An entry-level earphone with its head in the stars, the Starfield is a value proposition by Moondrop, a company that seems to do no wrong (just yet). It’s time to dive headfirst into the universe of Moondrop’s enchanting tuning.

“Catch a falling star and put it in your pocket, never let it fade away.” You’ve heard of a star fall, but how about a moon drop? Moondrop is part of the brigade of “holy crap, there they are again” fast-rising brands in Chi-fi, along with FearlessTin HiFi and the like. I’m sure there are others, but these three brands release new stuff at such a breakneck pace, it’s as if their lives depended on it.

Established in 2015, Moondrop started off as a studio comprised of enthusiasts. Early on, they released earbuds with fancy names and peculiar nomenclature (ShiroYuki, Liebesleid, and most peculiar of all, Nameless) before dabbling with in-ear monitors (IEMs). Over the years they’ve flexed their financial muscle, and now have independent R&D and manufacturing arms.

You choose your travel agent, I choose mine.

Their IEM tuning is famously based on the Harman Target Response Curve. They take a can’t-fail, research-based tuning recipe, apply a few tweaks, scour the earth for drivers that do the best job for the price, before unleashing a full range of IEMs from entry-level to flagship. And here’s the thing, they are remarkably consistent in what they do. I’ve never heard a badly-tuned Moondrop yet.

Today we look at their entry-level model, the Starfield. Powered by a single carbon nanotube (CNT) driver (ok just a variation of the dynamic driver), the Starfield (rhymes with Garfield) is marketed as the musical, easy-listening complement to the incisive, reference-tuned KXXS. I’m always tickled by CNT drivers because it’s one letter away from the most offensive word in English.

It’s can’t. Can’t is a horrible four-letter word.

The Starfield is available via Moondrop’s official Amazon and AliExpress pages. I’d like to extend my sincere thanks to Moondrop for the review unit and their patient communication.

This review was first featured in Headphonesty.

Equipment Used:


  1. Sony NW-WM1A “K” Modded, FW 2.0
  1. Moondrop Starfield
  2. Tanchjim Oxygen
  1. Aaron Neville – Warm Your Heart
  2. Bruno Mars – 24K Magic
  3. Fleetwood Mac – Rumours
  4. Hozier – Wasteland, Baby!
  5. Jill Barber Band – Mischievous Moon
  6. Macy Gray – Stripped
  7. Michael Jackson – The Essential
  8. Taylor Swift – 1989
  9. The Dark Knight: Original Motion Picture Soundtrack – Hans Zimmer & James Newton Howard
  10. The Eagles – Hell Freezes Over

Technical Specifications

  • Driver: 10mm dual cavity Carbon Nanotube (CNT) diaphragm
  • Sensitivity: 122dB/Vrms @1kHz
  • Impedance: 32Ω±15% @1kHz
  • Frequency Response: 10Hz – 36kHz
  • Effective frequency response: 20Hz – 20kHz (IEC60318-4)
  • Connector: 2-pin 0.78mm
  • Cable Length: 1.2m
  • Cable Material: 24AWG Litz 4N Oxygen-Free Copper (OFC)

This improper unboxing has Brad Pitt yelling “what’s in the box?” incessantly.

Packaging and Accessories

Well, I received the reviewer’s package, which is just a little baggie with the Starfield IEMs, cable, and 6 pairs of silicone ear tips of various sizes. The full retail package comes with delightful anime box art, and probably more accessories than you can shake a stick at, but I wouldn’t know.

The midnight blue cable looks like a variant of the generic Plastics One cable, with a handsome splitter of the Moondrop logo the only notable difference. I like the paint job, and at this price I shouldn’t complain, but I’d definitely like to see a thicker, higher quality stock cable.

Design and Build Quality

The Starfield is essentially the KXXS with a coat of woohoo paint. As a refresher, the shells are made of zinc/aluminum alloy, with a crease down the middle separating two halves. The angular faceplate exclusive to itself and KXXS, like brothers from a different mother. Wait, it’s the same mother. Being metal, they are heavy for their size, but are a joy to handle, and wins durability points.

