64 Audio (1964 Ears) TIA Fourte - Reviews
Pros: Excellent build quality
-Fuss-free fit with supreme comfort
-Well-implemented technological firsts
-Captivating, unique sound signature
-Elite tier resolution and transparency
-Natural, deep-reaching and swift bass
-The most euphoric and splendid treble I’ve ever heard
-Largest soundstage I’ve heard in IEMs
-Stellar imaging and separation
Cons: Price!
-Lacklustre packaging
-Bare-bones accessories
-Polarizing design and color choice
-Uninspired stock cable
-Incoherent sound signature
-Uneven mids tuning
-Sometimes sibilant treble
The journey to the summit of portable audio is fraught with hazards and bad decisions. But once in a while, something comes along that demands your undivided attention, daring you to take the plunge. This is the unraveling of 64 Audio’s finest masterpiece, the tia Fourté.

Ambition. According to an ancient Chinese proverb (ok, a classic Hong Kong film), “without ambition, you are no different than salted fish”. No point dreaming about lofty heights when you’re bathed and baked in sunlight until crispy. But with truckloads of ambition, and some hard work, ingenuity, and luck; even fish, salted or not, can fly.

64 Audio has been the epitome of ambition in the in-ear monitor (IEM) arena. From their humble beginnings as 1964 Ears, they have made an epic journey, even a pilgrimage, to sit amongst the titans of portable audio today. Innovation has always been their forte. Not only do they want your IEMs to look and sound good, they want you to hold a technological marvel in your hands.

They were the first company to adopt ADEL (Ambrose Diaphonic Ear Lens) modules, before coming up with their own apex (Air Pressure EXchange) venting technology. Apex helps reduce pneumatic pressure in the ear canal, which causes ear fatigue. Their crowning achievement, however, are the tia (Tubeless In-ear Audio) drivers.

Tia drivers are opened-up balanced armatures (BAs) that direct sound into the IEM chamber as opposed to conventional sound tubes. They are quite literally, drivers with the lid blown off, or with the roof raised, and bring extra clarity and transparency to the sound. 64 are so proud of them, that they are trickled down to most of their lineup today, like milking a prodigy for all its worth lol.

The Savior of Head-Fi. Would you like to pay by cash or cheque?

Today we look at the flagship that made all 64’s fairy tales come true, the tia Fourté. Introduced in 2016, the Fourté was the culmination of their IEM-crafting knowhow condensed into an aluminium casing the size of a gumball. It has apex, it has tia, it has frequency-shaping acoustic chambers, it has the hopes and tears and fears of their engineers… the whole shebang.

The driver configuration of the Fourté can only be described as Frankenstein-like. It has a dynamic driver for bass, two tia drivers for handling mids and treble, and a conventional BA for high-mid frequencies. It’s a collection of misfits and miscreants not unlike the Fast and Furious dudes, with the united aim of unleashing ultimate sonic fidelity in mind.

Tia Fourté retails for an astronomical $3599 and is available at their official site. Upon release, consumers like me were ready to burn them at the stake for the price tag. But I got hooked after one listen at an audio show, and purchased one used. This wasn’t your usual drivers, crossovers and tubes, it was something completely new, and maybe ahead of its time.

This review was originally featured in Headphonesty.

Really brought out the big guns for testing.

Equipment Used

  • Sony NW-WM1A “K” Modded, FW 2.0
Albums Listened
  • Amber Rubarth – Sessions from the 17th Ward
  • Daft Punk – Random Access Memories
  • Denean – The Weaving
  • Ed Sheeran – X
  • Fleetwood Mac – Rumours
  • Leonard Cohen – You Want it Darker
  • Melissa Menago – Little Crimes
  • Michael Jackson – The Essential
  • Simon and Garfunkel – The Essential
  • Taylor Swift – 1989

Packaging and Accessories

Let’s start off with the most disappointing aspect of the Fourté, the uninspired packaging. If you paid full retail for them on pre-order and received this regular cardboard box with an extremely pedestrian accessory set, I can already imagine the look on your face. And maybe a “chump” stamped across the forehead lol.

For the sake of completeness let’s run down the list of stuff you’re getting: A case (which you might not use), 6 pairs of ear tips (3 pairs foam and 3 pairs silicone in various sizes), cable, shirt clip, cleaning tool, and a uh, sticker. From the retail price, maybe about $100 went to the packaging and accessories. Everything else went to R&D and the earphones themselves, maybe even a retirement fund.

So you feel like you just paid top dollar to get front row seats, only to have a really sweaty guy next to you. Don’t despair, it gets better from here. Even in paradise, there’s bound to be a mud puddle or two.

Threadbare wares, or sparse farce?

Design and Build Quality

The Fourté’s design is polarising from the outset. The immaculate black aluminum shells are cut with precision and sleek to the touch, but the copper faceplate might turn heads for the wrong reasons. Billed as a unique finishing with varying degrees of patina, the orange/green combo has been described as classy or looking like erm, stomach contents, depending on where you stand.

Personally, the design takes getting used to, but as a friend once said, once you put them in your ears, it becomes someone else’s problem.

Things look up for build quality. The earpieces are machined out of a single block of aluminium and feel rock solid. They have to be, since each earpiece contains every new technology 64 Audio has developed so far, including the kitchen sink. The apex modules, tia drivers and so on have to be kept in tip-top shape, and precisely where they are to perform; and the well-built shells allow the components to do their jobs unimpeded.

Of speckles and freckles, and a faceplate subject to heckles.


This is tricky. The stock cable meant for 64 Audio’s higher-end IEMs has a name, and it’s simply called the Premium Cable. Yes, hurrah. While looks can be deceiving, it is an actual upgrade to the conventional Plastics One cable we’re all so used to. The 4-wire Premium Cable looks ordinary as heck, but is made from ultra-low resistance silver-plated copper.

In the sound department I can’t complain. Compared to Plastics One it does deliver a tighter, more disciplined lower end, and better resolution across the board. I just don’t fancy how unremarkable it looks, from the plain-Jane connectors, simple Y-split to the 90-degree 3.5mm jack, it’s as humdrum as it goes. It also tangles like a mofo, so you know I’m not fond of this.

Believe it or not, the cable can actually be purchased separately at $129, with an additional $50 for balanced 2.5mm or 4.4mm jacks. I’m not saying you should buy it, but it is an option, however uninformed. *Cough cough* there are many other aftermarket cables available at this price. *Hint hint*

The cable wasn’t enough to rope me in.

Fit, Isolation and Comfort

Being a specialist of custom IEMs, 64 Audio kind of put themselves in a spot when their flagship product is only available as a universal fit. There were plans to develop a custom version of Fourté; but its unique, pristine sound can only be produced if the acoustic chamber within each earpiece is consistent. A custom version adhering to individual ear shapes and sizes, simply produced too many variances.

So we are stuck with this black thing, like it or not. For the most part, the fit will agree with most ears, since it’s a medium-sized shell without awkward bumps or ridges. It’s a fairly straightforward fit. The weightlessness and smooth edges of the aluminum shells shine through, providing endless, pillow-like (might be an exaggeration) comfort. They’re not bad, just don’t hold your breath for a custom version.

Sound isolation is average. The nozzles are not meant for deep insertion (unless you source your own double-flange or triple-flange ear tips), and the shells are vented to accommodate the dynamic driver. So at best Fourté isolates 80% of outside noise, but you will hear some background humming when taking the train or airplane. Don’t cry dude, we’ve all been there.

Worth its weight in gold, and then some.

Sound Quality

So for something priced at an unholy $3599, and given the lackluster packaging, bare-bones accessories, and passable build quality; you might be wondering where all the money went. It’s high time for the Fourté to prove itself where it matters most. Not the technology, not the gung-ho marketing, but whether it sounds good enough to warrant the asking price, or just an old-fashioned shellacking. With whips.

Overall Sound Signature

Unlike many other flagships which strive for neutrality, tonal accuracy and resolution, Fourté’s presentation is meant to wow you, mouth agape, from the get-go. The tuning is discreetly U-shaped, and somehow uses every trick in the book to maximize air and the impression of space.

On describing the sound, Fourté can do it all. The bass is rumbly and analogue, with authentic, rounded punches. The mids are warm yet sufficiently detailed and textured, never outshone by the magnanimous bass and treble. But the treble, oh my the treble, is a highlight worth savoring over and over again. Kinda like Pringles, because once you pop…

To further up the ante on the wow factor, the playground for this sonic madness is mind-numbingly, soul-crushingly huge. Fourté has the largest and airiest soundstage I’ve ever heard in an IEM. Hearing the sparkly treble and the tremendous soundstage together – I’m drawing religious parallels here – is like having a purpose, or seeing light for the first time. It’s humbling, invigorating, and kinda like Pringles again, but godlier.

Before you press the buy button, here’s an awful truth. The Fourté might be crushed by the weight of its own ambitions. In pursuit of the best everything, it loses marks in coherence. The rounded, organic bass hits sound out of place with the sharp, bright treble, with a contrast that’s jarring. Like the Avengers teaming up for the first time, behaving as individuals rather than a singular, unified team. It’s not unlistenable but does take getting used to.

Listening Conditions

Critical listening was done after 100 hours of burn-in. It’s a used item, but you never know where they’ve been. The previous owner might have undone all the hours of burn-in by listening to music backwards. I’m not paranoid, just superstitious lol.

The main review rig was Sony’s NW-WM1A Walkman modded by Project K with the stock cable. The ear tips of choice were medium-sized Symbio N, which provided the best sound isolation and comfort.

Blooming heck, eh?


While everyone talks about leveling up, Fourté’s bass is all about doubling down. With a single dynamic driver leading the charge, the bass plunges into the abyss and stays around for lasting impact. Sub-bass reach is nigh-on impressive, hitting the lowest of blows so they are both felt and heard. The air-moving sensation is authoritative, physical, and pack a killer wallop!

Notes are smooth and well-rounded, with a hard-hitting attack followed by a rapid, yet unforced decay. Compared to the visceral, bottom-dwelling, bottom-loving sub-bass, the midbass is tamer. They are lean and mean but still bring the slam and punch, like special moves in, uh, Mortal Kombat. The midbass blooms naturally and decays briskly, leaving an abundance of air and cleaning up the stage posthaste.

But even with the warmth and air-moving physicality, Fourté is able to resolve fantastic amounts of bass detail. Layering is astounding, with the high resolution unearthing and revealing oodles of detail, while cleanly separating them. It’s a delight taking in the bass all at once and not hearing a muddled mess.

Overall, it’s a bass that is intricately detailed, yet pulsatingly fun. It spares no effort in starting and maintaining the beat and rhythm of the song, inviting the listener to join in the party. And like a good party guest he never outstays his welcome. Once he’s had his fill, out the door he goes. Like a friend everyone deserves, Fourté’s bass is class all the way.


I am a manly man, and wash my face foolhardily with soap and water. But every now and then when I feel the need to pamper myself, I whip out a fancy foamy facial scrub. The soft, smooth foam contrasts with the rough, granular exfoliants rubbing against my face, creating an unduplicated sensation. Until now.

On one end, the mids are steeped in mellow warmth and organicity, but at the other end unhinged with shrillness and brightness. With the full, rounded bass anchoring the lower end of the signature, the lower mids are full and natural. However, as we ascend toward the upper mids, notes take on a zingy edge, with a grainier texture as they resolve more and more detail.

The mids placement is a step behind the more prominent bass and treble. Note size is just right, never too thin-sounding, while instrument layering is stellar thanks to the airy and detailed mids rendering. The overall timbre is affected by this unique mids presentation, sounding both warm and bright. At best, the mids presentation is distinctive and remarkable; but at its worst, it sounds inconsistent and unnatural.

What it does best, however, is resolve remarkable amounts of detail, with an emphasis on clarity, articulation, and transparency. No detail gets lost here, none at all, as long as you get used to the tone.

Sounds addictive, but the radioactivity is optional.


