New Head-Fier
TGXEAR SERRATUS (Reviewed by Kenzo Stevens)
Pros: 🟢
• Highly refined balanced reference sound tuning.
• Neutral and transparent midrange tuning.
• Top-shelf resolution and soundstage imaging.
• Large, spacious, airy, and well-layered soundstage.
• Lifelike timbre, excellent imaging, and great for classical music.
• Good treble and bass extensions for earbud performance.
Cons: 🔴
• Requires power to achieve its full potential.
• Can sound sibilant due to mid-treble peak.
• Somewhat soft-sounding sub-bass notes.
• Open design means zero passive isolation.
• Not basshead-friendly.
• Can sound cold and thin if you are used to a warmer tonality.
TGXEAR Serratus:

Introducing the TGXEAR Serratus earbuds, the first released flagship model from the new and exciting brand TGXEAR. Jim Park, the man behind the brand, is a music-loving engineer who has been tinkering with headphones and earphones for years. The Serratus earbuds boast a 300ohm driver, a sensitivity of 102dB SPL at 1mW, and require a bit of power to really shine. Priced at $200, they offer a big soundstage and presentation that competes with headphones and IEMs that are four to five times more expensive. As an earbud enthusiast, I was excited to try out the Serratus and see if they could deliver the full potential of the earbud form factor. Jim's passion for music quality is evident in his designs, which are ideal for classical music. With several models already released, including custom options, and rumors of more models in the works, TGX Ear is the place to go for those interested in high-quality earbuds.


My Source and Reference:
  • Topping L30
  • Topping E30
  • Etymotic ER4SR


This is my first proper review on Head-Fi and I'm not an audiophile. Although I don't own Headphones or IEMs above $1000, I've had the privilege of experiencing TOTL models like Hifiman Susvara, Abyss AB1266, Focal Utopia, Audeze LCD-X, Empire Ears Odin, and U12t during my visits to audio shops in the Philippines like Egghead Audiohub. As for the audio gears I own, I have the Etymotic ER4SR, DT990 Pro, Topping E30 and L30 stack, and a few budget Chi-Fi IEMs and earbuds that I won't bother mentioning. Lastly, I began my journey into the world of high-quality audio with the iBasso IT00 as my first IEMs.

Just to clarify, this is an unpaid review and I purchased the Serratus earbuds with my own money. Jim didn't ask for a review nor provide any discount or incentive for me to do so. My goal is to share my thoughts and experiences with the Head-Fi community and try something new as this is my first review.


My Pre-ordering Experience:

I would like to express my gratitude to Jim Park for providing me with an exceptional purchasing experience. Although I may have been a really demanding customer, Jim was patient and accommodating throughout the process. Despite my indecision regarding the earbud shells and cables, Jim fulfilled all my requests with enthusiasm and professionalism. At one point, I even requested the Chrome MX500 shells, which he doesn't usually offer, and despite being ready to fulfill my request, I eventually changed my mind. I probably gave him a little bit of a hard time. Living in Bahrain, I was concerned about the shipping cost, but Jim went above and beyond by offering to cover the costs, even if they exceeded $80. I felt like a VIP while ordering from Jim, and his kindness and talent are truly unmatched. Additionally, his paintings are GOT TIER AF!



The earbuds come with a cheap hard case you can typically on AliExpress, but with TGXEAR branding printed in chrome. While the case is adequate, what I really like is the personalized touch of the handwritten product name and serial number by Jim. As far as I know, the VE Foam Pack is not included by default, but Jim kindly gave me two packs when I mentioned that I prefer the blue and red shells with matching VE Foams. Along with the earbuds, I received a TGXEAR business card with instructions on how to properly wear it, as well as a TGXEAR Badge. Jim informed me that since he provided two packs of VE Foams, he reduced the number of default black foams included. This doesn't matter to me, as I am satisfied with the VE Foams. The package also includes a 4.4mm female to 3.5mm male headphone adapter, available for an additional $25. Simply let Jim know if you'd like to add it to your order.


Build Quality:

The build quality is decent enough, though I wasn't expecting it to feel particularly premium. When I first heard about the Serratus from Head-Fi and saw that it uses MX500 shells, I knew it wouldn't feel like a top-of-the-line product. Even though I got the transparent plastic or resin bell shells, I already expected the quality to match that of the plastic or resin MX500 shells. However, that doesn't mean it sounds like it looks. I just like to think this is where they cut the corners, considering that these earbuds compete with IEMs and headphones above $1000, but the Serratus provides a similar experience for a fraction of the cost. Despite this, I think Jim could have made it feel a bit more premium if he had used chrome stainless steel MX500 shells like the VE Master or Tingo TC200. That being said, the cables are pretty good and feel nice to the touch. I haven't tried the stainless-steel bells yet, but I'm sure they would feel even more premium than the transparent variants. I decided not to go for it because I'm not a fan of its texture or brushed finishing. If it had a shiny chrome or smooth satin finish, I wouldn't have hesitated to choose those shells. But that's just my preference, and it may not matter to others. Despite this, I'm still happy with what I have. They feel light on my ears, and the soft cables are of great quality. Overall, I'm satisfied with my purchase.


The Fit and Comfort:

The first time I tried these earbuds, they were so uncomfortable that they hurt my ears when wearing them for more than half an hour, especially since I have really small ears. However, this may not be the case for everyone since we all have different ear shapes and sizes. Some people say that they fit them perfectly, and others say they're good enough. Initially, this was not the case for me. But after wearing them for two days straight, my ears started to adjust. Maybe I just got numb to it, I don't know. After that two-day period, they now fit alright for me. They don't hurt as much as before, and the more I consistently wear them every day, the more comfortable they become. However, when I stopped using them for four days, the discomfort started to return slightly, but it went away again after a short while.


Foams and their Impact on Sound Quality:

I use the VE Foams, specifically the blue and red ones, as they feel and sound better to me. I also use the rubber rings that come with them as the fit is more comfortable with the rubber rings and foams on compared to just foams and the plastic surface that covers the drivers. I didn't like the default black foams that came with the Serratus. The vocals and treble sound less satisfying with those foams compared to when I'm using the VE Foams. Sometimes, I find the treble too bright without any foam, but I also don't like how the default black foams tame the treble a little bit. They are okay, but I prefer the VE Foams more. The blue and red VE Foams are just the right one for me, and I used them the entire time I had these earbuds. I only briefly tried the default black foams as I wasn't very interested in them.


The Tuning:

Bass -
As someone who prefers neutral sound tuning, the bass on the Serratus is just right for me. It's not excessive or overpowering, but still present enough to give music a satisfying depth. The bass is well-controlled and natural, with enough impact for popular music genres. Despite not being bass-heavy, the Serratus still manages to provide a good amount of sub-bass, making the listening experience enjoyable for those who enjoy feeling the thumpy bass notes. As someone who previously used ER4SR as my main IEMs, I appreciate the clean, tight and defined bass on the Serratus. Overall, the bass on the Serratus strikes a great balance with the mids and treble, staying in the realm of neutral and complementing the overall sound signature.

Mids - When it comes to the mids of the Serratus earbuds, I have to say that they're really good and transparent. The way it presents vocals is clear and natural, and I like that a lot. However, as someone who came from using ER4SR as my main IEMs, I still favor the intimacy and transparency of ER4SR's Mids. The Serratus, on the other hand, has a spacious quality that I also appreciate.

That being said, the mids of the Serratus are gorgeous, with a lifelike timbre that works well for classical and acoustic music. The balance is well done, with the midrange being neutral and almost "flat", which creates a great sense of transparency. Instruments and vocals are presented as-is, without any artificial boosts in lower or upper midrange elements. This lack of warmth and loud high notes allows instruments and vocals to sound clear and open, without any overlapping or masking. Of course, this neutral midrange presentation might not be everyone's cup of tea. Some might prefer a bit of warmth in the lower midrange, which the Serratus doesn't provide. But for those who value accuracy, neutrality, and detailed separation of instruments and vocals, the mids of the Serratus are a real treat. The technical element is really something to behold at this price point, and the stereo imaging is among the best I've heard for earbuds.

