General Information


5 Driver, Hybrid IEM Design:

  • Universal in-ear monitor
  • 3 Proprietary Balanced Armature Drivers - Low, Mid, High
  • 2 Premium Electrostatic Drivers - Ultra High
  • 4-Way synX Crossover Network
  • EIVEC - Empire Intelligent Electrostatic Control Technology
  • A.R.C. Anti Resonance Compound Technology
  • Impedance: 3.9 Ohms @ 1kHz
  • Frequency Response: 10 Hz - 100kHz
  • Sensitivity: 111dB @ 1kHz, 1mW
  • Handcrafted Alpha-IV 26AWG UPOCC Copper Litz Cable

Price: 1099 US$

Latest reviews


100+ Head-Fier
Empire Ears ESR MKII (2021) - The truth and nothing but the truth
Pros: - Neutral, studio-grade sound signature
- Analytic without being without being too “flat” or boring
- Excellent channel- and instrument-separation
- Good soundstage for an IEM
- Well made, classy IEM and cable
- Very good price-/performance ratio
Cons: - Rigid cable


Empire Ears (EE) are opening 2021 with some new and exciting products. One of them is the ESR MKII, the next iteration of their ESR (“Empire Studio Reference”) in-ear studio monitor. At a retail price of $1099, it sits somewhere in the middle of their studio-collection. This is a markup of $200 over its predecessor.

While the original ESR had 3 balanced armature drivers, the 2021 ESR MKII sports a 5-driver hybrid design including 3 balanced armature drivers and 2 electrostatic drivers. The ESR MKII belongs to EE’s EP Series which is mainly targeted at professionals like musicians and studio engineers.


5 Driver, Hybrid IEM Design:
  • Universal in-ear monitor
  • 3 Proprietary Balanced Armature Drivers - Low, Mid, High
  • 2 Premium Electrostatic Drivers - Ultra High
  • 4-Way synX Crossover Network
  • EIVEC - Empire Intelligent Electrostatic Control Technology
  • A.R.C. Anti Resonance Compound Technology
  • Impedance: 3.9 Ohms @ 1kHz
  • Frequency Response: 10 Hz - 100kHz
  • Sensitivity: 111dB @ 1kHz, 1mW
  • Handcrafted Alpha-IV 26AWG UPOCC Copper Litz Cable

My review consists solely of my own thoughts, opinions and impressions of the product. I paid for the tested product, it was not given for free. All pictures were taken by myself unless stated otherwise.

Review gear


  • Burson Audio Soloist 3XP / Composer 3XP combo (main testing source)
  • Cayin N8 DAP
  • Cayin N6 II DAP with E02 module
  • Empire Ears Alpha-IV cable (2.5mm balanced)
Music selection/Testing playlist

Voices, midrange, acoustic guitars etc.

Tenacious D - Tenacious D - Wonderboy
Marily Manson - The Pale Emperor - Day3
Chris Jones - Moonstruck
Sara K. - Hell or High Water - I Can't Stand The Rain, Stars
Ana Tijoux - 1977 - Partir de Cero

Channel separation

Tenacious D - Tenacious D - Kielbasa
NIN - The Downward Spiral - Hurt
Johnny Cash - The Essential - Ring of Fire
Stephen Coleman - Westworld Season 2 Soundtrack - C.R.E.A.M.

Soundstage, treble, electric guitars etc.

Alice in Chains - MTV Unplugged - Rooster
Korn - MTV Unplugged - Freak on a Leash
Anneke van Giersbergen - Symphonized - Feel Alive
Howard Shore - The Hobbit: An Unexpected Journey - Blunt the Knives

Dynamics, bass, subbass

The Diary - The Gentle Storm - Endless Sea |Gentle Version|
Wardruna - Runaljod: Ragnarok - Tyr
Hans Zimmer - Man of Steel OST - Look to the Stars
Hans Zimmer - Pearl Harbor OST - Tennessee
Ice Cube - Raw Footage - Gangsta Rap Made Me Do It
Andreas Vollenweider - Vox - Enchanted Rocks

Packaging & Accessories

The packaging for all Empire Ears (EE) products is more or less the same which to me makes sense, because it shows consistency throughout their whole range.
You get a very nicely designed white cardboard box with the Empire Ears Logo and the name or logo of your particular product. It’s not too big or small and radiates class and style. It consists of an outer “slider” cover and a sturdier inside box.


Once you open the magnetic flap of the box inside you find a compartment with a quick manual and a “thank you” card from EE congratulating you to your excellent purchase :wink: Underneath looms the IEM and cable ready for you to rip out and enjoy the music. A classy drawer underneath reveals an aluminum sheet containing various Final Audio silicon tips to choose from. The great thing here is that Empire Ears not only gives you the standard S, M and L sizes but XS, S, M, L and XL instead, which simply gives you a wider range of tips to match to your ears. As my ear-canals are slightly different in size, it makes it easier for me to get a good fit. However, I would have wished for a selection of foam tips as I generally prefer foam over silicon. The included tips work well though.

Last but not least you get EE’s phantastic Pandora case, a black aluminum capsule to safely transport your precious in-ears. It’s built like the proverbial tank and is engraved with Empire’s logo and the name of your product.

Build quality & Fit



The build quality of the ESR MKII is excellent, just as it is with any of EE’s in-ears. I actually haven’t seen any difference in build quality from their entry- to top-level products to be honest. To me, that’s simply a sign that they make no compromise in quality no matter the price. I like that!


