Aroma Audio Thunder

TONALITY: 8.2/10
TECHNICALITIES: 8.8/10
CONSTRUCTION: 8/10
SOUND VALUE: Cannot apply


INTRO
Aroma Audio is an high end earphones company based in China. They create high end IEM since 2015 and have a solid fan base here on Headfi. They seem to specialize in hybrid and tribrid IEM. I didn't find much info about their story so I can't share anything more.
Today I will review their Thunder high-end IEM, which is an hybrid with 1 dynamic driver and 10 balanced armature.

Having tested about 20 pairs of earphones priced between 1000 and 4000$, let see in this review if the Thunder worth the big investment or is just a niche product for those audio enthusiast with too much money to spent.

CONSTRUCTION

Since these are loaner unit from a gentle canadian friend, I don't have all packaging and accessories so I will only comment on the IEM and cable.
The IEM construction is OK, nothing mind blowing, it use medical grade resin plastic and have a rather uninspired design.The housing is big and chunky with very thick nozzle, so, for people with small ear hole it might be too much. They are light and have a recessed tuning switch that need a tool or nail to be able to use.
I do encounter driver flex issue, but it's perhaps due to my ears.
At this price, the construction is underwhelming.But the cheap cable is even more underwhelming and quite an insult for serious consumers. As seen in the pic above, its similar quality level as the BQEYZ KC2 cable, which is a 35$ IEM. So, this cable cost less than 5$. This is unnaceptable for a 2500$ IEM and sure have a marketing strategy of making you invest in a cable upgrade. I find this approach quite cynical. The owner of these IEM underline me how bad and disapointing is the cable, and let say i feel very empathic for him so come on Aroma, you can do better! PM me, i can suggest you lot of great cable company with 10-30$ cables that will feel like TOTL compared to this joke.


SOUND IMPRESSIONS


The Aroma Thunder is all about smooth near neutral immersive balance, it wanna cuddle you in it's fully resolved tonality and intimate surrounding. It's not here to impress you with vivid treble or big bass boom, it's not an IEM using easy wow effect tricks to entertain the listener and tend instead to favor the fullness of presence over other part of frequency. Well, in fact, since it have 2 tuning choice, you do have the choice between a warmer bassier balance (Focus mode) or crisper more neutral and transparent musicality (Harmony mode).
The tonal balance can go from warm and thick L shape tonality to smooth, clean and airy (near neutral) U shape depending of tuning switch choice. You can decide if you want bass warmth to embrace tonality and boost lower mid range or go for a more lean and gently analytical tonality.

One thing that merit applause, its how cohesive the 10 balanced armature are tuned in a liquid organic way without any spike or harshness. The dynamic driver doesn't feel detached but to my ears do have a slightly warmer and denser timbre that can be perceive, in Focus mode the DD inflict warmth that thicken mids and tend to make overall listen more laid back.

In this review i will mostly describe the Harmony mode, because it's easy to imagine Focus mode: just add warmth that thicken timbre but affect transparency and resolution. Focus mode tend to affect negatively the technical precision and accuracy, but can be perceive as offering a more natural timbre, which is mostly positive for vocal that gain in lower mids harmonic.

So, in Harmony mode, the Thunder is far from being a fun or basshead tuning, it's not a treble head tuning either, but what we can call mature neutral that doesn't go analytical or cold sounding and have just enough bass boost to offer proper dynamic and note weight.

The bass is more about (colored) quality than quantity here, and it's safely tuned to avoid any fatigue induce by too loud punch. Tone and weight is favor above texture and proper definition and separation. We have more su bass boost with just enough mid bass boost to offer proper slam. I might not be for basshead, but the punch is there and well felt, with a warm transition to mid range, not a clean separation. The extension is deep with vibrant and thick rumble, not a lean and clean extension so for contrabass it will lack texture and extension stability making the string feel a bit mor hit than plucked. The bass is thick and well layered, it's not very resonant in impact, so toms instrument will lack a bit of fidelity in their acoustic propagation. It's not the fastest bass not the tightest. It's well rounded and offer juicy grunt that permit electric bass line to be well extracted (more so than acoustic). When you go Focus mode, the slam is warmer, thicker and a bit more impactfull, and the rumble have more headroom which stole spatial deepnest of Harmony mode.
I find the bass performance average for the price, and would say the same if the Thunder was selling for 1500$ less. It's too safe in proper punch definition and energy to be truely engaging and the dynamic feel tamed too, kick drum isn't very easy to perceive in presence and separation between bass and kick is dark, both instrument feeling at same amplitude level.