All in all, the mids of the Serratus are a strong suit, with a great balance and accuracy that makes them stand out in the market. While they may not provide the warmth and intimacy that some listeners prefer, those who appreciate a neutral and transparent midrange will find a lot to love with the Serratus earbuds.

Treble - The Serratus earbuds have an impressive treble response, characterized by their detail, transparency, and clarity. As someone who prefers a brighter sound signature like the ER4SR, I appreciate the revealing nature of these earbuds. They reveal subtle nuances in the music, extend well, and provide an airy overall presentation without causing fatigue or unnatural detail. Although the brightness can be tiring at times, this is not due to the earbuds' tuning. I think it's a general thing I experience on rare occasions, but otherwise, it never fatigues me. When compared to my ER4SR, I experience the same fatigue on those rare occasions. Therefore, I apply a general EQ to both for a slight adjustment in the treble section to reduce the brightness a little.

My Ibasso IT00 has a warmer sound signature, which is pleasant for long listening sessions. However, I find myself missing some of the finer details and nuances in the music. As someone who wants to hear everything and not miss any part of the music, this can be disappointing. With the Serratus earbuds, I am able to fully appreciate the intricacies of the music, from the delicate shimmer of a cymbal to the subtle vibrato in a singer's voice. Their impressive treble response provides exceptional detail, transparency, and clarity, revealing subtle nuances in the music and providing an overall airy presentation without causing fatigue or unnatural detail. It's astonishing to experience such a level of treble performance in a single 15.4mm dynamic driver earbud at a $200 price point.


The Technicalities:

Soundstage -
The Serratus earbuds are noted for their exceptional soundstage, which creates a sense of space and dimensionality in the music being played. Despite being earbuds, they are able to produce a soundstage that rivals some close-back or semi-open-back headphones. The size and openness of the soundstage would likely impress those who are used to in-ear monitors (IEMs), which typically lack the depth and complexity needed to mimic the experience of listening to speakers.

However, the quality of the soundstage experience will depend on the music being played. Earbuds do not have a passive soundstage like loudspeakers, so the soundstage experience relies heavily on the recording itself. Nonetheless, Serratus is able to project a soundstage that is both wide and deep, with a clear sense of layering and depth. This is due in part to the 8kHz frequency response, which is adept at creating the illusion of height. Having said that, these earbuds still cannot match the soundstage of headphones such as the HD800s or the Hifiman Arya. This might be a bit disappointing given the hype surrounding their soundstage, but it's the reality. The 15.4mm driver of the earbuds is not a fair comparison to high-end headphones like the HD800s and Hifiman Arya, or even to studio monitors placed in a well-treated room.

Stereo Imaging - In terms of stereo imaging, the Serratus earbuds are able to create a clear sense of separation between different elements of the music, making it easy to distinguish individual instruments and voices. The soundstage is also able to produce a range of spatial cues that make certain elements of the music appear above or around the listener's head, adding to the overall sense of immersion and realism.

Overall, the stereo imaging and soundstage of the Serratus earbuds is outstanding, offering a level of depth and complexity that is rarely found in earbuds. The ability to create a sense of separation and depth, along with the wide and open soundstage, makes the Serratus a top-tier choice for those seeking an immersive and realistic listening experience.


The Hype and My Expectations:

Before I got these earbuds, I was so excited based on all of the reviews that I had read and all the hype I got from it. I was thinking that these could be considered as my endgame, but I was mistaken. These are really good earbuds, and they perform just as well as the headphones and IEMs you can buy in the $1000 price range. But when I heard people saying that these blow away the Focal Utopia, and they are just as close as the Hifiman HE1000SE, having heard them first hand, I would disagree. If you want to compare these to TOTL headphones, I personally think that they still have a long way to go. Maybe I am wrong, considering that the source I am using is just a Topping stack and they might scale even better with more expensive sources and would perform a billion times better than mine. But we should also consider that the form factor of almost flagship headphones is significantly larger compared to these 15.4mm drivers of the Serratus. I don’t think they can present the same sound and overall experience like most flagship headphones. Maybe it's also my fault that I was expecting them to sound like headphones worth $3000 to $6000, but it is just not realistic. Let’s remember that these earbuds are priced at $200, yet they still blow away the competition versus twice to four times their price.

With that being said, these will not be my endgame, and considering the gear I have right now, I think my next purchase will be a good planar headphone that is in the $1500 to $2000 price range. Maybe with that purchase, I can say that I will be truly satisfied. I am currently eyeing the LCD-X or the MM500 since they are easier to drive, and I don’t want to spend a lot on sources that will stay on a desk. I want them to be at least transportable, where I can bring them from home to work and vice versa with ease. I've heard that Jim made a new earbuds called the Totem, and someone compared them to the Subtonic Storm, which is a bold comparison. I am kind of interested in buying those and pairing them with the Topping G5, but I also don’t want to blind buy them based on the hype they are getting.

What I want to get from my next purchase is the huge planar headphone experience I got from the headphones I tried in audio stores in the price range of $1500 to $6000, and I kind of doubt that I can get that from TGXEAR. Again, I still want to remind you that these are still amazing and a worthwhile purchase. They punch above their price point, but have more realistic expectations. Maybe after I had my next planar headphone purchase, then I might actually consider blind-buying the TGXEAR Totem and get the Topping G5 to pair it with. By then, I will predict that I will be happy with that purchase with the right expectations.



Overall, the TGXEAR Serratus earbuds are an excellent choice for those who appreciate the earbud form factor and are looking for a high-quality listening experience. Jim Park, the man behind the brand, has done an exceptional job of designing an earbud that competes with much more expensive IEMs and headphones.

The Serratus earbuds boast a refined, balanced sound signature with neutral and transparent midrange tuning, lifelike timbre, and excellent imaging, making them perfect for classical music. The large, spacious, airy, and well-layered soundstage, along with top-shelf resolution, make for an exceptional listening experience.

Overall, the Serratus earbuds are a fantastic option for those who appreciate earbuds and are looking for a high-quality listening experience. Jim Park's passion for music quality is evident in his designs, which are ideal for classical music. With several models already released, including custom options, and rumors of more models in the works, TGXEAR is the place to go for those interested in high-quality earbuds.


Reviewed by: KENZO STEVENS
Last edited:
Very nice review of the Serratus.
  • Like
Reactions: kslq
Thank you!


Headphoneus Supremus
TGX Ear Serratus – Great Things from Small Beginnings
Pros: Lifelike timbre, excellent imaging, great for classical music, custom options, more versatile tuning than expected
Cons: To achieve their true performance, a high-powered source is required, notable lower treble lift, not universally versatile
TGX Ear Serratus

I would like to thank Jim of TGX Ear for providing me with the Serratus earbuds in exchange for my honest opinion. No incentive was given for a favourable review.

  • 300 Ohms
  • Blue Sapphire PET diaphragm
  • Pure silver cable
  • 3.5mm single ended or 4.4mm balanced termination
  • Price: $199


I have been an earbud enthusiast for several years now and I love the form factor. Despite the eternal struggle to get a secure fit, I use them on a daily basis. More than any other gear I have around. However, because “audiophile grade” earbuds are quite a niche over here in Europe, there are not that many opportunities to try out the more interesting ones. I have been lucky to receive a few earbuds to review, yet I always had the feeling I was not really hearing the full potential of the earbud form factor. All too often I heard people talk about earbuds sounding like headphones and none of those I had heard were quite delivering that sort of presentation. I suspected this was perhaps because the earbuds I reviewed were all low impedance for easy portable use. So, when Jim of TGX Ear got in touch and asked me if I was interested in reviewing a pair of his high impedance ‘Serratus’ earbuds, I was obviously very interested. When he indicated the Serratus were tuned for classical music, I felt the sudden urge to do a little happy dance.