But here the star (sic) of the show is the “special painting tech” which coats the Starfield in a glittery navy blue/purple gradient. The colors change as you rotate the earpiece, and sparkles under a light source. The Starfield reflects a lot of light thanks to the angled faceplate, highlighting the intricate, innate beauty of the shells. This is vanity of the highest order, and I love it! They should market the Starfield with Coldplay’s “A Sky Full of Stars”, because those words describe their looks best.

“Do you happen to know the way to infinity and beyond?”

Fit, Isolation and Comfort

The Starfield softly whispers in my ear.
“I’m going to slide in now, ok?”
“Will it hurt?”
“No. Trust me.”
“Sure thing, sweetheart.”
“I forgot to bring lube!”

And in goes the small but sturdy earpiece into my ears. The faceplate might have all the funny angles, but the inner surface of the Starfield is smooth and seamless throughout. They fit comfortably, and despite being made of metal, stay put most of the time. The stock tips provided an excellent seal, top marks for that.

The Starfield has two vents on each earpiece, but despite that, isolate better than expected. I thought I would hear my colleague chew from across the room, or the randy cats outside the office, even with music at full blast. But lo and behold, the Starfield was able to block out as much as 70% of external noise, even the cats. This might be because the vents are at the inside surface of the shells.

Sound Quality

The Starfield is but a blip in a sky of budget Chi-fi IEMs, so what matters most is the sound, for a good tuning echoes in eternity. Or more accurately, rides the hype train a while longer.

Overall Sound Signature

According to Moondrop, Starfield’s tuning is based on the Harman target response curve, but with a few adjustments. What I hear is a fuller midbass and lower mids section compared to the other Harman-neutral IEMs, essentially making this a warm Harman, if such a term exists. I’ll call it the Warman Harman.

This particular beast veers close to L-shaped territory, owing to the boosted sub-bass and midbass, mildly elevated upper mids and lower treble, and a neutral mids response. Put together though, it’s a fun and agreeable tuning with emphasis on round, full-sized notes, with a soft and delicate touch.

This will not scrutinize nor slice through your music with the exactness of a paring knife, the Starfield is more like a big spoon that stirs all musical elements into a big pot for a harmonious broth. The best part is, the soundstage is large enough so the music doesn’t blend into a mess, like when you mix more and more colors and eventually everything becomes brown. A space oddity this is not.

Listening Conditions

Critical listening was done after 50 hours of burn-in, breaking down this stubborn CNT and rendering it a submissive, blubbering mess. I hear no difference after burning in though, so make of it what you will. The main review rig is Sony’s NW-WM1A Walkman modded by Project K, using the stock cable and stock medium tips.

Subtle purple is my proper people.


Across the universe, the stars crash and collide… in star wars. I’ve always wanted to say something epic and cheesy. The bass likes to think in grand proportions too, settling for nothing less than thick, full and rounded notes ad infinitum. The sub-bass reach is impressive, delivering boisterous and ballsy blows. It’s a welcome rush to the ears whenever the sub-bass bellows in full glory.

The midbass doesn’t shy away from the action either, and carries on the foundation laid by the sub-bass. It starts with rounded-off attacks, followed by a hefty note body, and finished with a smooth, lingering decay. Notes are punchy and physical, delivering might and fury whenever needed. It’s Thickasaurus time, all right!

Predictably, you know where this leads. The bass is heavy-handed, bloaty, and at times overwhelming. Bass speed, texture, detail and layering all take a back seat to the almighty full-on bass attack. This is not your textured, layered bass, but a fun, take-no-prisoner boom-boom Becker bass, that bleeds unapologetically into the mids after one too many drinks.


Picture a geyser, a waterfall, or a virgin gir… scratch that. The Starfield mids are so fluid, they might as well be wet. The calm, assured flow of one note to the next is so buttery and eloquent it’s like Bruce Lee standing next to you saying “be water, my friend”.

The after-effect of the midbass hump is a plump, luscious lower mids section. Male vocals have a bellowy, weighty edge, while bass guitars and cellos have an authoritative body. The middle to upper mids leave me spellbound, with sufficient richness to sound luxuriant, yet enough air to sound ethereal. Strings and female voices affect me as if they were real.

Notes have the right thickness, and decay with a gentle flutter. The texture is fine as silk, with nary a hint of grain. Transient response is, predictably, a bit sluggish, but coherence is just about perfect from the lower mids to the upper. Aided by the Harman curve or not, the mids are tuned wonderfully and a worthy highlight. It’s time to yield and be healed by the majesty of the Starfield.

