Thieaudio Legacy 4
Thieaudio Legacy 4
Thieaudio Legacy 4


1DD + 3BA Hybrid In Ear Monitor

    The proprietary 8mm poly-membrane dynamic driver
    Knowles TM and THIEAUDIO Customized Balanced Armatures
    3-Way Crossover Network is integrated into a 2-switch tuning system
    Paired with an OCC 4-core custom cable
    Optional Upgrade EST cable is 2.5mm balanced cable comes with 3.5mm and 4.4mm adapter
    Hand-crafted, tested for Quality Assurance
Regular price $236.55 USD
Sale price $236.55 USD Regular price $249.00 USD


Thieaudio was launched in 2019 as a creative endeavor of Linsoul Audio. The goal of Thieaudio was to serve as a creative platform for gathering the best teams of engineers to inspire revolutionary audio products for audiophiles and professionals alike. For each project, we hand select the most innovative and renowned engineers in his or her field to oversee the design, engineering, and manufacturing of the products. Gathering the momentum from the success of the Thieaudio Phantom planar magnetic headphones, as well as the Voyager, Legacy, and Signature series In-Ear Monitors (IEM’s), we are committed to the continual expansion on the limits of high-fidelity audio. We welcome you to join us and experience excellence in musical performance.

Legacy Series

The Legacy series capitalizes on Thieaudio’s proprietary Nano-Membrane Dynamic Driver to create a high-performance hybrid in-ear monitor. Geared towards the discerning audiophile and music enthusiast, the Legacy series re-envisions the qualities that make up high-fidelity audio to present a unique combination of enjoyable tuning that also excels in technical performance. With each model of our Legacy Series, we hope to reveal a refreshing new perspective on your daily listening experience, immersing you deeper into the music. 

Legacy 4

The Legacy 4 was designed concurrently with the Legacy 5 to provide a unique twist to the lineup. With the beloved budget model, the Legacy 3, and the natural and smooth sound signature of the Legacy 5 in mind, we wanted the Legacy 4 to be a middle ground - both in terms of the tuning and price. Utilizing a completely new in-house 8mm poly-membrane dynamic driver for the low end, the Legacy 4 provides the impactful slam of the Legacy 3 and 5, but with a faster speed and enhanced texture. This new driver, matched with the tried and tested American Knowles ED29689 balanced armature (BA) and intuitive low-mid passive crossover design emphasizes a natural mid-frequency presentation. With a less aggressive crossover design than the Legacy 5, the mids of the Legacy 4 presents a more musical experience that ever so slightly adds a dash of warmth to the overall signature. With the partnership of Bellsing, we have developed a custom dual BA tweeter for the Legacy 4 that perfectly fits the mid BA driver. From the relaxed and smooth treble delivery of the Legacy 5, we have tuned the Legacy 4 to bring more upper treble presence, highlighting upper frequency overtones and details. This tuning and the extremely capable treble extension of our new tweeters brings an even greater level of airiness and shimmer to the mix, making the Legacy 4 an excellent IEM for both professional musicians and music enthusiasts alike. You can trust that the Legacy 4 will provide one of the most natural, accurate, and enjoyable musical experiences among any IEM’s of its class. 

Tuning Switch

The Legacy 4 crossover network is integrated into a 2-switch tuning system that allows the user to define the level of bass and mids. This tuning system means you can find the perfect sound signature no matter your musical preference!

A Completely Redesigned Look

Our team has worked hard to completely update our look! Paired with an OCC 4-core custom cable, you’ll find the Legacy 4 in an all new beautiful storage and travel case. 

Hand Crafted, Test for Quality Assurance

Each Legacy 4 unit is hand crafted, from the medical-grade German resin, to the internal circuitry, all the way to the painting of the faceplate. You can rest assured that your Legacy 4 is both a one of a kind in design and in line with all of our quality check protocols. Every pair is individually tested for left-right channel matching and inspected for defects prior to packaging and shipment. At Thieaudio, quality always comes first.

Inside the Box

  • 1 x THIEAUDIO Legacy 4
  • User Manual

1 Year Warranty

The THIEAUDIO Legacy 4 Comes with a 1 year warranty on the In-Ear Monitors and 3 month warranty on the cable.

