Metal Magic Research Homunculus - Reviews
Pros: Amazing female vocals
Great DD lows
Well extended treble
Amazing build quality
Cons: Way too genre specific
Fit might not be optimal for many
Disclaimer: The Homunculus was provided to me for a few days in order for me to publish a review, with the option to purchase. I will be sending it for MMR's EU tour (to be announced soon), and no incentive was provided for a favourable review. Considering I've had a somewhat limited time with it, the review will be more of a general overview than a fully detailed description.

The packaging of the Homunculus is rather unconventional but purely awesome. On the exterior there is a sort of ribcage, and when you open it up there is the case with a mechanical heart printed on top. Huuuuge nerdgasm moment, and quite possibly the coolest unpacking experience I've ever experienced in the audio industry. I liked the case so much that I pleaded Joseph to purchase it from him, and thankfully he agreed :D


The IEMs themselves are built really, really well, with a sort of "disc" design. The unboxing itself is extremely unconventional, and so is the shell design - some would love it, some would hate it, but either way it is undeniably unique and the raw build quality is exceptional, so that gets a 10/10 from me. They fit me really well, but for someone with smaller ears I can imagine them either being painful or having to go for a shallower insertion.

Not only that, the stock cable that is included is the Eletech Prudence (SPC), which I find further enhances the vocals, and is an excellent upgrade cable. I loved using it so much during my time with the Homunculus, the first thing I've be doing is order one to pair with my other IEMs.


Where sound is concerned, I'd normally approach this as a bass/midrange/treble, but I feel like in the case of the Homunculus the overall presentation and tuning are so specific, it only really makes sense to discuss them as one whole.

In terms of its FR, I found the Homunculus to have a warm bass presentation, a relatively flat lower midrange and elevated upper mids as well as lower treble. It extends very well but the emphasis remains in the lower treble I'd say.

The tuning of the Homunculus makes it sound really well with female vocals above all. The elevated upper midrange results in male vocals sounding quite off, and quite a lot of EDM and pop to sound quite hot, but if you're after an IEM that specifically performs female vocals, there are few that do it as brutally well as MMR's middle tier IEM. Objectively speaking, they do not offer a realistic presentation, but instead a beautifully exaggerated and enhanced one.

The Homunculus is also relatively technical. I found the soundstage to be neutral in terms of width - not the widest of the most narrow one, but would fall behind popular options such as the Solaris in that respect. It is worth mentioning that they opened up noticeably with burn-in. They retrieve a good amount of detail, and offer great separation.

Considering that everything up until now was rather positive, you might be wondering why I took a full star off the Homunculus' rating, and that is mostly because I believe that an IEM should be able to present any and every kind of music at least reasonably well, and have a few genres or categories where it is outstanding. The Homunculus completes the second requisite, but falls short where performing various types of music well is concerned.

Comparing the Homunculus to other IEMs is particularly difficult, because it would be a rather black and white discussion - most serious choices around that price point would heavily outperform it in genres where female vocals aren't the centrepiece, and wipe the floor with their competitors when female vocals are the focus of the performance.

All in all, my verdict on these should be pretty clear by now. Heavily recommended if you want something to listen to female vocals with, or mainly listen to female vocals anyhow. The Homunculus doesn't do great as an all-rounder, but ultimately it wasn't designed to be an all-rounder, but more of a niche pick

Great work by MMR, and I look forward to publishing the Thumimm review a couple of days from now!

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Pros: Sensual tones
Beautiful soundstage
Great mids / high-mids
Great technical abilities
Cons: Fit could be difficult
Lack of dynamic
Few dB missing in subs

The Homunclus were graciously lent by Josph Mou / MMR to orgnize a french Tour on Tellement Nomade. I would like to thank him for allowing us to discover his new products and for the trust he has placed in TN.
I am in no way commercially linked to MMR and have received no compensation whatsoever for this return.


MMR, Metal Magic Research, is a Sino-Singaporean company founded in mid 2019 by Joseph Mou. He is also the father of Jomo Audio, an entity whose reputation is well known in the audiophile world, which generates great expectations on these new headphones. As a Jomo Trinity SS owner (after owning Samba and Flamenco), I'm very eager to discover MMR's proposals.

The four different MMR models that currently exist were presented to the public at the CanJam in Shanghai at the beginning of November 2019.

Hardware and Playlist:


I was able to test the MMR Homunculus with the following hardware.
DAP : Sony WM1Z K mod Ultimate, Plenue L and iBasso DX160
Cables: O.A.O Gold Twelve, EA Ares 2, Eletech Prudence and Plato, and PW1950

I was able to compare the Homunculus to the following :
64 Audio U12t, Ambient Acoustics MAD24 and MAD16, Empire Ears Zeus XIV Custom Retuned, IMR Rah, Jomo Audio Trinity SS, MMR Gaé Bold, Balmung and Thummim


I listen to a lot of different styles, with a predilection for female vocals, and my test playlist consists of about 70 songs. However, I was able to take advantage of the length of the loan to review my music in depth.

