Sound Analysis.
Note – Before anything, I want to tell you that ESR are very tip dependent and I don’t think the stock Final E-tips pair well for the sound signature. They do provide a comfortable fit but the sound signature is slightly harsh and intense with these on because of its prominent 8kHz peak. In fact, ESR sound way better with foam ear tips, even better if the foam ear tips are squishier. I tried multiple foam ear tips, from Comply to AliExpress T400 ones and they all work well.
The sound analysis is written with regular T400 foam ear tips on the ESR.
Summary – Empire Ears call ESR their flattest monitor targeted towards mixing and mastering engineers. But honestly, perception of reference depends on the school of neutral that one considers reference. Is it Diffuse Field Target (DF), Harman Target (HT) or a complete flat line that you consider reference or neutral sounding? Well, I’m a musician/audio engineer and so for ease of things, my primary and easiest test to decide on how good a reference IEM is, is to compare the overall sound signature to my near-field flat frequency response studio monitors in my studio that I use as reference on a daily basis for my work. Ideally, they are what I’d want a reference IEM to substitute in times when I’m on tour or travelling and can’t carry my monitors (or headphones) along. To give you quick insight, I have an acoustically treated studio room for my recording, mixing and mastering work. My studio monitors are also calibrated for absolute Flat Frequency Response (FFR) using Sonarworks Reference 4. Of course, I don’t expect the IEM to model near-field FFR studio monitors perfectly and so I’m comparing them more idealistically and not as stringently.
Here is how ESR sounds compared to FFR studio monitors (Sonarworks Reference curve) as reference along with Diffuse Field and Harman Target IEMs I have in my possession.
- Bass is nice, tight and impactful (depending on the song’s mix) but has more fullness than reference.
- Lower mids are north of neutral and are fuller sounding than reference and DF/HT-neutral.
- Upper mids are smoother and not as forward, prominent or defined as reference and DF/HT-neutral.
- Lower treble is much more sparkly than reference or DF/HT-neutral.
- Upper treble and air is on the smoother side compared to reference and DF/HT-neutral.
Let’s dig in deeper to find out more about ESR as well as how it sounds for casual listening.
Bass – Dua Lipa’s Pretty Please and Cool are nice reference songs indicative of well mixed bass. In that, ESR’s bass character makes bass pop while always keeping it in control. The sub-bass is not as prominent as it is in 64 Audio’s U12t or Moondrop S8 but is tight with nice rumble down low. Mid-bass is well present and the overall bass tonality and timbre are good, though the overall character is fuller than reference/neutral yet fun to enjoy bass playing.
Mids – Lower mids around 250-500Hz are fuller than neutral and so the instrument body is fuller and richer but ESR is still a clean sounding IEM. Upper mids aren’t as forward or prominent as you would expect from a reference IEM. As a result, instruments are not as prominent or sharply defined yet ESR makes up for it with good resolution, which is commendable since it is just a 3 driver config. If you consider Ultimate Ears’ UERM, it’s bass and lower mids were more neutral and not as full while the upper mids were more present and defined relatively to its own lower mids as well as compared to ESR. ESR has a slight tilt towards the lower mids which tilts the mids character to fullness and warmth rather than sharper upper mids definition. A bit more bite and crispness in the upper mids would’ve made ESR shine even brighter as a reference IEM. Nevertheless, if you take the reference aspect away, it is surely is a musical IEM which you can use for fun and casual listening.
Treble – ESR achieves its clarity and definition more from its prominent lower treble peak which is around 8kHz. Now even though it adds nice sparkle to the instruments, like UERM’s lower treble peak did too, ESR’s peak is more prominent and that in turn makes the sound signature sound a bit intense and harsh with the stock Final E tips. So, for that I use foam ear tips which reduces the peak enough to balance it out nicely with the rest of the signature, enough for it to not be a problem anymore. There is no sibilance with foam ear tips but is fairly present with Final E tips. With the Final E tips, this peak also adds sharp transient attack to instruments, particularly hi-hats and cymbals, making them overly sharp at times. Otherwise, ESR’s treble character adds some liveliness to its fuller lower mids body character and as a result opens up the signature, adding some depth, clarity and definition. Upper treble and air are on the smoother side and ESR could have surely done with better extension up top. Because of its bright lower-treble character, ESR is unforgiving of poor production and recordings but that doesn’t stop it from sounding musical with well produced music.