Technical Details

Legacy 4
Frequency range
Monitor Plug
0.78mm 2PIN
Noise isolation
Detachable cable

Authentic Products

Linsoul Audio is the authorized distributor. All products are authentic and genuine.

Worldwide Free Shipping

We are located in China but send our products worldwide for free. T&Cs apply.

1 Year Warranty

We provide 1 year warranty for the all products except the cables and accessories*.

Online Support

Need help?, we are here to assist you
Monday - Friday: 09:00 – 18:00 (UTC+8)

Customer Reviews

Based on 18 reviews
Decent set but

It has decent sound for upper registers, but it lacks depth and presence for lower ends. It could be good listening monitors for classical music, but not for others.

Hello there,

We are sorry that our product did not satisfy you.

The Legacy series re-envisions the qualities that make up high-fidelity audio to present a unique combination of enjoyable tuning that also excels in technical performance. With each model of our Legacy Series, we hope to reveal a refreshing new perspective on your daily listening experience, immersing you deeper into the music.

We believe that sound is very subjective, we will also give feedback to the manufacturer about your suggestions for the bass part of this product, and we appreciate your approval of its treble part as well. We believe that we will do better and better in the future.

If you encounter any problems in the future, we sincerely suggest that you contact us via email ( the first time,because we can solve your problems in a more comprehensive way.

Thank you for your support and understanding.

Pedro Martins
Extremely interesting

- Build quality 10/10
- Isolation and Noise canceling 10/10
- Soundstage 08/10
- Cable 10/10
- Design & Comfort 10/10

After 60+ days of burn-in I give 10/10 to this In-Ear. The sound of Thieaudio Legacy 4 is very detailed, neutral, clean and pretty well balanced

Great IEM for the price.

Nuno Filipe Oliveira


Lawrence Rositani
The Audio Legacy 4 almost perfect

For the price the build quality and sound reproduction is unmatched. Listening through a Schiit Jotunheim is a pleasure that has not lost its luster.

Thomas Jonsson

The best

Joe s
Great tonality and punch, but narrow soundstage.

I'm coming from legacy 3's, the T2, T2 plus, T4, bl03, ER2XR&SE, ER3XR, ER4XR and a bunch more. I find that the tuning is exactly what I want in an IEM, but the soundstage is somehow lacking compared to my legacy 3. Zeos mentioned this in his review, and I didn't want to believe it, but it's pretty noticeable. I'm really not as disappointed as Z was though. It's a fantastic IEM.

Ben Recasas
Lacking Bass and soundstage

Bass response is low and soundstaging is almost non-existent even after 200 hours of burn in.

Erik Rodriguez

Impressive detail with a light and clean sound. Nice stage and decent imaging. Bass is tight with a nice rumble, but it doesn’t kick hard enough for my tastes.

John Peterson
The Definition of IEM

Extension both ways with great detail and very good timbre. 5 stars for value and a complete reproduction of sound! If you enjoy separation and layering these are sure to please. I feel like any musician could use these on stage and get effortless clarity and would hear each element of the mix distinctly. If you like balanced armature sets but always feel better with the 'Bass Boost's on, these deliver the low end - and it's fast and textured almost as if the DD were a large BA.
These are an upgrade from my ikko OH1 and Tin P1. Bass is not quite as lush and full as ikko OH1 but the treble detail and extension is much better on the Legacy 4. I love the clarity of my P1s but vocals don't always sound natural. To me, the Legacy 4 delivers more pleasing vocals - even if they are just a step back in the mix. I was hoping for a bit wider soundstage but it's still there. I would recommend silicone tips. Experiment with different sizes and nozzle types.
As for the dip switches... leave them down/down (default). For me they seemed to decrease impedance and made them feel overly sensitive to the amplification I was using. I have used a slight midbass (125-300hz) boost with EQ to warm up the vocals and lower mids. Like most BA sets, poor recordings can get a bit shouty in the 3k-6k region but the treble is quite well controlled by the filters and configuration they are using.
For $200 IEMs these are an excellent value! Not too warm... Not too dry... Plenty of detail... Yep!

Not that good.

DD Qaulity = Very good
BA Qaulity = Very poor, Too harsh at high frequency. Texture is unnatural.
Too much hyped.

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