I put here some targeted tracks that allow me to test more specifically some aspects of the headphones.

Angus and Julia Stone - Take you Away / Guitar, vocals.

Cannonball Adderley - Somethin' Else / Tones, brass, space placement.

Criolo - Bogota / Voice, dynamic.

Ex:Re - Where the Time Went / Tones, voices, placement.

Flatbush Zombies - Smoke Break and Fly Away / Bass texture, and subs.

Montserrat Figueras - La Folia : Yo Soy la Locura - Henri du Bailly / Tones, voices, soundstage.

Patricia Barber - The Beat Goes On / Tones, voice, soundstage, atmosphere.

Rone - Flesh (Remix by Sasha) / Bass, soundstage, placement.

Sixto Rodriguez - Sugar Man / Beware of the harshness.

Tool - Pneuma / Dynamics, atmosphere, texture.

Technical Overview

Homunculus have what could be called now a pretty «commom» hybrid configuration but only with 4 drivers :
- 2 Electrostatics for highs
- 1 Vented Balanced Armature for mids wich is very intriguing
- 1 Foster Dynamic Driver for bass

Frequency Response : 10Hz - 80kHz
Impedance : 35ohm
Noise Isolation : -18db (UIEM)

They come with Eletech “Virtues Series" PRUDENCE cable made out of OCC Silver Plated Copper worth $250 by itself. They also use Eletech Proprietary Internal Litz wiring.

Retail Price : $1699


Homunculus have an uncommon look, with a titanium flying saucer shaped shell which is, like Thummim, rather strange for in-ear. When you combine this with the configuration of the drivers and especially this mono BA to handle all the midrange, you think you're looking at an UFO.

I won't hide the fact that I have had difficulty getting a proper Fit with almost all the tips I usually use (Whirlwind, Spiral Dot, Sedna). Luckily, the combination with the Acoustune's provided is just perfect for me, exactly like the Thummim. So the seal is excellent and the in-ear doesn't move, but I can't go out for running with them. No pain at all felt in my small concha.
Once properly installed, they offer a full and spacious sound, with a definite focus on the midrange and a soft extension at both ends of the spectrum.

Bass rendering is rather slow for a DD. Subs (<60Hz) are deep and offer a rather light slam. Basses (60 to 250Hz) are very well mastered, more proeminent then Thummim ones, but without the boomy side of the Balmung, and with a nice texture and definition.

Low-mids (250 to 500 Hz) and mids (500 to 2000 Hz) are not neutral but rather slightly forward. Their density as well as their emotional load are magnificent, and nothing is done to the detriment of the legibility of the restitution.

High-mids (2000 to 4000Hz) is a little bit more prominent, with small peaks around 2500Hz and 4000Hz that bring just the right amount of openness and presence to the voices.

Treble (>4000Hz) is very pleasant. The plateau from 4 to 6KHz and the peak around 7KHz allow to highlight a lot of details, bringing at the same time softness and definition without any sibilance or harshness.

Soundstage is really wide in width, but reasonable in depth and height. It unfolds slightly out of the head, and the listener is rather positioned in the first rows of the audience.

Tones are really beautiful. On voices, whether male or female, one feels the emotion immediately, and brass or guitar are both tasty and crispy.

The technical skills of Homunculus are very good, and the magic square is really very homogeneous.
Resolution -> very good
Separation -> excellent
Definition -> excellent
Transparency -> very good


- U12t are a little more technical, with faster and more present / impacting bass, a more contained overall midrange and a shallower high-midrange. Treble is also less pronounced bringing less air. The stage is not as wide but depper.
- MAD24s are a little more technical and faster too, with more subs and bass, with an equivalent low-midrange/midrange and a slightly fuller high-midrange. Trebles are comparable. The stage is deeper but a little less wide.
- Zeus XIV Custom Retuned are technically equivalent, with deeper bass and less low-mids. The high-midrange is a little more projected. Treble is not as pronounced. The stage is equivalent.
- IMR Rah are technically inferior for me. Bass is more imposing and the midrange slightly fuller. High-mids are much less projected. Treble is clearly set back.
- Trinity SS are a slightly more technical, brighter and bassier. The low-midrange/midrange is clearly recessed in comparaison but the high-midrange is more open and the highs are more natural. The stage is equivalent in width but deeper.
- Thummim have more subs, less bass, less low mids and mids but more high-mids felt. Treble is more pronouced for me with more air in it. Stage is larger and deeper. Higher too.

