Thieaudio Legacy 3 IEM Review

Thieaudio Legacy 3 Faceplates

Thieaudio is one of the brands that’s been receiving lots of praises lately. They are the result of Linsoul’s efforts in establishing their own brand. And with their experience with dealing and collaborating with different manufacturers, they are able to make products that not only meet the needs of consumers but also deliver products that exceed the quality of their competitors. 

And unlike most CHi-Fi brands, Thieaudio’s isn’t only focusing on mid-tier and budget markets. They have more premium offerings such as the Thieaudio Clairvoyance and Monarch that have caught the attention of lots of consumers. 

In this review, we will be checking out their entry-level offering, the Thieaudio Legacy 3. We will be checking out its build quality, sound quality, and overall value proposition. We will find out just how well Thieaudio’s products truly are. Keep on scrolling to learn more. 


We would like to thank Linsoul for providing the review unit and for making this review possible. However, this does not influence our review in any way. Everything written here is my honest opinion.  


Thieaudio Legacy 3 Review

Packaging and Accessories

legacy 3 packaging

Before we get into the IEMs, let us quickly check out the Legacy 3’s packaging. Most Chi-Fi brands tend to neglect this aspect and instead focus more on the IEM’s performance. However, we believe that giving the user a good first impression is always important. 

The Thieaudio Legacy 3 immediately sets itself apart from the pack with its premium unboxing experience. Opening the Legacy 3’s box felt more like opening a luxurious item as opposed to a budget-oriented product. The Legacy 3 comes in a green flat box with a sliding mechanism that reveals the IEMs and its accessories. 

There isn’t a product photo/art or specs on the box. It just has the Thieaudio logo on the front, which makes the overall design very clean. 

Inside, you get the IEMs as well as a leather case that contains the cable, the spare ear tips, and the sim ejector tool. The leather case was a very pleasant surprise. It feels very premium and is one of the best stock carrying cases that we have seen. 

I did find it odd that Thieaudio did not include foam ear tips. However, I will not take away any points from them since I mostly do not use them anyway. 

The tool included for the hardware EQ switch adjustment is a basic sim ejector found on most smartphones. Most companies opt to use a cleaning tool which I would have preferred since it is more useful. 

But apart from those minor quirks, the Thieaudio Legacy 3 is off to a very good start. Let us see if it keeps its momentum in its build quality and sound quality. 


  • Magnetic Leather Case 
  • 3 Pairs of Silicone Ear Tips (S, M, L)
  • Sim Ejector Tool for Adjusting the Dip Switches 

Design and Build Quality

IEM Shells

legacy 3 shells

Thieaudio is very proud of the build quality of their IEMs. They claim that no other mass-produced product, especially in this price range, can match the craftsmanship and attention to detail of their products.

That is very evident with the Legacy 3’s shells. Our review unit comes with the default option, which includes transparent blue shells and a clockwork faceplate design. 

Thieaudio claims the shells are handbuilt with medical-grade resin, and each unit comes with actual watch components in the faceplate. This makes each unit a unique piece and sets it apart from the rest of the competition. Also, each unit takes almost an entire day to build, which helps them iron out any quirks during production.

The overall craftsmanship is great, and the build quality feels very solid. There are no gaps, and I can see this IEM surviving both casual use and more demanding tasks such as live and studio use. 

legacy 3 without ear tips

The internals can also be seen through the clear shell. The wirings are neatly done, and there are no obvious flaws. The Legacy 3 has two dip switches located at the back, which can be accessed using the provided sim ejector tool. 

The feel of the dip switches is pretty standard. They do not feel fragile and should not encounter any issues even if they are constantly used. 

In terms of the overall design, I prefer the cleaner look of the Gaia colorway. There isn’t anything wrong with the clockwork design, but to me, the Gaia finish looks more premium. This is purely a matter of personal preference since both designs look great. 

But if you dislike the Legacy 3’s default designs, Linsoul offers several customization options. This includes different shell colors and lots of faceplate designs. The customization is pretty in-depth since you can choose different faceplate designs and shell colors per ear. 

