MMR Balmung – broadsword of bass


The Balmung was purchased with my own money at a hefty discount from MusicTeck USA ( on one of their periodic sales. No incentive was sought or received for writing a review, and all opinions (however misguided) are 100% my own.

Rating and specs

(From back of main box)

Price: $2599 RRP (at time of writing)


MMR (which stands for Metal Magic Research) are an in-ear monitor manufacturer from the fertile audio playgrounds of Singapore. The brand is the brainchild of a certain Mr Joseph Mou, who the more IEM-aware readers may know is also the chief designer and proprietor of another Singaporean brand, JOMO Audio. The brand was born out of a desire to push the technical and sonic boundaries of earphone design, concentrating on more esoteric (and expensive) materials, shell designs and driver implementations to produce something a little different from the usual “run of the mill” in ear monitor. At time of writing, MMR currently offer four different models, ranging from the $1099 5-driver Gae Bolg through to the flagship Thummim triple-hybrid model at $4499. The Balmung is the “all BA” flagship of the range.

Unboxing and accessories

The Balmung comes in quite an impressive package, the shoebox sized rectangular box sporting a rather large graphic of the Azure Balmung (a mythical sword) on the front sleeve, along with the MMR logo and some Celtic looking patterning. The back is adorned with a large scale technical drawing of the IEMs themselves alongside some marketing blurb. Removing the sleeve reveals a simple hinged black box with another silver MMR logo. Popping open the lid gets you straight into the action, with the Balmung showcased in some thick intricately decorated grey foam, alongside a metal registration card and a blue IEM carry case, again sporting the same sort of mystical and intricate white artwork.

Popping the carry case out of the foam surrounds and opening the zipper reveals the included IEM cable (a special design from fellow Singaporean cable manufacturer Eletech), some Acoustune branded ear tips in a small plastic box and a couple of MMR stickers. As IEM load outs go it is pretty basic, but all the elements from tips to cable to case are obviously high quality, so in this case I appreciate the simplicity of just including a barebones accessories pack where everything is obviously high end. As will be noted in the tips section, the Acoustune tips are specifically appreciated, as nothing else I tried on the Balmung sounded as good as the bundled ear tips. It’s almost as if these guys do this sort of stuff for a living…

So, if unboxing experiences are your thing, the Balmung doesn’t disappoint, giving a nicely luxurious and decadent feel to the package design and a simple but elegant selection of accompanying gear. If quantity over quality is your bag, you might want to look elsewhere for your what’s-in-the-box endgame nirvana.

Design and build

The Balmung is an all balanced armature design, using twelve “new generation” armatures in a 2/2/4/4 split, working from low to high. The pair of low drivers are vented (in other words have a hole in the casing, unlike more standard armature designs), as are the matched pair of midrange drivers. The mid-highs are covered by a quad-BA set, with four tweeters rounding out the driver complement. All this armature goodness is controlled by a 4-way crossover system, with everything feeding into a specially designing acoustic chamber before passing into an asymmetrical tri-bore waveguide and making its way to the listener’s ears.

Acoustic chambers aren’t a new invention (the most famous IEM to use something similar is the Campfire Audio Andromeda), but it does allow the IEM designers some additional control over the frequency response and more ethereal characteristics of an in-ear monitor like phase and timbre than a straight sound-tube-to-the-ear-from-the-armature design. The design wizards at MMR have experimented with various aspects of the geometry and material density to tweak the sound to their desired output, and whatever they have done, I have to admit, it sounds pretty darn good.

Getting into the real meat of this section, the build of the Balmung is an aluminium and (possibly) polished chrome affair, with possibly the most intricate and visually appealing IEM faceplate I’ve come across in person. The shell of the IEM is roughly oval in shape, with a tapered IEM barrel protruding out of the lower half of the inner face at about a 30 degree angle. The inner face is mainly flat, with a small raised plate above the nozzle where the concha usually meets the IEM body to offer a little additional comfort. The design language is almost reminiscent of the Campfire Audio Andromeda in terms of the usual look of the shells and the angular lines, but in wearing, the Balmung proves to be a supremely comfortable IEM for extended listening sessions, with no discomfort or hotspots anywhere for my larger-than-average ears.