Founded by Jim Park, TGX Ear is a fairly new brand with roots that are decades old. Jim is one of those people who has music and engineering running through his veins. It all started growing up in a home that was always filled with classical music. His mother was a piano teacher and so from an early age Jim was exposed to the constant sound of one of the three upright pianos in their home being subjected to various degrees of torture by his mother's students. The wide range of talents visiting their home meant that Jim developed a trained ear for distinguishing between the skilled students and those who meant the piano tuner would be coming around again that week. Jim himself preferred the violin. He started playing the violin from a very early age and kept it up for nearly thirty years.

This is how Jim developed his ear for music quality. Of course, that meant a standard pair of headphones or earphones simply would not do and he started modifying those from an early age as well. He developed his engineering skills through trial and error over the years. From there it became pretty much inevitable that he would combine all his skills in the development of his own earbuds. TGX Ear was born.

I had come across a few pictures of Jim's first earbuds on Head-fi, although I wasn't aware that the Serratus were already the fourth model he developed. The Serratus have been such a step up that the previous three models were ready for retirement. At the time of writing, I believe there are already three more models: Tantalus (no.5), Alpha (no.6) and Ripples (no.7) being the latest. But that is a bit misleading because there are also different versions of various models such as the Bell Tantalus, which have a small bell-shaped shell and a very nice red version of the Serratus. Even then I feel I have barely scratched the surface, with various custom options popping up on the Head-fi forums and hints about a number of new models in the works. There have even been rumours about IEMs coming from TGX Ear, but Jim tells me he has not made a decision on that yet.

For now, if you like earbuds and especially if you have custom requests, TGX Ear is a great place to start looking.

The unboxing experience is as basic as you can get it. Just a small and practical case with inside the Serratus and a few accessories. Even there it is limited to just the foams, an instruction card on how to wear earbuds and a branded pin.



As far as I am concerned this is perfectly fine and all you need. There are some accessories that I can think of that would be a good addition, such as ear hooks or rubber surrounds for those who have fit issues. And in fact, when I mentioned this to Jim, he indicated that he would be including rubber surrounds with all his earbuds as standard. How about that for service!

Build quality and fit
From what I understand the Serratus have a fairly standard plastic flathead earbud shell. That means you know what to expect if you are familiar with those. This immediately exposes my relative ignorance when it comes to earbuds, because this is the first time I have used earbuds with this type of shell and I was surprised by how well they fit (more on that in a bit). Beyond the fit, my experience with other plastic earbuds is still limited (shees, you'd think I built up more expertise than this by now), but the Serratus feel pretty much as I expected. Just simple plastic shells that are nice and light while still durable. Inside the lovely transparent shells are the brightly coloured, 300 Ohms Blue Sapphire PET diaphragms with on the right side a small red detail to identify which side is which.

The pure silver cable feels quite premium and has a good suppleness to it. The termination is 4.4mm balanced (you can also opt for 3.5mm single ended) with a simple design for the plug.

As I explained, the fit was very good for me. Pretty much the most secure I have been able to achieve with earbuds. Still not perfect though and I found that especially the left side would tend to fall out if I was more active. My primary conclusion from this test being that my ears are very likely to be asymmetrically shaped and now my OCD is not happy with my ears at all. Jokes aside, the fit depends entirely on your ear shape and so my findings will not provide much for you to go on. Always best to see if you can try it for yourself. Or keep an eye out for accessories such as the rubber surrounds mentioned earlier or ear hooks, in case you are already aware of difficulties with fitting earbuds. Alternatively, there are of course the other shell options that TGX Ear can offer.


Usually this is only a short section where I merely mention the specific sources I used for the review in order for people to know how I got to my impressions. With the Serratus being 300 Ohms tiny little earbuds, I found it important to spend some time to explore the consequences of various sources on the performance of the Serratus.

From my little experiment, I can say that for optimal performance a powerful source is essential. Important here is to note is that this is separate from the volume level that can be achieved.

To test this I used a $3,000, TOTL DAP, the Lotoo PAW Gold Touch -aka "my precious"- and compared that to more powerful, less expensive sources. With the LPGT I get plenty of volume and the Serratus sound nice enough. However, despite the source being a TOTL DAP, the Serratus do not set themselves apart from other earbuds I have heard. When I switch to a powerful source such as the Shanling M8 (Turbo gain) or EarMen Angel (Gain+), that's when the Serratus come alive and perform considerably better than I expected from such tiny little earbuds.

Jim explained that this has to do with maintaining the accuracy of the loud transient peaks and preserving dynamic range. This is consistent with what I hear, even though I can't explain it in technical terms. When I listen with a powerful source the image is cleaner, more accurate, better separation, more air, a bigger stage, etc. Across the board the Serratus simply perform better. Even with a superb source such as the LPGT, the lack of power causes a fuzzier image that doesn't feel as big as I know the Serratus are capable of creating.

Underpowered the Serratus still sound fun and engaging, but when powered properly they genuinely transform and perform at a much higher level. This means that when you consider buying the Serratus, you have to also consider the source you have available for them. If you do not yet have a powerful source, then these $199 earbuds can quickly become a lot more expensive because you have to add the cost of another source or they will end up underperforming for their price. If you already have a good quality desktop source, then the Serratus will offer outstanding value because you get their full potential without requiring any additional investment.

For this review I ended up relying primarily on the EarMen Angel because I felt a more neutral source paired better with the Serratus.


The Serratus have a well-balanced and natural tonality. Emphasis feels to be primarily placed on timbre and detail retrieval, with a notable lower treble lift to increase the clarity of note articulation. That lift can be pushing it a bit for some, especially if they are sensitive in that area, but I expect this is an intentional trade-off in order for the Serratus to perform as well as they do. And they do perform impressively well.

What struck me most about the Serratus is the presentation as a whole, with two aspects working as a rock-solid foundation. Jim has been able to achieve an incredibly lifelike timbre that is presented through clear and precise imaging. I guess this is what Jim was talking about when he said the Serratus were tuned for orchestral music and concertos. The image is very stable and thanks to a large and airy stage, the Serratus present the positioning of the individual instruments of the orchestra with great clarity against a deep dark background. I can honestly say that I have never heard earbuds do this (probably due to my limited experience), only ever IEMs, and only ever higher end IEMs.

Each instrument is not only clearly presented, every one of those sounds lifelike. I intentionally use the term "lifelike" here because it is something more than "accurate" or "natural". I actually ended up reaching for my HD650 (paired with the Eletech Inferno aftermarket cable) to do a quick comparison and indeed, the Serratus have in my opinion a very similar quality timbre. That is not the only similarity I found. Remember how I had never heard earbuds sound like headphones? Well, the Serratus have that quality. They sound far bigger than their small size would lead me to expect and again reminded me a little of the HD650. I don't mean that the Serratus are the HD650 in an earbud. There are notable differences as well, such as the more pronounced lower treble lift, but in these two aspects they did remind me of those iconic headphones.

The bass on the Serratus is very well done. Nothing excessive, but a good quality bass that has proper extension into the deeper regions. It is a very well controlled bass, although I wouldn't call it tight or articulate. It is more of a natural bass with enough control to position bass instruments correctly. For instance, a tympani sounds lovely and full of texture without overpowering any other instrument. There is a good level of impact that works perfectly well for more popular music too. This gives the Serratus more versatility that I had initially expected.

The mids are gorgeous with that lifelike timbre, which not only works well for classical, but is great with acoustic music all-round. I don't find the mids on the Serratus particularly forward or pushed back in any way. To my ears the balance is really well done and just right for classical music. The vocal foundation feels good and natural, but the lower treble lift unfortunately takes away from that. I used the Serratus for some general-purpose listening and voices in games or on YouTube (etc) can come across a little nasal. This does reduce the versatility of the Serratus somewhat.

