ThieAudio Legacy 3 Custom Review

Thieaudio Legacy 3 review featured
TESTED AT $119-$179

Linsoul website:

ThieAudio is a relatively new brand coming out of China. They premiered in 2019 with their Phantom planar magnetic headphones. Now they are making in-ear monitors too and in today’s review, I’m checking out the Thieaudio Legacy 3 earphones. Legacy 3 is a triple-driver hybrid with one dynamic driver for bass and 2 balanced armature drivers. Do they deserve your attention? Let’s find out.

Disclaimer: This sample was provided for the purpose of an honest review. All observations and opinions here are my own based on my experience with the product.

ThieAudio Legacy 3 Review

  • Unique appearance
  • Great build quality and comfort
  • Natural, unforced sound
  • Tight, controlled bass
  • Exceptional value

  • No documentation for the switch functions
  • Micro-detail retrieval

Package and Accessories

Legacy 3 custom comes in a Pelican style case

I received my Legacy 3 in a plastic Pelican style case with nothing else besides the earphones and cable. It happens to be quite a good case but my ears (and therefore my custom in-ear monitors) are quite large and only just fit inside along with the cable.

Build Quality and Design

Considering the price which is very low for a custom in-ear monitor, I had fairly low expectations as far as the build quality is concerned. I needn’t have worried though because my custom Legacy 3 has an immaculate build.

I left the design up to Thieaudio/Linsoul and they chose the “Chinese White” design which is white with a blue flower pattern. It looks very much like the popular Chinese porcelain patterns that have been around for years. It’s definitely unique for an IEM but I suspect the look will be too feminine for many people. However, there are several other styles available to choose from so that shouldn’t be a deterrent.

In terms of build quality, these are superb. I can honestly say that the workmanship and materials used are comparable to other CIEMs in my collection costing well over $500. This isn’t surprising due to the fact that many custom monitors are now made using 3D-printing. A few years ago it would have been impossible for this price.

Thieaudio Legacy 3

The 2-pin sockets are not recessed and thus are flush with the shell. Just in front of the socket is a small vent, presumably for the dynamic driver. On the top side are 2 dip switches for tuning. Just like the Voyager 3 IEM (review here), the left switch is for the bass and the right switch is for the high frequencies.

Overall, I am extremely impressed with the build and finish of this custom Legacy 3 unit. Every time I look at them and think of the price I’m in awe at what Thieaudio has achieved here.

Comfort and Noise Isolation

As I always say in my custom IEM reviews, the fit and comfort will depend largely on the quality of the ear impressions you send to the company. Make sure you get good impressions and you’ll greatly increase the likeliness you’ll be satisfied with the fit of your in-ears.

My set turned out perfectly in regards to the fit. They’re very comfortable and I can wear them for hours at a time. Noise isolation is excellent and about average for a properly-fitted CIEM. They passively block somewhere around -26dB of external noise, making them ideal for stage performers or anyone who wants to hear nothing except their music.

The silver-plated copper cable handles beautifully

The included cable appears to be the same silver-plated copper (SPC) as the one I got with the Voyager 3 albeit this time with a 4.4mm balanced termination. It’s an attractive cable with a mixture of grey and copper coloured insulation. The cable is soft and malleable and handles extremely well.

The straight plug and Y-split are aluminium with a band of carbon fibre in the middle. There is a transparent plastic chin slider and soft, flexible preformed ear guides. Lastly, the 2-pin connector housings are aluminium and are colour coded for easy identification of the left and right sides.


Sources used for testing:

  • FiiO M6
  • Soundaware M2Pro
  • Topping DX7 Pro

Thieaudio Legacy 3 is a very efficient earphone making it easy to drive. It can be connected straight to a smartphone or low-powered MP3 player or DAP. The general sound signature is fairly neutral and very clean sounding. It has good detail retrieval and the clarity throughout is really substantial too.

Of course, things can be changed up slightly by using the dip switches. Instead of trying to explain the different settings, I’ll just include the diagram from Thieaudio. While I found myself enjoying both the “Default” and “Detailed” settings the most, Legacy 3 is one of the few ‘tunable’ IEMs that I can enjoy in all configurations.

Thieaudio Legacy 3 dip switches

Tuning Switches


While I do enjoy all-BA IEMs, I really love dynamic drivers for bass. The Legacy 3 indulges my preference not only with a DD bass but a darn fine one at that. It’s fairly neutral, especially with the “Default” switch setting. But neutral doesn’t mean boring or anaemic: Legacy 3 finds a great balance between weight, speed and tone.

This is a bass that sounds natural: it is not overdone and doesn’t bleed into the mids nor dominate the overall presentation. Yet it still has a satisfying weight and enough impact to induce toe-tapping and head-nodding. Hinkstep’s “Lost I” is a track that is driven by its bass. Legacy 3 responds with an enthusiasm that is engaging but highly controlled.


What can be said about the Legacy 3 midrange? Well, it is detailed, articulated and like the bass, it is quite neutral. In fact, I’d go as far as to say the mids are just a little dry. The reason? They’re not coloured like most IEMs in this price range, which tend to make notes rounder and more full-bodied. I wouldn’t say this midrange is cold: that generally correlates with a more forward treble which the Legacy 3 doesn’t have. Let’s just say they’re transparent and clean.

One of the surprises here is the vocals, which are lively and vigorous. Both male and female vocals shine with musicality and texture. “We Watch the Stars” by Fink is a good song to highlight the Legacy 3’s vocals delivery. Despite the track being quite bare in terms of accompaniments, Fin Greenall’s vocals sound lifelike, present natural and lifelike. I also liked the timbre of the guitar and violin.