The outer shell is where the real magic happens, with a two tone design of azure blue backing and a raised polished metal design of the Balmung sword motif. The IEM faceplate is crafted by high precision CNC milling then hand polished, and it shows – this is a genuinely stunning and extremely complex design, rivalling anything I’ve seen from the likes of the artisans at JH Audio or other boutique in-ear manufacturers. If you are looking for understated or don’t fancy wearing something that looks like gothic jewellery in your ears, these probably won’t be for you, but if you appreciate beautiful design and don’t mind a little bit of ear-bling, these are a genuine conversation starter.

The Balmung cable is made by Eletech, and designed to match the sword theme, with an angular silver splitter bearing the MMR logo and a 4.4mm connector (other terminations are available) fashioned like the hilt of a sword. The cable itself is a silver colour – no indication of the cable makeup is given in the packaging, but I would hazard a guess it’s some sort of silver-plated copper configuration. Apart from the lightly flimsy feeling (and looking) splitter which could probably be replaced by something a little more in keeping with the rest of the package, the Balmung cable matches up to the aesthetics of the main IEM, the flat 2-pin terminations slotting neatly into the flat sockets on the IEM shell to give a seamless look. If you are purchasing a $2k+ in ear you probably already have a few aftermarket cables kicking about your collection, but the Balmung isn’t an IEM purchase that needs an accompanying investment to replace the normally poor stock Plastics One style cables thrown in by most manufacturers these days.

In terms of comfort, the aluminium shell is light and pleasant in the ear, and the cable is similarly light and hassle-free without flying away over the ears or otherwise tangling. No complaints from me here.

Initial impressions on sound

MMR pride themselves as having a “unique” house sound, and the Balmung certainly sticks to that mantra. On first listen, the overwhelming impression the Balmung gives is of a rich and overwhelmingly analogue tone, with a tube-amplifier like glow to the sound that can almost come over as stuffy or rounded. The tuning is a sculpted XXx from low to high, with a surprising amount of bass for an all-BA design, and mids that are velvety and intimate, pushing forward to envelop the listener. Highs sit a little further back in prominence, still having adequate body but definitely feeling lighter in approach and more laid back in stage than the ranges sitting underneath. It’s almost the antithesis of the Harman or diffuse field tuning, the frequency range being sculpted to produce something inherently musical in tone and delivery without overwhelming any individual element.

Once you get a few tracks in, the realisation dawns that the Balmung is detailed, but without the usual sharpening or artificial boosting of frequency ranges to create a perception of clarity. In fact, the Balmung is very detailed – flagship level resolving. It has a lot of “inner resolution” which is made obvious by the clear space around each note. This gives the impression of being partially hidden by the warmth and general presentation when you aren’t used to the sound, so is less “obvious” on first listen, but once you realise all that micro-plankton and room sound you are used to on more classically “analytical” in ears is there in the presentation, your brain seems to snap into focus and on subsequent sessions that detailing is all laid out clean and clear.

One thing it doesn’t take a while to adjust to is the stage – the sound from these small in-ears is unashamedly large, with a broad sweep of stage and laser sharp precision when it comes to instrument placement. Whether it’s the effect of the acoustic chamber or just the general IEM design, this is an IEM that sounds “big” in the ear.


Going into more detail on the individual frequency ranges and starting off with sub-bass, “Heaven” by Emile Sande kicks off the review playlist with plenty of sub bass in the intro, and the Balmung doesn’t disappoint here. It’s not as booming as some of my basshead dynamic driver sets, but there is a satisfying thrum as the track fires up, and a nice punch to the “heartbeat” of the bass drum as it fires off throughout the track. It doesn’t feel as visceral or physical as a dynamic or hybrid IEM on this track, but there is definitely enough sub to keep most listeners honest.

Looking for ultimate sub bass extension, “Why So Serious?” from the Dark Knight soundtrack lead off is again handled well. The subsonic tones that kick in around the 3:20 mark are present, if not hugely loud, with the Balmung offering a solid bass foundation for the other incidental noises above it. As a side note, the clarity of the BA drivers is apparent here, with the ultra-faint ticking that kicks in at around the 3:48 mark being clearly audible, which can sometimes take a few more seconds to kick in on some of my less resolving gear, usually being masked by the sub until the volume ramps up. This IEM won’t rattle your brains with sub bass, but it certainly doesn’t disappoint in either quantity or extension for an all-armature design.