The treble has of course the lower treble lift I already mentioned, but that is of course not the whole story. The treble extends really well to add plenty of air to the Serratus' presentation. There is also a lovely, slightly cooler sparkle to the Serratus that allows small treble details (e.g., triangles in symphonies) to come through with plenty of clarity.


I was considering doing a couple of comparisons with the Astrotec Lyra Collection and the FiiO FF3, but ended up deciding against it because it simply does not make sense. The TGX Ear Serratus are in a different league, they are aimed at a different use and require a different source. I find comparing them could lead to confusion. Where earbuds such as the FF3 are great for easy portable use even with a phone, the Serratus are only portable if you have a portable source powerful enough to drive them to their full potential. I therefore prefer to underline this difference and (hopefully) avoid disappointment for those who are specifically looking for easy portable use.

I do believe Jim might be working on lower impedance earbuds, so there might be options coming up from TGX Ear for this as well.


The Serratus are great high-impedance earbuds that excel at timbre and imaging. The tonality creates very lifelike sounding instruments in classical or acoustic music and there is a lot of detail coming through. The presentation is big and airy and resembles headphones more than IEMs. The only potential issue for some can be the notable lower treble lift.

Some different versions of the Serratus are available, both cosmetically and (I believe) in the shape of the shells for those who might get a better fit with smaller shells. The accessories are very basic, but TGX Ear makes up for that with very personal customer service and various custom options.


Headphoneus Supremus
Serratus - Summit
Pros: + Neutral and transparent midrange tuning
+ Top-shelf resolution
+ Top-shelf soundstage imaging
+ Deep and clean bass response
Cons: - Sibilant due to a mid-treble peak
- Can sound cold and thin if you are used to a warmer tonality
Reviewers are good at picking apart head-fi products. How do they fare when they build head-fi products themselves?

Pretty well, apparently. If you have been around head-fi communities recently, you would no doubt hear about the DIY flathead earbuds from tgx78, a long-term and well-known head-fier. Leading the pack is Serratus, flathead earbuds that, according to feedback from the community and reviewers, can trade blows with multi-kilo buck IEMs.

I have been daily-driving Serratus for a couple weeks to answer a burning question: does Serratus stand up to its hype?

Let’s talk about one of the most hyped DIY earbuds on the market.



  • I purchase this unit at a discount from tgx78 for this review.
  • You should treat this review as the subjective impressions of an audio geek rather than an “objective truth” about the IEM. Your experience with any IEM would change depending on your DAC/AMP, music library, ear tips, and listening volume.
  • I rate IEMs by A/B testing them against a few benchmark IEMs, regardless of price point. This approach ensures the consistency of the ratings in my ranking list. It means that if two IEMs score the same, they perform more or less similar.
  • I believe that great IEMs are the ones that can achieve multiple difficult things simultaneously: (1) high resolution (meaning lines of music are crisp, clear, easy to follow and full of texture), (2) 3D soundstage with a strong sense of depth, (3) bold and natural bass with a physical rumble, (4) natural timbre, (5) relaxing and comfortable tonality.
  • Ranking list and measurement database can be found on my IEM review blog.


  • Driver: 15.4mm dynamic drivers with PET diaphragm.
  • Connector Type: fixed silver cable with 4.4mm connector
  • Impedance: 300ohm
  • Sensitivity: unknown

Non-sound Aspects​

I really like the presentation of Serratus. Don’t get me wrong, the packaging of Serratus is nothing like a premium product from an established manufacturer. Instead, the whole presentation of Serratus makes me think of a fellow audio geek who tried to make things as upscale and thoughtful as possible within their limited resources.


Serratus comes in a red carrying case with a handwritten product name and serial number (mine is 0082). Inside the case, you find:

  • The earbuds themselves
  • A business card showing how to wear flathead earbuds
  • Many pairs of special thin foams for replacement. Serratus was tuned to use these foams.
  • A TGXear metal pin.
  • Silica beans (Candies! Just kidding, don’t eat them.)

The earpieces are made of frosted plastic and have the standard shape of Sennheiser MX500 shells. To help with identifying the left and right channels, tgx78 puts red and black tapes on the cable inside the shells. Red means right.


The cable of Serratus is not removable. Tgx78 told me that MMCX connectors have a high failure rate when worn in a cable-down position. Therefore, he decided to use a fixed, pure silver cable terminated with a 4.4mm balanced jack. The cable is a perfect match for flathead earbuds because it is very soft and light and therefore does not pull the earpieces out of my ears. The handling of the cable is superb. I really want a similar cable for my DIY projects. However, as far as I know, this cable is custom-made for tgx78 by XINHS.

How it sounds​

Sources for listening tests:

  • Topping G5 (for all A/B tests)
  • Hidizs XO
  • Hidizs S9 Pro
  • Fiio KA3
  • Shanling UP4
Local FLAC files ripped from CDs or bought from Qobuz were used for most casual listening and A/B tests. My playlist for A/B tests can be found on Apple Music here.


Tonality and Timbre: 3/5 - Average​

Frequency response of Serratus. Measurements were done with an IEC-711-compliant coupler and might only be compared with other measurements from this same coupler. Visit my graph database for more comparisons. You can also find the official graph by tgx78 here.

Tonality, tonal balance or “tuning” is where I have the most problem with Serratus. These buds can sound sublime with instrumental and orchestral recordings. However, they can turn strident and sibilant with particular vocals and YouTube videos. Let’s talk about Serratus’ tuning in detail.

Serratus has a neutral, almost “flat” midrange that invokes a great sense of transparency. That’s a lot of jargon, so let’s unpack the statement. By neutral, I mean that musical instruments and vocals are not overly boosted in lower frequencies to make them warm, dense, and “musical”. There is no insane boost in the upper midrange between 1kHz and 3kHz to artificially highlight midrange elements either. In fact, the midrange of Serratus is almost identical to that of Etymotic ER2SE in my A/B tests. Both present instruments and vocals as-is, without any attempt to “touch up”.

Due to the lack of warmth and loud high notes, instruments and vocals in the midrange are clear and open. Nothing overlaps or masks these elements, so I can easily hear the minute details that the drivers manage to distinguish. For example, let’s consider the “organised chaos” music of Polyphia, such as New Levels New Devils. Serratus renders all instruments with great separation, preventing them from mushing together into a blob of sound even when many things are happening simultaneously.


Why would one want a neutral or “flat” midrange? The transparency that I described previously is one advantage. Another is the correctness of the timbre of instruments and vocals. For example, when I listen to Goldberg’s Variations arrangement for violin, viola, and cello, I can easily distinguish the instruments even when they play in the same range. Even with large orchestral pieces, all instruments are easy to recognise because they sound as they are supposed to.

Of course, there are valid reasons why you want something other than a perfectly neutral midrange. For example, if you are used to head-fi gears with a bit extra “warmth” in the lower midrange around 250Hz and 500Hz, you will feel Serratus a little cold and thin. For example, Andrea Bocelli sounds colder and less emotive in Besame Mucho with Serratus comparing to other gears with slight colouration such as Fiio JD7. The cello of Mischa Maisky in Bach Cello Suites also sounds dry. This kind of midrange presentation may be authentic, but we don’t always want perfect authenticity for enjoyment.


The treble region is where I have the most problem with Serratus. Before we go on, let me just quickly clarify the terminology, as treble region covers a wide frequency range:

  • 5kHz region controls the note attacks, such as sticks hitting the snare drums or guitar pluck. I call this region the lower treble.
  • 8kHz region controls the cymbals, hi-hats, chimes, and vocal sibilant (the sss sound when a singer or a narrator hits a word with the letter “s”, “sh”, “ch”, or “z”). I call this region mid-treble.
  • 12kHz region controls the degree of the metallic tint of the overall tonality of IEMs or earbuds. For example, some IEMs render vocals with harshness that feels “metallic”. The culprit is usually too much energy around 12kHz.
  • 15kHz or “air” control the perception of stage and micro details such as reverb of sound in a room. You might not hear 15kHz, but you can feel it. You can use EQ to add a lot of 15kHz and hear the soundstage expanding. Excess 15kHz can make the overall tonality a bit uncanny.
Serratus’ treble response is characterised by a significant 5kHz dip, a prominent peak at 8kHz, and well-balanced and controlled from 12kHz up. The 5kHz drop is good because it smoothens Serratus’ response when rendering instruments rather than emphasising every note. The prominent peak at 8kHz is troublesome, however. Suppose you have a trebly DAC/AMP and you want to listen to sibilant songs such as Ed Sheeran’s Shivers or Bon Jovi. In that case, you might cringe whenever the singers hit high notes or sibilant words. To my surprise, even Joshua Valour’s videos can be sibilant with Serratus.

