting the Xe6, budget for a better cable if you don’t already have one – at least the scorpion cable sounds good. But, the cable is so bad that FiR doesn’t even mention it on their site under the Xe6 page – it is mentioned under the custom-built cable section, which seems to be a completely different cable. So yeah, get a better cable – 3/10 points.

Xe6 Cable.jpg

Build Quality/Comfort (4/10):

Again, the poor Xe6 loses points here because, despite being made with stainless steel, the gold finish on the IEMs and the cable is extremely easy to scratch with tiny little scratches or even dents (as shown on the cable connector pic, no, I didn’t do that). Almost every single Xe6 out there has tiny little micro-scratches on it. Or, just a bunch of fingerprints because the Xe6 finish picks up fingerprints like an FBI fingerprint kit. I can just see someone getting arrested because the cops were able to pull fingerprints off his Xe6. The Rn6 fixed THIS issue as well with the sleek, durable black coating. Don’t get me wrong, the Xe6 is pretty gorgeous with the sapphire glass faceplate and $10 worth of gold flakes on the faceplates and the gold coloring – it’s just not very durable.

That stainless steel, while providing a nice heft to the IEMs is also one of the biggest complaints of the Xe6. They’re heavy. Tiny, the Xe6 is one of the tiniest IEMs at above $3k, but heavy. For a lot of people, that means they are constantly being pulled out of their ears – a very frustrating feeling. I really didn’t have that issue with the Spinfit W1s, but since a good seal is important to sound quality, I can understand how that would be super annoying. Other than the weight, the Xe6 are very comfortable due to their small size, which is pretty comparable to…every 64 Audio IEM ever since they’re all basically the same size/shape. Again, the Rn6 fixed this issue with an aluminum shell that cut down on weight, making them one of the most comfortable TOTL IEMs out there.

Xe6 Back.jpg


Check out the below. I’m comparing the Xe6 to the Trifecta since I have both on my desk, and I’ve added in the Rn6 FRG as well since I got it after the Xe6 was already out the door. The Trifecta and the Xe6 are not too far off with casual listening and it’s only when critically listening that you can start to pick apart the differences here. Obviously, the Xe6 has more bass, and what the FRG can’t show is the Kinetic Bass response since that speaker sits outside the microphone on the Xe6. So, just imagine that the sub-bass line is closer to 75 than 65 and you’ll get the idea of what the Xe6 really sounds like. Other than that, their lows are pretty similar, with the Xe6 a bit more pronounced. The Trifecta’s upper-mids and highs are almost the exact opposite of the Xe6 and where the Xe6 has pretty neutral highs, the Trifecta looks like a Colorado mountain range. They almost dip and peak in exact opposite places as well. The tests below will attempt to highlight what those differences sound like.

Xe6 Rn6 Trifecta.png

I am powering both off of my HiBy RS8 on the A/B amp (class A doesn’t seem to make much of a difference on IEMs) on Medium gain at around ~38/100 volume. The Trifecta is even easier to power at around 30/100 – both are more efficient than most IEMs, including the cheaper ones. I’m using the 4.4mm balanced port on the HiBy with the stock cables from both. The Xe6 does benefit from an increase in volume, providing a bit more voltage to the drivers. 4/10 points here – it’s already been improved upon.

Lows (15/20):

I’m starting off with the Mid-bass/Sub-bass test I’m using David Guetta’s “I’m Good (Blue).” Damn, that’s some hard-hitting mid-bass, though I can hear that rattle that I get here from bassier IEMs on this song. The sub-bass is intense and gives me that breathtaking feeling I love from bassier headphones – this reminds me a bit of the Aroma Thunder here. While I don’t like that extra rattle (which usually happens on DD bass), and my highest-scoring bass headphones don’t usually have any of it (Rn6), I really enjoy the impact and sub-bass rumble that these provide. It’s definitely a trade-off you either like or don’t like – personally, I don’t want my headphones to sound like a Honda Civic with 10” subs in the back. 8/10 points here – if it weren’t for the rattle, which I only hear if I’m listening for it, these would be a 10.

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. The bass here never overwhelms the mids and prevents you from hearing them, but it definitely can take away from the forward focus of the mids, which should be the primary focus with this song. The bass should be in the background here, but it’s often equal to the mids. So, it can bleed into the mids more than it should. 7/10 points here.

Mids (16/20):

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. Ooh, nice intro clean guitars, with a massive soundstage. The distorted guitars also sound detailed with the high-hats and drums still coming through clearly. The bass guitar can be heard clearly, but it doesn’t overwhelm the vocals. The cymbals don’t get overwhelmed in here and I can appreciate how clean everything is represented, especially on a song that can be overwhelming on cheaper IEMs (and some not cheaper). The guitars can still be heard, but they do feel more in the background than I’d really like in a perfect world. That’s my only complaint here and I really appreciate that there’s no sibilance or sharpness either, which can show up on this song with some IEMs (Trifecta), so 5/6 points.

Staind’s “Something to Remind You” has clean electric guitars and wonderful vocals – this song tests vocal quality and background noise. The guitars are not in the background here at all – they sound really nice with excellent layering and separation while you can clearly hear the detail of the fingers running across the strings in the background on the left side. There are very detailed and full-bodied guitars here and nothing feels distant or thin. The vocals are crisp while maintaining a full presence and focus in the foreground. The bass guitar can hit pretty hard toward the middle of the song, even occasionally overwhelming the mids, but it’s not really noticeable unless you’re looking for it. There’s no unwanted distortion or unpleasantness of any kind here and the Xe6 earns 6/7 points here.