Behold! The color gradient in all its radiant glory!


Like dipping your French fry in ice cream, the Starfield treble is a crispy snack wrapped in layers of creamy smoothness. Like the rest of the signature, the treble is playful with a side of mischief. With a nice bump in the lower treble, notes are quite energetic and airy. Cymbals and hi-hats have an audible crunch and good shimmer, with details to spare.

At the same time, there is a fullness to the notes that prevent the treble from sounding brittle or too airy. The solidity and smooth flow of the notes dial back the flippancy and adds a dash of seriousness, like putting glasses on a toddler. Before the notes take flight in a flurry of sparkle and air, gravity and weight make sure the notes are well-fed at the start.

The extension is alright, with a dip starting in mid-treble. Some treble-heads might want a dangerous, strident treble with more glory and panache, but for the most part, the Starfield is executed well, with musicality and agility in equal measure, if a bit too safe.

Soundstage and Imaging

Space… is as big as it gets. You think of the planets, the cosmos, the reaches of the sky we have yet to discover… I’d like to say Starfield’s soundstage is like its namesake, but that’d be an outright lie. But still, it’s quite good, better than many in its price range, with a width that’s more appreciable than its depth and height.

Importantly, notes have space to play and breathe, and a good amount of air tails behind. Except for the midbass, you’ll never accuse the Starfield of sounding congested. Imaging does its job, with well-defined cues in all three axes. You relax and drift away as the music envelops you and unfolds naturally. It’s like sitting in the front row of a performance, not as engaging as onstage, but you won’t miss anything either.

The Starfield is so attractive, he’s forming his own solar system.


Tanchjim Oxygen

As you may know, Oxygen was a hit-or-miss, save for the brilliant mids. But does that mean I dislike the Harman tuning as a whole? This then, is the litmus test, a tale of two Harmans. We might never know what a verbatim Harman tuning sounds like, since Sean Olive and company came up with the frequency graph but left the IEM-building to other manufacturers.

So implementation of the graph becomes paramount, and Oxygen’s hollow lower mids and treble bluntness killed most of my love for it. Still, Starfield, at less than half the price of the Oxygen, seems to have a mountain to climb. The Starfield already has a leg up with a more attractive design, scratch resistance, and better fit, but it’s all about the sound.

Comparing the two, you hear similarities in tone. The boosted bass, forward mids and natural, realistic timbre are the main selling points of both, but there are many differences to be had as well. Although both are tuned to be smooth and tuneful, Oxygen on the whole is more resolved and immediate, while Starfield is more open and laid-back.

Oxygen is better extended in the sub-bass with a more visceral response, while Starfield has a much meatier and engaging midbass, sometimes to its detriment. Oxygen’s main weakness, the recessed lower mids robs male vocals and plucked strings of body and presence. Starfield glides through this area effortlessly, with a fullness that Oxygen can only be envious of.

The highlight of both IEMs are in the mids, and are equals in tone, note density, and lushness. However, Oxygen is more aggressive and forward, and can be shouty and raspy especially in the upper mids. Starfield is more controlled and refined throughout, with an airy finish to the notes that’s never harsh.

Starfield’s playful treble is shimmery with plenty of air, while you already know I don’t like Oxygen’s. Crucially, Starfield has a much larger soundstage, lending a more spacious and calmer presentation. I can wade through any musical mess with ease, while Oxygen just sounds suffocated at times. It seems you have to look to the stars for answers, and to me it’s clear. Starfield is simply a better-tuned IEM.

Sights firmly set on the Woodywood Walk of Fame.

FInal Words

Starfield, high yield, a stellar earphone is now unveiled. If you’ve ever wanted a taste of the Harman tuning on a budget, this is an outstanding example. Starfield has many things in its favor to illuminate the price bracket, particularly the luscious, warm signature that soothes the soul. The marvelous starstruck design is just the cherry on top.

Sometimes though, there is no happy ending. The Starfield, as good as it is, might get lost in a tsunami of similarly-priced Chinese-made IEMs, especially when dozens are rolled-out every month. The worst part is, the standard of budget has been raised for some time, and it is harder to find a genuinely bad IEM these days.