Serratus is not bass-shy. Its bass response focuses on the sub-bass, meaning Serratus emphasises the thumpy feeling in your eardrums, throat, or chest when bass notes hits. The mid-bass is not overly boosted but not neglected. You can still hear “boom boom” sounds if your music has them, but Serratus does not actively try to make everything “boom boom” like some bass-boosted IEMs.

How do I rate the tonality of Serratus? It depends on the genre. For instrumental and orchestral music, I’ll say 4/5. For harsher genres or even some YouTube videos, 2/5, as Serratus can be tiring and strident. That’s why I converge to the 3/5 rating for Serratus tonality.

Percussion Rendering: 4/5 - Good​

Percussion rendering reflects how well the tuning and technical performance of an IEM work together to recreate realistic sound of a drum set. Good drum hits have a crisp attack (controlled by frequencies from 4kHz to 6kHz), full body (midbass frequencies around 200Hz), and physical sensation (sub-bass frequencies around 50Hz). Good technical performance (“fast” driver) ensures that bass notes can be loud yet detailed. IEMs that cannot control bass very well tend to reduce the bass’ loudness to prevent muddiness.
You will be pleasantly surprised if you listen to Serratus with the expectation that it cannot do bass. The bass of Serratus extends deep into the sub-bass yet maintains a clean bass response, likely thanks to the PET drivers and the custom bass tubes that tgx78 adds to the back of the earpieces.


For instance, the first bass drop at 0:17 of G.O.A.T. feels like a quick punch “POW!” that I can feel around my the nape of my neck. At the same time, the bass notes from the drums only linger as much as they need to. The bass line’s cleanliness is shown clearly from 2:40 onward of the track. Every bass note hits sharply with significant impact but does not mush into the ones after.

How does Serratus compare to my benchmarks? Firstly, it clearly outperforms my Blessing 2 (3/5) in terms of impact and “speed”. The jumps in volume at the beginning of the bass notes of Serratus are simply larger and faster. If Serratus’ kick drums are “POW!”, Blessing 2 are rounded punches to a pillow.


On the other hand, Serratus is no match against the massive and textured bass notes of a fully-driven Final E5000 (5/5). The bassline of E5000 produces a rumble in my chest at around 2:22 of G.O.A.T.. Of course, Serratus can win regarding the cleanliness of the bass line, but it’s not a match in terms of sheer power, rumble, and impact.

Before we conclude, let’s compare Serratus with Fiio FF3 (4.5/5), a pair of earbuds with superb percussion rendering. Right off the bat, I hear these earbuds pursue different responses. Serratus provides a more Harman-ish, sub-bass-focused, agile, but hard-hitting response. FF3 follows a more “old school” bassy approach with big, enveloping bass. FF3’s bass line is not as crips, but it is still clean and full of texture and liveness. Which one is better? It’s up to you and your music library.

How do I rate Serratus’s percussion rendering? 4/5 - Good. It sounds like a modern high-end IEM.

Resolution, Detail, Separation: 5/5 - Outstanding​


Resolution is a fascinating subject due to the difficulty of pinning down what it really is. To me, the resolution is closely tied to how many quiet and minor details you can hear. Of course, if you turn the music louder, you can spot more details. However, you can only turn up the volume if the tuning does not have random peaks that stab your ears and mask minor details around them. Moreover, you can only hear details if the drivers manage to separate them rather than presenting a blob of sound. Earphone DIYers very well recognise this “true resolution” difference between drivers.

Serratus is an outstandingly resolving. Thanks to the transparent midrange tuning, I can hear nuances in instruments and vocals without much effort. The 300ohm drivers in Serratus do an exceptional job distinguishing similar sounds and breaking down blobs of sounds into small details.


In my A/B tests, it is clear that the true resolution of Serratus at least matches my Andromeda 2020 (5/5) across the frequency range. For example, when I listen to I Vow to Thee, My Country by Westminster Abbey Choir, I can hear the voices in the choirs rather than just blobs of vocal sounds. Serratus even slightly out-resolves my Andromeda in the bass and lower midrange region, where the BA woofers in Andromeda do not do a very good job. For instance, I can hear the subtle reed and air sound of the clarinet (or oboe?) from around 0:20 of And the Waltz Goes On with Serratus, but I can’t with my Andromeda. Shocking.

So, when you see impressions online that Serratus can compare with multi-kilo buck IEMs in resolution, they are not (totally) hyping. The only limitation of Serratus is the 8kHz peak that masks some details and sometimes forces me to reduce the volume. Still, when you listen to Serratus, you are listening to a top-tier level of resolution. 5/5 - Outstanding.

Stereo Imaging (Soundstage): 5/5 - Outstanding​

Stereo imaging or “soundstage” is a psychoacoustic illusion that different recording elements appear at various locations inside and around your head. Your brain creates based on the cues such as the loudness and phase differences between the left and right channels. Most IEMs do not differ significantly, nor can they compete with headphones or loudspeakers. However, some IEMs offer a more spacious soundstage than others. Best IEMs can create multiple layers of sound from closer to further away and make some instruments float slightly above your head.

Flathead earbuds have a massive advantage in soundstage imaging compared to IEMs. Serratus is no different.

In terms of soundstage size, like most decent flathead earbuds, Serratus can project as far as some close-back or semi-open-back headphones. My HD560s is still a bit larger. Still, if you come from IEM, the size and openness of the soundstage would surely impress you. Of course, because earbuds do not have a passive soundstage like loudspeakers, your soundstage experience would rely a lot on the music you listen to.

There must be more than just a large soundstage to produce a good experience. The stereo image produced within that soundstage matters. I am glad to report that I can hear a clear sense of depth and layer with Serratus. Moreover, due to the 8kHz, Serratus is adept at creating the illusion of height. When I listen to And the Waltz Goes On, some instruments appear above rather than around my head. Realistic? No. Fun? Yeah.

5/5 - Outstanding soundstage imaging.

Source Pairing​

Despite having an impedance of 300ohm, Serratus can easily get loud. You can get loud and clear sound from almost every audio source with a balanced output.


However, getting loud is different from getting the full performance. Moving from G5 to Hidizs AP80 ProX (balanced), I hear a smaller and more congested soundstage with the movement 3 of Summerperformed by Janine Jansen.

Most dongles in my collection, such as Hidizs XO, are not better than the tiny DAP. They can squeeze decent sound out of Serratus, but they cannot project the same soundstage and separation as the G5.


A few unusual dongles can approach the performance of G5 with Serratus. For instance, the Hidizs S9 Pro drive Serratus to almost the same level as Topping G5 at only a 5/32 volume level. However, the S9 Pro is a touch less resolving compared to G5. The VE Megatron also drives Serratus well, though the soundstage feels a bit shallower, and the layering illusion is less noticeable than G5.

Some Comparisons​

In this section, I compare Serratus with some relevant earbuds. You can use my ranking list to compare Serratus with others. Due to how I rank IEMs, if two IEMs score the same, they perform more or less similarly.


Fiio FF3:

  • Serratus sounds edgier but at the same time more lively and sparkly, thanks to the extra treble peaks.
  • Serratus has an “academic”, “well-tuned” bass tuning, whilst FF3 has an old school and fun bass response.
  • Serratus has noticeably better resolution.
  • Serratus has more 3D stereo images.
VE Master:

  • Both follow a similar sound signature with natural, lean, and open midrange.
  • Both aim for a clean bass line, but Serratus extends into sub-bass, whilst VE Master rolls off the cliff early.
  • Serratus is edgier than VE Master.
  • VE Master is fancier looking, but Serratus is more comfortable due to its low weight.



