Thieaudio Oracle MKII review: Great design, terrific sound

Thieaudio is audio retailer Linsoul's in-house brand, and while it is best-known for its Monarch series of IEMs, the brand has ventured into a lot of new areas over the course of the last 12 months. The Wraith is a good showcase of Thieaudio's efforts at making a planar headset, and the brand followed it up with the Ghost, a budget headset that offers a fabulous value.

The Oracle MKII are a reworked version of the Oracle that debuted back in 2021, and the key difference is that they deliver much better sub-bass frequencies. The Oracle ticked a lot of the right boxes when it comes to tonal accuracy and layering — thanks in no small part to its use of various drivers — and Thieaudio is looking to build on that with the Oracle MKII. The IEMs are available on Linsoul for $589, and you can choose between the Black Scarlet and Tiger color variants.

Like the Fiio FX15, the Oracle MKII use a combination of three drivers — a dynamic driver, balanced armature driver, and an EST driver. Thieaudio notes that each driver is selected for its unique profile, and the difference is noticeable versus IEMs that have a traditional configuration — particularly when it comes to the treble.

We'll get to the sound in a moment, but I want to talk a little bit about the design. I'm using the Tiger variant of these IEMs, and the design looks gorgeous; the vibrant pattern makes these stand out quite a bit, and the build quality is among the best in this segment. Thieaudio went with a resin shell that's paired to a metal sound nozzle that extends out a little more than most IEMs, and you get Oracle MKII branding on the inside, with the brand's logo emblazoned over the faceplate.

I think Thieaudio did a brilliant job with the design of these IEMs, and they deliver a good fit as well. They are on the larger side, but the design of the shell is such that it sits over your inner ear instead of exerting too much pressure, and I found these to be comfortable to wear. The only quibble is that because the sound tube extends by up to 6mm, it tends to nuzzle a little further inside your ear, and that can be irksome occasionally.

A side effect of the elongated sound tube is that it offers excellent noise isolation — much more so than any other IEM I used. On the whole though, the Oracle MKII have a great design, comfortable fit, and good sound isolation, and Thieaudio did all the right things in this area.

The packaging includes a decent hard shell carrying case along with a braided cable that's of a good quality, and the best part about the cable is that it has interchangeable plugs. You get balanced 2.5mm and 4.4mm plugs in addition to the standard 3.5mm, and having used plenty of Fiio IEMs that offer a similar style of cable, I like that Thieaudio is also going this route.

What isn't so great is the limited selection of ear tips; you get a total of six in the box, and that's considerably less than what other brands offer — Fiio's FX15 comes with a total of 16 in the package. The bundled tips don't quite measure up to the likes of SpinFit and other custom options, and you should consider picking up aftermarket ones if you're eyeing these IEMs.

Coming to the sound, the highlight of these IEMs is that they use a combination of three drivers, each aimed at a frequency range to deliver the best possible sound. The 10mm dynamic driver is tuned to elevate low-end frequencies, the dual BA drivers are aimed at the mid-range and treble, and the dual Sonion EST drivers provide a lot of sparkle in the high-end.

The original Oracle IEMs had a neutral signature that made them great as reference monitors, but Thieaudio is changing things with the MKII model. This time around, there's a clear boost in the low-end frequencies, and while these IEMs don't have that neutral sound any longer, they sound fantastic. The sub-bass in particular has a wonderful energy and vigor, and it has a fast attack — not quite measuring up to planar drivers, but much better than usual dynamic drivers in this segment.

The exaggerated low-end makes the Oracle MKII a fun listen, and Thieaudio did a good job ensuring the bass isn't so overwhelming that it bleeds into the mid-range. On that note, the mids are natural and clean, and the vocal-forward presentation means these IEMs hold up well across a variety of genres.

Similarly, the treble has a lot of extension and airiness, and the EST drivers make a tangible difference in this area. There is some harshness at higher frequencies, but it isn't too bright, and there's no sibilance. The soundstage is wide as well, and you get excellent layering; Thieaudio got a lot right with the tuning of these IEMs.

With a sensitivity of 100dB@1KHz and impedance of 11Ω, it's easy to drive the Oracle MKII, and I used the IEMs mostly with Fiio's M15S audio player and the BTR7 portable DAC. As they have a unique sound signature, using an analytical source like the M15S makes you get the best out of the IEMs.

Overall, Thieaudio did a great job with the Oracle MKII. They're not as neutral as their predecessor, but the focus on the low-end frequencies means they're fun to listen to, and they have a comfortable fit and a fantastic sound with a lot of character. Fiio's FX15 are a good alternative to consider, but if you're aiming to get the best value, the Oracle MKII are still a fabulous choice.