What Starfield has going for it is Moondrop’s name recognition, spotless reputation, and tuning mastery to weather through the Chi-fi storm. The Starfield will appeal to many with its pleasing, mellifluous tuning, but is that enough to stand out and last beyond flavor-of-the-month (FOTM) status? Only time will tell.


- Value for money
- Eye-watering design
- Excellent build quality
- Assured fit and great comfort
- Good isolation
- Well-implemented (if modified) Harman tuning
- Fluid, coherent tuning
- Beautiful mids
- Even treble response

- Soundstage size and imaging


- Too much competition in this price bracket
- Fragile cable
- Midbass bloat and bleed
- Bass speed and texture
- Overall sluggish transient response

- Treble is a bit too safe

Rating: 4/5
We present an earphone with a peer-reviewed sound signature that should by right, please everyone. With the age of research comes the Harman tuning, and the Tanchjim Oxygen is one of the fruits of this endeavor.

Air. Water. Food. Earphones. The universe is pretty clear about what is absolutely needed for living organisms to survive, and has given warning signs should your life be threatened. We have come so far and lived so long because we react to thirst, hunger, breathlessness, and deafening silence. The absence of music just worries me to death, you know?

Thankfully, many are on the same page as me. We slave all month to earn that paycheck and spend lavishly on food, beverages and in-ear monitors (IEMs). Luckily the air is free, but not so fast. Tanchjim likes to think that their greatest creation, dubbed the Oxygen, is as essential as air itself.

But who are they? Tanchjim (probably pronounced “thanks Jim”) is a Chinese company formed in 2015 and specialize in IEMs. They create their IEMs based on two tenets, that is cleanness of build and sound quality. To achieve the former, their IEMs are packed in neat, minimalist boxes. For the latter, they turn to the Harman Target Response Curve.

The Harman Target Response Curve is, in simple terms, a very educated guess at an ideal sound signature that will please most people. Conducted by Dr. Sean Olive and Todd Welti of Harman International, the research produced two target curves, one for headphones and the other for IEMs, as a guide for manufacturers to build better transducers. Products that follow either curve are deemed Harman-neutral.

Pristine and pure, just like an ad for whitening cream.

Today we look at Tanchjim’s flagship IEM, the Oxygen. Using a single 9.2mm graphene dynamic driver contained in a stainless steel shell, this Harman-neutral IEM represents the fulfilment of Tanchjim’s philosophy. A simple and pure IEM made to please your eyes and ears. They definitely turn heads, but will they move mountains?

The Oxygen is currently available at Apos Audio. I would like to thank Apos for the review sample and tremendously fast shipping. It has been a pleasure dealing with them.

This review was first featured in Headphonesty.

Equipment Used:


  1. Sony NW-WM1A “K” Modded, FW 2.0
  1. Tanchjim Oxygen
  2. FiiO FH5
  3. FiiO FA7
  1. Aaron Neville – Warm Your Heart
  2. Celine Dion – The Colour of my Love
  3. Fleetwood Mac – Tango in the Night
  4. Macklemore & Ryan Lewis – The Heist
  5. Queen – Greatest Hits I
  6. Roxette – A Collection of Roxette Hits!
  7. Sade – Soldier of Love
  8. Taylor Swift – Lover
  9. Tears for Fears – Songs from the Big Chair
  10. The Eagles – Hell Freezes Over

Technical Specifications

  • Driver: 9.2mm graphene dynamic driver
  • Sensitivity: 110dB/mW
  • Impedance: 32Ω
  • Frequency Response: 10Hz – 40kHz
  • Connector: 2pin 0.78mm
  • Plug: 3.5mm gold-plated straight plug
  • Cable Length: 1.2m
  • Cable Material: Silver-plated oxygen-free copper (OFC)

Cubes are awesome. More things should come in cubes.

Packaging and Accessories

Tanchjim loves hygiene. Besides (probably) washing their hands before and after assembling their prized IEMs, a lot of thought was given to the retail package. To project the image of cleanliness, who better to draw inspiration from than the masters of packaging, Apple? The gray Oxygen box resembles iPods of old, with few words, big graphics and catchy names (except Tanchjim, can’t help you there).