To test classical instruments in the mids, I’m using The Piano Guys’ “Code Name Vivaldi.” The intro cello sounds great and of course, the intro cello-bass is epic. That epic bass really drowns out the mid-strings though and makes the piano hard to hear when the piano is quieter, and the bass-cello is louder. The same goes for the mid-cello, it can get drowned out when the bass-cello is playing at its loudest. While that is a letdown (and admittedly an ongoing theme with these IEMs), the overall song is filled with emotion, power, and clarity. This is why the Rn6 was created – because this bass bleed was the biggest complaint with these IEMs. 5/7 points here.

Highs (16/20):

To test sibilance on headphones I use Panic! At The Disco’s “High Hopes.” There is some sibilance here, but it’s nowhere as bad as the Trifecta, which was brutal. That’s one of those peaks on the Trifecta chart that the Xe6 dips at instead. Overall, this isn’t perfect, but it’s a little above average. 5/7 points here – the rest of the song sounds great.

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.) Surprisingly, the highs can be heard quite clearly over the mids here. It’s not quite up to Trifecta or VxV level, but still really good. You can hear individual cymbal strikes – all while the mids and high-mids still come through well. Yeah, the bass and drums can overwhelm a little at times, but we’ve hit on that on previous songs, so I won’t double tap here – some really impressive highs considering. 6/7 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. There’s a touch of sharpness here, but it’s still far better than some of the sharpest IEMs I’ve heard. 5/7 points – still a good showing from FiR.

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

I use MGMT’s “Time to Pretend” to test soundstage, instrument separation, and imaging. Yeah, you already guessed the Xe6 is going to do well here. Instrument separation is fantastic as long as the bass isn’t going super hard – then it can get a bit blurry (3/3 points). The soundstage feels huge, like Mentor level huge (3/3). Lastly, the imaging is very good also – you really get that 3D feeling from the Xe6, none of this forward 180 degrees feeling like you can get from the Ronin and several other IEMs. There is true immersion on the Xe6, especially with the kinetic bass, which you can really feel. It’s equal to the Multiverse Mentor (at least to me, others disagree – go read their reviews if you care) here and earns the full 10 points.


I think the comparison here to the Trifecta is pretty easy if you’ve read my Trifecta review. The Xe6 has significantly more bass overall, though both can overwhelm a bit on the lows (nothing like tha Fatfreq mini though, ugh). If you want more bass, with less resolution, get the Xe6, if you want cleaner, more detailed bass, grab the Trifecta. You can really feel the bass on the Xe6 though, which is why it’s called kinetic bass – it’s a much more concert/club-like experience than the Trifecta. Both do pretty well with mids, but the Trifecta is the clear winner there with a much more forward mids presence that doesn’t get overwhelmed (it still has one of the highest mids scores I’ve ever given). For highs, it’s a challenge, if you’re sibilance sensitive like me, get the Xe6 as long as you’re cool with the bass. If you’re not sibilance sensitive, and you really love insane highs quality, get the Trifecta, they have some of the best highs I’ve ever heard with no sharpness. Yeah, like all things in life, it’s a trade-off. I prefer the Trifecta’s bass and mids, but I prefer the Xe6’s highs while it bass and mids aren’t far behind the Trifecta’s. You do you Boo.

Oh, yeah, you probably want to know how it compares to the Rn6 huh? OK. The Rn6 has less bass, a MUCH better cable, a better build quality and finish, a Red module (which most people like the most), better mids and highs, no bass bleed, a smaller kinetic bass hole, and is one of the most balanced IEMs I’ve ever heard. It’s probably the highest-scoring IEM I’ve ever reviewed. BUT, and this is a big but (heh), it loses the emotional connection you get from the Xe6. So yeah, the Rn6 is cheaper, limited to 300 units, better built with a really nice cable and an excellent sound – basically perfect – but less special at the same time. *Shrug* get whichever one matches what YOU’RE looking for. Or, get the Trifecta which can do all of the things pretty darn well.

Xe6 Front.jpg


As many previous reviewers have mentioned, the Xe6 is a purely emotional experience. It’s not meant to be broken down and analyzed (like I just did). It’s meant to be listened to and enjoyed with its insanely large soundstage and immersive feeling. Its score can’t reflect how the overall presentation can make you feel – and frankly, it doesn’t deserve a score this low, but that’s how it breaks out when we dissect each individual piece instead of looking at the overall presentation. Yeah, it’s not quite a mids-focused set like the Ronin and Trifecta, and yeah, the lows can bleed into the mids a bit (a lot). But, with really well-balanced highs (that avoid most of the sibilance), fantastic detail and resolution throughout the entire frequency band, and some very compelling bass response – the Xe6 is one of those IEMs that will keep you coming back for more time and time again. There’s something about Xenon.

Headphone Scoring (v3):
Accessories / Earpads / Eartips (10 pts):6​
Cable (10 pts):3​
Build Quality/ Design / Comfort (10 pts):4​
Lows (20 pts):15​
Mids (20 pts):15​
Highs (20 pts):16​
Soundstage / Instrument Separation / Imaging (10 pts):10​


  1. Thank you for this incredible review, I’ve been torn for the last month on what IEM to buy. Been looking at the Empire ears evo because I love bass, but the tuning of the mids had me hesitant. And then I found your review of the Xenon 6 and Radon 6. I was going to get the Radon 6 because of the incredible score you gave it, but then I read the conclusion of your xenon 6 review and it spoke volumes. So I pulled the trigger on it, and as luck would have it I found Eliseaudio had a one off black resin Xenon 6 called black beauty LE. The only one in the world, I knew then it was audio destiny. I am grateful our small community has people as passionate as you about sound. Cheers from Mozambique.

Leave a Reply