Soundstage, Imaging, Separation & Resolution.
ESR’s soundstage has a big performance room like sense of space where width is good but height and depth are slightly above average. Imaging is accurate even though instrument definition isn’t the sharpest because of its smoother upper mids. Separation between instruments and resolution for bringing out the details is good, especially for a simple 3 driver setup.
Comparisons.
Custom Art Fibae 7 – Custom Art recently introduced special pricing of €990 for universal Fibae 7 stock shell design which puts it in ESR’s competition. Fibae 7 has 7 BA drivers whereas ESR has 3. Fibae 7 is actually tuned closer to Harman Target curve and so it has a more forward and defined upper mids presentation. Fibae 7’s sub-bass shines in isolation because of cleaner lower mids presentation whereas ESR’s bass and lower mids both sound fuller and punchier. ESR’s lower treble is more present which can sometimes come off as harsh with the wrong ear tips whereas Fibae 7 has more natural treble. Fibae 7’s upper treble has better extension than ESR. Fibae 7 has a bigger soundstage which is wider and deeper. Fibae 7 also has better resolution and instrument definition owning to 7 drivers and forward upper mids tuning.
ItsFit Fusion – Fusion is a tri-brid with 1DD+2BA+1 Magnetostatic driver. Fusion is tuned towards a lively and dynamic signature. Fusion has a dynamic bass presentation with more sub-bass presence. Fusion lower mids are cleaner but positioned slightly behind in the soundstage whereas ESR’s lower mids are fuller and more forwardly presented. Fusion’s upper mids have more definition with an airier feeling whereas ESR’s upper mids are flatter yet defined and resolving. Fusion’s treble makes its signature more lively and exciting whereas ESR’s treble is smoother for the most part except for the singular lower treble peak which adds more clarity to instruments. Fusion has a wider and deeper soundstage whereas ESR’s expands naturally.
Shozy Pola39 – Pola39 has a config of 1DD+2EST. ESR’s bass has more of BA bass strengths but good impact like a dynamic driver whereas Pola39 flaunts its dynamic driver character with good speed. Lower mids in ESR are fuller whereas Pola39’s are cleaner and not as full. Even though both’s upper mids aren’t that forward, ESR’s upper mids come off a bit more forward and defined whereas Pola39’s upper mids sound smoother and more open. Pola39’s treble is more exciting, open and airy whereas ESR’s remains flat till around 8kHZ but then has a sudden high peak there which adds sparkle but can also sound a bit harsh with wrong ear tips. Pola39 has more air post 10kHz which allows for its unique open signature. ESR’s upper treble is on the smoother side. Pola39’s soundstage is bigger and airier whereas ESR has natural expansion and more realistic presentation.
Moondrop S8 – S8 is an 8BA set which is tuned to Moondrop’s version of Harman Target curve called Virtual Diffusion Sound Field (VDSF). As a result, S8 falls in Fibae 7’s category and has a more forward and defined upper midrange character, more neutral lower mids and mid-bass. ESR’s bass is no slouch and has good bass impact whereas the lower mids are fuller. ESR has more present lower treble whereas S8 sounds smoother and more natural. ESR’s soundstage is little wider whereas S8’s soundstage is deeper. They both have good resolution but S8 has better instrument definition owing to its forward upper midrange character.
Conclusion.