Growing up in a conservative nation, I abhorred and tolerated censorship in all forms. I yearn to be my own moral police, unbleeping cusswords and lifting black bars so I can see everything in its true form, unaltered and unfiltered. It’s actually because I like to look at jiggly bits, but yeah, freedom and liberty and all that too.

Fourté’s treble is not the most accurate nor truest to life, but resolves detail like there’s no tomorrow. No aspect of the sound, however minuscule or minute, is spared. Everything is laid bare, warts and all. This is thanks to a lower treble peak, and another one at the middle treble, interpreting treble with the highest resolution possible, with a bright slant to the timbre. You’ve never heard sparkles until you’ve heard the Fourté’s sparkle, it’s shining, shimmering, splendid.

Notes are fine but edgy, depicting texture so vivid you can palpate them with your ears. A bountiful amount of air surrounds each note, so they are cleanly separated and easily heard. It’s an ethereal, otherworldly feeling. The ultra resolution does hurt the Fourté when it comes to poorly mastered recordings, you will hear imperfections like studio artifacts, audio feedback, random boops, and blips.

On the flipside, Fourté immerses you into the music like no other, and you swear you can hear pages turning, feet shuffling, and eerie micro-details captured on recordings. But back to the treble, soaring skywards and never looking down. You will be enthralled, captivated and sometimes hurt (it does get sibilant), but if you dare to take the plunge (or rise, more precisely), Fourté will take you on a journey into the unknown, to a whole new world.

Songs about rainbows and what’s on the other side.

Soundstage and Imaging

I’m constantly reminded of the Beatles’ Across the Universe here, because when earthly ideas and virtues aren’t enough anymore, we look to the cosmos. Fourté may well possess the largest and most atmospheric soundstage in IEMs today. It is gobsmackingly massive in width, height and especially depth, like Ben Hur, Star Wars and Gladiator rolled into one.

We’re talking the scale of concert halls and stadia, the epoch of epicness in action. Listening to the Fourté, at times I could’ve sworn someone was calling me from across the room, or a party was going on next door. This is hyperbole, but I’m hyperventilating. The vast expanse and sheer magnitude of the stage dimensions go on and on and on across the… well you get it now.

Imaging is among the elite. Given a huge space to play with, and aided by ungodly amounts of air, notes, and passages are easily dissected and scrutinized, with pinpoint-accurate placement. Despite the size, the stage diffuses naturally and does not sound disjointed one bit. Moreover, the beautiful black background helps in sharpening the imagery further, as notes attack and fade hurriedly into the infinite darkness of space.

Make no mistake, Fourté hit it out of the park here. It traverses the very limits of soundstage and imaging capabilities in an IEM, and threatens to go further. The very definition of epic, it will make a believer out of you.

Keeping things classy like Freddie Blassie.


Jomo Audio Flamenco

Flamenco is an 11BA masterpiece showcasing Jomo Audio’s tuning philosophy in conveying great speed and detail while still sounding melodious and enjoyable. I once called Flamenco “the final word in clarity, detail and resolution“, but that needs rethinking now.

But first, the positives. Flamenco conveys a more realistic timbre than Fourté in mids and treble. Instruments and vocals sound more lifelike despite possessing thinner, speedier notes overall. There’s also a more unified coherence to the sound signature that’s easy to immerse yourself with. Flamenco presents itself as a serious audiophile’s tool, precise and meticulous.

Here’s where it might go downhill for the Flamenco, depending on your preferences. Fourté is, unequivocally, more transparent and extends further, particularly in the treble. Flamenco sounds tame and smooth in comparison, despite being known as a detail monster too. Imagine Flamenco being a window to the music, whereas Fourté removes the window altogether and puts you in the thick of the action.

Thanks to the dynamic driver, Fourté’s bass sounds more natural and visceral compared to Flamenco’s clinical and tight bass. It’s a no contest in the soundstage department too, with Fourté simply dwarfing the modest Flamenco in sheer size and scale. Flamenco might be an imaging masterclass, but Fourté exacts similar imaging precision thanks to the huge soundstage and abundant air carrying each note. All in all, Fourté gets my nod.

Tremble at the sight of the enfants terribles of treble.

Empire Ears Legend X

Fourté and Legend X are two hybrid titans at the height of their powers, with different tuning philosophies. Legend X builds its sound upon a solid, bulletproof low-end, while Fourté ventures skywards with a transparent, treble-focused sound. Both feature elite levels of resolution, balanced with foot-tapping, head-bopping fun.

Legend X wows listeners with the intense, full-bodied and tubthumping bass, in all its grandiose glory. It’s a bass-first signature that doesn’t shy from hitting hard and often. The extension down low and layering ability are unrivalled, Fourté included. However, the bass can be overwhelming, and Fourté provides reprieve with a quicker and tighter bass that satisfies with its measured hits.

Similarly, Fourté has an extraordinary, even preposterous amount of treble extension and sparkle, but can be the sonic equivalent of staring into the sun. Legend X reins it in, providing just enough extension but dials down the excitement levels for a smoother, more involved listen.

In terms of tuning, Fourté is more the risk-taker, like Austin “danger is my middle name” Powers. More intent to awe and surprise the listener with technical wizardry, while Legend X leans on a safer, mellower tuning. Legend X has the upper hand in coherence, timbre and mids tuning, but when Fourté gets it right, dear lord, it absolutely floors you.

The combination of supreme airiness, soundstage size and treble extension masks Fourté’s sonic flaws very well. With the right songs – particularly binaural, EDM, and maybe jazz – it approaches divinity. You shudder because you’ve never heard music presented this way, like they were meant for the ears of celestial beings. Although Legend X seems the saner, safer IEM to own, Fourté is capable of delivering highs like no other.

Brimming with personality, even when left on a rock.

Final Words

If Fourté was a film, it would be a special effects-driven action/fantasy. A visual and aural extravaganza, it would easily win awards in technical departments like sound editing and visual effects. It isn’t a character-driven, triumph-against-all-odds drama that would scoop Best Picture, much like how IEMs with the most accurate timbre consistently get the most accolades.

64 Audio’s tia Fourté, the $3599 mega-flagship, is a hard sell. It has its flaws, that to many will seem unacceptable given the asking price. The wonky timbre and weird incoherence will throw off many a seasoned audio connoisseur. But I implore you to listen before you judge. If ever you get the opportunity to test them, hold on to that chance like the last piece of chocolate in the box, because other people will be gunning for it too.

I remember the first time auditioning them to this day. Fourte’s sound stuck as profoundly as a first kiss, or the best steak of my life. A beautiful, untainted memory. And boy did I crave the inimitable, incredible and magical treble and soundstage. The craving was real. I had withdrawal symptoms wondering how the Fourté might interpret a treble-intensive or particularly atmospheric passage. There were gaping holes in my ears that needed filling, so to speak.

Stick with its lows, and I promise you, dear reader, there are many rewards to be reaped. You’ve never heard anything like the Fourté. The daring, unique tuning and jaw-dropping presentation will hook you in as soon as you press play. I love Fourté irrationally for the way it consistently thrills and surprises me with pomp and bravado at every turn. Maybe it might move you the same way.
Thank you for your suggestion. Unfortunately, there is no effect's dealer in my country :frowning2:
(1 of 2) Phenomenal review, man. Your writing is superb. The analogies you use are extremely tangible and entertaining (nice Aladdin reference,) and I agree with most of them. I demoed the Fourte and U18 concurrently and ultimately purchased the A18t. However, the Fourte's presentation is extremely unique, no doubt.
(2 of 2) Your ability to incorporate and touch upon the undeniable key weaknesses of the fourte (coherence, colored tonality, and at times harsh treble,) and still make me yearn to hear these all over again, now more than ever, is a real testament to the impact of your review.
Pros: Build. Sound.
Cons: Size. Cost
Fourte & Opus2 01.jpg

~::I originally published this on THL. Now I wish to share it with my Head-Fi fellows. Enjoy::~

No disclaimer. I bought this ****er. hehe

64Audio tia Fourté sells for $3,599
10 Ohms @ 1Khz
4-Way Crossover
1x tia High
1X High-Mid
1X tia Mid
1X Dynamic Low
Internal APEX M20


So… Pinky was not searching for a new IEM. I don’t know what I was looking for—maybe nothing—but seeing as I found myself on the Head-Fi Classifieds I imagine a shrink might claim otherwise. The demon was at it again, driving me to the rhythm of insatiable lust. This culminated in a feargasm the likes of which the Earth has never seen when I stumbled upon an ad, selling a B-Stock tia Fourté for $2300.

I knew in my heart I would pay it. Yet dignity demanded that I at least ask for $2000. As I waited for a response, I began the psychological rigmarole of deescalating my hysteria, consoling myself with the reality that these IEMs were almost certainly sold. The price is too good, and Fourté is a goddamn hotcake. No way a deal hasn’t already been struck.

Then I heard back from him. $2000 was too low, but could I do $2200? I hemmed and hawed and said you bet your ****ing ass I can!

It turns out I was right; this was a hot-ticket item. Folk were offering him much more than his asking price. But it also turns out he knew me and liked my reviews. Though I suspect what really synched the deal was the most serendipitous aspect of it all: We both live in Kansas City. In fact, we made the hand-off in the parking lot where I work, mere moments after I clocked out for the day.

Words cannot express how unlikely all this is. The Mid-West is a dry-zone for audiophiles. There are no high-end stores in which to audition prospective buys. Indeed, this was the first time ever I got to listen to something before I sent payment.

It took less than five minutes of Fourté in my ears before I said, “**** yes! I’ll buy it!”

Unboxing 01.jpg
Unboxing 02.jpg
Unboxing 04.jpg
And here we are. I’ve enjoyed tia Fourté for over a month now… maybe two. Hard to keep track. My impressions of it have changed some over that time, but for the most part, it is as I originally knew it. But we mustn’t get into all that just now. Let’s talk about build, first.

You could be forgiven for thinking Fourté is ugly. It looks particularly bad in the photos. In person, I find it less offensive. Part of that is due to the obvious quality of its construction. Solid black aluminum housing, and textured faceplates. Color scheme aside, it’s a fine piece and looks and feels upscale.

The only thing that makes these B-Stock is a subtle double-stamp of the name on the inside shell. And for that, I saved $1,400.

B-Stock Defect.jpg
These are fairly large IEMs. Not JHAudio large, but still. They’re certainly bigger than my U12, which is hilarious, considering how many more drivers U12 contains. But I’m not complaining. The acoustic chambers Fourté uses may take up space, but the sound they deliver is well worth the sacrifice. I may not feel that way if they were much bigger. As it stands, these monitors fit rather comfortably, and don’t stick out much. Actually, it’s only on my left side they stick out at all. Nice and flush on the right. They isolate quite well, given the APEX tech and the Dynamic venting port. I’d say they’re about as good at blocking out environmental noise as most universal multi BA IEMs.

APEX port.jpg
tia Driver.jpg
tia Fourté showcases two tia drivers. One for the upper frequencies, which 64Audio is calling the tia High Driver, and incorporated into their A18 co-flagship. What the A18 does not have, however, is Fourté’s tia Mid Driver. Just wait till you hear that crap! Fourté is also unique among 64’s lineup due to the Dynamic Driver dedicated to bass response. Then, just for kicks, they threw in a single traditional Balanced Armature for the High-Mid crossover. So let’s recap: That’s a 4-Way driver config, but a 3-Way hybrid. A mother****ing hybrid using three different driver technologies.

This is officially the Frankenstein IEM.

As is my twisted habit, I refused to even look at the included ear tips. JVC Spiral Dots worked great, as always. But it was the MandarinEs Symbio W that won a permanent position on these lordly earphones. They simply stay in better than all others, and make a more lasting, complete seal.

