Thor Mjolnir MKII Review

Thor Mjolnir MKII

You’re telling me this IEM was made by Thor? Technically yes, this is a new IEM that is made by a single in-house engineer who crafts earphones as a hobby. This designer goes by Thor, like how Noble’s in-house artist goes by The Wizard. Let’s have more designers use cool names. Anyway, Thor is mainly known for their aptly named Mjolnir model which was sold limitedly. Now Thor looks to expand their name with the release of the Mjolnir MKII, a deserved update to their previous model. It goes for $399 so let’s see if it is worth that price.

Thor Items

What You Get

For the Mjolnir MKII, Thor gives these IEMs a simple package. The plain black box you are given contains the earpieces attached to their 2-pin to 3.5mm cable as well as two sets of ear tips in s/m/l. No carrying case is provided.

Thor Single

Look and Feel

The design of the Mjolnir is quite nice. I don’t think I’ve seen this particular shape used on many IEMs but its housing is a perfect size and fits naturally in the ear. The artwork on the Mjolnir reminds me of what you might see on an IEM from Kinera. In fact, this IEM reminds me specifically of the Skuld, with its sparkly scales under a black surface. On the Mjolnir MK II you get a more silvery pattern, but both IEMs are still comparable.

Thor Cable


Underneath its housing is one of the first dynamic drivers to feature a custom fashion diaphragm. This 12.56mm unit combines a composite diamond-like carbon with polyetheretherketone and polyurethane materials. All of these big-worded components are meant to give the Mjolnir MKII its desired acoustic performance, affecting the signal flow with its rigidity and responsiveness.

Impedance: 16Ohm
Sensitivity: 115dB
Frequency response range: 8-40000HZ

Thor Pair


I’ve listened to a lot of IEMs with good soundstages recently, and I’m not sure if I’m becoming more numb to ones that are just good, or the one I happening to be listening to just isn’t delivering. Thankfully, the Mjolnir MKII doesn’t fall into that category, as its ability to layer its stereo field and communicate its spatial imaging outdoes its price point. I felt like the imaging was continuing to grow the more time I spent with it, as its width and height never seemed to reach a hard limit no matter what track I was listening to. Its headspace appears like a picture of the music being shown to you in front of your face, where your whole field of vision is being encompassed by the sound. Instruments and vocals are properly separated but never feel too apart, as the imaging still provides you with a fullness that is hard to replicate. Some elements seem elevated, giving tracks a floatier aura, which is an effect I really enjoy.

Low End

Before listening to the Mjolnir MKII for the first time I was hearing that this was going to be a bass head IEM. While a part of that notion is true, I don’t think it is what some people may be expecting. This is a bass response that offers you a great amount of rumble and hefty vibration, but it is a lot more subtle than I had anticipated. There’s an articulation to these lows that gives you the best of its fulfilling texture while also reproducing pinpoint accuracy. Its smoothness comes up from under you and results in a gripping pool of resonance that’s as rich as it is clean. Taking the track “Prayers for Rain” by The Cure, for example, the opening blast of all the instruments coming in sounds incredibly explosive with the Mjolnir MKII, and it sets a strong foundation for the rest of the elements to perform on.


There’s definitely a good body to the midrange of the Mjolnir MKII. The frequencies lean a little bit to the warm side but never cloud the rest of the sound signature in its resonance. This is due to the emphasized low-mids that give the timbre a lot of its drive. Some of the tonality can add a lot of meat to your tracks, making the Mjolnir MKII great for heavier music. You also get some nice accentuation from the upper-mids as well, giving vocals some added aggression and crispiness.


The treble range should be enjoyable for listeners with all types of preferred sound profiles. It is both smooth enough to not cause issues with peakiness, and detailed enough not to feel too thin or hollow. You get some good extension here, with ringing artifacts that give the sound signature some air, as well as a tight glisten. Its brightness never strays into a harsh territory, and always adds a touch of sparkle to heighten its lush timbre.


For a four hundred dollar IEM made by one person, the Mjolnir MKII is incredibly impressive. Soundwise it is a pleasure to listen to, with exceptional bass and treble response that will tonally soothe anyone listening. Its artistry and comfortability are also rock-solid, leaving you able to use the MKII for long hours without fatigue. Comparisons to other brands will come with its notoriety, but for now, I think the Mjolnir MKII houses a fine listening experience worth checking out.

Pros Cons
·         Layered imaging

·         Good soundstage

·         Smooth bass

·         Meaty mids

·         Crisp highs

·         Comfortable

·         Stylish design

·         Comparable to other brands

·         Limited accessories

The Thor Mjolnir MKII is available from Linsoul.

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Alex S. is a sound designer and voice-over artist who has worked in film, commercials, and podcasts. He loves horror movies and emo music.