The customization options do not end there. The Legacy 3 also comes in a CIEM option from Linsoul. This makes the Legacy 3 one of the most affordable CIEMs, which should appeal to users who have never owned one. The build quality is already good with the universal version that we have, so we have no doubts that the CIEM version will be excellent as well.

Overall, the Thieaudio Legacy 3 is a very well-built unit, especially for its asking price.


legacy 3 stock cable

The Thieaudio Legacy 3’s stock cable perfectly complements the shell. The Legacy 3 comes with a 7N 8-core OCC copper cable that has everything that I am looking for in a good stock cable. These include good overall build quality, quality metal parts, and ease of handling. 

The stock cable does have a more rubbery feel compared to other cables that we have tested. However, its texture did not become sticky and did not cause any issues throughout our testing period. 

The only thing that I would have wanted is metal housings for the 2 pin connectors and a balanced cable option. The ability to choose between balanced and unbalanced cables would be nice and would perfectly compliment the vast customization options seen on the shells. 

But overall, I am very happy with the cable that comes with the Legacy 3. Users should not need to upgrade unless they want to use it with a higher-end DAP or a DAC/Amp with balanced outputs. 

Sound Quality

Tested with: Fiio M11, iFi Nano iDSD Black Label, Audirect Beam 2SE

Hardware EQ

legacy 3 hardware EQ

Before we get into the sound quality, let us quickly go through the two hardware EQ dip switches. Unfortunately, like most IEMs equipped with hardware EQs, both switches are only labeled as “1 and 2”. 

We hope manufacturers, including Thieaudio, will do something about this. But anyway, here is what the switches do. 

Switch 1 – Bass Boost

Switch 2 – High Boost  

Tuning Used: Switches 1 and 2 Turned On


legacy 3 sound presentation

The Thieaudio Legacy 3 is a triple hybrid driver IEM. It has a single 10mm dynamic driver that handles the lows and has two balanced armature drivers for the mids and highs. 

With the stock settings, the Thieaudio Legacy 3 has a balanced tuning with a slight bump in the lows. It is a very safe tuning with no harsh peaks or offensive frequencies. Thus, it plays well with most genres of music. 

I find the overall sound of the Legacy 3 to be very pleasing. It has enough detail to compete with other IEMs in this price range. It does not try to over impress and reach far beyond its price point and instead executes everything within its capability as solidly as possible. 

And with the two hardware EQ switches, the Legacy 3 gives you more options in terms of how you want to enjoy its signature. But unlike other IEMs that feature dip switches, the effects of these switches are very subtle. They just give you a slight bass and high boost to give more punch and detail. 

legacy 3 with leather case

I do not consider the limited options with the hardware switches to be a downside. To me, Thieaudio knows exactly what the Legacy 3 should sound like. The goal of these switches is to help refine the sound rather than to completely change the sound signature. 

A lot of Chi-Fi IEMs tend to blindly add these kinds of sound-shaping options but do not have a clear goal on their target sound signature. The end result is a messy sounding IEM with switches that end up being useless. They can even possibly end up making the IEM sound worse. 

But with that said, there are some things that can be improved with the Thieaudio Legacy 3’s tuning. I do not consider these to be faults since the overall performance perfectly aligns with the Legacy 3’s asking price. We’ll talk more about those in our detailed breakdown of each key frequency. 


The Thieaudio Legacy 3’s lows are a bit boosted in its stock settings. However, it does not feel too excessive and is perfectly controlled. The dynamic driver does its job by providing thumpy and detailed bass. They do not overdo it, and as a result, they do not bleed into the mids. 

But with that said, I find the thickness of the lows to be a bit lacking for a hybrid driver. The way it handles the bass is very similar to the performance of balanced armature drivers. And while I do understand the intent of making an overall balanced signature, I wish that the DD driver had more impact. 

As a result, I engaged the 1st switch of the Legacy 3. It did help a bit and did not make the lows muddier since the boost is very subtle. I was still not satisfied with how thin the low end was for a dynamic driver, but again, its performance is very much acceptable for its asking price. 


The mids are very well done on the Legacy 3. They sit well in the mix and are neither over nor under-exposed. They are also not colored, which helps make vocals feel very natural. 