If you’re familiar with the traditional 2-pin stock cable that comes with most high-end IEMs, Fourté’s cable is a step up. It’s sturdier, thicker, and has an altogether nicer feel. But even that wasn’t enough for me. The moment I got home with this baby, off went the stock cable and on went one of my custom jobbies. I have a number of nicer cords terminated for 2.5mm TRRS, so I can use the balanced output on my DAPs. I shall include a cable-pairing section towards the end of the article, to give you some sweet options.

It comes with a carry case and tips, cleaners, and other random accessories, blah, blah, blah… NO ONE CARES! Let’s move on to sound. Next page, please.

Fourte & Opus2 03.jpg
The 64Audio tia Fourté is heaven on earth. To say these are airy doesn’t cover it by half. The emphasis on upper treble, combined with the sheer audacity of its extension, blows the roof wide open, letting in unimaginable air and height. Reference seems the aim here, with a rather flat line of superb tuning. This is not usually to my tastes, as I’m more of a warmth fiend. Fourté, however, won me the **** over. In spite of an abundance of clarity and treble, Fourté renders a remarkably smooth signature. It doesn’t hit you with harsh spikes; it progresses upward with a linear stroll that seems to go on for hours with nothing but a gentle hump at the higher frequencies for that little extra magic.

That’s right, tia Fourté is magical. Not to mention, energetic. They give the impression of a perpetual explosion of sorcerous power somehow contained by older and wiser spellwork. Every note releases like a solar flare from the sun’s fusion furnaces and vanishes just as quick. If that containment field were to weaken, we’d all die instantly. Details are presented with excitement and a level of resolution that will slake anyone’s hunger for technical brilliance. Yet there is a restraint at play which keeps things from getting too aggressive or violent. It’s an artful balance.

Fourte & Opus2 02.jpg
64Audio’s tia High technology is one of those things you know you’re hearing from the first few notes of whatever song you play. It doesn’t sound like anything else. The closest contemporary it has is Campfire Audio’s TAEC system, and even that fails to match the grandeur of Fourté’s treble. TAEC sounds big, but also queerly sweet and thick. It can come off rather unnatural. tia, however, is airy, thin, and ethereal, and shimmers in a most free and effortless manner. Of course, to be considered truly natural, I believe treble ought to possess a good measure of warmth. Fourté’s upper range does not contain any real warmth. I wouldn’t call it cold, however. There’s far too much life in there for such a cadaverous description. No, it’s just bright. The overall signature is not bright, but the treble certainly is. No way around it. While this is not, strictly speaking, a natural tone, it is where most of Fourté’s magic comes from. The tia High driver brings every instrument into vivid relief, and produces more of those overtones than we usually get to hear in IEMs… or even headphones, for that matter.

tia’s improbable extension also fills the stage with class-leading air and atmosphere. This adds an organic touch to the proceedings which invokes a naturalness the tuning alone fails to capture. It’s a give and take which culminates in a thoroughly engaging, hyper-real experience. “Hyper-real” meaning “more than real.” tia Fourté is a fantasy. It aims for reference, yet overshoots, landing in Narnia. Its ability to reveal and expose goes beyond great. We’re approaching HD800 territory here, with nearly the same penchant for resolving an image. Beware, though! If you’re shy of treble, these may put you off.

Clarity and transparency of the highest order are the defining traits of Fourté’s mid-range. It is a cliché to talk about how a new headphone makes it sound like the artist is in the same room with you… but sweet Jesus these do sound like that. These are the best IEM’s I’ve come across at removing the veils between you and the music. It just sounds so… naked. Fourté comes dangerously close to HD800’s level of transparency. It’s so good at this some may come away from an audition feeling the mids were thin. I think that’s the wrong term. While vocals may not seem thick or particularly warm, they are not really thin. Freakishly clear, yes, but not thin.

Perhaps part of the reason they avoid weakness is the sheer power and dynamism on display. They transcend the normal pitfalls of super clear tuning. Fourté’s vocals possess weight and authority without the orthodoxy of thickness and warmth. Could this be a characteristic of the tia-Mid Driver? Don’t know. What I can say is I don’t crave the lusher tuning of my old favorites.

tia Fourté’s mids are crazy neutral. I would not say there is any inherent warmth in them, nor any coldness. Both male and female voices sound vivacious and alive. Melissa Menago sings her songs with a warm, sweet, and airy tonality. Warmth exists because she brings it. Patricia Barber, however, sounds thinner, airier, with a very natural brightness. When David Draiman sings The Sound of Silence, you get all the depth and richness of his lower key opening, and when the song shifts upward, he sounds smooth and angelic. Fourté recreates it all truthfully. No range suffers or sounds anything less than… real.

Fourte 03.jpg
The hyper-realism is helped along to greater heights by Fourté’s stellar resolution. Again I’m reminded of the HD800 here. You can hear the subtlest of breaths, and the wetness of a singer’s tongue. The precise location of each guitar string… hell, even the individual vibrations of the string off the frets. Okay, I might exaggerate some, but not by much. tia Fourté is the best I’ve found at rendering these things.

My review so far probably reads like rotten hype. So let’s talk about Fourté’s weakest feature: Bass. And really, the “weakness” I speak of is just about personal preference. You see, I like a demon in my sonic basement. I want to feel a little overwhelmed by that darkenss. Fourté fails to accomplish this. Which is a damn shame, as it’s packing the perfect weapon for the job; a Dynamic Driver can kill a man with awesome. And in fact, I can Equalize Fourté to do just that. Which goes to show how under-utilized it currently is.

Fourté’s low-end is not really tuned light. From a certain perspective, it’s quite appropriate. Very neutral. I’m sure a great many purists want it just the way it is. Sub-bass is raised over mid-bass, making for a clean, tight presentation. That sub-bass delves to some exquisite lows, too, rumbling where you feel it more than hear it. Kicks land with decisive impact, visceral and honest. The amount of detail and texture Fourté conveys is right up there with the best of them.

Bass notes sound organic, but a little dry. By its nature, bass is a warm tone, yet Fourté fights to keep that under control. Undoubtedly this aids Fourté’s technical brilliance, but it also robs you of a little musicality. A major benefit of this profile, and the splendid treble extension, is how much air imbues even the lows. They are more a part of the stage than is often the case, existing beside the other instruments, instead of merely permeating the atmosphere. Again, we see that give and take. The result manages to give me a cohesive, satisfying experience, in spite of how my bias leans towards that bassier sound.

Speaking of cohesive… that’s a great way to describe the soundstage. It’s massive, but in every direction. tia Fourté creates a cube to live in, but a very big cube whose boundaries lie beyond the head. The elements on this stage are fairly large as well. Voices are front and center and in your face. Instruments are placed all around the singer in a spacious manner, though not exaggeratedly stretched-out. The musicians are arrayed naturally, not forced to opposite ends of a super wide stage. It feels so… cohesive. Imaging is utterly without fault, both horizontally and in terms of depth. Fourté is the king of holographic earphones, illustrating the space between layers better than anyone else. It’s so bloody good, this might just be its most impressive skill.

Fourte & M3s 01.jpg
Pitting this against my old favorite, the 64Audio U12 ($1,599, Review HERE), the first thing which stands out is the loss of vibrancy and clarity. The U12 is much warmer, and thicker, but this comes at a cost. Fourté’s mids are phenomenally transparent, with a level of detail and resolution that U12 pales before. You feel that immediately. There’s a wooly impression when comparing against such clarity. U12 is one of the warmest IEMs in the TOTL category, and while Fourté is nowhere near as warm, it does not come off cold or analytical. But there is so much weight in U12’s mid range, that Fourté can feel light. This is really only felt when switching from one to the other. After just a few short minutes of listening to tia Fourté, you hear there really is nothing thin or hollow about it’s mids. Vocals are utterly naked with Fourté, and they seem to be quite clothed with U12. The U12 is lush, and sinfully smooth. Fourté renders as though they are literally there in the same room as you. Frightfully realistic.

The U12’s bass is hard to beat. It’s hands-down the closest I’ve heard any Balanced Armature setup come to mimicking a good dynamic driver. Sadly for U12, tia Fourté packs just such a weapon for its low-end. Fourté’s bass delves deeper and strikes with more visceral impact… in spite of U12’s greater quantity. Indeed, U12 has significantly more bass, a sort of ever-present bass that enriches everything, adding tremendous warmth. Its mid-bass, especially, is good and fat. But this carries with it the consequence of bass-bleed, which clouds the vocals. Fourté wields a much cleaner sub-section, with no noticeable bleed. It’s also shockingly quick and articulate, which is more commonly the province of good BA drivers. U12 actually sounds slower and looser in comparison. And Fourté, somehow, manages better resolution and texturing. I know! It’s bizarre!

Nothing quite separates these two IEMs more than their take on treble. Yet oddly enough, they both execute their highs in such a manner that you may need some time to adjust to it before you fall for them completely. They come at it from opposite extremes, though. U12 is hushed in the high frequencies, mixing them lower in volume than any other part of the spectrum. Whereas tia Fourté is rather aggressive up top. I haven’t seen a graph, but it wouldn’t surprise me if the treble is given a little more volume than the rest. Certainly parts of it must. U12 possesses profoundly smooth, non-fatiguing treble. It’s warm and laid-back, with no real sparkle to speak of. tia Fourté sparkles better than any IEM out there. There’s nothing laid-back about it, either; it has serious energy that makes everything pop. Yet both earphones do share nice extension, though Fourté reaches much higher. The tia drivers kill U12 with detail, which doesn’t utilize its standard BAs as wisely as other TOTLs. U12 lacks a lot of air when listened against Fourté, who sounds so big and open, and has such great light up top that every note is under its own spotlight.

Fourte 02.jpg
Soundstage goes to Fourté: It’s a little wider, much taller, and unfair in its representation of depth. And since U12 is one of the very best in this category, what Fourté accomplishes is no mean feat. Both are very, very good at imaging, but Fourté has superior separation and layering. It renders the space between elements so much better than U12. The major contributing factor to this is tia Fourté’s impossibly high resolution. It’s quite a few steps above the U12. As is transparency. Fourté is simply so far ahead of the game in this regard the comparison feels like a sham.

Noble Audio Kaiser Encore ($1,850, Review HERE) is a kindred spirit to Fourté. In fact, I think of tia Fourté as Encore Ultra. Everything Encore does, Fourté does better. Encore’s mids are super detailed, wildly transparent, and anything but thick. Fourté has greater detail, is more transparent, and even airier. They’re both vivid and remarkably natural, but Fourté explodes with superior energy, sounding more vibrant. Encore has a little extra note weight and feels more grounded because of it. Whereas Fourté seems unable to do anything but soar through the heavens. While this is glorious, it does lack a certain tangibility.

Bass is tuned the same between these two, with leaner mid-bass and good, deep sub-bass. Encore is fast, detailed and textured… and so is Fourté. However, Fourté owns the Dynamic Driver, and therefore the more impactful, natural quality. In truth, due to the way it’s tuned, Fourté’s Dynamic Drive is more like a Balanced Armature than most hybrids I’ve heard. So the difference between these two IEMs is less than one might expect.

Treble is again tuned the same. It gives brightness, air, and great detail. The linear extension is very much alike. Both are capable of irritating those who fear treble, but are not inherently harsh. The main difference is found in Fourté’s tia-High Driver. That crap takes what Encore is doing and goes ****ing pro. Those highs open up and breathe like no other IEM; they shimmer and decay in a freer, more effervescent fashion. It’s like being led, floor by floor, to the top of a grand building by the eccentric owner. The madcap display thus far has thoroughly wowed you, only to learn you have yet to see the penthouse. Indeed, the frivolities have only just begun.

As for soundstage, Encore is one of the widest performers on the market. Its depth is pretty good, but height is not a goal here. Fourté is a little wider, significantly deeper, and oh so very tall. The resulting sound is just bigger… bigger in every way. Imaging is about the same, both possessing serious gift. Yet because of Fourté’s depth, you can place an object with even greater accuracy along that axis. Resolution… Encore is really ****ing good. Fourté is a step above. The same is true for transparency. Encore was the most transparent earphone I’d experienced, until Fourté blew it out of the water. Again, I’m exaggerating. They are quite close. But there’s no denying which is better.