A full unboxing and uncovering of the layers reveals a moderately well-stocked accessory set. They are:

  • 6 pairs of silicone ear tips in assorted sizes
  • Zippered carry case
  • A silver-plated OFC cable
  • A microphone cable
  • A metal sticker
  • 20 nozzle filters
  • Manual and warranty information
I’m scratching my head at the metal sticker too. The stock cable is lightweight and attractive, with compact and svelte splitters and connectors that project minimalism at every turn. I would prefer a more premium, sturdier cable, but then again that’s not their design philosophy. The metal sticker is probably a loyalty pledge, while the nozzle filters are welcome if your ears are waxy and well, unhygienic.

The carry case is small, and can only carry the essentials, just the Oxygen and the stock cable. The ear tips selection is sparse, and only in silicone. Unlike the glorious tip buffet of FiiO models, if none of the stock tips fit you well, you’ll have to scour for third-party. The mic cable wasn’t of use to me. I’d have preferred a Bluetooth cable since the industry is squarely headed in that direction.

Gotta say, the reflections all over make this a b*tch to photograph.

Design and Build Quality
The Oxygen has a simple, clean (there’s that word again) design, with stainless steel earpieces and sandblasted faceplates. The Tanchjim logo adorns the right faceplate while the word Oxygen is in the left. The shells are medium-sized with rounded-off edges, projecting a sense of calm and understated class. Or perhaps, the sterility of a laboratory.

As for build, the Oxygen is made of food-grade 304 stainless steel with a mirrored finish, like the Tin Hifi P1. Both designers probably had a eureka moment while lunching. The shells are solid and well-built, with uniform smoothness throughout, even at the seams. This is a design that will please many, and should last a long time.

After a few months of use though, the flawless shells invited scratches and smudges, as evidenced in the photography. This is despite normal usage and keeping them in the carry-case when not in use. I don’t keep pets or rabid animals in the house either, just my family lol. So the Oxygen is decidedly high-maintenance, like the ex-girlfriend who can tell fake Chanel.

Fit, Isolation and Comfort
The Oxygen’s all-metal build, thankfully, has rounded edges throughout, so don’t worry about sharp edges poking where it shouldn’t be hehe. The earpieces slide into my ears without any fuss, although the short nozzles might prove worrisome. The ear tips provided are wide-bore, short and stubby, and, compounded by the short nozzles, is difficult to maintain a good seal.

The stock tips seal well when I’m seated and immobile, but when walking around the Oxygen tends to fall off my ears because of the poor seal. At moments like these, I turn to my Final Audio Type-E ear tips which provide maximum comfort and seal. I sound like an ad you can’t click away, but these tips really work for me.

Isolation is not very good. Not only do you have to scuffle and tussle with the fit, the vented design of the Oxygen works against you too. This is not an IEM to bring outdoors unless you like the “ambient” function of true wireless earbuds. A lot of outside noise is heard, and you can see (hear?) why the Oxygen is mainly an IEM that stays indoors.

In an alternate universe, ladies would gift these to you as jewelry.

Sound Quality

For people who haven’t quite gotten the gist of reading a frequency response graph (that would include me), don’t despair, I have a whole section and plenty of words to describe the sound of these babies.

Overall Sound Signature
Transducers that follow the Harman target curve are called Harman-neutral, as is the case with the Oxygen. But what does that mean actually? The adjustments to the sound signature include an elevated sub-bass and midbass, neutrally-placed mids, and raised upper mids to lower treble, aiming to deliver both detail levels and fun.
So if every IEM was Harman-neutral, would they all sound the same? Not necessarily so. The Harman curve only tells you the amounts of bass, mids, and treble in relation to each other. Other parameters like tone and timbre, soundstage size, imaging accuracy, and note characteristics cannot be measured. It also depends on the driver among other things.

For the Oxygen, they’ve decided to go full Sade. Like her biggest hit “Smooth Operator”, the Oxygen aims to project smoothness and relaxation at every turn. Like drinking a quality smoothie, not those poorly-made ones with uncrushed ice at the bottom, which will land you in the hospital if you took a hard sip.