I enjoyed the Legacy 3’s performance in vocal-heavy tracks. They have enough detail and are capable of capturing the small nuances in tracks that I usually listen to with more expensive gear. 

There isn’t a switch that controls the vocals, so you can’t make the Legacy 3’s mids pop out a bit more. However, this is perfectly fine, and I am very satisfied with how the mids are positioned in the mix. 


As mentioned earlier, the Legacy 3 has no harsh frequencies or peaks, especially in the higher frequencies. The highs are well controlled, which results in a very relaxing listening experience. My only critique is that treble lovers such as myself may find the highs to be a bit lacking even with the second switch activated. 

Again, most IEMs in this price range pretty much have the same approach when it comes to treble. It is, after all, very easy to mess up the treble. So overall, I would take the Legacy 3’s treble performance over an IEM with more detailed but shouty or peaky highs. 

Imaging and Soundstage 

The imaging and soundstage are pretty standard for the Legacy 3’s price point. The soundstage isn’t too wide but does manage to give some sense of space. Imaging of instruments is also quite limited, but it is easy to discern their positioning.

These two are significantly improved when upgrading IEMs, and I expect Thieaudio’s higher-end models to be much wider and have more precise imaging.  

Power Requirements 

The Thieaudio Legacy 3 is very easy to drive. It is designed as an entry-level IEM, so you should not have trouble driving it with dongles such as the ddHiFi TC35B or the more expensive Hilidac Audirect Beam 2SE

Of course, its performance is increased when using it with a more expensive DAC/Amp or DAP. But it is certainly possible to enjoy the Legacy 3 without upgrading your source. 


BQEYZ Spring 2 

The BQEYZ Spring 2 is also a triple hybrid driver IEM. However, it utilizes a piezoelectric driver for its highs which makes its treble response more engaging and detailed. The Spring 2 focuses more on the mids and the highs, which makes it very good for more complex pieces and vocal-oriented tracks. 

The Legacy 3, on the other hand, is much safer and has a more balanced sound. Both are appealing choices; however, some users may find the Spring 2 to be lacking in bass or a bit shouty in the highs. 

I would say the Legacy 3 is better for entry-level users who do not have a preferred sound signature, while the Spring 2 is better for those who specifically want an IEM that focuses more on the mids and highs. 

KBear Believe

The KBear Believe is one of our favorite IEMs in this price range. It utilizes a single beryllium coated driver that manages to give an engaging and detailed sound. Compared to the Legacy 3, the KBear Believe delivers better bass and an overall more natural and coherent sound. However, I found the mids to be more enjoyable on the Legacy 3 despite being slightly behind in terms of technicalities. 

One thing to take note of is that the KBear Believe requires more power to drive, which may not appeal to entry-level users who are only using their IEMs with their smartphone. 


legacy 3 conclusion

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Overall, despite playing it safe with its sound quality, the Thieaudio Legacy 3 is an excellent IEM. It is a great all-rounder that I recommend to first-time IEM users who are still discovering their preferred sound signature. 

While there are some aspects that can be improved in the sound quality, the overall tuning and technical performance are very satisfactory. And when you factor in the high-quality accessories that you get out of the box, you get a complete value-oriented package that should last you until. 

The Thieaudio Legacy 3 serves as a great introduction to the brand. We have no doubts that the higher-end Thieaudio IEMs will continue to impress the audiophile community. 


  • Impedance: 8.6 – 9.5 Ω
  • Frequency response: 20 Hz- 20 kHz
  • Sensitivity: 108dB SPL/mW
  • Noise Isolation: 26 dB
  • Driver: 1 DD + 2 BA

Albums Used For Testing 

  • Milet – Who I am 
  • Babymetal – Legend Metal Galaxy 
  • Mamamoo – Travel
  • Periphery- Periphery 3 and 4
  • Blackpink – The Album 
  • Final Fantasy VII Acoustic Arrangements 
  • Square Enix Jazz- Final Fantasy VII At Billboard Live Tokyo
  • Sawano Hiroyuki – Best of Vocal Works
  • Yorushika – Plagiarism 
  • Intervals – Circadian

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