I’m borrowing the Empire Ears Zeus XR ($2,399) from a friend. subguy812 over on Head-Fi was kind enough to loan his universals to me for the purpose of this comparison.

Right off the bat, I’m struck by how little bass these have. And I thought Encore and Fourté were a little light down below for my tastes. Even using the X setting, which is the warmer, more vibrant configuration, Zeus’s bass fails to bring a smile to my face. When listening to Black Sabbath’s fist album, the bass is jacked up to a quantity that sounds pretty good, yet still doesn’t do anything truly special. This is that unapologetic Balanced Armature Bass: Fast and textured, but soft, and lacking visceral attack. The exact opposite of Fourté’s Dynamic. To my ears, I’m hearing more mid-bass than sub-bass. In fact, I’m hearing very little sub-bass. It’s there… a bit. Enough to get some low rumbles. But I’m not feeling it like I should.

Zeus is known for its mid-forward “special” vocals. I can understand why. They have remarkable note weight and definition, though aren’t enormous on the stage. Maybe that’s because the stage itself is more intimate than any of the other IEMs mentioned in this review. Zeus’s vocals are warmer than Fourté’s, and less transparent. Zeus sounds more physical, while Fourté tends towards the ethereal. It’s like Zeus brings the music to you, while Fourté lifts you up into the heavens. They both feel like you’re there, just through vastly different philosophies. Zeus has good air in the mids, but Fourté outdoes it with ease.

Zeus’s treble is warmer than Fourté’s. There’s very little brightness to it. It’s rather natural. Extension is most excellent, though not quite on tia level. There’s great air and realistic sparkle and decay. Fourté is brighter, more energetic, but less organic. Zeus is detailed and revealing, but Fourté pops more and has better vibrancy. The highs on Zeus give you a darker, warmer presentation. Oddly enough, this makes for less blackness in the background compared to Fourté.

Soundstage is quite a bit smaller on all axes, staying well within the bounds of your human head. More intimate, less grand. Imaging, like in all the TOTL IEM’s I’ve talked about, is the very example of perfection. Resolution and transparency are indeed wonderful, but I would give the edge to Encore, with Fourté outpacing them both. Where Zeus really gives Fourté a run for its money is layering and dimensionality. Zeus renders a marvelous 3D image, better than just about any other… except Fourté, who honestly takes it that extra mile further.

Fourte 01.jpg
As promised, here are some cable options to pair with tia Fourté.

plusSound X-Series GPC Litz: The most naked, transparent cable I’ve found. This is what I use when I am comparing IEMs, as it gives what I consider to be the truest, most natural tone. There’s a touch of warmth and a little extra body. The treble is warmed ever so slightly, which is very nice for the likes of Encore and Fourté.

Effect Audio Thor Silver II: The unusual silver. This one smoothes out the highs and attenuates them to some extent. It creates a bizarre liquidity, flowing around you in a dizzying three-dimensional display. The power of Fourté only amplifies this, taking you into Wonderland territory. When you finally gain your feet, it’s like listening to whole new gear. Fourté seems to mimic the traits of the LCD-2 with this cable.

Effect Audio Leonidas: Take the liquidity and 3D holographic qualities of Thor II, increase transparency and treble clarity, thicken the bass and warm the mids, and you’ll have some idea what Leo is about. But you won’t be prepared for the apocalyptic musicality. If Fourté is a fantasy, Leonidas twists it into a fever dream. This is my favorite way to listen to these earphones.

Ordinarily I would suggest pairing a brighter monitor with a warmer source. And I guess I still do. But I’ll be honest with you, nothing I’ve thrown at Fourté has sounded bad. On the contrary, it’s all sounded so very, very good.

Fourte & Opus2 04.jpg
My main DAP is the Opus#2 by theBit ($1,149, Review HERE). With neutral-warm tuning, immense soundstage, and the ability to resolve at the highest level, Opus reveals the truth of the transducer like none other. Fourté is at its most transparent and realistic here. Dimensionality deepens, and layers become more observable. Notes take on extra weight, feeling properly tangible, and the background is pitch black. No hissing whatsoever. In simple terms, Opus#2 pushes tia Fourté to its limits.

I’ve been testing out a preproduction unit of Cayin’s soon-to-be-released N5 2nd Gen, the N5II. This player sounds so good with everything, and Fourté is no exception. It’s maybe a little less warm than the Opus#2, but still organic and musical. Clarity and resolution is top shelf, and soundstage is quite big. The N5II is dynamic, vivid, and refined to a fabulous degree. Even though it nudges Fourté a little more into the bright category, it remains free of all harshness or fatiguing elements. This device also gives off no audible hiss. After many days of sessions that lasted hours, I can say the N5II>tia Fourté is sonically flawless and a system anyone should feel proud to own.

Fourte & N5II 01.jpg
Fourte & M3s 02.jpg
If you’re looking for something a little closer to the budget-range—and after buying these IEMs, I can understand why—I can recommend the Shanling M3s. Tuning wise, it’s more like the N5II than the Opus#2. A slightly brighter sound, though not really bright per say, and definitely not cold. The M3s has leaner notes than the others and a slightly smaller soundstage. Like the N5II, it is clean and astonishingly smooth. Compared to the other DAPs, Fourté lacks just the barest amount of depth and resolution on the M3s, but the final result is like supreme honey on the ears.

Fourte & Thor II 01.jpg
Prior to Fourté, my favorite IEM was the 64Audio U12. I bought that one used as well. It fed my spirit better than any other IEM or headphone. Even the technically superior Encore couldn’t fully steal my heart from the bassy lushness of the U12. So when I tell you I sold the U12 after a couple of weeks with Fourté, try and understand what that means. Despite my sonic preference leaning towards the U12’s tuning, tia Fourté so outclasses it, I simply had no use for the U12 any longer. Whenever I put them in, I felt like I was listening through a blanket and missing out on all the details. I just couldn’t go back, even for a single prolonged session. So I sold my beloved U12, to help pay down the charges incurred by this insane purchase.

Do I miss it? Yes. But there are other ventures on the horizon. And Fourté’s magic is such that one must surely forget past loves whilst enthralled by this new pinnacle of personal audio. I should never have imagined parting ways with the U12 before tia Fourté came along and raised the bar so very high. Now, I can hardly imagine going back. tia Fourté defies preference and taste and simply decimates you with pure awesome. It dwells somewhere between the Audeze LCD-2 and the Sennheiser HD800, as a sort of best of both worlds paradigm. If that sounds like biased hyperbole, you’re probably right. Pinky has been compromised. I don’t know how to talk about these IEMs without going too far. That’s what happens when you find your new ultimate favorite audio gear. Restraint, objectivity, and measured sentiment, go out the bloody window. You are in love, and only the poets can guide you from here.



Pros: expanded soundstage, deep analog textured bass, revealing mids/treble supercharged by TIA drivers, custom storage case, quality stock cable.
Cons: price, non-replaceable internal apex, universal-fit only.

The product was provided to me free of charge for the review purpose in exchange for my honest opinion. The review was originally posted on my blog, and now I would like to share it with all my readers on head-fi.

Manufacturer website: 64 Audio.


It's common to see companies release their new flagship IEMs either once a year or every other year because it takes a lot of research and development time for manufacturers to come up with something new and original to make their product stand out from the crowd. Likewise, it usually takes audiophiles longer to research and to compare available flagships before narrowing it down to their next TOTL purchase. On rare occasions, this process can get even more complicated if a manufacturer offers more than one flagship, exactly what happened when 64 Audio revealed new TIA driver tech and introduced two new models: U18 Tzar and TIA Fourte.

One might think, choosing between 18xBA drivers and 4-way hybrid is an easy task, but you will be surprised. After reviewing U18, which still impresses me every day I use it, now it’s time to look at its sibling that shares the same DNA. Though Fourte has a different driver config, it still features TIA drivers, built-in apex module, tubeless design, and acoustic chambers. Since I already shared my thoughts about 64 Audio flagship iem pricing in U18 review, I’m not going to rehash that topic. Instead, I will focus on how Fourte compares to U18 and other flagships, and how it pairs up with different sources (along with unboxing and accessories sections which are partially recycled from U18 review). So, let’s take a closer look!


Like U18, Fourte arrived in a larger box, bigger than a compact packaging I got used to with other 64 Audio IEMs I have reviewed. Their previous packaging box was about the size of their new custom travel case used with different A/U models. Here, 64 Audio decided to do something different, giving the box more room to showcase a glossy, nearly 3D hi-res image of TIA Fourte shells popping out of the sleeve cover wrapped around the main box. When you flip it over, you get a lot of detailed info about Fourte with a CAD drawing of the inner guts, the philosophy behind the design and the sound, and the spec in thumb images with a corresponding description. Furthermore, there is info about 64 Audio’s TIA technology, covering open balanced armature driver design, and a detailed description of the inner shell, driver placement, and tubeless design. You will also find the info about their new cable and the description of apex tech.

I always say, this is a type of packaging you would expect to see on the shelves of traditional brick-and-mortar shops, reminiscent of the days when people used to go to the actual store to browse the isles, to read what's on the cover, to learn about the product before making a purchase decision. Obviously, you can't go to your local Best Buy to pick up a pair of 64 Audio IEMs, but I do appreciate the effort put into the packaging design and can see owners proudly showcasing it on their desk at home.

With a packaging sleeve off, you are looking at a black cardboard box with a magnetic latch front cover which has a glossy 64 Audio logo, also in black. After you flip the cover open, you can read a personal message from Vitaliy Belonozhko, founder and CTO of 64 Audio, with a Thank You note at the end of the message. Inside of the box you have a foam cutout securely housing Fourte shells with an attached cable, 64 Audio custom travel case inside of another secure cutout opening, and a small cardboard tray with 6 pairs of eartips.

Overall, it was a satisfying unboxing experience, and I was able to read about the product without going on manufacturer webpage.





TIA Fourte arrived with a handful of different eartips. Here you will find two sets with 3 pairs (S/M/L) of foam eartips, and 3 pairs (S/M/L) of generic silicone eartips. Choosing the right eartip is a matter of a personal preference which going to affect not only the fit and the comfort, but also the sound. For me personally, I have dozens of other spare eartips and usually take my time to tip roll, to find the right one with the best seal, making sure I get the full doze of the bass! I didn't find any of the included ones to work well with my ears, so I end up using a pair from my private stash. I do wish 64 Audio would include a better selection of eartips, maybe another set with hybrid silicone tips that have a firmer cap and a longer stem.

Other included accessories were a custom storage case which I'm going to talk about next, 64 Audio round sticker, and a product manual with some useful info about the fit, care & maintenance, handling detachable cable and apex modules, and volume advisory. Inside the storage case you will find a small dehumidifier, cleaning tool, and a shirt clip.


The storage case.

In my previous 64 Audio reviews, I referred to their new case as a “VIP case”. Everything from an easy to handle wide latch to an air valve eliminating build-up of inner case pressure when you close it, individual earpiece storage sections with removable rubber lining to a custom built-in cable winder, a spot to plug right angled headphone connector and to place the included round dehumidifier container, as well as a built-in organizer to hold securely a shirt clip (included), and a cleaning tool (included) – all this was custom tailored and well thought of. There is even enough room if you decide to use a thicker replacement cable. Since this is universal case to accommodate other 64 Audio IEMs, there was also a placeholder for 2 sets of apex modules (M15/M20), but none were included since Fourte's apex technology is built-in and not replaceable.

When you are placing the order, you can also specify if you want your name to be etched on the top of the storage box to personalize it. While many companies use off the shelf Pelican or Otterbox storage cases with a pre-cut foam inserts, 64 Audio went one step further with their own custom designed case which protects your investment and keeps everything organized inside.