The new ESR MKIIs are black with brushed silver faceplate and silver logo which “hovers” above the brushed silver. The design is rather subtle and to me it looks quite stylish and noble. Fit and comfort, at least for my average sized ears is good with a rather long nozzle enabling a good seal. Hence the IEMs do not sit flush in my ears but stand out a couple of millimeters, which is no problem for me.






EE are using a variation of Effect Audio’s Ares II which they call Alpha-IV or simply A4. You get to choose from 3.5mm single ended or 2.5mm balanced. I always go for balanced but that’s my personal preference. It’s a beautiful, classy and well made cable and I particularly like the sleek connectors and super small y-split. Yes, that cable looks gorgeous in my opinion.

What I don’t like so much is the rigidness of the cable. I have mentioned this several times in previous reviews as for me, flexibility, especially for an IEM cable, is an important factor of good usability. I clearly prefer softer, more flexible cables.
However, cable noise is at an acceptable level / no issue. Soundwise I have no complaints whatsoever. It’s a good cable.


Now how “flat” and true-to-the-source are these upgraded studio in-ears?

Overall tonality

As the name ESR (Empire Studio Reference) suggests, EE considers this IEM their reference of a flat and uncolored studio monitor. Since I usually prefer their X-Series consumer products as I am not a professional, I did not really know what to expect. I do own their Phantom studio monitor though (which is a lot more expensive) so I had a rough idea of how a “flat” reference studio in-ear might sound. I was both right and wrong.

The overall tonality is indeed nicely balanced and, as far as I can assess, neutral.
No frequency seems to be elevated and I assume the frequency response matches the description of “flat”. Since I don’t do measurements, I cannot confirm this with data. It’s just my impression after spending a week listening to music, watching movies and doing some gaming with the ESR MKIIs.

One thing instantly noticeable is that the ESR MKIIs will deliver the music as it is, meaning good recordings sound good, bad ones bad. But that’s the whole point of a reference studio in-ear monitor, right?


The combination of balanced armature- and dual electrostatic (e-stat) drivers deliver a nicely detailed and smooth treble without elevation. Strings and guitars to me sound very natural. Since there seems to be no treble elevation, you might miss that typical “sparkle” you’re used to getting from other, more consumer-tuned gear, but that is not true. It’s all there but you need to get used to a very different tuning or rather - the absence of one.

I first noticed with my EE Phantoms, but after a while I really started enjoying the overall quality of a natural frequency response. For long listening sessions, this is just perfect.


Vocals, male and female alike, are rendered very naturally and stand out from the rest of the composition without the impression of artificial frequency elevation. Like the treble, the whole midrange is nicely separated and balanced overall.


The bass from balanced armature (BA) drivers is very different from dynamic drivers (DD). The response is flat,neutral and tight, which is of course intended. There’s no eardrum-shattering impact and rumble like on the EE Valkyrie MKIIs or the EE Legend X that employ dedicated subwoofers.

This bass response mirrors what has been recorded, no more and no less. Still the ESR MKIIs surprised me in a good way here, because their bass performance is by no means lifeless or entirely free of sub-bass which was what I expected. It’s all there - when it is in the recording. Listening to Jeff Goldblum and the Mildred Snitzer Orchestra’s Cantaloup Island is a joy. I feel like actually attending the concert.


Surprisingly, the soundstage to me seems above average. Live recordings sound spacious while everything in the music - the instruments, the singer(s) the audience - is well separated. I had one key moment when I was playing a game and I suddenly heard a noise from outside. I took off the ESR MKIIs just to realize that the noise had actually come from within the game.
Channel separation/Instrument separation

Channel separation is very good indeed. Instrument separation, depending on the source material, is excellent. You can tell these IEMs were made for professionals that need to be as close to the truth as possible.


The ESR MKIIs are neutral sounding IEMs with a seemingly flat frequency response that present you with what is in the music without leaving anything away and without adding or elevating anything. These are in fact made to analyse music, to dissect music, but - somehow still manage to transport emotion and enjoyment. I can make neither head nor tail of it really. And I mean that in a good way!


The ESR MKIIs are rather sensitive IEMs, they don’t need a lot of amping power to do their work. And since their field of expertise is the faithful reproduction, they will play out their main strength with a neutral source. I found the combination with Burson desktop DAC/Amps a good match in that regard. I can imagine a good synergy with Astell & Kern DAPs too as they tend to be rather neutral as well.

Should you desire to deviate from the path of total truth, you can pair them with less neutral sources. I tried with my Cayin DAPs and enjoyed the bit of warmth and energy the ESR MKIIs gained from this combination. So basically, you can tailor these studio IEMs quite a bit to your current task, which I find quite interesting.



Paired with the right source, the ESR MKIIs will give you the truth and nothing but the truth. They are targeted mainly at music professionals, but will certainly fulfill the needs of other users as well. Anyone that prefers a more neutral musical reproduction or simply wants an in-ear for a more relaxed and fatigue free listing experience should find these a very interesting set.

I have enjoyed my week with the ESR MKIIs even though I usually prefer the more fun-oriented type of earphone. Funny enough, I used them even for movies and games and never once missed anything. Never once I felt the need to switch to another set of in-ears. As I said I am not a sound engineer or musician but I do believe these IEMs will certainly please a larger variety of users than just professionals. They are more expensive than their predecessors, but they make up for it with largely improved internals, beautiful looks and most important of all a sound reproduction that really deserves the name Empire Studio Reference.

Other reviews

Empire Ears Valkyrie MKII

Empire Ears Bravado MKII
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  • Like
Reactions: Xinlisupreme
Thank you for your beautiful review!
This EE sounds as i love.
@fabio19 you should consider it...


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