The mid range is the highlight of the Thunder, and more you listen to it, more you are rewarded with it's understated and cohesive richness. In Harmony mode it's transparent with realist timbre free of harsh grain or overly boosted texture. Thunder doesn't struggle to present each instrument in its full singularity, each of team being carved in 3D rendering with smoothed definition edge that can make the mids feel darker than they truely are in fact. That's the marvel here, it's smooth yet highly detailed mid.While a bit thin with Harmony mode,the Focus mode go notably warmer and thicker, but to the cost of resolution and transparency. So, you have both choice between lush or lean mid range.
Harmony mode offer excellent imaging capacity, it feel open and deep in spatiality and near analytical in presentation. The attack is fast and thighs, more so than bass DD driver. Unlike lower end hybrid or multi-BA, the piano note attack have natural and clean resonance, it's refined and don't feel noisy in sustain-release.
These are the kind of mids that favor male vocal over female vocal. Male vocal are fuller bodied while female vocal are more about presence and have thinner body. We can say the same for bassoon against saxophone or piano against clavichord.

Now, the treble is quite detailed and snappy, but not very agressive nor very sparkly or airy. It does have minimum of openess to it as well as enough brilliance edge to permit acoustic guitar attack being well define, but whatever how much balanced you add, you will never get the sparkle with natural decay of a dynamic driver or EST. But this can mean half cooked treble too, which isn't the case at all for the Thunder wich is full and gently crunchy enough with rich treble texture that will extract every details of percussions in a very elegant and delicate way. With the Thunder, you will not miss any percussions info, which are presented in fast and accurate way, very clean and well timed, if the kick drum was as well resolve, i would suggest those to drummer for pristine monitoring of their playing.
Nonetheless, these are near master of jazz trio, for blues too it might offer tremendous immersive and accurate experience, while for classical it's hit or miss, due to thin violin presentation that have fast and abrasive attack but not the most pleasant timbre. Electric guitar too sound a bit thin and tamed in dynamic, but the presence is textured and detailed enough.

Spatiality is rather intimate, in the sens its average wide and tall but have rich deepness to it. This is due to center stage being a bit more recessed too, which explain some part of mid range being thinner than other. But we can dig in transparent sound layer in all freedom, which is a sign of high fidelity rendering.

Imaging is excellent, very accurate and precise even if not the most spacious in instrument separation when it come to bass and mids. Treble have more space, for ex, percussions doesn't feel compressed at all and add slight sens of stereo openess.

SIDE NOTE:

The Aroma Thunder don't benefit big amping but clean stable audio source with low impedance. They sound better at low gain with both the Hiby RS6 and Moondrop Dawn 4.4 which was mostly used for this review. RS6 pairing tend to make mids a bit more upfront, bodied and natural sounding, while Dawn 4.4 add a bit of spatial openess and deepness.
I struggle alot to find proper ear tips with those, and finaly go for short wide bore ear tips that open up headroom a bit and improve imaging and layering of bass, mids and treble. With those tips, i encounter driver flex which is certainly worrysome for an IEM of this price, but this might be due to my ears.
The stock cable is very underwhelming and justify fast upgrade, i get cleaner more dynamic and open sound with Tri Grace S cable.
The tuning switch is a little annoying since it's recessed and you need a tool or nail to push it, so, it's not very practical if on the go you want some vocal euphony while your on Harmony mode.

Construction and design is a bit underwhelming for this price bracket, in fact, back design motif are very same as Kiwi Ear Cadenza, plastic quality too, medical grade. The fact 2pin connector are flush on a curved body make cable connection not very well secure, so be cautious to not wear those under the rain since on water drop under 2pin connector can equal in dramatic damage.

Now, this is the part where i want to get philosopher about sound benefit we get with this very IEM. We can begin by saying those IEM are aimed for rich people and not true audiophile from middle or lower class. I would not say this for the Final A8000, GSaudio SE12, nor the UM Mext, and to a less extend, not even for the pricer Fir Audio Xenon 6.
Why? Because we get (long term) WoW effect with all of those, but no truely exciting one with the Thunder unless you haven't listen to alot of IEM in different price range like I do, which is very possible.
Sure, treble speed, details and snap did impress, but it doesn't stand apart in term of quality, spatiality and especially extension. These IEM doesn't age well due to fast tech evolution and especially electro static drivers that are implemented in tribrid to permit proper sparkle, air and brilliance BA just can't achieve.
So, the benefit return here is near 0. Because the Thunder are a ''Jack of all trades, Master of none'' earphones at a price range that should promise something different, engaging and highly impressive in musical experience. Simply put, if i was rich I would be a kilobucks high end IEM collector and these will most likely take dust, while Sony Z1R and even bass light Shure KSE1500 (i'm not that afound off) will not take dust.
Thats my personal opinion based on real money value. IEM priced above 1000$ should deliver a sound experience we want to go back into eagerly, that trigger emotionality and wow effect, in a well balanced but very engaging way. This can be achieve in all tonal balance possible.