The inherent weakness among Harman-tuned IEMs are, manufacturers willingly follow a tuning template that should please most people. But when you think about it, does anything really? So critics of the Harman curve say the tuning follows an overly safe, inoffensive route, sort of like vanilla ice cream. It’s… nice, but hardly lands in anyone’s favorite lists, yeah? But let’s not put the Oxygen on the chopping block just yet.

Listening Conditions

Critical listening was done after 100 hours of burn-in, breaking down the thick and rigid graphene dynamic driver and reducing it to a delectable, beefy stock. The transients are a tad faster after burn-in but it could just be my mind messing with me. The main review rig is Sony’s NW-WM1A Walkman modded by Project K, using the stock cable.

I fall for shiny objects, but my fingerprints say otherwise.

Speaking of vanilla ice cream, Oxygen’s sub-bass licks are tender, loving and gentle. Extension down below is excellent, with an audible thump and good rumble, like sitting on a massage chair who wants to get friendly. It’s not head-rattling nor overdone, which is nice. This is a well-behaved sub-bass that will please, surprise surprise, most people.

At the midbass, a mellow bloom lends warmth. Notes are rich and rounded, flowing from one to the next with good timbral accuracy. Attacks are smooth-edged and cut back on urgency, while decay takes its time. This is a warm, gooey and relaxed midbass that I wish would hit harder and faster. The slam isn’t satisfying enough, dynamics are subpar, and there is smearing in fast passages.

Moving up, the upper bass is de-emphasized, with a big scoop from here to the lower mids, which prevents bass bleed and increases airiness, but thins out the sound. The music seems uninvolved and lacks character, like drinking soup with too little salt. I want commitment and conviction! Overall, the sub-bass is worthy, and details and layering are decent, but the bass is let down by a weak punch and lean upper section.


Let’s start with the worst part of the mids, since there’s no escaping the specter of the upper bass to lower mids recession. The meat of the music may be in the mids, and here’s where it’s the boniest. The Oxygen renders male vocals, bass guitars and cellos with trepidation and hesitation, sounding reedy and nonchalant, and pushed back in terms of placement. This is the tardy kid of the signature.

From the middle mids, things get better, and finally, Oxygen gets his moment to shine. Your toes start tapping and jaw starts snapping, for the soul of the music is back. The center mids are so good they paper over the cracks and imperfections of the rest of the signature, sounding remarkably natural, organic and full-bodied.

Female vocals, guitars, and pianos sound enchanting and soulful, with a hint of speed. Notes are well-rounded and decay beautifully, imbuing a sense of air and fleet-footedness. This carries on into the upper mids, violins and brass instruments ring out with majestic bravado and supreme confidence. The timbre is spot-on and well-balanced, providing enough details to go with the euphony. The highlight of the Oxygen is here, and the mids alone are worth the price of admission, helping you forget about past transgressions.

Needs some heavy makeup to hide all the blemishes and shame.


This is where you might want to ask for your money back. Listening to the treble is like a trip to the dentist, or Sade’s second-biggest hit “Tooth Operator”. The notes have no bite nor urgency, like a meal of porridge after losing a few teeth. It’s overly smooth and inoffensive, providing just a bit of shimmer at times, but averse to risk and perhaps, rewards.

No doubt, timbre is still quite good, with a natural and realistic tone from the lower to middle treble. But with excitement levels akin to wearing socks with flip-flops, it’s hard to be aroused or enthused by the sonic equivalent of warm drinking water. It’s no surprise the treble leaves the party early too, as the extension levels fall short and the signature lacks airiness up top.

This is a treble tailor-made for mild-mannered people who veer on the safe side of everything, who dip their toes into the pool and return indoors. Some will find this agreeable, but for me, it’s an aid for curing insomnia. A good tone but devoid of transparency, air, details, and most of all, energy.

Soundstage and Imaging

Like Sade’s third-biggest hit “Booth Operator”, the Oxygen’s soundstage size felt boxed-in and intimate. It wasn’t impressive in terms of width, depth and height, providing an on-stage feel with the musicians surrounding you in a game of musical chairs. The music surrounds your head, sometimes entering it, providing little breathing space despite being named Oxygen.

Imaging and separation do much better. Anchored by the winsome mids which take centerstage, imaging cues are precise throughout the X and Y-axis. While the smearing in the midbass prevents a thoroughly clean and airy stage, the Oxygen does enough to immerse the listener in the music, aided by the small soundstage in fact. You feel like you’ve just booked a private, one-on-one session with your favorite musicians.