Legacy 3 has an interesting treble. It’s easy on the ears but not what I would call relaxed because there’s still plenty of liveliness there. The extension is good and the treble sounds light and airy yet still has good density. There’s not any hint of sibilance either, although some instruments in the lower treble/upper mids (horns and piano for example) sound quite forward.

There’s a good amount of detail in the treble but some minutiae will not be revealed. However, the upside is a non-fatiguing presentation with a pleasing, natural tone.


The soundstage is slightly elongated with above-average depth and moderate width. It has a stable central image and a neutral stage position. It has a good amount of instrument separation and pretty solid imaging where the location of various instruments is easy to determine. Vocals are positioned at the front of the stage but there’s a comfortable distance between them and the listener.

Thieaudio Legacy 3 faceplates with teacup


ThieAudio Voyager 3 ($159)

The Voyager 3 (review here) is a triple balanced armature driver IEM from the same company. What stands out immediately is the Voyager 3’s BA bass which lacks the extension and authority of the Legacy 3’s dynamic driver. Both IEMs are somewhat reserved in bass quantity, going for overall balance more than outright punchy fun.

Voyager 3 is sweeter in the mids, with rounder, smoother notes compared to the drier mids of the Legacy 3. It has more body in the midrange too, a side effect of slightly warmer upper bass and lower midrange.

In the high frequencies, Voyager 3 has a more forward treble. It’s similar in tone to the Legacy 3 but a bit clearer and more detailed. This, in turn, increases the Voyager 3’s midrange clarity to a degree as well.

What the Voyager lacks compared to the Legacy 3 is character: that hard to define quality that makes it sound unique and captivating. This is not a criticism of the V3, it’s just that the V3 sounds more typical of a multi-BA IEM i.e. very clean and predictable. Legacy 3 has that X-factor that makes it stand out from the crowd. In some ways, it reminds me of the legendary Tin Hifi T2 in this regard.

Moondrop Starfield ($109)

The Starfield (review here) is a single dynamic driver IEM. It has a tuning that follows the Harman target which is a popular choice among music lovers. It has a slightly warmer tonality than the Legacy 3 but many similarities in other areas.

Starfield digs a little deeper when it comes to sub-bass. It’s more forward in the bass but slightly recessed in the midrange compared to Legacy 3. The Starfield has slightly better clarity, instrument separation and detail in the mids.

That extra detail comes from Starfield’s more forward treble which, in addition to extra detail, gives it a wider soundstage as well. Legacy 3, on the other hand, has more bass texture and forward midrange. Which IEM would suit you better depends on personal preference and music choice but both offer great value and sound quality.

Thieaudio Legacy 3 white China porcelain design with teacup


It seems as though this relatively new brand is on the rise, judged on the 2 entry-level IEMs I’ve tested thus far. The Thieaudio Legacy 3 offers a balanced, mature sound that ticks a lot of boxes. Oddly enough, it doesn’t go for a wow effect with big bass and bold sound nor does it try to impress by being ultra-detailed and precise. Instead, it simply offers a natural tonality and delivers it in an effortless, almost blasé fashion. Somehow it all comes together and it just works.

Now, something I’ve kept in mind all throughout this review but haven’t really talked about is the fact that I have a custom version of the Legacy 3. The fact that this CIEM costs less than $200 still blows my mind. Yet, it is as well built as my other custom monitors that cost a whole lot more. And it has 4 different tuning options! If you’ve always wanted to try a custom in-ear but felt prohibited by the high prices, this is the perfect IEM to get your feet wet.

  • Sensitivity: 108dB SPL/mW
  • Frequency range: 20Hz-20KHz
  • Impedance(IKHz): 8.6-9.5
  • Driver: 1HI+ 1MID+1DD
  • Noise isolation: 26dB
Founder of Prime Audio
Notify of

Oldest Most Voted
Inline Feedbacks
View all comments
David Newbury
David Newbury
8 months ago

Hi All

Just a heads up, as of September 2022 Linsoul are no longer customizing this model, or any of their budget models.

In my experience, I contacted them about this model specifically and provided links to this and another review to them. They asked me to get a set of impressions made and to email them photos to check that they were ok. Only once doing this did they inform me that they are no longer customizing this model, but they did provide me with a list of ~$1k iems to choose from.

So it appears that Linsoul no longer has any budget friendly customizable IEMs.
Might be worth making 100% certain that they will customize the model you are after if you plan on ordering from them… But I don’t know how much more certain I could have been after multiple emails and providing them with links to 4 reviews of this model.

Hope you all have better luck with Linsoul in the future.

2 years ago

What’s the best way to do ear impressions? You buy what? I known in my poor country no one will do 3D scans I somewhat sure about that.

Abigail Chiu
Abigail Chiu
2 years ago

Thanks for an awesome review. I’m sold. I’ve never own a custom iems, so if you don’t mind a couple of questions. What’s the process with ThieAudio, I get the impression and get approved then send in my impression? are they using my impression to make the earpiece? if not would I get the impression back?

It looks hard and not soft like silicone, how hard are they? The cable that was on the video looks different than the cable on their product page, that one looks black, are they upgrades.

Thanks so much for answering

3 years ago

Is this unit terminal QDC? Is it a normal 2pin?

Did you ask for the part about the cable or unit in the custom request?

Something other than ArtCustum.

Would love your thoughts, please comment.x