COMPARISONS



VS MANGIRD XENN UP (1DD+4BA+2EST-700$)

The Up are more of a crisp smoothly balanced W shape which make the Thunder feel mid centric and warmer, yet not lacking in layering capabilities.
Bass of the Thunder is warmer, looser and less punchy than more define and texture bass of the UP which seem faster and more controlled. Mids are thicker, darker, less transparent with more smoothed upper mids, so attack is less edgy and define, more foggy, layering while decent is more muddy and less clean in separation than UP. Up have thinner but more textured timbre, it have greater sens of openess too and imaging for mids range is notably superior, less dark and warmly saturated.
Treble is notably more extended, crisper and sparklier with the Up, again ,Thunder have a thick presentation, smoother and fuller sounding treble but less sharp in resolution, less define in attack, less generous in micro details. Sens of air is very present with the UP while lacking with the Thunder. The EST of the UP certainly add more brilliance and well felt attack timing, which is lacking with the Thunder.
Spatiality is notably more open, wider, taller and deeper with the UP, while more intimate with the Tunder, so with the Up you feel in front of stage and with the Thunder in middle of the band.
Imaging is superior in all department with the UP, both in proper spacing for separation and proper transparency for sound layering articulation.

All in all, The UP is superior in technical performance byt quite a big margin, yet for tonality it will depend since its very different, but personally i prefer more mature and refined harman target inspire tuning for the UP over smooth mid centric to bassy neutral balance of the Thunder.

VS GSaudio SE12 (8BA+4EST-950$)

Now we have a dynamic driver less hybrid that is notably more vivid, sharp and bright, as well as thinner sounding, more airy, detailed and technical.
The SE12 is all about speed, resolution and snap, it offer spikier W shape balance with faster more define but less extended bass. What hit first is how fuller sounding and more cohesive the Thunder sound, how timbre is more warm and natural but resolution a notch darker on top, again, we have more mids presence and body which make both male and female vocal more enjoyable and wider in presence than S12. Here, we feel S12 is more V shape, then the treble extend furter, open up spatiality in deepness with more recessed center stage. So, overall treble is more thick and organic, smoother and less fatiguing with the Thunder so you can enjoy your music in a laid back way free of fatigue.
Let say if you seek wow effect, the 4 est of the SE12 sure deliver that more than the more understated (and balanced) highs of Thunder. Treble is notably faster, snappier and better separated and define that the Thunder, level of micro details offering is way higher too.
Spatiality is similar in wideness, but taller and deeper with the S12. Imaging is sharper, more accurate, precise and analytical.

There no doubt that technical performance wise, the S12 is from another league, but tonal balance is more cohesive and smoother with the Thunder, yet you most force yourself to be engage within it's niche, safe and wannabe natural tonality.



VS Fir Audio Xenon 6 (1 kinetic DD+4BA+1EST-3900$)

Ok, we are into big boi battle here and well, only thing these 2 have in common is the overall natural and laiback musicality, presented in a very different manner and tonal balance.
The Thunder is more neutral to mid centric with sub bass boost while Xe6 is more bassy L shape to warm W shape. What hit first is how more closed and intimate sound the Thunder compared to wider more open and holographic sounding Xe6.
Then it's the bass, which is more boosted in punch, deeper in rumble and extension and more physical with the Xe6 (especially with bass tuning module), the rumble is more sustain thich and vibrant, it feel better layered too, the kinetic DD make us think their 2DD in there, bypassing limit of lower end acoustic law. With Thunder, kick and sub bass line can feel on same level and lack proper articulation difference in dynamism, while the Xe6 can offer both full bodied bass line and kick punch without canceling each other dynamism.
The mids are notably fuller sounding and more natural, vocal blossom in a wide way and feel more compressed and artificial with the Thunder. Timbre is denser and better in timbral balance fullness. Its not as detailed and transparent, yet, sound layer have more space for proper articulation.We can say Focus mode is slightly more similar in tonality, but suddenly darker, so again, its Harmonic mode i compare too here. Treble is the part we technical performance is superior with the Thunder, yet, less open and musical as well as less sparkly. EST offer sharper brilliance and more decay to sparkle. When it come to lower treble, it's smoother too but fuller, so violin sound more natural and bodied, lusher than Thunder. Overall treble is thinner and colder with the Thunder too.
Spatiality is night and day difference here, the Xenon 6 is way way wider and taller, more holographic and center stage isn't as recessed so it's a bit less deep than Thunder that have a ''tunnel vision'' spatiality.
Imaging is more realist with the Xe6 but your even more in middle of music, it's more 3D and holographic, while it feel more static with extra highs positioning for the Thunder.