Flathead earbuds are experiencing a renaissance, thanks to the effort of manufacturers like Fiio and DIYers. Serratus is a shining star of what flathead earbuds can do, especially the ones with high-impedance drivers and custom bass tubes.

My final verdict of Serratus? I respect it, even though I don’t find it entirely enjoyable. Should you buy Serratus? If you know that you have no problem with an 8kHz peak and enjoy an Etymotic-like midrange, then by all means. Of course, one can argue that you can always buy DIY components to experiment with and build your own top-tier earbuds. However, everyone needs to start from somewhere, and inspecting Serratus with your hands can be a masterclass experience.

  • Neutral and transparent midrange tuning
  • Top-shelf resolution
  • Top-shelf soundstage imaging
  • Deep and clean bass response
  • Sibilant due to a mid-treble peak
  • Can sound cold and thin if you are used to a wamer tonality
@Serge Bernamej I think I can do the boost and hunt technique to find the peak and Eq it down. I aim to give a complete impression of the tuning vision of tgx78, so I didn’t use EQ in this review.
Serge Bernamej
Serge Bernamej
Of course and you are right ! The review is very impressive.
I finally got around to ordering a set this week - looking forward to them, first bud I've purchased in a while and I think they will be well suited to my modern classical library. Great review!


Headphoneus Supremus
Serratus the timbre king
Pros: Highly refined balanced reference sound tuning.
300 Ohm earbuds when fed proper power sounds nothing like a small form bud.
While it does require power.
It can be used on the Fiio BTR7 which gives it plenty of power and volume to sound full on
Versatile for all types of music despite being made for classical and orchestral music.
Comes with a solid 4 core pure silver cable in balanced 4.4mm
Large spacious airy deep well layered head stage that mimics open cans more than earbuds
Superb comfort and ease of use.
Superb staging imaging and layering.
Superb accurate timbre and tonal character
Superb detail and ample body of note.
Very good treble and bass extensions for earbud performance.
Sound that mimics TOTL level IEMs.
Cons: Open in every way. Means zero passive isolation. Its a bud.
300 Ohms means they need some power to strut what they can do.
Somewhat soft sounding subbass notes.

This hobby of ours, the one where there are always new audio goods that promises higher end sound. That demands your attention, you read about earphones and headphones and wonder, does the hype actually live up to the actual sound? So I am guilty of stoking the flames of some of that hype among headfiers. I will admit that, but I am much like you. I read about phones on the threads and always wonder. Is this going to sound any better than what I already own?

Now let me take you back a bit. I have been on headfi since 2011 about the same time as this guy TGX78 he called himself Aka Jim as far as I can remember, he has always been a positive voice on the threads as far as his views goes for IEMs and sound. One thing for certain: I have always known Jim as a neutral head. It got a proper neutral sound with good technical chops and he was usually on board. We have gone back and forth throughout the years and it was only recently I discovered that he has gone onto developing his own earbud company in the form of the old school style earbuds called TGXEAR. If it was just any headfier it would be one thing but it is our good buddy TGX78 who knows a thing or two about what proper sound. To be honest I trust this guy's ears for good sound vs your random Chinese manufacturer making new IEMs on a weekly basis. This being said, I have always known he had a legit talent for modding and tweaking what was already good on an earphone to sound even better.If you know his background you will get a good idea why he has a passion for accurate audio.

When he got a hold of me to hear the Serratus I read a few impressions and a review about them and so far it has been nothing but praise about the buds. In fact I challenge anyone to find anything that is considered mediocre or average descriptor about the Serratus on the threads. I will spare you the time to look, there is none. OK I am game, I had to hear them for myself. With that, I would like to thank Jim for a sample of the Serratus for this review. You can check out his site and order you a set from here. They have been tested using my sources. Ibasso DX300Max, Fiio M15, BTR7, IFI Signature, IFI gryphon, Shanling M6 pro.

Admittedly I am an IEM guy. Always have been but lately it has dawned on me that maybe there are more to IEMs than just throwing in a bunch of drivers in a housing and calling it good. The Serratus seems like a passion project and is one of three models Jim has for sale on his site. These are high impedance earbuds meaning they will require some power to drive correctly and sound correct. Serratus is the most efficient out of the 3 buds having a 300 Ohm impedance. The Tantalus at 500 Ohms and Alpha being 600 Ohms. Jim plans to have 5 models by the end of 2022 and toward 2023 with one being a planar bud.

The Serratus for a DIY project turn production is quite nice on several fronts. It comes within its case a set of foam tips that is using a thinner foam material and another set of foams that uses a thicker foam material. And yes the thicker foams actually have more of a fullness effect including its bass presentation. So bass foams are what they are called. The balanced foams are what I prefer as it gives the best balanced sound from the Serratus. Found out it was tuned with these foams so it most definitely gives the best sound production between the foams. The Serratus uses a 4 cored pure silver cable terminated in a 4.4mm balanced for my review set. When I asked about the cable, he wanted to go with the most transparent cable he could source for the Serratus. 4.4mm balanced as most players put out the most power in balanced mode.

By default, these buds are not made for your phones, well that is unless it is attached to a portable amp. They aren’t really made for walking around with either as they are clearly an open type bud even more so than your typical closed bud housing design with a few vents. There is a large vent hole on the back end of the Serratus which effectively opens up the sound of the Serratus. Think open can and you might have a good idea just how much sound leaks.

On open listen, I was pleasantly surprised at how accurate, natural, open, balanced, spacious and airy the sound was, then I was greeted with a layering of the sound that I couldn't believe. I will put it out there these don’t sound anywhere remotely close to anything I have heard at the price range.

So what does roughly $200 worth of cash get you for IEMs, headphones and audio goods in general nowadays?. It gets you a very basic entry level DAP, might get you a bluetooth source. Gets you a fairly basic headphone that has some ok dynamics and stage but what about accurate timbre and balance? SQ wise not exactly lofty in how a $200 level headphone will sound but serviceable. This is how I would describe most IEMs, headphones and audio goods in the price range. Most hybrid IEMs will leave you wanting better timbre and better stage, most dynamic IEM does better with timbre but what about staging and balancing. Some do this and that better than others but most will not have all of what I consider a higher end sound. The Serratus however is different.

Never in a million years would I have guessed you can get a reference grade sound from a $200 earbud of all things. I know some of you are earbud fanatics and love what they do for sound for the bucks. The Serratus is the closest to a neutral reference tuned anything I have heard in the $200 range and really there is no close 2nd.

They don’t sound like your traditional ear buds first of all. Most earbuds I have heard are all about the mids and bass and while some do treble better than others most bud trebles I have heard are just ok. If it has ample treble it's not the most articulate or does it have the best extension. The Serratus is different. I have no idea how Jim was able to tune these things to sound like the way they do but I remember messaging a good buddy of mine and fellow headfier what I was hearing the first time I put these buds into my ears. I was shocked. They sound like a full blown headphone even the imaging is portrayed in a much grander scale than most. To get this level of refined spacious sound, there is no possible way I was hearing what I was hearing from them. But I was. OK now this is something new on me.

Forget what you know about earbud sound and go take a listen to some of the highest end IEMs in the market today and then you might have a good background to understand what Jim was going for and how the Serratus will sound like. These don’t sound like your typical bud at all. They sound like stupid high end in ear speakers. No other way to put it.

With that out of the way. So exactly how do they sound? First of all the tonal balance from trebles to bass is insanely great. There is not any aspect of the sound that feels out of place, out of rhythm, or out of phase. What you hear seems like a clear clean glass window to the performance. If this is what Jim was going for. Serratus nails it. Then there is its technical ability. These $200 buds achieve a technical level I have not heard in anything that is sold at its price. Its imaging in space, sounds separation, cohesion, range, texture, body, transient response, timbral accuracy, tonal accuracy all of it is on point presented in a large spacious wide and deep airy head stage. Yes from a $200 earbud.

