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Thieaudio Legacy 4 Review

Upping the Game From the Legacy 3

Christopher Coke Posted:
Hardware Reviews 0

This summer, we asked if the Thieaudio Legacy 3 was the best IEM of 2020. Today, we’re looking at its successor, the Legacy 4. It’s a step up in tier, featuring four drivers instead of three, a massively upgraded package, and improved tuning, but is it worth the step up in price? Find out in our review!


  • Current Price: $195 (Linsoul, Amazon)
  • Drivers: 4 total: 8 mm poly-membrane dynamic driver, Knowles ED29689 balanced armature, Bellsing dual balanced-armature tweeter
  • Frequency range: 20Hz-20KHz
  • Monitor Plug: 3.5mm
  • Connector: 0.78mm 2PIN
  • Sensitivity: 108±0.5db
  • Impedance: 9.4Ω
  • Noise isolation: 26dB
  • Detachable cable: 120cm

Thieaudio is the house brand of Linsoul, one of the major retailers bringing Eastern HiFi gear to the West. They’ve been on an upward trend with each release, at least in part due to how receptive they’ve been to user feedback. I’ve been lucky enough to try several of their IEMs at this point and it’s been an interesting journey to watch. From the Voyager 3 to the Legacy 3, the tuning had improved enough that I went from just enjoying the former to questioning whether the latter was the best earphone of 2020 for the price, even after the impressive Moondrop Starfield

The Legacy 4 isn’t exactly a successor, since Thieaudio technically released the Legacy 5 first, but in the ladder of their products, it feels like it. The Legacy 4 upgrades the 3 with an additional with a total of four drivers, composed of a new custom 8mm dynamic driver and a trio of balanced armatures. The number in the title then, refers to the number of drivers rather than product order, but it still works to align everything in a proper sequence for the caliber of earphone in Thieaudio’s line-up.

The Legacy 4 does a bit more than simply “add another driver” to the mix, however. The company has replaced the dynamic driver on its previous models with a proprietary model that definitely improves the tightness and clarity in the bass response. Compared to the Legacy 3, this makes it a better fit for gaming and entertainment where punch and slam add to the fun — which also makes it fun for music listening, also. Likewise, the Legacy 4 includes a brand new dual balanced armature tweeter and the highly regarded Knowles ED29689 balanced armature for added detail and resolution.

Thieaudio has also upgraded its packaging from the Legacy three. The IEMs now come in a large zippered hard-back case. Inside, you’ll find the IEMs, a small travel case that holds the cable, and a metal plate holding the six included sets of silicone tips. It’s a premium package that well outperforms any American brand I’ve tried at this price and competes only with the Kinera Freya. The larger case is good if you’re planning on taking the whole kit with you but is a bit impractical for day to day use. Still, I like that it’s included and adds value to the overall package.

The earphones themselves are beautiful. They feature painted faceplates in swirls of sparkling color. Even though they’re universal fit, I find these to be some of the best fitting and more comfortable IEMs I own. They’re contoured to match the natural folds of your ear and I found them to sit nearly flush while also offering an excellent seal. Thieaudio is really one of the best in this department. I’d almost forgotten from my last experience with their earphones, but this was such a pleasant reminder of how an earphone should fit.

On the back, we also have our tuning switches. The three-way crossover (the part that allows the drivers to function in unity with one another) ties into these switches and allows it to be tuned for added treble, bass, or clarity. As on past models, the differences here are very small and aren’t really explained, so I left them both in their default positions pictured above. 

The Legacy 4s also come with an excellent cable. It’s composed of four strands of silver cable woven into a braid. It’s not the best I’ve seen from Thieaudio but is excellent at this price. This style of cable seems to resist tangling and has no memory, reminding me much more of a silver rope than a headphone cable. It definitely lends to the almost jewelry-like aesthetic.

Where the Legacy 4 really sets itself apart is in the sound. The new dynamic driver is an immediately noticeable upgrade from the Legacy 3. The sub-bass extension — the very low end, which adds texture and feel to bass notes, sometimes thought of as rumble in headphones — is much improved. The kick drums in Elevate by Eminus have a depth the Legacy 3 just couldn’t offer. It’s also fast, which allows it to nail the double-kick drum in Atreyu’s Bleeding Mascara with a crispness that often feels muddy on lesser tuned IEMs. 

I also appreciated the texture they brought to the table in guitar-driven music. I listen to a lot of rock and metal and in busier tracks, the nuances of guitar tone can become muddy and just sound distorted. Here, they’re much more true to life, even as the instruments begin to layer. The same is true in the treble regions. Sticking with Atreyu, I was surprised at how much detail the Legacy 4 resolved from the high hats and cymbals. Snares also really snapped and toms resonated with realistic decay, even over Spotify. The Curse isn’t an album I ever considered amazingly mixed (it’s not bad, but doesn’t stand out as special in any way) but it sounded almost new on the Legacy 4s.

That said, that brightness that allows those details to shine can be fatiguing over time. I noticed this more in really sharp heavy metal with guitar solos, octaves, and high gain chords. This may be an issue if you prefer to listen for more than a couple hours at a time and also enjoy this genre, but I could listen for 90 minutes or so before needing a refresher for my ears.

For gaming, the soundstage is going to leave you wanting, but it still feels slightly larger than the Legacy 3 while being much more constrained than a normal pair of open-back gaming headphones. That said, I was surprised at how responsive they were to Dolby Atmos. Playing World of Warcraft and PUBG, there were times sound cues actually sounded distant. Games need solid directional audio and spatial engineering to really pull this off, but when they do, the Legacy 4s can deliver surprisingly good results in games.

The other high point for applies to music, games, and movies alike: vocals. These really draw out male vocals especially and pull them forward in the mix. That means callouts, narration, and dialogue will come through clearly, even in a busy soundscape. Playing Battlefield 5, I had no trouble hearing both in-game shout-outs or voice chat, even mid firefight after balancing my volumes. 

Final Thoughts

At $195, the Thieaudio Legacy 4s come in on the expensive side of the IEM spectrum but darned if they don’t sound great. I loved the Legacy 3s and these are a noticeable upgrade and a lot of fun to listen to, whether that’s folksy acoustic music, melodic electronica, driving post-hardcore, or gaming. These are clearly targeting audio enthusiasts above all else, but don’t let that scare you. They have an approachable and all-around impressive sound that marks another solid step forward for Thieaudio in this price bracket.

The product described in this article was provided by Linsoul for evaluation purposes.
  • Improved bass and resolution from Legacy 3
  • Great package - dual carrying cases
  • Beautiful design
  • Very nice included cable
  • Tuning switches to dial in the sound
  • Rather tight soundstage
  • Added brightness can be slighting fatiguing
  • Tuning switches continue to be very modest


Christopher Coke

Chris cut his teeth on MMOs in the late 90s with text-based MUDs. He’s written about video games for many different sites but has made MMORPG his home since 2013. Today, he acts as Hardware and Technology Editor, lead tech reviewer, and continues to love and write about games every chance he gets. Follow him on Twitter: @GameByNight