All in all, the Fir Xe6 sound more musical and less technical than the Thunder, offer more mids body and lush presence as well as more physical and punchy bass experience and smoother but sparklier treble. Their no doubt the musicality is way more engaging and emotional with Xe6 and could justify an impulsive car selling to enjoy this sound experience, while for the Thunder I will not even sale my rusted old bike.

CONCLUSION



The Aroma Thunder are ''Jack of all trades, Master of None'' IEM, and being so at very high asking price is not really a good news.
If you are seeking for wow effect or intensely engaging or emotional musicality, look somewhere else.
If your seeking for a safe tuning that can go from clean transparent U shape to warm gently bassy L shape, this might be an interesting buy, but at this price the sound benefit is very low or inexistant.
My biggest qualm about these is small soundstage, poor bass separation and thin mid range (especially in Harmony mode)
And well, the price, if i can omit thinking about sound value even in term of musicality my subjective enjoyment isn't met, it lack dynamic heft, mids presence and fullness and spatial wideness.
All in all, it's not an IEM I would suggest to anybody caring about their hard earned money.

The Mangird Xenn Up can be found for 5 times less money (550$ on Ali) and is superior in all department to the Thunder.

Overview:

The Thunder Rolls! Up for review today is Aroma Audio’s Thunder. With a name like that, you really expect these to have a ton of bass, but instead, we get a well-balanced and insightful IEM (that still has lots of bass.) Aroma has put together a 10x Balanced Armature and 1x Dynamic Driver (developed in-house by Aroma) IEM – that’s a lot of nuts drivers! The DD, of course, covers the lows, where DD does best; then, you have 4x BAs covering the low and medium frequencies; another 4x covering medium and high; and 2x more covering the ultra-highs. Dang. That’s basically a driver dedicated to every 500 Hz of the main listenable frequencies. If you don’t feel like reading the review below, know that the Thunder sounds really freaking good.



Build Quality / Comfort:

The build quality on these is great – photos don’t seem to do the shells justice – they’re far more beautiful in person than you would think (very hard to photograph.) They have an almost lava-like style to them. They are also a smaller width than the Thieaudio Monarch Mk2, though quite a bit thicker. They will stick out of your ears quite a bit, so if that bothers you, don’t get them. Aroma sealed the Thunder so that it looks like it’s all one piece, which I like a lot. The Thunder also sits in my ears more comfortably than the Thieaudio Monarch Mk2 (MMk2.) If you’ve read any other reviews of these, people complain about driver pop – this is the first time I’ve experienced this. It’s a thing alright – and it’s pretty annoying. Every time you put these in your ears, they will make a weird popping noise. It’s not pleasant, but only happens when putting them in – so, whatever.

Now For The BOX…ok, the BOXES – there are two and they are a pain. The first is a wooden box (yayyy), but in order to access the treasures within you must solve the FIRST of your challenges (should you choose to accept it.) It literally feels like a puzzle box since there are NO directions included. Not even like…a sticker with an arrow. The trick is to slide the lid towards the right while the Aroma is facing you (there are small cuts in the corners also.) Then, YOU MUST PASS THE SECOND CHALLENGE! Which just so happens to be another box. So, if you smashed the first box with a hammer in frustration, you’ll be happy to know that the second box inside is made of really good quality shiny metal. And yes, once again, there are no indications on how to open the dang thing. Apply your previously learned lesson and you should be able to open the box to reveal the IEMs, a few OK ear tips (I’m using the Spinfit W1 here: https://amzn.to/3DyQ0HB), and a crappy cable. Oh, and the Spinfit W1 DO fit on these nozzles - barely, the nozzles are the biggest I've ever seen (bigger than Monarch) so keep that in mind if you have small ear canals - these WILL NOT FIT your ear...probably, I don't know - I haven't measured your ear.



The Cable Rant – Seriously? What is with $2k+ IEMs coming with the world’s crappiest cables? Spend less on the stupid puzzle boxes and more on the cable. I don’t need a tank/hammer-proof metal case that is impossible to open - I need something like the Monarch or Campfire Audio include – tough, easy to open (zipper), not nuclear proof. I do however need a cable that feels higher quality than the TRUTHER HOLA ($19.) Seriously, just make a deal with Kinnera and get the Leyding for all of your headphones – it’s GREAT (here if you want one: https://amzn.to/3WNqmpm) and it’s modular – they’d even probably color match it for you (black cables are really boring on the $2500 IEM.) Take a page out of FAudio’s book and include a NICE cable for frick’s sake! Stop making me take away points from otherwise good IEMs for a bad cable of all things. When the TRUTHEAR HOLA ($19) has a nicer cable than you, you have a problem. At least it's 4-braid 4.4mm and lightweight – but it’s also tangly and the thinnest wire I’ve ever seen from a cable.

