Thieaudio Legacy 4 Review: Carving Out a Legacy for Itself

Pros: Energetic and Lively, Fast and Detailed Bass, Great Technicalities and Extension, Accessories and Cable, Great Fit

Cons: Mid-Bass to Lower Mids hollowed out, Upper Mids and Treble Potentially Fatiguing

Driver Setup: 8mm Poly-membrane Dynamic Driver + 3 BA

Price: US$195


Disclaimer: This review set is a demo set graciously lent to me by a friend from his personal collection. This review is written of my own accord and all thoughts here are my own. Should you find yourself interested in a pair, you can get it online here.

In such a short span, Thieaudio has released its 4th IEM in the Legacy series, the Legacy 4. As indicated by its name, it is a hybrid with 4 drivers in a 1DD+3BA configuration. The Legacy 4 sports a new dynamic driver developed in-house by Thieaudio and as expected, has quite a different bass response when compared to the other IEMs in the Legacy 4. Read on to find out more about how the Legacy 4 spices things up.

Accessories and Build Quality (Score: 9/10)

Build quality of the shells is once again stellar from Thieaudio. The faceplate design is intricate and gorgeous without being too gaudy. This is complemented with a smoke shell that allows you to admire the drivers within.

I especially like how they have moved away from the QDC connectors which tended to crack.

The cherry on top of the cake is really the packaging and accessories. The IEM comes in a huge zipper case containing the IEMs, tips and cable, and another small zipper pouch. This has got to be the most comprehensive set of accessories I’ve seen for an IEM at its price point.

The Legacy 4 also comes with a new silver 2-pin cable with a 4-wire braid. Although thinner than the previous 8-wire stock cable, it’s sleeker and much more aesthetic.

Fit (Score: 9/10)

Fit is great for smaller ears. The shell is overall quite slim and manageable, somewhere in the middle of the Legacy 3 and 5. I preferred the fit of the Legacy 4 has it has a longer nozzle than the 3, providing a much more secure fit. I also did not experience any driver flex.

Sound (Score: 8.6/10)

I used the Down-Down (DD) switch combination for my review

The frequency response for all the switch combinations

Sources Used

  • Hiby R5
  • Lotoo Paw S1

Albums and Tracks tested with

  • Bon Jovi – Living on a Prayer
  • Spinners – Essentials
  • Itzhak Perlman – Paganini Violin Concerto No.1/Carmen Fantasy
  • Michael Bublé – To Be Loved
  • Robin Schulz – Sugar
  • The Lumineers – Cleopatra
  • The Police
  • Tears for Fears
  • Eurythmics
  • Boston Symphony Orchestra
  • Tokyo Kosei Wind Orchestra

Bass (Score: 9/10)

Having heard the Legacy 3 and 5, the bass on the Legacy 4 is quite refreshing. This is apparently due to Thieaudio’s “new in-house 8mm poly-membrane dynamic driver”. The bass emphasis leans more towards the sub-bass with incredible extension and detail retrieval. Listening to songs by The Police like “Every Breathe You Take”, drums are extremely fast and tight with little to no midbass bloat. There is a very nice punch in pop and rock songs.

However, on more instrumental tracks like orchestras and wind symphonies, the snappy bass response and quick decay work against it, where the sound becomes a little dry and sounds less organic.

Mids (Score: 8/10)

There is a region stretching from the Midbass to the Lower mids which is left sounding a little hollow. This impairs the overall coherence of the sound overall but also contributes to a sense of improved clarity and detail retrieval. Listening to songs by Michael Buble and The Lumineers, the L4 takes out a bit of the soul and emotion in the vocals in exchange for a more sterile presentation.

That said, the energy levels are off the charts in the upper mids and lower treble. Electric guitars sound truly electric, and synths create an intensely lively atmosphere that truly transports you. I thoroughly enjoyed the Synths and beats on “Sweet Dreams are Made of This” by Eurythmics and tracks from Tears for Fears.

My biggest complaint about the upper mids would be that they are a little too intense and fatiguing after a while, and instruments like trumpets and horns sound a little thinner and shriller than they should. This is said from my personal experience of playing in wind orchestras and being regularly exposed to how these instruments sound in real life. It isn’t to the point of sounding metallic but strays from the natural tonality.

Treble (Score: 8.5/10)

I don’t have much to comment on for the treble, apart from its good precision and accuracy. There is a nice shimmer to crash cymbals but I could tell it is a little pushed back and not too forward sounding which was a nice touch. The upwards extension is rather well done despite the lower treble emphasis. I personally would have preferred a little less of that emphasis for a more comfortable listen.


Out of all the Legacy series IEMs I’ve tried, the L4 has the most V-shaped tuning. It is very competently tuned and has the technical chops to back it up. The biggest difference I’ve noticed is the bass response and it is a welcome switch-up from the 3 and 5. Another standout point I noticed in the L4 was its imaging. It was very well done and made everything livelier and more engaging.


VS Moondrop KXXS (Review here)

Given their similar price points, I thought to make a quick comparison despite their different driver setups. My first observation was how the bass detail retrieval on the Legacy 4 blows that of the KXXS out of the water. The KXXS has a slower decay for a richer sound whereas the Legacy 4 punches hard and fast. As for the other aspects of sound, they are both respectable performers in terms of their technical capabilities with the Legacy 4 having the edge in technicalities and the KXXS having the better timbre of the two.

VS Legacy 3 (Review here)

Comparing the Legacy 4 to its younger sibling, it is a very significant upgrade in technical ability, especially in the bass and treble detail retrieval. However, I would say that despite their similarities in appearances, they have a very different target tuning, and the Legacy 4 is not exactly an immediate upgrade over the Legacy 3.

Despite the significant improvements made, there are still aspects of the Legacy 3 that I wished to have seen in the 4, like its lush and fluid mids that seamlessly connected and synergised with the lower frequencies. The L4 seems a little disjointed in its area. The L3 is also easier to listen for longer listening sessions, but take note that this may all purely be personal preference and YMMV.


The Thieaudio Legacy 4 is a very mature product with competent tuning. Thieaudio has grown a lot since its first few IEMS such as the Voyager 3. It really shows through the little things that they pay attention to such as the packaging, design and build. The Legacy 4 indeed switches things up in the Legacy lineup such that there will be a Legacy for everyone’s tastes at various price points and this inclusiveness and variety combined with its variety is what makes Thieaudio IEMs so enjoyable to review. I do hope that Thieaudio does not despite the back to back releases as I have one or two bad experiences with QC of my own. That said, I do look forward to more releases from them and although the Legacy 4’s tonality and tuning may not so much be to my tastes, I do see it being a comfortable recommendation for many especially at its price point.

Overall Grade: A-


Click HERE for our grading list for earphones

Leave a Comment

Your email address will not be published. Required fields are marked *