Of the Serratus is substantial. I never thought buds can have the type of treble that is total in how it performs. When I say total or should I say TOTL. Refined trebles need to be airy, articulate, sparkly, extended and needless to say detailed in the right way. That is exactly how I am hearing the Serratus treble. I have to put it out there the Serratus has one of the very best complete sounding dimensional trebles I have ever heard in a bud form. And I think this is what really separates the Serratus from other buds I have heard. These just don’t sound good for trebles. It clearly shows articulation. Treble timbre that is accurate. What music and instruments should sound like. It is quite astonishing. What good is balancing for an IEM or a bud when the treble has off tonality or sounds canned. Open airy trebles is one aspect but that also includes a dimensional character I never thought was possible using a single larger dynamic driver…. In a $200 bud. This is something I expect in super high end IEMs not so much for buds. Let me put it that way.

But then there is the mids
The strong suit for most buds is how they present the mid bands. The mids of the Serratus is quite simply spectacular in how it performs, seamless, ambient and liquid with a technical element that is really something to behold at its price level.. The effortless well balanced mids production of the Serratus has such great accuracy, neutrality, which all lends to one of the best stereo imaging for earbuds I have ever heard. The airy trebles continue through the mid bands on the Serratus. Its supreme timbre and tonality is something to behold, everything that needs accuracy to come correct. You're going to hear it accurately. Details that seem to be ghostly in how they produce sound. Mids have very good neutral body of sound and seem to adapt to the tracks you're listening to. Combine these aspects to the substantial imaging it has and you get a reference level neutral presentation for the Serratus.

Orchestral scores sound stupendous out of the Serratus. You gotta understand, Jim has been a classic violinist for 30 plus years. So a bud he produces will absolutely have to have an accurate timbre with a realism to string instruments. I haven’t heard his other buds yet but I am willing to bet money the other two will have some very nicely done timbre as well.

The Serratus is clearly a passion project that came into fruition for him. And we are the recipients of his talents. The Serratus reproduction of stringed instruments is one of the best if not simply the best I have ever heard from anything I have heard in that regard. It will be my new benchmark for stringed instruments. Let me put it that way. I am very surprised how good vocal performances come from Serratus. Vocals for both female and male performances sound superbly dynamic with excellent center imaging in space. Rangy, defined superbly accurately and spot on in tonality. All within a holographic large airy head space. I keep on mentioning the word accurate in my sound descriptors but I have no other words to describe how the Serratus portrays your music.

OK so these are not going to be the bee's knees for bass genres or something like EDM as they are neutrally tuned but all is not lost. They do have excellent versatility as it actually has a good bass foundation included with its sound balancing. Being the easiest to drive out of the 3 I figure Jim would make this one the most versatile in its tuning..

I had a good feeling these were going to be neutral but I had no idea it was gonna include some outstanding bass as well.

The bass end of the Serratus is there more to support the unbelievable mids and treble presentation of the Serratus but it has its own bass presence as well. Bass for the Serratus is clean, tight defined like the rest of the sound signature. When listening to pop music and or bass genres these have a moderate physical punch including some deep reaching rumble. The Ibasso DX300Max and the Serratus makes for a potent 1 2 punch and I have never heard my DX300Max sound as good as it does with anything else.

Its sub bass is not as pronounced as some commercially tuned buds, nore are they the final word on bass texture for sub bass performance but at the same time it represents the fast tight accurate type of mid bass and its overall bass is more at a moderate level more so than anything that sticks out of the tuning. Again that balancing is there including the bass end. The Serratus is not all about classical and orchestral scores. It can do modern genres just fine. Surprisingly great for old rock and metal music. But if you are at all into your large orchestral and instrumental music. You're in for a treat like you wouldn't believe.

Bass here is not an afterthought but is very much equal to the emphasis and details in the mids and the treble end. Natural bass lines sound about as authentic and real as it gets. It is only when hearing synthetic overly saturated bass lines that the Serratus is not the best for so yes they are not perfect but damn folks if that is all that is not at a 100% level on these at their price point. You have to pay attention to these things. I would imagine the other two buds being made with Beryllium composite material would provide that extra texture for the bass end.

Overall I have to give it up to Jim and his tuning skills on this one. For a guy that has never made a retail product in the form of a bud before. These are astounding for his very first run at it. We have a talented tuner among the headfi crew and a guy that clearly knows what he is doing. A clear direction and the type of reference sound that the Serratus represents is something that you can’t really get in comparable $200 products at all. You have rolled your eyes to the giant killer description that you see on the threads. I mean what does that mean anyway?. How can the sound of a $200 earbud compete with TOTL level IEMs that are sold in the thousands?

Throw the Serratus on a nice dac/amp and hear them and you tell me what you're hearing. These are a marvel of engineering and tuning. I never would have guessed just how good these things would sound. And they sound spectacular. If you're a timbre head, instrument head, accuracy head, classical music head, or an orchestral whore, a jazz person. Get yourself a Serratus and find out for yourself. Pretty great for vocal performances as well I might add.

If there is such a thing as a giant killer, I really can’t see how sound can get better at this price range. These my friends are the true definition of GIANT KILLERS. And it comes in the form of a $200 bud.


  • DSC00349.JPG
    888.7 KB · Views: 0
Last edited:
Would it work out of fiio KA3?
It should work fine out of the KA3 but you will be pushing maybe 90% volume to get good power out of it. Not exactly ideal but should be plenty loud enough. If you can get a dedicated portable amp that would be better. KA3 should work though.
Yet another excellent review. When I’m looking at something always pleased to find you’ve covered it. Except for the fact I end up spending money…
  • Like
Reactions: Dsnuts


Reviewer at nymzreviews
TGXEars Serratus: A love letter to music
Pros: Everything that is not written on the cons list
Cons: Needs some power
Won't be suited for all genres
Earbud isolation
Not basshead friendly
You won't find it in the usual stores

Disclaimer: This unit was provided by @tgx78 with a discount in exchange for a written review. Despite me and him being close and speaking regularly, that fact won’t influence my opinion of this unit and I won’t tell him my feedback until the end of post this review for a matter of transparency. No incentives of any kind were given and the review you are about to read are my own thoughts and opinions. Thanks once again to Tgx for the opportunity and support.

Driver Setup: Single Dynamic Driver (300ohm Blue PET Polymer Resin Crystal Diaphragm)
Price: $200
Purchase link and contact info: https://www.instagram.com/tgxear/

Comfort, fit and isolation: Typical MX500 shell fit and comfort with zero isolation
Foams used: Stock
Source used: Topping E30 + L30 stack (high gain), Singxer SA-1 (high gain), Ovidious B1
Test playlist with some of the songs used: Tidal


Music, art and a passion to mess around and build stuff - three things that gave Jim his reputation across the online audio forums. Violin player since a young age, the “timbre checker” as some call him, tried out more gear than I could ever list, especially the ones labeled as TOTL. Later down the road he found his love for earbuds timbre and had this crazy idea of buying parts and trying to make them himself. The result of all this passion, knowledge and hard work is TGXEar.

Being relatively close to him, I had to try his work at least once to find out what he is made of, and since he asked nicely, I agreed to do a review on them and raised myself this question: is all that experience what it takes, or do you need something else?

To answer that question and more, let's quickly analyze the Serratus, his first released flagship, but not before unwrapping it first.

Build quality, accessories and driveability

1659088070190 v2.jpg

Big full stop ahead. Serratus has a 300ohm driver, a sensitivity of 102dB SPL at 1mW and it is power hungry. I don’t mean you won’t be able to run it through your regular bluetooth amplifiers, but I feel that the performance won’t be the ideal one if you care about that. As always, YMMV but beware you will need some juice to put this up in the air.