Oh yeah, and there’s a switch. This is becoming another pet peeve. Just stick with the tuning you want the IEM to sound like, don’t make it adjustable - it’s barely noticeable. The two modes are Focus Mode and Harmony Mode – Another TEST! I still don’t know which is which…because who labels stuff like that – also, I haven’t found anywhere that tells you which direction is which. They can be broken down into bassier mode (barely – Focus) and Harmony (uh…less bassier and less treble-ey also? What?) I gave up after switching them back and forth 3 times. Hardly a difference, I couldn’t tell which mode was which, I’m guessing Focus is up – got sick of the popping noise every time I put them back in. Feel free to play with it if you get a pair.



Sound / Source / Comparisons:

Looking at the squig.link frequency response graph from tgx78, the MMk2 is way off where it should be from a better source, but this is the only Thunder graph I could find. The MMk2 has higher mid-bass and low-mids than that Ah well. It appears that the MMk2 and Thunder have similar sub-bass, but I would say the Thunder has more bass without a doubt. The mids look all pretty different, but I would also say that these have somewhat similar mids with the upper-mids being more pronounced on the Thunder. The highs are actually pretty similar between both, so not much to mention there on the freq chart. Quick Note: The MMk2 and Thunder tuning sounds really similar to me while doing back-to-back comparisons, the differences noted below are the main notes to be aware of.



I will be running the Thunder and MMk2 from my Shangling M3 Ultra (M3U) from Tidal Hi-Fi using 4.4mm balanced. The Thunder is much easier to drive (24/100) than the MMk2 (35/100) using a balanced connection. 3.5mm would obviously be harder to drive. The Thunder will use less battery than the MMk2 over time. Now, on to the MUSIC, which is the only reason anyone cares about the Thunder at all – because they sound really good.

As usual, I don’t like breaking down headphones solely by frequency range since every song has bass, mids, and highs (and I can’t tell the difference between vocals at 1900 Hz and 2100 Hz.) So, I will start with bass-heavy songs, then move to mids-focused and lastly highs-focused songs, then break down each song by how all the pieces are presented. You can find my Tidal test tracks playlist in my signature if you want to compare them to your headphones. Our first test song is of course David Guetta’s “I’m Good (Blue.)” The intro bass drums come in hard with a lot of impact and a little more reverb than I like here – it’s not a fast decay, and the bass isn’t as tight as I’d like (personal preference.) The mid-synths come in very clearly and the sense of a massive soundstage can be felt. Surprisingly, the mids are not recessed here despite the soundstage. They feel very forward and at the front with the rest of the sound surrounding you and the sub-bass kicks you in the face. Speaking of the sub-bass, it’s really strong and at the level I like it to be at without overwhelming the mids – it still sounds a bit dirty like the mid-bass, but the overall impression is really good. Hi-hats can be heard clearly so the highs are good as well. The MMk2 has better-controlled bass (tighter), but less of it. The mids are more forward but of similar quality. The sub-bass on the MMk2 is actually more annoying, and kind of overwhelms the mids more than on the Thunder. The hi-hats can still be heard just as clearly on the MMk2. Overall, these two are very close, but the Thunder wins with soundstage and better mids.

OK, I can’t review the THUNDER without using “Thunder Rolls” as my mids-test song. But, since I’m not a Country fan, I’ll be using Overscene’s version. Oh man, does this sound good on the Thunder – almost as if this song was made for it. The intro thunder rolls across both earbuds and the rain makes you feel like you’re really there. The clean guitars come in beautifully along with the singer’s voice. You can hear him taking breaths like he’s singing in your ear – it’s sick. There is so much detail and such a wide soundstage here on the Thunder – I absolutely love it. So, how do the distorted guitars sound at 1:49? Also good, but further back this time – the vocals still take the front (as they should.) 2:30 shows how good those distorted guitars can sound. The drums come in cleanly with good impact without overwhelming any part of the song. Seriously, this is great. So how does the Monarch compare? The thunder in the intro doesn’t sound as close or as good. The rain still sounds solid and the guitars come in nicely. The vocals are good, but the soundstage is smaller and the little details the Thunder displayed are missing. Separation isn’t as good either (in all fairness, the Thunder cost 1.5x more.) The distorted guitars at 2:30 still sound really good, and overall the song still sounds great, but the Thunder is better.