So there you go! ESR falls short as a true reference IEM but ends up working well as a musical sounding IEM instead. I know I’m being nitpicky here, but hey, blame it on my trade which involves using reference products on a daily basis for my job. What ESR does well is balance, resolution and coherency but you need to use the right tips to achieve the best balance (or just take my tip and use foam ear tips like I did). $700-1200 price segment has a lot of tough competition, with us having tested a couple of them recently. Even though ESR is just a 3 driver, it does resolution and details well to strongly compete with those IEMs with all its calibre. So, definitely give it a try if you get the chance and if ESR hits close to your preferences.
Gear used for testing and review.
- DAPs – iBasso DX160 and Hiby R6 Pro
- Laptop – Apple Macbook Pro 15″
- Phone – OnePlus 7 Pro
Reference Songs list.
- Normandie – White Flag album
- Dua Lipa – Future Nostalgia album
- Dave Matthews – Shake Me Like a Monkey
- Foo Fighters – The Pretender, Best of you & Everlong
- Coldplay – Paradise, Up in flames & Everglow + Everyday Life Album
- Ed Sheeran – Thinking out loud, Bloodstream & Galway Girl
- Chainsmokers – Somebody, Sickboy, This Feeling & Closer
- John Mayer – Slow dancing in a burning room, Stop this Train & Say
- Gavin James – Always & Hearts on fire
- Switchfoot – Meant to live & Dare you to move
- Porcupine Tree – Sound of Muzak, Blackest Eyes & .3
- Our Lady Peace – Do You Like It & Innocent
- Linkin Park – Papercut, Somewhere I belong & Talking to myself
- Maroon 5 – She will be loved, Payphone & Lost stars
- Lifehouse – All in all & Come back down
- Breaking Benjamin – Diary of Jane
- Karnivool – Simple boy & Goliath
- Dead Letter Circus – Real you
- I Am Giant – Purple heart, City limits & Transmission
- Muse – Panic station
- James Bay – Hold back the river


Nice review. Agree with “warm, musical but not quite reference.” I found the spinfit CP240 worked well for me. I changed the Ares to a hybrid 8W which opened the soundstage and clarified the treble.
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Hi!! I wish you are fine during this COVID situation!
I really love your web and read it periodically. I love music and I prefer iems rather than headphones because I wear glasses and also headphones make my ears extremely hot…
I have a modded Sony MH755 (lovely for the price, with mmcx cable), IMR Z1 zenith, 1more triples and some soundmagic.
I would like to improve and find my “endgame”, I love listening to music as recorded, neutral tunning, but fun, I love music and I listen to almost everything: classical, rock, hip-hop, OST, orchestral, electronic music…
I have read your ranking but, for an average worker with a mortgage and other hobbies… are extremely expensive. I live in Spain and I cannot test iems. Based on your experience, what would you suggest me, being iems with the best cost/performance ratio, and great sound?. I would like to spend once rather than having some mediocre iems and not be satisfied, my budget is about 500€ but I could spend up to 1000 if you consider that it is necessary. A friend has encouraged me to buy a Campfire Audio Andromeda and that that iems will satisfy me completely…Looking forward to hearing from your opinion, David.
Thanks in advance, David
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Hey David! Thanks a lot! Tw6 team appreciates your love and support. Well IMO, you don’t have to spend the biggest bucks to find an IEM which plays your music well to keep you happy and satisfied for a long time. 🙂 In order for me to suggest some IEMs for you specifically, can you please tell me if you are sensitive to any specific frequencies and if you have a specific tuning in mind? Also, have you looked at some other options besides CA Andromeda?
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Hi! Thanks in advance, many thanks, sincerely. In the IMR the treble make me fell upset, I have reviewed all your posts and also in HEAD FI but there are so many models that I don’t know…the Andromeda seems to be recommended by everyone. I would prefer a big soundstage and the other preferences I wrote before, neutral but fun if possible… thanks in advance, David
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I have a couple of IEM suggestions. Please PM me on Head-fi since this will take some back and forth. Here is a link to my profile – https://www.head-fi.org/members/animagus.502720/
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