One Dot Audio, also known as ODA, is a brand famous for its beautifully crafted IEMs, but they are very hard to find. The reason is that they mainly targeted the Asian markets, especially Korea. However, the good news is that they've recently expanded into the global market, and 'Helios D100' is one of their latest releases aimed at audiophiles. With a 10mm single driver inside, an eye-catching wooden shell on the outside, and a hefty price tag of $284, can this IEM make a strong impression in this crowded chi-fi scene?
ODA Helios D100 Review
A shiny wooden jewel that will make you crave to try them, even for once! And when you do, that can be a really nice experience or your worst one. I fell for its look at the very first time I saw it! I will describe it as a ‘warm-bassy IEM,’ but not a bass-head level kind of thing. I mean, it has a very strong bass presentation, but it lacks the quality I prefer. Not all genres sound good with it. If you like modern pop, EDM, R&B, and Hip-Hop, then this can be a good choice. But for those who are in love with the old 50’s to 90’s era classic rock, jazz, blues, country, and folk music, it may be a bit unpleasant to listen to.
Besides all of this stuff, pairing is really easy and effective. It catches up the tonality of the sources very well. I will cover this later in this review. And I find it’s a bit ear tips sensitive, so you need to explore in this regard. I will also cover it in a different part of this review.
DISCLAIMER
One Dot Audio [ODA] was kind enough to send me the ODA Helios D100 to review. I am not affiliated with Tipsy Audio, and of course, I was not asked for any copy-checking before publishing. All opinions shared in this ‘ODA Helios D100 review’ are my subjective thoughts.
One thing more: The review is based on my personal experience and what I hear from different sources. Your experience may vary because of personal preference and physical differences like the shape and depth of the ear canal.
For your personal purchase, check out One Dot Audio [ODA] for their fantastic products and promotions (non-affiliated link).
GEAR USED
● DAP: Cowon Planue R2, Cayin N3 Ultra, Hiby RS2, Hiby R4, Snowsky Echo Mini, F.Audio M20.
● DAC/AMP: xDuoo MT-604, Fosi Audio GR40, Hiby FD5, KAEI Design TAP2, ifi Hip DAC 2, xDuoo XD-05 Plus (with MUSES 8820 OP-Amp), Cayin RU6, Cayin RU7, iBasso DC04 Pro, Dunu DTC 480, Fosi Audio DS-1, Celest CD-10, Celest CD-20, Hiby FC05, Hiby FD03, Moondrop Dawn Pro.
● Smart Device: Poco X3, Xiaomi MiPad 5.
● Files: Tidal, Qobuz, Spotify, local Hi-Res FLAC & DSD files.
AUDIO TESTING PREFERENCES
I desperately love the music from the 60s to the 90s era. Music was alive then. The genre I love most is ROCK ‘N ROLL. Though Jazz, Blues, Metal, Disco, and Pop are also my favorite genres. I have a collection of albums with high dynamic range recording. Most of the time, I test audio gear with those albums to understand the sonic capability of the specific gear. If you have a Tidal subscription, you may click here to get the playlist.
TECHNICAL SPECIFICATION
● Driver: 10mm single DD
● Frequency response: 20Hz – 20kHz
● Impedance: 16Ω
● Sensitivity: 112dB
● Cable: 4-strand Silver-plated copper
● Pin Type: 2pin, 0.78mm
● Cable Length: 1.2m
● Plug Type: 4.4mm
WHAT’S IN THE BOX
● Helios D100 IEMs
● Silver-plated copper cable (4.4mm)
● 2 types (wide bore & narrow bore), 3 sizes (S/M/L) ear tips
● PU leather carrying case
● Cleaning tool
● User Manual
UNBOXING EXPERIENCE
Unboxing experience is a mixed bag of emotions. I love the dark tone of the box with that golden ‘Helios’ seal on it. It looks elegant to me. Inside, everything is well-organized, and you will have everything you need to use this IEM. But does it justify the price tag of $284? That’s a big question. Think about the $160 Twistura WoodNote; the experience was top-notch. But here I felt like it’s an $80-$100 IEM unboxing. The included ear tips are on par when it comes to quality, which could be better with more choices.