Moving on to Panic! At the Disco’s “High Hopes,” the intro horns come in nicely. The snare drums come in clearly in the background and the 0:35 shift comes through cleanly. There is no significant “S” sibilance to speak of, which is great (there’s a tiny bit, which is common.) The drums come in nicely, though a little muddy, and there are little details I hear in this song I haven’t heard before – the horns are just great. In case you’re wondering, that soundstage is still huge. The Monarch has equally good horns in the intro, though the vocals feel further away and flatter than the Thunder (a surprise.) There is the same amount of “S” sibilance on the MMk2 vs the Thunder, but it is so close that it hardly matters. The drums are definitely subdued on the MMk2, with faster decay and less thump. It’s still good though.

Nightwish’s “Nemo” is the last song I’m going to test with and it’s sort of a grab bag of lows, highs, mids, etc. The highs of the piano come in beautifully and the bass is really well represented. The vocals are clearly heard in the mids and high-mids. The distorted guitars can be a bit much a 0:46, but they never once overwhelm the vocals on the Thunder. The bass guitars also come in nicely, with just a touch of that over-reverb I’ve noticed on the Thunder. The 1:48 vocals sound great, and the soundstage once more is fantastic. Nightwish has vocals that are about as high as you can get, and the Thunder has no issues displaying them perfectly. The 2:36 guitars also sound awesome – the Thunder can do metal AND classical really well (yes, The Piano Guys’ “Code Name Vivaldi” sound great on them as well, though the low-end has too much bloat to beat the Mezzo here.)



Conclusion:

If you like your bass tight, but less of it, and don’t mind the smaller soundstage and worse instrument separation, get the Monarch (it’s cheaper and comes with better accessories.) If you’re OK with a little bass bloat with your increased bass presence and want a massive soundstage, good instrument separation, tons of detail, great mids, and great highs, then get the Thunder. It’s the best all-rounder I’ve heard and it’s nice to finally have something that can beat the Monarch almost entirely across the board. These are great. Ignore the crappy packaging and accessories: Buy a Kinnera Leyding and some Spinfit W1s and just enjoy never having to put the Thunder back in the boxes again. This is my current #1 IEM for sound quality.

Aroma Audio Thunder... the Goldilocks of IEMs

Introduction

I have to open this review by saying I am shocked, horrified, and dismayed that there are no reviews already for Thunder - this is an absolute disgrace! - tongue in cheek, but only sort of. I have bought and tried many IEMs over the last couple of years and I can say with certainty that Thunder represents the best all-rounder I have heard, beating even Traillii or X when it comes to playing absolutely everything in my library with ease - in addition, it is one of the most comfortable; an IEM I can wear for several hours with zero discomfort, the shells sit perfectly in my ears and are incredibly light and smooth to the touch.

The Aroma Audio brand was first brought to my attention by @Xinlisupreme around July 2021. He had bought 'Witch Girl 6.2' directly from Aroma, and his positive reaction to that led him to Thunder a few weeks later - he more or less insisted I buy it, but there were some others in the queue at the time! Thankfully I finally got there, and thank you @Xinlisupreme once again for your strong recommendation.

As a slight downside, it is also the first IEM I've experienced driver flex with. I experience a 'pop' sound on insertion in both ears, very brief but certainly audible. I've read about this before and wondered what it entailed - now I know. I reached out to Aroma and they were very quick to respond, explaining that the pressure/vacuum effect on insertion can create movement in the diaphragm which makes a brief popping sound. Not an issue, but worth being aware of. Oh and I must note also, Aroma are incredibly responsive to any questions - I love when a manufacturer is happy to engage with their end users.

Moving on to caveats. I bought Thunder as I buy most things from @MusicTeck and Andrew kindly provided a discount in exchange for my impressions, these are my honest thoughts and in no way influenced by the discount - I have more than enough $$$ investment in these! As I always note in my reviews - I am not a professional reviewer, it's my hobby and my passion - I enjoy exploring new IEMs across the price spectrum and sharing my impressions with the community. I lack the technical skills to go deep on some components, but do my best to convey what I hear in a way that I hope is useful.

While I've already noted my surprise at there being absolutely no English reviews as yet for Thunder, I'm proud also to put 'pen to paper' as the first on Head-Fi - an utterly incredibe IEM, that I guess is somewhat overshadowed by the big brother/sister 'Jewel' which is gaining a great following as arguably one of the best IEMs in the world - hardly a day seems to go by now without someone else announcing they've taken the plunge with Jewel.