Many IEM manufacturers are starting to pay more attention to included cables, and lately I noticed quite a few releases with other than cheap OFC stock cables. Not everybody has a collection of aftermarket cables, and some people don’t realize that a metal conductor can have an influence on the sound of IEM. Just like we go through eartip rolling (with universal IEMs) to finetune the sound, you can do the same with cables. Here 64 Audio did their own homework, testing various wires to settle on a new SPC (silver plated copper) cable they include standard with A/U18 and TIA Fourte. TIA drivers can give you super revealing details which can be masked by OFC cable or turn grainy with silver or other exotic wires. Also, considering all SPC cables are not the same, I found this new 64 Audio cable to have sound characteristic closer to pure copper cable. I will talk more about its sound property in the follow-up aftermarket cable shootout.

As far as the cable goes, it feels very durable and still flexible enough without springy memory effect. It has 4 separate conductors, all inner-twisted, with a tight rubbery black shielding, and no microphonics effect. The headphones plug is a premium gold plated 3.5mm TRS right-angled by Neutrik which has a built-in rubber-boot strain relief. This is a single ended TRS plug, but since you have 4 separate conductors, if you’re up to a challenge you can try to re-terminate it to a balanced connector. The y-splitter is a common heat-shrink tube, nothing fancy, and the chin-slider is a clear oval piece with enough friction to keep it from sliding freely. Toward the earpiece connectors, you have a memory wire which you pre-shape for comfort. I’m not a big fan of memory wires, but this one works fine and felt secure. The 2pin connector is universal which can be used in both surface and recessed 2pin shell sockets, and it’s conveniently color-coded with a Red dot for the Right side and a Blue dot for the Left side.


Aftermarket cables.

I'm a cable believer because I hear the difference, either a subtle or a more pronounced, and I have mentioned in many of my other reviews that intent of my testing with different cables is not to stir up a controversy, but rather to share my experience of what I hear. Feel free to skip this section if the talk about cables offends you. In this test, I analyzed Fourte and compared various cables to 64 Audio stock SPC cable. I did volume match by ear because many of these multi-conductor thicker cables have lower impedance which usually result in a louder sound that could be misleading when analyzing and comparing to a stock cable. Last, but not least, I hear the changes but nothing is night'n'day. Cable doesn't function like an EQ to drastically change the sound, but I hear a noticeable refinement of the sound, described below.

SPC to 1960 2wire - soundstage is a little wider, close to U18 now, bass is similar, just with a little better definition, and mids are pulled back a little bit, making the sound more balanced, also treble is a little smoother. This is by far my favorite pair up with Fourte since it takes just a little edge off the upper frequencies and balances out the sound.

SPC to 1960 4wire - soundstage is wider, sub-bass has a little less rumble, mids are still a little forward, revealing, micro-detailed, but a touch smoother, and treble is still crisp and airy. Overall sound is a little more coherent, but still on a brighter side.

SPC to Thor II+ - soundstage is a little wider, sub-bass is similar, while mid-bass has a little more impact now, mids are still a little more forward, revealing, but a touch smoother. Treble is the same. Sound sig is a little more balanced now.

SPC to Lionheart Psquare - soundstage is wider, maybe even a touch wider than U18, bass is very similar, and while mids are still a little more forward and as revealing and analytical, they are a touch smoother. Treble is the same.

SPC to TWau - soundstage is a little wider, bass is a little bit tighter, mids are still a little forward, but now also a treble pushed a little forward as well.

SPC to Ref8 - soundstage is a little wider, bass is very similar though has a touch more sub-bass rumble, mids are still a little forward, and treble a little crisper now.



There are a lot of similarities between Fourte and U18 when it comes to their exterior shell design. Both have a similar shape, machined out of a solid piece of aluminum, slick and durable anodized aluminum shell with rounded corners, a smooth finish, and a copper faceplate with a patina inlay. While U18 shell has a slightly "aged" red shell finish and a faceplate inlay with reddish details, Fourte shell is black with a faceplate inlay that has darker colors with green touches. Though I'm not too picky about IEM colors and faceplate artwork, I know others like to customize their IEM shells. A design with all BA drivers is easier to implement in CIEM, thus U18 is available in A18 custom shell. But I have a feeling that TIA Fourte, with its hybrid design that includes a dynamic driver and internal apex module vented to outside, is more challenging to implement in a custom shell. In my opinion, if 64 Audio could stuff 18 drivers in such a compact shell, I hope that down the road they will figure out how to turn Fourte into CIEM too.

Each shell weighs about 6g, even less than U18 (8g), though in reality that will make a very little difference when you wear it. Don't expect to be able to put your head with ear down on the pillow, but at the same time - Fourte doesn't stick out too much. Plus, the nozzle length and the shell depth (nearly identical to U18) enables a comfortable and a secure fit. Unlike U18 where you have a replaceable apex module, a compromise was reached to offer apex module internally to the shell. As a result, it's not removable and according to Fourte spec with -20dB of isolation - it's implied to be an equivalent of internal M20 module. Upon closer examination, you can see a larger hole drilled on the bottom of the shell facing forward so it's not blocked by your ear - this is dynamic low driver back vent, and I can reassure you I never experienced driver-flex with Fourte. There is another smaller pinhole vent, on the back, which is part of internal M20 module. I'm not going into all the details about apex modules since I already covered it in my U18 review, and similar to U6/U12 with Adel modules and U12/U18 with apex modules, TIA Fourte with its built in apex module had a similar fatigue-free listening experience with an open-back like performance and no ear pressure build up.

Inside, we are dealing with a hybrid 4-way design with a single dynamic driver for lows, one TIA BA mid, one BA high/mid, and one TIA high. Balanced Armatures are typically self-enclosed with a single opening port, and usually they are grouped and tubed (in multi-BA IEMs) to be routed to a specific bore in the nozzle. Open BA driver has one of the enclosure walls removed, to enable direct-radiating of the inner diaphragm which no longer has a 4-wall confinement. Inside of the shell, 64 Audio partitioned the space with custom pockets, creating acoustic chambers which allow drivers to be placed without sound tube and allowing to fine tune the driver sound performance. From the diagram on the back of Fourte packaging, I can see a separate acoustic chamber for one of TIA drivers (probably mids), and then dynamic driver pumping the sound into the main part of the inner shell which narrows down to a large single bore acoustic chamber with high/mid BA driver and high TIA driver going into the nozzle which acts as another acoustic chamber where everything gets mixed before going to a mesh covered single bore opening. This last TIA high driver is closer to your earcanal/eardrum and shouldn't be affected by any artifacts of resonance associated with tubed sound routing.

It looks to me that one of the main challenges with U18 was to position 18 drivers, including TIA, inside of a very compact shell design. Fourte is 4-way hybrid where you have less drivers, but now have other challenges such as dealing with a larger dynamic driver, built in apex, custom acoustic chamber partitioning, etc. 64 Audio met these challenges and were able to use the shell with nearly the same dimensions as U18.


The fit.


Sound Analysis.

Prior to starting my critical listening, I did put TIA Fourte through 100hrs of standalone burn in, just to be sure that its dynamic driver, cable, all the solder joints, internal wiring, and crossover components have reached their prime condition. Either if you believe or don't in a burn-in, many manufacturers do recommend it, especially when it comes to dynamic drivers. Also, it’s hard to talk about Fourte without direct comparison to U18, thus you are going to read many references to both as I describe Fourte sound using a stock cable.

Soundstage: a very similar 3D spacing, with U18 being a touch wider, while Fourte having a touch more depth. Not sure if it’s a placebo effect, considering U18 has removable apex modules while Fourte has one built in, but I felt like U18 sound was a little more expanded with an "open back" perception, while Fourte gave me a sense of just a little more intimacy. Both have an excellent imaging with a convincing placement of instruments and vocals, though I found Fourte to excel a little more here due to an improved layering and separation between the sounds, with more air between the layers. Both U18 and Fourte exhibit a good level of transparency and the sound dynamics, the sound never feels congested, but layering and separation goes to a brighter tuned Fourte. With Fourte, spatial positioning details are more precise and some of the sound nuances popped out of nowhere from a few tracks I'm intimately familiar with. I felt like a noob, surprising myself with a discovery of percussions in one of the songs, positioned far left which I never knew even existed in that track.

While U18 has a more balanced coherent signature with a smoother natural tonality, I hear Fourte as having a more fun sound with slightly mid-forward signature with a brighter, more revealing tonality supercharged by two TIA drivers. The multi-BA tuning of U18 has coherent driver tuning where despite the low-end impact, you still hear all the drives working together in unison. Fourte's hybrid design is tuned with a solid foundation of distinct layer of smooth velvety analog bass under layers of revealing, brighter mids and treble. It reminded me of a few ultra-wide bandwidth single dynamic driver IEMs, though Fourte is not v-shaped like those other drivers, and has a more balanced mid-forward sound perception.

Bass: here, I hear Fourte going deeper, even with a little more sub-bass rumble, while U18 has an edge with higher quantity and faster mid-bass impact. I never considered U18 bass to sound like a typical fast BA performance, it has a speed of BA drivers, but the bass is more rounded with a slower decay. Coincidentally, Fourte dynamic driver is also a bit of a mixed breed where I do hear a medium speed attack with a more rounded textured tonality, perhaps a little faster than a typical dynamic driver, but the decay is slower than U18 bass, yet still has plenty of control while creating this layered separation between the bass and the lower mids. While neither U18 nor Fourte have bass performance typical of their corresponding type of drivers, upon closer listening you can still hear U18 bass being a little faster, more layered, and with cleaner edges, while Fourte bass is more visceral, smoother, and with a more analog flavor.

Mids: Lower mids are closer to neutral, keeping the body of the sound lean, and then going to upper mids is where you have a slightly forward push, especially around 1k mark. The mids in Fourte are more revealing, more micro-detailed, more layered, and at the same time a little colder and dryer in comparison to U18. If you are a fan of smooth, organic, laid back mids and a more natural vocals tonality, you might find Fourte to be a bit too revealing. But if you are a fan of micro-detailed level of analytical performance and want to hear all the nuances in sound, you will be pleased with Fourte tuning.

Treble: Both U18 and Fourte have a great treble extension, with treble being crisp and well defined, but Fourte takes it to another level with more airiness and a little boost around 10k to add more definition to upper frequencies. Even with all this enhancement, I never detected any sibilance, but at the same time Fourte tuning makes it less forgiving when playing poorly recorded audio or when paired up with brighter or even some neutral audio sources. In comparison, U18 is smoother and more forgiving, and not as picky when it comes to pair ups with different sources.

All this comparison was done between U18 w/M20 and Fourte, making a difference in tonality a little more obvious. But when you switch U18 to M15 module, you get performance a little closer to Fourte where the mid-bass of U18 goes down a bit in quantity to be more aligned with Fourte, and U18 mids become a little more forward and brighter, not on the same level as Fourte, but somewhere in between of U18 w/M20 and Fourte. Even with M15, U18 is still smoother and not as micro-detailed as Fourte. But at the same time, this is one of the advantages of U18 by having a flexibility to switch between M20 and M15 to fine-tune the tonality.

But everything is up to a personal preference. For example, I noticed when switching between Fourte and U18 w/M20 modules, going to Fourte felt a bit bright to my ears until I let my brain adjust to the sound, and going back from Fourte to U18 w/M20 felt like sound was a bit congested until I adjust to it as well. With M15 module in, the brain adjustment was a lot faster.


Pair up.

In my pair up test with different sources, I decided to be consistent and use TIA Fourte with an included 3.5mm SE stock cable. While Fourte has 114dB sensitivity, I wasn't sure what to expect due to its 10 ohm impedance and how it will affect the hissing with different sources, a similar concern I had with U18.

Plenue 2 - the sound is very expanded, great bass texture; bass is lifted but not exaggerated; mids are more forward with nearly analytical retrieval of micro-details, a little on a colder side, very nice layering and separation; treble is crisp, bright, airy, well extended. No hissing.