And the stock cable? It’s a 4.4mm Silver-plated copper cable, which is thin (that’s not a big issue though) and has no interchangeable plug! Come on ODA, it is 2026, and the price tag is $284! The inclusion of an interchangeable cable is very normal nowadays. But the PU leather carrying case is really premium. Overall, the unboxing experience was ‘so so’ for the price.
BUILD & DESIGN
Oh, this is where the ODA Helios D100 will have all the praise. Those shiny wooden shells with a ‘tequila sunrise’ type of color will blow your mind at the very first glance. The build is so good that it will give you the confidence to use it for daily wear & tear. Design-wise, it’s jewelry for your ears. The textures are so eye-catching and natural-looking. Though a bit thin, the stock cable is free of microphonic, and it’s tangle-free, which is practical for a daily use scenario. The PU leather-made carrying case is really premium and practical, though it’s not pocketable, it’s easy to transport. I’d prefer not to talk about the stock ear tips.
FIT & COMFORT
First, fit is perfect if you pick the right ear tips for you, since the stock tips don’t seal or fit well. Even my average-sized ears weren’t sealed well with the stock ones. When they seal and fit well, they feel really comfortable. I didn’t feel uncomfortable even in my marathon listening sessions. And surprisingly, they didn’t create extra pressure in the ears, because there are two air vents in the shells, one in the side and another just beside the two-pin connector. And the stock cable is comparatively soft and comfortable, with no tangles or microphonic issues.
SOUND IMPRESSIONS
Though the D100’s sound signature was ‘bashed’ by some of the reviewers, to me, the sound seems very nice. The sub-bass is warm and loose to my liking, while the mid-bass holds a solid authority. The pick in the 5K region was nicely handled by the lower frequencies. Vocals are also fantastic, and the treble is extended with a nice spark. But does the whole presentation justify the $284 price point? I will explain it step by step.
Here is the frequency graph :
Let’s dive deep…
SUB-BASS
Sub-bass is one of the strongest points of the D100, which digs deep with good authority. It has a dense presentation with good texture. It is remarkably there when the track calls for it. I’m a sub-bass lover, though not bass-head level, but I enjoy quality sub-bass. For me, the whole presentation is a ‘love-hate’ kind of thing. ODA tuned the sub-bass focused on quantity, I think. This is somewhat problematic and lacks definition when it comes to my preferred genres, such as classic rock, jazz, blues, and country. But with electronic, hip-hop, and reggae, the story is totally different. The IEM shows its strength in sub-bass tuning with those genres. So, it’s a more genre-based presentation, in my opinion.
MID-BASS
I found the mid-bass goes deep with good weight. The fantastic slam and authoritative presentation make it the star of the show. If you are a mid-bass lover, you will love the Helios D100 at the very first audition. It is articulated, stays at its very own place, and never bleeds to the midrange section. The smooth bass curve from 50-500 Hz in the frequency response shows its bold but smooth presentation. Moreover, it has a satisfying texture and detail. Especially, in genres like EDM, pop, and R&B, the whole characteristics of the mid-bass make the listening session enjoyable. But in genres like classic rock, jazz, and blues, you will find the low end of this IEM a bit softer than you expect.
VOCALS
D100’s vocals are slightly forward, but not on your face. The tonality is natural with excellent timbre and texture. It shows good clarity for both male and female vocals. But in some bright recorded tracks, you will hear those disturbing S, SH, T pronunciations.
MALE
I spent quite some time shuffling through the albums from my favorite male artists. What I found is interesting. The male vocals have a good sense of heft in them with proper density. The wooden chamber plays a good role here, I think. The presentation is rich with velvety texture that will make you feel as if you are listening to any old expensive analog deck set. This is that kind of sensation that many modern, thinner-sounding IEMs simply miss. But on the other hand, I noticed that because the sub-bass has a large extension, it occasionally creeps into the lower-mids and robs the singer of their articulation.
FEMALE
In my experience with the D100, female vocals are the true highlight. I found them remarkably clear and energetic, which has an awesome ‘shine.’ And that makes female vocals very enjoyable. Though they are shiny and energetic, they are far from being sibilant, and there is no fatigue in longer listening sessions. The lift in the upper midrange of this IEM, which, I noticed, gives the female tone a lovely sense of shimmer and crystal clear presentation. Though that upper mid lift tries its best to keep the tone on line, I felt a little ‘fog’ in the female vocals due to that sub-bass extension.