Final Thoughts

The Homunculus play a score that will delight lovers of sweet and sensual tones. And they succeed in doing so by offering in addition a very beautiful soundstage, a very appreciable high-medium opening and a very good capacity of analysis. However, some may complain about a lack of impact and dynamics, as well as a lack of presence at the bottom.

Magic Square :
"Resolution is the ability to individualize a voice or instrument"
"Separation is the ability to feel space between the various sound sources"
"Definition is the ability to perceive as much information as possible"
"Transparency is the ability to transcribe the nuances and subtleties of music"

My topic on Tellement Nomade here :
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Pros: - Extraordinary stage width
- Super performance on high medium / treble register
- Great level of details and of precision
- Stock cable of very good quality
Cons: - Shell in titanium may not be suitable for everyone (fit, seal, cold)
- Not a good choice for dynamic music
Hi everyone and first a big thank you to MMR that made available for a tour in France a few of their iems, thank you also TellementNomade French forum and its team that organized the tour. It has been a great experience for my first tour and formal review. The original review was posted on TellementNomade in French. Sorry for my English as it won't be as good as the other reviews you will find here.

As you will see, I've oriented my feedback based on specific tracks and feelings before coming to a more generic conclusion.

Item used for the review

I've mainly used the QLS QA361 as the source for the review. This has been my main portable source for quite a few months now and I don't have much to complain about it. Before I had a DX200, a Sony WM1A and a few other ones but the QLS just ticks all the boxes for me in terms of sound and simplicity of use.
I also tried the E1DA 9038S, the "magic usb DAC at $80" but it has been quite a disappointing match with the Homunculus. Finally, I also put the iems on the RME ADI2 DAC for a few hours and results were kind of similar than with the QLS.

For the cable, I stick with the stock cable as it seems a very high quality cable. I don't have much info on the material used (silver probably?) but it looks strong and I used it briefly with my personal Flamenco and did not suffer any specific loss vs. my usual Dunu Hulk.

MMR Homunculus

A short introduction for those who haven't followed the story of MMR: Metal Magic Research is the new adventure from Joseph Mou, one of the co-founder of Jomo Audio, that offered the well known Flamenco, but also Samba and high praised Trinity. MMR's line up is composed of 4 iems at the time of this review: 2 custom and 2 universals.
The brand is on the high side of the scale in terms of pricing, as the entry level of their lineup starts at 1080 EUR, and the TOTL price is above 4000 EUR for the Thummim.

Homunculus is the entry level for MMR universal lineup, at 1530 EUR. For this price, you have what they call a "4 Triple Hybrid Drivers". This is not very clear for me so I'd rather call it at "trybrid" with 1 DD, 1 BA for mids and 2 electrostat.
The main specificity of the universal iems from MMR are they shell in titanium. With this material, you get a quite round shell, with an oblique nozzle, a bit like the iSine from Audeze.

In fact, I'll start the actual review here in terms of fit as it has been the first issue I encountered with these iems (of course before judging the sound, you need to put the iems correctly in your ears :wink:). Indeed, it the MMR's description of the Homunculus makes promises about an iem that "offers perfect ergonomics that is befitting of daily usage" I definitely experienced something else.

The Shells

As said above, the specificity of these iems are their titanium shell. For those who are familiar with the iSine, they are just put in the ear without having to find a proper seal, which is quite different from traditional iems.
My first experience with the Homunulus was kind of similar except that, unlike the iSine which could be defined as "open" iems, we are here with iems that require a proper fit and seal to provide all their qualities.

That's basically the first difficulty you may have when trying the Homunculus: get a fit/seal that is good enough to enjoy the iems adequately.
I've tried a dozen of tips before I could find a pair that provided a proper fit (see the picture) but even with this tip, it still feels like the iem could fall out of the ear should we make a brutal movement.

So the round part of the shell can be maintained by the lower part of the concha but it remains a bit fragile and I wouldn't have dared to walk in the street with the Homunculus. I'm curious to get other reviews on this as I eventually wondered if my ears are not standard or if I just could not manage to find how they should have been worn.

Last point on this shell: titanium is metal, so the contact with the skin is pretty cold and not that pleasant, at least during the winter.

Anyway, the fit/seal of these iems is definitely quite unique, and not for the best according to me.

The Sound

Once the fit and seal were correct, the first thing that immediately impresses is the width of the scene: damn it's large (hey another point in common with the iSine !). They are also quite power hungry: I was 20/25% above my usual listening levels with the QLS compared with the Flamenco.