LPG - wide soundstage, nice expansion; bass has more rumble and stronger mid-bass punch, mids are smoother more balanced, treble is bright and crisp. Overall, the tonality is a little more balanced because of a slightly more elevated bass and smoother mids. A mild hissing.

Opus#2 - wide soundstage with some improvement in depth too; bass has a similar rumble as P2, but mid-bass is a little stronger; mids are a little forward, very detailed and revealing, but now have a touch more smoothness, treble is crisp, bright, airy, well extended. A very mild hissing.

DX200 - wide soundstage with some improvement in depth; bass has a nice textured rumble with a smooth mid-bass punch, quantity of bass is not overexaggerated which makes mids perception more forward, still very detailed and layered, but with a touch more naturalness in tonality; treble is bright, crisp, airy, with a good extension. No hissing.

AK120ii - here soundstage is wide, but a bit less then with other daps, and instead I hear a lot more depth in staging; bass has a great sub-bass texture and nice mid-bass punch, but it's a little bit more behind mids which are leading the way, being more forward in this pair up; mids are still revealing and detailed, but a little smoother and with a touch more body; treble is crisp, well defined, airy, but a little less bright. No hissing.

i5 - wide soundstage; nicely textured sub-bass rumble, stronger mid-bass punch, bass is a little more elevated, mids are a little more balanced, very detailed, layered, revealing, not as forward, and more organic in tonality; treble is crisp, well defined, extended, but not as bright as I hear it with other daps. No hissing.

X7ii - wide soundstage, even with some depth improvement; very nice sub-bass rumble and a well-controlled mid-bass punch, bass is very articulate and well controlled. Mids have a forward perception, with excellent retrieval of details, maybe a little less analytical and a little smoother; treble is crisp and airy, very snappy and extended. No hissing.

Note 4 - soundstage is still wide, but not as much; the sound also changes its signature, becoming more balanced with bass coming up and upper mids and treble becoming smoother, warmer, more organic and a little less forward. That micro-detailed revealing tonality is no longer there, but I hear the sound to be more toned down, smoother, more laidback. I did miss the resolution and transparency, but it wasn't too bad, there were still plenty of details, just not as vivid.



Using Plenue 2 as my source, I kept TIA Fourte with a stock SPC cable, and volume matched every pair by ear.

Fourte vs Vega - Fourte has a wider soundstage while Vega has more depth; both have a similar quality of sub-bass rumble, while the quantity is more elevated in Vega, and the same with mid-bass which is a little faster in Vega - it has more impact with a stronger punch. Lower mids in Vega have a little more body, while upper mids are pushed a little back in comparison to a brighter, more revealing, more transparent, and more forward mids of Fourte. Fourte treble is crisper and has more airiness. These have a noticeably different signature with Fourte being a little more mid-forward while in relative comparison Vega is more L-shaped.

Fourte vs SEM9 - Fourte has a wider soundstage while SEM9 has a little more depth; both have a rather similar sub-bass rumble, but Fourte is more textured. With mid-bass, both seem to have a similar quantity, but Fourte is tighter and with more body while SEM9 is more hollow and more relaxed. Lower mids a little more neutral in SEM9, but upper mids have a similar quantity, though Fourte has a better retrieval of micro-details and more analytical sound. Fourte treble is better defined, crisper, and has more airiness.

Fourte vs RE2000 - RE has a wider soundstage with more depth; both have a very impressive low-end performance with a deep textured sub-bass rumble and analog quality mid-bass with a strong punch, though RE bass is a touch faster. Lower mids have a similar amount of body, but upper mids is where I hear the most difference with Fourte being a little smoother and more natural, while RE is brighter, thinner, and more splashy in comparison. Both have a very revealing micro-detailed upper mids, but Fourte sounds just more natural in comparison. Also, RE treble is brighter, crisper, with a little more airiness. Overall, these two are not too far apart, just that for my own personal taste Fourte is a little smoother and has more natural mids.

Fourte vs W900 - Fourte has a wider soundstage while the depth is the same; W900 sub-bass goes deep but it's not as textured as Fourte which has a little more rumble as well, but W900 mid-bass punches through a lot stronger and has a higher quantity in comparison. Lower mids are similar, but upper mids in W900 are warmer, smoother, not as layered or revealing, while Fourte is more layered, more micro-detailed, and more revealing. While W900 treble extends far, it's nowhere near having the same amount of sparkle, or airiness, and in general it's smoother.

Fourte vs K10UA - Fourte has a wider soundstage while the depth is the same; K10 sub-bass goes deeper, with a little more rumble, and mid-bass punch is faster and more articulate. Fourte has a little more bass quantity, but the bigger difference here is in quality where Fourte has a more dynamic analog bass while K10 has a faster BA bass with a short decay. Lower mids are similar, while upper mids in Fourte are more analytical, more micro-detailed, a little brighter. Treble has a lot of similarities, being bright and crisp, but I just hear Fourte having a little more control and airiness.



If you take a closer look at "Fourte" name, you will see a combination of "four" and "forte" which defines this flagship as a four-driver hybrid which suppose to excel in the sound tuning and the design. Just like U18, Fourte is not for everyone, these high-end flagships are intended for serious audiophiles whose focus and priority is more on the performance and the unique technology rather than price/performance ratio. And even if we talk about the price, like I mentioned in U18 review, some of the other $2k-$2.5k flagships with premium cables can reach the price bracket of U18/Fourte. I'm not making excuses for 64 Audio price, it’s high. But if you are willing to look into TOTL flagships and to pay the premium price, you need to consider every available option, especially when you have a specific sound sig target in your mind.

But as a reviewer who was given a unique opportunity to test and to compare these IEMs, considering how much I enjoyed U18, I thought it will be an easy decision to choose which one I like better. But the more time I spent with these IEMs, the more I got addicted to both because they are not competing but rather complimenting each other. I like the strong authoritative impact of U18 bass, but I also like the deeper analog texture of Fourte bass. I'm a fan of U18 smoother, resolving, natural upper mids and lower treble, but I also enjoyed Fourte with its more transparent, revealing, detailed mids/treble that wasn’t too fatiguing. Both have an open sound. Another thought, they both have an all-metal shell where for the first time I was able to handle expensive IEMs with more peace of mind due to their durability. And while U18 offers a flexibility of using either M15 or M20 modules, I think Fourte would sound the best with its built-in M20 (vs M15) without compromising the bass quantity.

Based on talking to my readers, as well as seeing the comments on Head-fi in 64 Audio threads, it seems that many U18/Fourte customers are those who tried these flagships either at CanJam events or store demos (e.g. at Music Sanctuary) or recent participants in Head-fi tour. Either of these flagships is a serious investment which you need to spend your time with to listen, to compare, and to appreciate, but if you don’t have access to it – I hope my review can provide some helpful guidance. Also, keep in mind, 64 Audio offers occasional B-stock deals and holiday sales, and once they even offered a trade-in program for those who have their previous flagships.
This and U18 Tzar's reviews are the best reviews I have ever read. Thanks! I already own Tzar but now I am wondering if i should buy Fourte as well haha.
Hi, twister can u use Tia fourte with leonidas 2 then pair them with wm1z and give me some impression pls? Does it lose any sparkle on treble because of its smooth ?
Pros: Resolution, Speed, Air, Balance, Layering, Musical, Comfort and Ergonomics
Cons: High cost
The last few years have seen a proliferation of new in ear monitor (IEM) products as personal/portable audio continues its incredible growth trend within the global audio industry. Increasingly, headphone enthusiasts and mobile technology consumers are looking at IEM’s as their primary headphone of choice. Thankfully, the performance level of IEM’s has improved across the board with great products at all price ranges.

The 64 Audio Tia Fourte is a flagship category example of this new trend of high performance IEM’s, and features cutting edge technology, called Tia. I received a production review sample of the Tia Fourte in early July and have had a chance to spend a lot of time with the product both in both home and travel situations, as well as extensive use on airplanes. The Tia Fourte is 64 Audio’s most expensive offering at $3599, and is available as a Universal Fit model only.

64 Audio and Tia Technology
64 Audio is based in Portland, OR and was started by Vitaliy Bolonozhko, a sound engineer with many years of experience working with musicians and production companies in the Northwest. The company’s name is derived from the year 1964, a “pinnacle year for rock music”. 64 Audio offers a wide range of custom and universal fit in ear monitors and the Tia Fourte represents its latest innovation, the Tia system.

Tia stands for Tubeless In-ear Audio and the Tia driver is an open balanced armature speaker design that according to 64 Audio, “brings new meaning to resolution and transparency”. The idea behind this is similar to common speaker designs, where opening the balanced armature produces the sound with the direct-radiating and fully unobstructed diaphragm. This method eliminates the need for conventional sound tubes and dampers and coupled with the design of the acoustic chambers, results in a more open and smooth sound with less unwanted resonances.

Let’s open the package and take a peek.

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Packaging and Build Quality

The packaging of the Tia Fourte is workmanlike with a small selection of foam and silicone ear tips, instruction manual, and a nice 64 Audio sticker. The standout of the provided accessories is the carrying case which is a nice balance of hard protection, size, and ease of use. I like that the each earphone piece has it’s own separate chamber with a larger section to wrap the cable into. The supplied cable is a very well built and solid braided cable with a standard two prong connector and a heavy duty right angle 3.5mm connector.

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The Tia Fourte earpieces are machined out of a solid block of aluminum and feature a copper patina finish inlaid on the faceplates. While looks are completely subjective, I do like the look, feel, and overall comfort level of these earpieces. They are a lot smaller in person than most flagship IEM’s on the market and are the first IEM’s that I have been able to wear for longer periods of time (over one hour) without any discomfort or pressure in my ears. They are, in fact, the first IEM/CIEM I have used that seem to fully “disappear” during extended use.

I’ve primarily used 2 types of ear tips with the Tia Fourte: Comply’s and Ultimate Ears Silicone tips and have come to overall prefer the UE ear tips as they provide me with a balanced sound signature and the best comfort level. Ear tips can change things up and I would definitely encourage IEM users to experiment with different types whenever possible to achieve the best possible fit (and sound). Pictured here with Comply's.

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Sound Impressions
I first heard the Tia Fourte at CanJam Singapore 2017 and it was one of the clear highlights of the show for me. Plugging into my AK380, I sat at the booth for around 30 minutes and did not really want to get up. This experience was similar to the one I got when first listening the the Focal Utopia last year. There just seemed to be so much more musical information passing into my ears than what I was previously used to and the music was being delivered in such an effortless and coherent manner. The other thing that really struck me was the visceral impact and bass slam, which delivered in spades but not at the expense of other frequencies. It was all there and it was really impressive.

Since receiving the Tia Fourte review sample, I’ve primarily used it directly with the AK380 as this is the most common application that I would use an in ear monitor for. It does scale higher when adding the Chord Hugo 2 to the chain and higher still when plugging directly into the Chord Hugo TT or into the DNA Stratus 2A3 tube amp, both of which were dead silent with the Fourte.

I would describe the Fourte’s sound signature as in the reference (neutral) category but with a slightly elevated bass response which gives it a distinctly musical and engaging type of sound signature. This is a very “big” sounding earphone, with a wide and deep soundstage and is among the closest approximations to my full sized reference over ear headphones that I have yet heard from an IEM. The resolution of the Fourte is top notch and it seems effortless with very open and airy sound. Despite its musical nature, the Fourte is extremely transparent, with excellent layering of instruments and vocals in a very deep sound stage.

Most other IEM’s that I have heard usually have clear strengths in certain areas with some weaknesses in others; the Fourte is remarkably well balanced and for my sound preferences, seems to check all the boxes.

Sounds Impression Comparisons with other IEM/CIEM’s

IEM Shootout.jpg

Here is where I can describe some of the sonic differences between the Fourte and some other IEM/CIEM’s that I have on hand. All of these comparisons are with stock cables and using the Chord Hugo 2 and AK380 as source.