Thunder is available HERE from @MusicTeck and at the time of print with a selling price of $2,560



Specifications

Configuration: 10 x Balanced Armature / 1 x Dynamic Driver
Sensitivity: 108dB SPL/mW
Impedance: 17Ohm(1kHz)
Frequency: 10-22kHz
Cable: OCC 1.2m 3.5mm (note: you can specify 4.4mm on ordering from Musicteck)

The driver configuration is as follows:

• Ultra-high frequency: 2 x BA
• Medium / high frequency: 4 x BA
• Medium and low frequency: 4 x BA
• Low Frequency: 1 x DD

Sources

The vast majority of my listening has been with the wonderful Shanling M9, a flagship DAP that I feel has been overshadowed by other recent flagship DAPs to hit the market, making it a bit of an underdog... but I've already spoken about that in my M9 review, and won't derail this narrative! I have also used to a lesser extent the Sony NW-WM1A and L&P W2.





Unboxing and Accessories

Thunder arrives in an unassuming vacuum packed plastic packet with the wooden box inside. I must say, this set my pulse racing with anticipation, being a sucker for anything that arrives in a wooden box. Upon removing the plastic, heart pounding and ready to dig in, I encountered an unexpected problem: after sliding open the wooden box, there is another metal case which obviously contains Thunder - what's the problem with this I hear you say? - well, let me tell you, it took me about 5 minutes to figure out how the heck to open the box! Eventually, after pushing/pulling/yelling/sweating, I figured out that you need to slide it in one direction, and voila, you are presented with the goods - I guess as my Grandmother used to say, "all good things come to those who wait"....







In the box...

Nothing extravagant once under the hood - you get the basics and all presented nicely in a beautiful wooden box (I did mention I'm a sucker for wooden boxes...)

• Metal case, arguably not fit for purpose as its a nightmare to open and close as noted previously
• Small selection of tips: small, medium, large of a silicone type standard stock tip

Design and Fit

Thunder are a relatively compact shell considering the driver configuration. They are on the smaller side of multi-driver IEMs I've owned and as noted previously, incredibly comfortable. Upon insertion, I really can hardly feel them in my ears - I think this is key to a 'great' IEM experience as it allows extended listening sessions, when balanced with a tuning that complements, which that box is absolutely ticked here too. The shells are very light and while I don't know what the material is, I'm guessing some sort of resin which has a lovely smooth, soft touch.

There are two tuning modes which you adjust by moving the switch in or out (where the blue arrow is pointing in the below picture), out for harmony and in for focus.

1. Harmony - bigger stage, more airy and detailed (I prefer this mode and the default choice for my listening)
2. Focus - narrows to a more 'focused' presentation, enhancing bass and reducing the sense of space (I've not really used this yet...)

Thunder appears to be available in Red or Blue - I don't see an option to choose when ordering and I was a bit torn anyway on what colour and left it as a surprise...





The Cable

I've mixed feelings about the cable - on the one hand, it is very light and not too much in the way of microphonics - on the other hand, it tangles very easily and is quite wiry. I suspect many people will change to their cable of choice or hunt down something else but the stock is absolutely fine if you don't have anything else.

Thunder appears to ship with a 3.5mm jack but I sent a note to both Musicteck and Aroma to request a 4.4mm jack which there was no problem in facilitating.



Listening Impressions

I listen to a very broad selection of genres. To put that into perspective, it can be anything from Supertramp to Orbital... Brian Eno to Aphex Twin - and all in between. Thunder can play any genre, and sound excellent - ambient, rock, techno, classical, jazz, pop... you name it, Thunder will embrace it, and do it with aplomb.



In summary, this is an IEM with an exciting, but refined tuning - it leans slightly warm and while technically capable, I would say it's emphasis is more musical engagement. It has a good size, expansive 3D soundstage with excellent imaging and layering. There is a fantastic sense of air on the stage, leaving everything plenty of room to breathe, but cohesive in delivery. It is very responsive to the music its playing: lively and energetic music will be presented with an exciting delivery - chilled ambient and you've got a nice relaxed, smooth outcome. As noted in the intro, this is an IEM that is a real Goldilocks, i.e. everything is 'just right' - never offensive.

Bass

The name possibly suggests a bass-head IEM, I would say it is not - no slouch however in this department, but I wouldn't consider it skull-crushing or IER-Z1R levels. Mid bass slams with good authority and impact, and digs nice and deep into the sub realms - I'm very satisfied with the balance of the two, this is something I've been paying closer attention to of late, I need a good mix of sub and mid bass - if lacking in the former in particular, its probably not for me. There is no bleed of the lows into mids either, I guess due to the specific dynamic driver handling these frequencies. So again, while not a bass-head IEM, I'd be surprised if the amount of bass disappointed anyone.