So I started on some of my traditional tracks with the QLS QA361:
- Art Blakey & the Jazz Messengers - Moanin'
The listening was very pleasant, we feel quickly where the Homunculus bring a lot of added value: the high medium/treble part of the spectrum is perfectly managed. Lee Morgan's trumpet is well placed and when he blows strongly the Homunculus make you feel that way, they transpose the energy in a perfect manner. The attack of the notes is greatly transcribe. On the saxophone tenor, it is a bit less perfect but we stay at a very high level of quality. As the instrument can play in various part of the spectrum, it's a pure pleasure for the high part (around 4:45) and when it goes a little bit down in the Hz it can be a tiny bit less stirring.
Undoubtedly, the first part of the track is a great moment of music and of sensation with the Homunculus.
There goes the solo piano, alright it's a bit hard to judge here as the quality of the track is not that good on this part.... however, when the contrabass arrives, it's a bit more confused in terms of precision of the sound with the Homunculus.
I listened to this track again and again, and also tried it with the E1DA 9038S where I found it quite harsh with nearly metallic sound (no joke inside), really not a good match with the 9038S. Then with the RME: everything goes fine, I just enjoyed the track.

- Keb Mo' - Every Morning
The voice is transcribed in a superb way, it puts us right in front of the singer with his voice and his guitar, very nice feeling. We feel Keb Mo scratching his guitar and singing only for us. Nice impression of space on a rather intimate piece, really a great success for the Homunculus here.

- Nirvana - Oh Me (live unplugged)
Overall the same feeling, we are in front of the stage and the voice of Kurt Cobain comes directly to our ears. The applause around us, a real feeling of live! Excellent!

- Ali Farka Toure feat. Ry Cooder - Ai Du
Again we have a particularly pleasant feeling of space around the musicians. The subbass is quite discrete and also the the DD does its job, I missed a bit of impact here.

Then several pieces of woman voice: Amy Winehouse, Macy Gray, Melody Gardot etc ... it's excellent, clearly the description of MMR on the Homunculus is just right about that.

On classical music, the iems are doing very well. I am far from being an expert on this type of music so difficult for me to have a solid opinion but I do not feel any loss, on the contrary it is really very good. The location of the instruments is precise, there is detail, power, in short all good.

The slap in my face: Ray Charles - Unchained my heart (vocal on the album Genius loves company): voices arise from everywhere, we are enveloped in this song and the sensation is just extraordinary. The song allows to combine the 2 strong points of Homunculus for me, namely space and voices. Whoa a great experience !

When I go on more foot-tapping songs the performances are more anecdotal and we can clearly see that we are leaving the area of comfort of the Homunculus:
- C2C - The beat
I am definitely not enjoying the track like I'm used to, we are quite far from a restitution that makes you want to get up and move your head. It lacks passion. The lack of seal is / may be partly responsible for this result.
I also put on funk but same, we miss the magic a little and the Funkadelic side, completely delusional, is missed. For rap I pass quickly, it is clearly not the target of the iem.


Homunculus are fairly divisive iems:
- the titanium shell gives a very special fit and feel that will not suit everyone (not me at least)
- on the sound side, there is a fairly clear bias which focus on the voices (men included), on the high mid / treble register and which gives a remarkable stage width. Jazz, acoustic music and live music are a pleasure to listen to. The DD is more discreet and the fit problem makes the agility of Homunculus much less obvious on the dynamic music .
Although I am not in line with the promise of perfect MMR ergonomics, their definition of Homunculus seems to me particularly fair, however, as my listening experience reflected these strong points: "Homunculus is engineered with the perfect female vocals, realistic portrayal of unplugged and live acoustic "

Post mortem

After I finished my review, I checked on the Internet to see what was said about these iems. And I must say that I am definitely in line with Deezel's feedback here on HF :
"Homunculus: The Homunculus had a reverse-L-shaped response, emphasising the mid-to-high regions over the low-end. Its overall timbre was airy, light and delicate; clean and articulate. Thankfully, the top-end wasn’t overdone to my ears. The electrostats remained smooth, refined and silky. So, that light, nimble tone didn’t have any brittleness or stridence with it. Rather, what it had was tons of openness and headroom, and an effortless delivery of detail. The stage was vast and clean as well, which made live performances and classical music an absolute joy to listen to.

As you could probably surmise by now, the Homunculus won’t be for you if you like a lot of low-end presence. While the Foster dynamic driver did show in the low-end’s physicality and texture, it didn’t ever inch forward, really, in terms of quantity. Like the mids and highs, it had a brighter tone to it as well, with kick drums that had more thwack than thump. It’s a bass that was more airy and clean than it was full-bodied or guttural. But, again, it still had that DD-esque texture and solidity; it’s just that there wasn’t too much of it. The Homunculus is a great pick if you’re into classical or acoustic genres, or you simply like spaciousness in general."
Excellent review in both content and style. Never apologise for your English ability again!!
Is homunculus updated..because when I heard it... It was seriously bad sounding

Inverted soundstage and something sucking my ear drum out