Ultimate Ears UERM (Customs)
The UERM has been a reference monitor for several years now and still holds its own with many newer offerings. The biggest difference between these two earphones is the bass presentation which is noticeably lacking in the UERM when directly comparing with the Fourte. While the UERM strengths are its strong resolution and excellent mid and high registers, it does have a smaller and narrower soundstage in comparison with the Tia Fourte.

Noble Audio K10 Prestige (Customs)
The Noble K10 Prestige is a good all around earphone with a balanced sound. In comparison with the Tia Fourte, the Fourte reveals itself as clearly more resolving across all frequencies and an overall more coherent and full sound.

Jerry Harvey Audio Layla (Customs)
The Jerry Harvey Layla is a fun sounding earphone with a very strong and tunable bass response. Since my sonic preferences lean more towards neutral, the Tia Fourte is a better sonic fit as it has higher level of resolution and transparency in the mid and upper ranges. It also sounds more balanced to me.

Campfire Audio Andromeda (Universals)
The Campfire Audio Andromeda is the closest to the Tia Fourte in terms of sound signature with the Fourte pulling ahead in terms of soundstage depth and resolution. The Fourte has more air, is smoother, and sounds more refined than the Andromeda. However, the Andromeda is very close to the Fourte in terms of it having a coherent and balanced top to bottom sound signature. It’s comfort and ergonomics are also a close second to the Fourte compared to the rest of the group.

Hifiman RE2000 (Universals)
The Hifiman RE2000 is the new flagship earphone from Hifiman. It has a very big and diffuse soundstage with powerful bass, even more so than the Fourte. The Tia Fourte does sound more three dimensional and is more present. The RE2000 is a little more laid back, yet still very detailed, musical, and balanced sounding with a touch less transparency and sparkle than the Fourte.

Shure KSE1500 (Universals)
At CanJam London 2017, I was able to briefly compare the Tia Fourte with the Shure KSE1500 system along with a few other Head-Fier's in a quiet listening environment; in the end we were evenly split on which was the preferred IEM, and not surprisingly, this came down to personal preference and which musical genre was being played. Those that preferred classical music as their primary genre leaned towards the KSE1500, while those that preferred rock and other modern genres, leaning towards the Tia Fourte.

The Tia Fourte is a remarkable earphone and a truly innovative flagship. It is extremely engaging and musical, and to my ears has achieved a near perfect balance of detail, clarity, and transparency together with musicality, bass response and an overall smoothness to the sound which is quite intoxicating. Additionally, the ergonomics and comfort level of the Fourte are second to none due to the small size of the ear pieces as well as the Tia system, which helps alleviate the usual pressure build up in the ear canals during use.

Anyone looking for a flagship class earphone in this price category should have the Tia Fourte on their short list to audition. And hopefully, we will see the Tia system technology trickle down to future products in more mainstream price categories. Very highly recommended.
Pros: Natural
Full textural bass
The Greatest timbre
Naturalness of sound
Cons: Price

I have been given a wonderful opportunity to demo the Fourte and tzar18 per tour through @barra. It has been an eye opening experience to say the least to be able to try equipment that is truly exceptional in audio quality and playback.
Some background on me before we start to give you an idea of what I look for in signature and in headphones particularly.
I am very much of the mind price does not always reflect performance. Some of my favorite headphones include the Sony Mhc-1, MEE P1, and more recently the Nt6pro of which I was also able to demo for around a week. I mostly prefer DD over typical BA implemented systems, though, recently I've seen and have had a great appreciation for what BA systems can do when implemented right. Some BA iems I felt could have been better done include the Lime aether and custom art 8.2 harmony. The first I found somewhat of a gimmick with the switch for the bass and the sound somewhat exciting for my tastes with overall cohesion lacking where even my MEE P1 excel. The 8.2 for the most part was a pleasant experience though I was not a fan of the tuning and honestly came off unimpressed and the experience wholly forgettable. For sources I have a LG V10 and Venturecraft sundroid valoq limited edition 627sm as my main rig with a Nakamura headphone conditioner.

The Package

When looking at the box I'm instantly struck with the a classy notion of prestige. 64 audio have in the last 5 years really established themselves in the iem market and truly have revolutionized and innovated where others are still satisfied with today's offerings on a technological perspective opting for filters or different tunings to separate themselves. Introducing the Fourte. While they have released two top tier iems, one marketed as reference (Tzar18) and the Fourte as more less a warmer,fun sounding alternative.

Build Quality

As evident from my picture you can see the Tia drivers themselves are not the only thing elevating the Fourte to a TOTL status, but also the way the whole iem has been approached from the ground up. Truly impressive and for the asking price it makes sense. The housing is sturdy and sure, alluring with the choice of copper patina and splashy faceplate. The cable is solid and I particularly approve of the heavy duty right angle 3.5mm plug. The accessories for this asking price is a bit of a let down. A much more thorough tip selection could have been the least. Additionally, I feel that 64 audio perhaps could have engaged the consumer a bit more by including a small sd card with 64(see what I did there?) songs or audio samples, that the team as a whole would feel really show off the capabilities of their own product or perhaps a temp tattoo and classy yoyo, who knows just saying... Alas the hard plastic carrying box is definitely a fine idea given the cost of these headphones.

Subjective Sound Impressions

Before the Fourte was tested I spent considerable time with the u18. This was done for a few reasons, that was based off of reviews and feedback from the forums. I was convinced that while the Fourte would be no slouch, the u18 would have all I want and perhaps enjoy the most. When I did decide to use the Fourte it was initially with my LG V10 as the u18 and LG V10 was really just bad synergy. The Fourte softened things a bit with its relative warmth and initially allowed me to enjoy the LG V10 all over again. That feeling wouldn't last long though as I moved on to my main rig. Just as before with the u18 the phone showed its faults and eventually wasn't used outside of the couple of days dedicated to understanding what I was listening to. While I sang praises for the u18 synergy with the Venturecraft sundroid valoq, I would come to ultimately realize the Fourte is really a cut above the u18 as per my tastes. Initially, when testing the included cables I found the u18 to pull away a bit and be ahead of the Fourte sonically, offering a very balanced and transparent signature that is added by its deep bass slam and precision like spatial cues. A signature that until I added the inclusion of the prion4 cable, was what I felt wouldn't be topped by the Fourte. With the included cables Fourte is not able to come off the leash so to speak. It's restrained, unable to show itself for what it truly is. A sonic renaissance. With the original cable you still get great detail and a cohesiveness that is thoroughly impressive. Match that with its DD bass slam and Tia mids there isn't much else to want. However, for those lucky owners with extra cables at their beck and call, know that the Fourte can ultimately go further than the u18 Tzar. With the prion4 we go further still. Sound is more pinpoint accurate, micro details are pushed forward a touch, though still being edged out only slightly by the u18. Layering, timbre, and texture go to the Fourte with the soundstage on both being fairly similar though again, is just barely taken by the u18 width, with the Fourte having more depth.

Autumn's Grey Solace is a band I quite like and with this particular song I find is great for seeing about sibilance, timbre of bass and naturalness of vocal delivery. The Fourte captures this angels delivery in a way that leaves me stupefied. For all intents and purposes the u18 should be able to get close, chalk it to those Tia drivers in the mids but the naturalness of her voice just can't be done by the u18 like the Fourte. With the prion4 the stage is a touch wider and slightly deeper with the bass timbre surpassing that of the u18.

Again we have the song Rush off the Cowboy Bebop OST. This is a wonderful song for many reasons. Layering, timbre of bass, trumpets and sax and spatial cues can all be revealed depending on set up to varying degrees. With the Fourte I'm speechless. While the u18 does have better precision the Fourte keeps up with its level of spatial cues and cohesiveness that, when taken together with the prion4 cable deliver those uncanny micro details and a effortless more natural performance with better depth than the u18. I feel that in regards to reproducing real instruments the Fourte excels in a more realistic way of delivery

edIT's Crying Over Pros For No Reason is truly exceptional as a whole album and in my opinion one of the best electronic based glitch music out there for its raw emotion its able to convey without much words at all. The Fourte while quite capable does fall to the u18, do to precision and that bass back end at its disposal. However, the Fourte keeps up but adds in that panache that's thickens the sound ever so slightly adding that little bit of molasses to the bass texture and details, which is not at all to be taken as a slight. The u18 on the other hand just gives it has is and in this case comes out on top because of its reference tuning and bass slam and better precision.


While initially I was to believe the u18 at its asking price was everything I could want. The Fourte had a way of changing my mind when used with the prion4. Without that cable I would pick the u18 based on bass slam and overall precision, with the added flexibility of its modules. However, with the prion4 cable I now see the Fourte as my new reference to base all others against for natural sound done exceptionally well. Micro details, bass decay and texture and those sweet sweet mids means that I could be a happy camper for a very long, long time. I would like to thank 64 audio for taking the game to a new level of cohesive implementation and Tia drivers reproducing a lifelike intoxicating sound quality. I would also like to thank @barra for setting up this tour to give all involved a chance to test out a luxury piece of equipment.


Pros: Dynamic, open, highly resolving sound
Cons: Very expensive
Disclaimer: The TIA Fourte was loaned to me long term by 64 Audio for the purposes of this review. 64 Audio will always have a special place in my heart, not because I’ve had experiences with them for the longest time, but I was given the amazing opportunity to be a beta tester and reviewer for the TIA Fourte and the U18 Tzar. Some of you might have read my impressions on the pre-production prototypes, and I’m glad to say that 64 Audio has improved on them greatly in the final production model. Some parts of the review with regards to my thoughts on 64 Audio as well as the background would be reused from my previous impressions.


I’ve always liked 64’s products, and the way the company has grown over the years. I remember back when 64 audio was still 1964 ears, with the original V series, the V6 was my favourite product of the range. It had a highly competitive pricing and sounded great. Two years ago however, 64 Audio stepped up their game and came up with A series and the U series. There was quite a noticeable rise in the price of the line up, but along with this increase in prices, came a very noticeable step up in sound quality. 64 Audio was no longer competing at the lower tier of the custom IEM market, it was now considered a strong contender in the premium custom IEM market. The A10 and the A12 continue 2 years later, to be excellent earphones which continue to play at the very top of the game.

I had a few sessions on the phone with a few of the guys at 64, and most particularly Vitaliy. We had a really great conversation where he shared the inspiration and the concepts behind TIA. For those of you who haven’t you owe it to yourself to watch the rendered breakdown of the TIA Fourte on the 64 Audio website. Basically, it’s a whole radically new approach to earphone design that has not yet been tried before.

Personally, I find that many balanced armature earphones, especially with custom multi balanced armature earphones, have really strong colourations in their sound. The typical custom IEM with multiple balanced armatures has the sound passed down a sound tube to the ear. Try talking into a pipe, and you’ll realise that everything comes out honky and awfully coloured. There is a reason for this. The pipe, depending on its length, would exert its own character on the sound. It has multiple resonant frequencies, and this causes huge resonant peaks as a sound wave passes down the pipe. This is precisely what happens with most balanced armature earphones. In order to deal with these resonances, acoustic filters are often used, and this often impedes the transparency of the sound signal.

Now, I’m not saying that sound cannot be done right with this traditional approach, because many companies have made wonderful earphones this way, 64 audio included. But what if we could eliminate these colourations? That is precisely what the TIA aims to do. In most balanced armature drivers, the armature moves in a planar like fashion. This is good for producing sound. However, the problem comes when the sound has to squeeze out through a little aperture at the side. This creates a lot of distortions. With the TIA however, the largest surface parallel to the armature is opened up. This allows for direct firing of the sound waves without having to squeeze through a tiny aperture and allows for a really planar soundwave to be produced. This, coupled with the lack of sound tubes but instead, acoustic chambers to specifically tune the sound with their size and shape, allows for a far more extended response with much more detail and less in the way of resonant peaks.

Well that all sounds really good on paper, but how do they really sound?