INSTRUMENTS SEPARATION
The separation between different instruments is good enough to give you a sense of space. I can easily differentiate the back voice from the main vocal. And all other instruments in the composition also hold their own place. The whole presentation didn’t get muddled up in simpler tracks. But in busier tracks, I feel the scenario is kind of different. Instruments with similar notes came out like a tangled solid note. In my opinion, the extensive sub-bass was the villain here, and it made it harder to pick up the perfect placement of different instruments.
TREBLE
Helios D100’s treble is on the safer side. It has a good spark without any sibilance. As I’m a treble-sensitive guy but still love myself some quality treble, that’s a good point for me. The hi-hat shimmer or the sweet sound of crash cymbals, ride/ bell cymbals come out right with a natural tone. It also presents a good amount of air and has a comparatively well-defined texture. But I miss the extension. The extension is somewhat just ‘good’ here, but for the sake of musicality and enjoyment, you may want a bit more of it.
SOUNDSTAGE
Good weight, moderate height, and lacks depth- this is my expression on the soundstage of the D100. Weight is definitely good, and I can easily hear the left-right pan and that feel of wide space. The height is not so congested nor so tall; it falls in between. That was a really heartbreaking situation for me when it comes to depth. It’s like a solid wall of music, and everything is in front of you without any breathing space for the whole band. In my honest opinion, it doesn’t justify the price tag of this IEM with this type of soundstage presentation. Sorry ODA! 😥
TECHNICALITIES
Dynamics: Dynamics is just ‘so so’ here. I didn’t feel the perfect contrast between the quiet and loud passages that makes the sound alive.
Speed: Though mid-bass has a good thump and body, the speed is just average in my opinion. The blurry bass decay makes it slower than I’d like it to be.
Analytics (Detail Retrieval): Nah, man, the detail retrieval is nothing special considering the price. I asked for a few more details, but the bass extension always shadowed the finer details.
SOURCES
This IEM is an easy-to-drive type of set. But we all know that a quality current supply can make any earphone come alive. And there is no exception here. A decent DAC dongle can easily drive this IEM, but with some good stuff like the Cayin RU6, iBasso DC04 Pro, Dunu DTC 480, or the Fosi Audio DS1 can bring most out of it. It scales up really well with desktop sets like the xDuoo XD05 plus, MT-604, etc. Just keep in mind that the bass region of these earphones is already too extended, so don’t even try to pair them with any warm sources like the iFi Hip DAC2.
CABLE & TIP ROLLING
This IEM, the Helios D100, is really tip sensitive. A wrong tip can give you a worse experience, so beware. In my very first testing session, I used my beloved NUARL Track Ear+ ear tips, and that was a huge mistake. They made the sub-bass bloated, and it bleeds to the lower mids. That’s a true nightmare for me. But then I realize my mistake and roll some ear tips. These earphones show a very good performance with the TANGZU Tang Sancai Noble and Softears UC ear tips. And when it comes to the cable, the stock one is fantastic, and you don’t need to pay extra for any aftermarket ones.
FINAL THOUGHTS
The ODA Helios D100 is the most polarizing IEM I’ve ever reviewed. The experience is so mixed up. I’ve been expecting a lot more from it. Though those nice wooden shells are the first thing that will make you crave for that, what you will hear after you start listening to it may let you beg for more. Yes, there are a lot of audiophiles who adore that ‘warm-bassy’ sound of this IEM, but for my personal tastes, I expected a bit of clarity with a reasonably good soundstage. I’d highly recommend trying to get an audition before you drop the cash.
WHATEVER YOU’RE THINKIN’ OF BUYING—DAC, DAP, IEM, HEADPHONE, AMP, WHATEVER—JUST MAKE SURE YOU GIVE IT A DEMO RUN FIRST. TRY IT OUT, LISTEN TO IT WITH YOUR OWN TRACKS. SERIOUSLY, ONE QUICK AUDITION CAN SAVE YOU A BUNCH OF MONEY AND REGRET LATER ON.
You are welcome to read other reviews by SONIC MANTRA.