Mids

There is fantastic clarity and resolution in the mids with excellent sense of space. Busy passages with various instruments competing are handled without any issue, allowing everything to be heard if you like in isolation as you shift your listening focus, or as the full package. Both female and male vocals have excellent body and depth with an accurate representation typically sitting more centrally. There is an overall captivating, lush appeal to the mids, but not at the expense of clarity or detail.

Treble

As much as Thunder isn't a bass-head IEM, nor is it one for high-energy treble seekers. Treble is nice and sparkly, reaches sufficiently high for my taste and general library - never touching on harsh or sibilant, but enough energy there to retrieve details up top. It doesn't have the same zing as say Z1R or EST implementations in the likes of Traillii or X, both of which have a super ethereal sensation due to this configuration and tuning.

Technicalities

The stage is a very good sized oval shape that extends a good distance in every direction, giving a distinct outside your head experience. The sense of instrument positioning is superb, with locations very easy to pinpoint in that wonderful holographic stage with a nice mix of air, clarity, and relatively lush delivery, and importantly, very cohesive in the overall presentation.

Comparison Test Tracks (there are a few so for the sake of space, hidden in a spoiler)



Comparisons... (I might add more and expand on current over time)

Oriolus Traillii



The key difference I hear when I switch to the bird is a significant increase in definition and soundstage - this shouldn't come as a suprise really, Traillii is known for her technical and tuning finesse prowess and not many IEMs can beat it, some may argue none do (subjective, YMMV etc!). The drop in bass however is evident, especially mid bass impact but sub doesn't dig as deep either as Thunder. I am a big fan of the EST treble on Traillii, beautifully implemented and incredibly visceral. Going back to technical, the sense of imaging and layering on the massive stage is several steps above Thunder - but this is to be expected, and not really a fair fight... Jewel a better contender to step in the ring with Traillii, and a battle I certainly plan at some point. While Traillii is well capable of dealing with any genre, I don't consider it an all-rounder in the way I do Thunder - mostly due to the lack of a DD. I need my DD bass for genres like techno for example, it's impossible to replicate a pounding kick drum with the same level of authority with a BA, they just don't satisfy me in the same way.

Sony IER-Z1R

Most will know the Z1R is considered class-leading when it comes to bass and that is indeed immediately evident here - both sub and mid bass are nothing short of spectacular and without question beat Thunder. It has in general a more 'precise' razor-sharp sound to Thunder, and with a V-shaped tuning, the mids take a step back with bass and treble jumping forward. The Z1R stage is somewhat smaller, certainly not extending to the same height or depth and as a result, the sense of layering and imaging drops a bit back versus Thunder. As mentioned, the treble extends further on Z1R, and sounds almost bright in comparison upon switching - I do enjoy that extra bite up top, but longer sessions can definitely result in fatigue and some music can lean harsh occassionaly. I would class Thunder as having 'safer' tuning than Z1R which maybe has a bolder personality, and not one that everyone will get along with. In addition, there is the Z1R elephant in the room: the fit - for some they don't fit at all, for others they do but need to keep pretty still, and an even smaller group appear to be able to move about with them. I see Z1R as a more risky buy, Thunder a much easier recommendation.

Elysian X

Back up with the big boys here when X rolls in - an IEM that costs around $2k more than Thunder so again probably not a fair fight, but let's hop in anyway and see how we go.

I tested 'Time to Breathe' first by Calibre - this is a nice melodic D&B track with a lot of lush synths, complex/fast drum programming and supporting vocals. X sounds utterly fantastic with music like this, well able to present every single element with superb authority and absolutely wonderful bass and treble - like Traillii, there is this really captivating ethereal signature that just lures me in every time. The stage is a lot bigger on X, with more detail retrieval and a greater sense of layering and imaging.

Like the Z1R though, we have more of a V-shape tuning on X and as a result, mids are not a strong point - I would not feel inclined to reach for X if choosing a more vocal centric album such as the Kevin Morby or Julia Jacklin tracks I posted above. Kevin's voice sounds thin and too far back on X versus Thunder, likewise Julia Jacklin - Thunder much more vibrant mids and vocals more lush, central and forward. In addition, X demands a lot more power - I need to crank up the volume by almost double that of what's needed on Thunder, so a powerful source is needed.

Conclusion

Thunder has become my benchmark IEM as an absolute all-rounder, capable of playing any genre in any listening scenario and doing a wonderful job. Coupled with excellent comfort, it as the potential to be a 'one and done' IEM that could satisfy a music lover with a broad music library for years to come. I've tried many IEMs over the last couple of years, and quite a few have been sold on - out of what's remaining, Thunder absolutely occupies 3rd place in the collection, and that is very high praise. Highly recommended.