Frustrated with life in the spotlight, they make a hasty retreat.


FiiO FH5

At the gates, my $300 benchmark awaits. The FH5 has a detailed, exciting W-shaped signature that is the direct antithesis to the calm, smooth and if I may, bland Oxygen. I won’t pretend to be unbiased, because FH5 possesses one of my favorite tunings, and I’m struggling to reason why you should get the Oxygen when the FH5 is available for nearly the same price.

If we look at the sound characteristics, FiiO’s mid-tier hybrid has more visceral sub-bass, punchier and tighter midbass than the Oxygen. Crucially, the treble is crisper, airier and a magnitude more detailed. These are the most obvious changes, but what a glaring difference they make to the sound, injecting pace, rhythm, urgency and most of all, a sense of fun to the mix.

Looking at technical ability, the FH5 is more extended in both ends, with a sharper attack, swifter decay, and much better note definition and transparency across the board. The FH5 is clearer, hits harder, and handles music with more finesse. The Oxygen is made to eat humble pie and like it.

The Oxygen doesn’t go home empty-handed and get some nice party gifts. The mids are a tier above in terms of tone and timbre, while the imaging is more accurate. But mids alone can’t save the signature when the FH5 is obviously a better all-rounder. Their both shared weaknesses are the lower mids dip and a small soundstage, but taken as a whole, consider Oxygen’s butt well and truly owned.

Out in the wild, their prospects of survival aren’t glittery.

FiiO FA7
The previous battle was inexplicably one-sided, but what about lesser opponents? The FA7 takes a similar route as the Oxygen, going for a warm, luscious sound that is gentle on the ears and high on emotion. Both IEMs weave some mondo mids magic to entice and enchant our gullible hearts and wallets, so this should be on more of an equal footing.

So across a warm climate and template, they are evenly-matched. Oxygen boasts a more robust, thumpy sub-bass, chugging away at the bottom while FA7 is better-extended and more energetic in the treble region. FA7’s mids are more liquid and dense, like thick maple syrup, but Oxygen manages the same arresting tone while sounding more nimble and airy.

The slugfest continues and spills all over the arena. FA7 has a bigger soundstage but Oxygen has sharper imaging. Oxygen has a more solid build but FA7’s accessory package is better equipped. Their main weaknesses, Oxygen’s lower mids dip and FA7’s midbass hump are equally infuriating, robbing both IEMs of greatness.

This is a battle of the flawed titans with no clear winner. That being said, both are equally suitable for prolonged, non-fatiguing listening sessions with beautiful mids, so pick your poison.

Nothing rhymes with oxygen, I’ve tried, and was left flummoxed-ygen.

Final Words

Sometimes, all I need is the air that I breathe and to love you. The Harman target curve has the noble intention to elevate tuning expertise as a whole, by providing a usable blueprint for manufacturers to follow. It’s like publishing a recipe for a foolproof, fail-proof soup stock so nobody would ever have to make do with bad soup again.

Of course, recipes can be followed to the letter, or you can take several liberties with them and call them your own. Tanchjim chose to tune their flagship with a beautiful tone in mind, and for all intents and purposes, they’ve succeeded. The Oxygen has a tone to fall headfirst in love with. Even when taking into account its weaknesses, you have to admit, nothing is jarringly wrong with the tuning.

Yes, you can pepper the sound with more excitement, the bass could be meatier and more wholesome, but given the chance, the Oxygen stands on its own as a well-implemented take on the Harman tuning. And this, my friends, is just the beginning. With more and more companies tweaking and releasing their own version of the Harman signature, this might just be the new mainstream.


- Good, clean packaging
- Good, clean design
- Lightweight and durable
- Pleasing, inoffensive tuning
- Sub-bass response
- Mids tuning and timbre

- Excellent imaging capability


- Sparse ear tips
- Shells prone to scratches
- Short nozzles, needs tip-rolling for best fit
- Poor isolation
- Bass lacks slam and definition
- Recessed upper bass and lower mids
- Rolled-off, overly smooth treble
- Overall detail and transparency

- Small soundstage

Rating: 3/5