Now, with that behind our backs, let’s talk about build quality. The almost industry standard MX500 shell is used but the crystal clear skin leaves nothing to the imagination and reveals the star of the show dressed in blue.

From the gorgeous looks to the most small color coding detail, nothing was left by chance, and that moves along into the cable chosen. Distancing herself from the rest of the DIY competition, Serratus packs up a delicately thin 4 core litz 4n silver cable, 4.4mm terminated with a working chin-slider.

This gorgeous, tangle free and well built XINHS cable is proof that Tgx moved miles until he got what he wanted, as the included foams are no exception: carefully tested and picked to match the tuner's intention for the frequency response.

To wrap it up, a simple but personally written red-case, displaying the model name on the front with the serial name on the back, done with a silver marker.



Neutral, accurate and audiophile are the three words that came through my mind when I finished my first passage.

Jumping to the low end, it almost comes close to your ever-so-neutral type of earbud on a first look: a touch of a rolled off sub-bass in the tail but close to flat. Given it’s an earbud and we have no proper way to measure it but using our ears and doing a sine sweep, I proved myself right and to my surprise, the roll off felt minimal at 20 hertz.

Hypnocurrency” by Deadmau5, the now classic “Why So Serious?” or even “Dream of Arrakis” both by Hans Zimmer, showed a complex and articulated sub-bass, with enough rumble to be at the bare minimum felt physically (let alone compared to the majority of the earbud world). Despite its great texture, and as expected for the genre, I will disclose right now that the sub-bass is the weakling of this neutral focused tuning, but it’s so good in the grand scheme of things that you can already guess where this is going.

Once you go a step further on the frequency response, things just keep getting better. Mid-bass follows and don’t let the “neutral” tuning fool you: this will hit you in the chest. “Packt Like Sardines In A Crshd Tin Box” by Radiohead, during its intro, will show you just that. Again, the word articulation comes to mind as the bass has the right amount of speed to never feel too fast and for sure not slow, just a beautiful balance hitting the right spot along with its tightness. On more jazzy tracks (Mark Letteri - Magnetar comes to mind) you will even forget you are hearing a neutral tuned IEM, as the bass guitar and drums are so present and separated, despite the bandwidth share.

Moving up the candyland, the mid-range. Transparency but not enough to feel thin, as the shelf left some weight to it - it just sounds correct and accurate. It’s north than neutral, meaning they are slightly forward but still not your face and congesting the whole frequency. If we were talking about IEMs, I’d probably compare it to something that most people don’t know I like by now (wink wink) such as the Letshuoer EJ07 or EJ07m.

Let me try to explain the above paragraph with some music. Pianos never feel thin, over blurry or out of scale - they sound right, they feel right. Hania Rani, Nils Frahm, Yann Tiersen, Sawano, you name it and Serratus gives it back.
Agnes Obel’s vocals are reminiscent of my favorite replay (done by RSV), with a touch less bite and less in your face, and the male counterpart just follows suit (Dead South - In Hell I’ll Be In Good Company).

Every good thing has to come to an end and, oh boy, what a way to close it by talking about the treble region. Cymbal hits, claps, brass, electric guitars, you name it and it’s good, without any hint of sibilance. And that ain’t even the best part.

The air and extension on Serratus is something breath-taking and I’ll try to explain to you why. It’s usually very hard to have the cake and to eat it at the same time. Everytime you try to raise these most upper frequencies you get slapped with either fatigue or the sense of unnatural details. This has none of that. Zero. As expected as it is from a more neutral tuning to put the treble at the center of the show, I was certainly not expecting this. The last nail in the coffin.

To leave a note on library compatibility, I would say these won’t fit any bass addicts or genres that need sub-bass to shine like hip-hop or modern pop/K-pop that are sub-bass heavy.

Technical chops


The best was saved for the end, but I never told you it was regarding tuning, right?

One of the most difficult concepts to ever explain to someone that never experienced it is center imaging that is usually found on speakers. I will describe it as putting the vocalist in front of you but with some depth and the rest of the sound to appear on the sides and behind the vocalist. IEMs are one of the worst at this, they basically position the vocalist inside your head, close to your eyes and try to spread it around you (when they can), as they lack stage depth and can’t mimic 2-way channels.
This imaging and the giant stage even for an earbud are the first thing I noticed and I kid you not, I have been A/Bing Serratus vs my Edifier S3000 Pro since I got them and my conclusion is that Serratus is a mobile pair of speakers, and I think that speaks volumes on itself.

All of the above couldn’t be done without a brilliant sense of separation and dynamics, accompanied by the best level of resolving power I’ve heard in a bud. Serratus' sense of clarity is truly mesmerizing, even if I compare it to IEMs, and justifying the speaker comparison once again.

Now, to end this the best way possible and to give you even more reasons to think I am crazy or a shiller, I will touch on the best technical ability of this set: its timbre. It’s not good, it’s not very good, it’s not exceptional - it’s perfect by my ears.

Once I heard the first cymbal strike, I knew I was up for something with that decay. I decided to incarnate the tuner and went straight ahead into some jazz and classical and here I am, around 8 hours of playtime later and still not letting these go.

The first classical track I played was Vivaldi’s Spring 1, reassembled by Max Richter:

The positional cues of the violins acting like birds in front of me, the hype building up and the stage evolving more and more, filled with a cluster of instruments correctly separated. Don’t ask me what happened but I got shivers all over my body and before I noticed, I was crying while listening to this Vivaldi play. Oh, it’s been a while.

The verdict


I’ll be straight to the point, the TGXEar Serratus are the best earbuds I have ever tried and one of the best overall monitors I have ever heard and despite the higher-end price as far as buds go, these get the highest recommendation. If you are into buds, the money can be spent and it matches your library, look no further.

You might be guessing why I consciously avoided comparatives and well, I feel it wouldn’t be fair at this point. In fact, I had to re-do all my bud tierlist and drop everything down to make room for the newcomer.
Since the beginning of the year I had started a quest to find an ultimate version and upgrade to my forever beloved K’s Earphones LBBS (if you ever want to get into buds and you enjoy instrumental music or neutral tunings, start with these). No earbuds gave me that feeling so far since that one until now. This is the end of the line for me and I can now peacefully go back to my earbuds and not look for anything else, unless Tgx cooks something new.

On most technical fields the Serratus puts the majority of IEMs to shame. This won’t go without saying that there are two potential flaws to any person that wishes to buy these: earbud isolation and power requirements given they are 300ohm and hard to drive to its full potential, but nothing close to impossible.

Last but not the least, the price. For some $200 are just a mere IEM cable, to others are a lot of savings. These ain’t cheap, but to me they are worth it and after learning how long does it take to produce a single serratus, seeing the store price for every single part, Jim throwing away anything below perfection and the countless hours he lost in R&D, I truly think he is selling these on a loss and I wouldn’t do it as cheap.

To @tgx78, that will be reading this all I have to say is thank you. I have no words.

Value ranking: 5/5. Personal rank: S+.

Thanks for reading!
Last edited:
Go Jim Go!
Congrats my friend, your buds is going to be better and better!
Great review!
I've had the Serratus for a few months now and they are so good I stopped looking at iems. I got addicted to the open sound and these are so good that they beat, in timbre, iems at 10x's the price. I know that sounds like hyperbole but if you like how earbuds present music over iems, and you prefer a clean more neutral sound then these are amazing. Yes they do need power. When I first got mine and tried them with an RU6 dongle, they sound a bit anemic and thin. Give them some power and the tone fills in, the stage opens and the bass seems to have no business being this good without the seal of an iem.

I also have the Tantalus and though it doesn't have the vast stage of the Serratus, I think it presents vocals near peerlessly from the iems/buds I've heard. The timbre on the Tantalus is both lush and detailed.

As I don't need the isolation afforded by iems, I have given up looking further than @tgx78 's earbuds.
@SBranson Can you please elaborate more on serratus and ru6 as pair. How exactly they perform