Packaging and accessories

One of my biggest complaints about 64 Audio’s previous IEM offerings, was the packaging they came in. Now a lot of you might be thinking, what’s the big deal with the packaging? All that matters is the earphone itself! Well yes, that might be the case, but very often, I find a good packaging provides a sort of an opening statement and introduction to a product. A good packaging doesn’t make up for a bad product, but it surely does enhance the experience.

The TIA Fourte has a much improved packaging from its predecessors. It comes with a well thought out packaging which goes into some explanation of the TIA technology, and more specifically, the innards of the TIA Fourte. Now, in my opinion, this is rather interesting. The TIA Fourte has a design that is remarkably different from any product on the market of any type or form, be it an IEM, or a headphone, and I think it is only with these blow-ups that one can really start to appreciate the complexity, thought and precision in the design of the Fourte.

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Opening the box reveals a message from the the man himself, Vitaliy. 64 Audio’s slogan “Hear Everything” also reveals itself rather tastefully. Truly, with the Fourte’s you hear everything.


It also reveals the Fourte sitting magnificently in the foam inlay, as well as a compact carrying case with some cleaning tools as well as a desiccator. I am not the biggest fan of this carrying case, being an avid user of third party cables. That said, with the included cable, it is in fact a very well thought out, compact, and protective case.


Build quality, ergonomics and design

The Fourte has a build deserving of its flagship status. The faceplate and the chassis are both milled from solid aluminium. The surface finishing is smooth with clean cut edges, and the faceplate and the body meld well together. There’s nothing really to complain about with regards to the build quality.


The Fourte, despite its size, actually fits very well in the ear. Personally, I am able to achieve an extremely good fit. It has moderately long nozzles which really help the eartips to sit securely within the ear. Personally, my ears tend to do well with IEMs with short nozzles. However, I know of many who prefer slightly longer nozzles, and I think this would probably benefit them greatly.

If I had one complaint about the ergonomics, it would be that I would prefer for the nozzles to be slightly angled forward and upwards. That said, I understand that given the design of the Fourte, this would probably have an impact on the sound, and I trust that the guys at 64 Audio would have thought about this and made a compromise to find the best balance between sound quality and ergonomics.

Now the design of the Fourte is unfortunately not something I’m the biggest fan of. Personally, I would have gone for something a little more plain, and simplistic, but what do I know? Regardless, I wouldn’t let this distract me from an otherwise incredible IEM, and neither should you.

Now there is one thing I would like to bring up at this point about the build quality. The pre-production sample I was loaned previously was made of a 3D printed resin chassis. They sounded great, but I’ve always had my issues with plastic. In my experience, plastic tends to resonate in a much more unfavourable manner than other materials such as metal or wood. Now, some might say that it’s all part of the tuning, but I disagree. I think that the chassis should always be made to be as inert as possible, so that the drivers can be designed to shape the sound as the designer intended. Besides, it’s not only about the tuning or the voicing. Having better resonance characteristics doesn’t simply mean having a more neutral voicing. It means lower distortion figures, phase errors, resulting in sharper imaging, better transparency and resolution. In my opinion, this becomes really obvious when comparing the production Fourte with the pre-production sample.


In my previous review, I described the Fourte as the King of the Hill. Now, I don’t like to give away too much before I’ve gone into detail about the different aspects of the sound, but in my opinion, 64 Audio has not only managed to maintain its place up there, but possibly pulled ahead of the pack even more.

The Fourte is mostly a very balanced sounding IEM, with a slightly coloured and fun approach to it. It has a slightly warm, rich tone to it with a deep and powerful weight behind each note. Despite its rich and deep sound, it has an incredible sparkle, air, and extension up top which really creates a sense of liveliness and air.

Technically, the Fourte is hard to fault. To my ears, it is among a handful of the most resolving IEM’s I’ve heard to date, easily on par with the Dita Dream and the Shure KSE1500, despite its rather rich tonal balance, and somewhat bigger bass, it maintains a good bite to its notes. Notes are well defined, clean, and precise. Some people talk about resolution, detailing, and transparency as different parameters. To me, they are one and the same. I don’t hear resolution simply as the ability to resolve details and textures in instruments and voices. I find another key aspect of resolution and transparency to be the ability of a piece of equipment to resolve nothing. What does that mean? It means to resolve the space and air between sounds, the space and air that not only separates the various aspects of a piece of music, but creates the very soundstage that we so often crave and listen out for. The Fourte does it remarkably well. With the Fourte, it seems like a layer of fog is lifted off the music, and not only are details and textures more apparent, but the background becomes blacker, and space becomes even more realistic.

The Fourte has a slightly forward sound. That is not to say, however, that it lacks depth. Despite a more forward presentation to its sound, the actual space extends very far forward, very deep. This creates an exceptional sense of layering, with the contrast between the nearest and furthest sounds being quite remarkable. Personally, I’ve always preferred a slightly more distant presentation, yet despite the forward and intimate presentation of the forte’s centre image, I just can’t get enough of it. It creates a somewhat intimate feel to it, as the Miss Saigon and Diana Krall come so close to me, yet it sounds exceptionally realistic due to the extension of the space and certain instruments far beyond the lead voice.

The Soundstage is equally, if not even more remarkable in its width and height. The sense of space that the Fourte creates is simply astounding. It is immense. A friend of mine who’s spend the better part of the past few years listening to speaker setups in the tens of thousands, has commented that the Fourte driven out of a good portable source, is the first IEM he’s heard that begins to recreate that feeling he has with speakers. He has tonnes of experience with TOTL headphones and head fi setups as well, and coming from him, it’s really quite something remarkable. I’ve never even heard him comment like this on open headphones.

Besides the sheer size of the soundstage, an area in which the U18 doesn’t fall far behind in, the Fourte also has exceptional layering, separation and spatial cues, and this is something that the U18 doesn’t match up to the Fourte. The near far contrast is exceptional in both the Z axis as mentioned above, as well as the X and Y axis. As previously mentioned, the Fourte also recreates space and air extremely well. This all adds to an incredible separation. But more importantly, the Fourte images better than any IEM or headphone I’ve heard period. It’s not simply about precision. Many headphones and IEMs have precise imaging (Even though the Fourte does it better). The thing that truly stands out for me with the Fourte, is its ability to not only be precise in its imaging, but to have such a weight and realness to it that there is this visceral solid, tactile sensation to the sound it produces. If you’ve read my review of the Vega, you would realise this was something I loved about the Vega. The Fourte has only taken this further.

The Highs of the Fourte are extremely well extended, airy and sparkly, and this is better done than almost any multi BA IEM I’ve heard. There is a little of a peak up top which enhances the sense of brightness in the upper registers. However, it peaks at a frequency and amplitude that prevents it from being truly harsh. As someone who loves crisp, airy and sparkly signatures, this really works for me. I’d like to think that this is something contributed to by the TIA drivers. Vitaliy promised me that the TIA drivers would be able to create a smooth, extremely extended response, something that tubed BA drivers have a challenge with, and I think there’s definitely some truth in that.

The midrange of the Fourte is organic, smooth, rich, yet articulate. I once let someone who worked for a top headphone maker have a listen to the Fourte, and the one thing he spoke about immediately was the midrange. He described it as being as close to tonally perfect it could get to his ears in the midrange. Now I don’t know if I would say that it was tonally perfect, I don’t think anyone can ever say this about anything, but I do know for sure that it sounds fantastic to my ears. I previously mentioned the slightly forward presentation of the lead on the Fourte. This, coupled with the rich tones of the Fourte’s midrange, really comes together to create a silky, organic, and romantic feel to the music. Everything just seems to come to live. This, coupled with incredible, class leading transparency only helps to add to the realness of the Fourte’s sound.

When I first heard of the TIA Fourte’s configuration, one of the first things on my mind, was how 64 was going to handle the bass driver. Coming from a purely BA background, the Fourte is truly something out of their comfort zone. To be honest, to this date, I’ve only heard a handful of successful hybrid IEMs. They have great potential, yet at the same time, none that I’ve heard have truly wowed me up till the Fourte. The Fourte’s bass is powerful, decisive, hits extremely hard and extends incredibly deep. It’s like a subwoofer in your ears. It’s not the tightest, quickest bass though I must say. It’s got a little bloom to it, a deep, slightly aloof rumble and thundering, and it takes it’s time ever so tastefully. Yet, when called for, it slams like there’s no tomorrow. Compared to the pre-production sample, the bass is better controlled and more balance. Some would like it, and some wouldn’t, but personally, it’s a step in the right direction.

Some thoughts on TIA

I started off believing very firmly in the dynamic camp. My reasons were rather simple. I always found Balanced armature IEMs, in their current form and implementation, to be extremely coloured with horrible midrange and upper frequency resonances resulting in a honky, pipe like sound.

This changed over the years, and I have found Balanced armature earphones to have progressed drastically, with massive improvements in the sound quality. In some ways (detailing, speed and soundstaging), balanced armatures tend to perform remarkably well, but in other areas (bass, dynamics, and realism), I have typically found them to lag behind their dynamic counterparts.

I also find traditional BA technology to be starting to stagnate. Unlike DD’s there’s not much room for improvement of traditional BAs. With DDs, there’s so much to improve on, diaphragm material, topology, shape, chassis material and shape, voice coil technology, etc, but with BAs, you’re stuck with the same chassis quality and design, the same armature quality and design, etc. Of course, this isn’t a bad thing, the fact that BA IEMs have come so far means that these BAs are capable of producing good sound. Yet this progress is limited by the quality of the BAs. As long as it doesn’t improve, the sound of BA IEMs will be bound to stagnate.

I believe that the TIA has really achieved what it has set out to achieve. It is, in my opinion, one of the best I’ve heard, possibly the best in BA technology. It is, after all, not a typical BA. It’s something new that has never been done before. Sure it’s extremely expensive, but I think that it has also achieved new heights that traditional balanced armature designs have till now been unable to achieve. I have never heard a BA extend so far and high with this much air and sparkle without resonant peaks. It is truly impressive


The TIA Fourte was, to my ears, considered the King of the Hill when I heard the pre-production sample. A lot of time has passed since then, almost a year now. A lot changes in a year in the summit fi market. Yet, I think I would very confidently say that despite all the progress in the IEM market, the Fourte has almost effortlessly kept its place as the king of the hill. There are perhaps one or two IEMs which I feel are competitors, but it’s a bit of a toss up, they’re better at some things, and the Fourte is better at others.

What the Fourte does well though, no one comes close. That big, authoritative, speaker like sound presentation is something that no other IEM comes remotely close to competing with. That with the visceral, tactile feel of its imaging, creates this sense of realness that makes me almost forget at times that it is an IEM.

I don’t know what else 64 Audio has in its books, but the Fourte will keep me more than happy for a long, long time to come. Many IEMs come and go, they create some splash and hype, and then a month later nobody talks about them. Not the Fourte. Be it its sound, or its ostentatious price tag (This I cannot deny), the Fourte continues to garner an immense interest amongst audiophiles, whether they have the intention (or the means) to buy it or not.

One year on. Still the King of the Hill.
Fine detailed review. What was the source used?
With a price that high, these really beg a comparison to the KSE1500. Hell, you'll have $600 left for a DAC to go with the Shure's.
On your review's concluding remarks, prices sure are getting ape**** high as of late. I'm well aware of RnD costs, but these technological milestones will never get down to the masses if people keep paying that much. That's before we even had the DAC/Amp discussion. Damn shame.
Thanks folks for the support the fourte is truly a remarkable earphone, you guys just have to hear it

With regards to the source, They were mostly done with a mojo and Hugo, but also the auralic vega and Taurus just to see how well they scale (and boy do they scale). I'll update that bit too. Thanks!
Nice review!  I was curious about the sensitivity.  With much discussion about the EE adel hiss with various sources, did you find the Fourte to suffer any of the same, with the Mojo and Hugo?  Thanks!