Going for my final sub bass tester for sheer power and impact, “Disc Wars” by Daft Punk is on deck. Again, the solid thrumming that underpins this track is probably about medium in intensity but still 100% present. The orchestral sweep that appears at the 0:31 mark shows the power in the low end, giving a nice ease of dynamic oomph to the track. As the bass moved further up the frequency ranges it becomes noticeably more present in the mix, highlighting the almost “anti-Harman” slow rise in quantity from sub to mid bass in the tuning.

Focusing more on the mid-bass now and looking for punch and slam, “Bad Rain” by Slash paints the drums with a solid but not slamming presence. Each kick and snare hit is clear and forceful, but doesn’t carry a huge amount of physical slam factor, sounding flatter than it will on a quality DD setup. Detailing is high, and everything feels very “real” in terms of timbre here. The growling bass guitar adds more volume to proceedings, and paints a very detailed and textured sonic picture, but again, doesn’t have some of the snarling energy and bite that it can on other IEMs. That isn’t to say that the Balmung is tame, but the emphasis here is on detail and texture (of which it has plenty on both counts) rather than on raw power or impact. To be clear, the sound is very musical and certainly not lacking in anima, but definitely leans more towards the listener who likes a more laid back but sonically detailed type of presentation. Coherence with the mids is superb on this track, with the bass and guitar blending together seamlessly.

“Hello, It’s Me” by Sister Hazel follows a similar line, with the liquid bass line opening the track packing in tons of detail and a raspy texture that means you can almost picture the heavy gauge strings vibrating against the fretboard as they are plucked. The Balmung resolves plenty of finger noise and keeps the bass tight but silky smooth at the same time. This track can sound like liquid chocolate with some gear – with the Balmung, it is slightly lighter in density but still unctuous enough not to sound dry. I’m scraping the barrel for metaphors here, but it’s probably the audible equivalent to a nice pouring syrup instead, sticky and sweet but still sliding neatly off the spoon.

Pushing up into the upper bass areas, the upwards slope in terms of quantity continues, with the plucked bass guitar of “Drift Away” by Dobie Gray carrying plenty of decibels of presence and driving the track forward. There is definitely more bass in the mix here, and while it doesn’t bleed into the crystal clear mids, it adds a nice sense of substance. In fact, with the bass riffs at the 1:05 mark, it almost borders into ice-cream headache territory’s on a few licks, just managing to shy away from going full “whuuuuuung” and keeping things just the acceptable side of balanced.

Looking for a final take on the overall resolution of the bass, “We Shall not Be Moved” from Mavis Staple is a masterclass in separation and layering. The deep baritone in the opening bars is so easy to hear it should almost be used as a tutorial for other IEM designers around how to present low voices, packing in a metric tonne of detail into something that can sound blended or just plain mushy on “lesser” gear.

In summary, the Balmung is a competent but not expert sub bass performer, and certainly doesn’t suffer from that “all-BA” design much in terms of the quantity of low end it can produce. Where it excels is as the frequency range rises, and the excellent mid and upper bass really shine in both quantity but more importantly quality. It won’t blow the doors off an avowed basshead’s IEM locker, but for more people, this is high quality stuff.


The midrange is relatively forward and has a warm analogue sort of tonality, inheriting some of the warmth from the upper bass to give everything a gloriously “tube-like” sheen. The note sizing and stage position bring the mid range forward towards the listener, filling the stage with a wall of thick, chunky instrumentation and vocals. As previously stated, on first listen the Balmung can almost sound veiled or a little congested, but once your brain adjusts to the more stylised tonality, you realise that all the detail and clarity you are looking for is there in spades. This is joy (and subjectivity) of psycho-acoustics writ large – that initial feeling is more to do with the fact that your brain doesn’t expect something that sounds so warm and musical to also be uber-resolving and highly technical rather than any inherent shortcomings of the IEM itself.

The warmth and richness of the mids give the Balmung a superb timbre and sense of realism. Listening to “Since You Were Mine” by Smith & Myers, the tone of the piano echo in the simple keys and vocals arrangement is very real sounding, with the reverb and the room echo of Brent Smith’s voice sounding ultra clear as well. The purity of Smith’s distinctive vocal is beautiful, with a richness but also very clear sense of detail and emotional heft.

Sticking with Smith & Myers, their track “Bad At Love” has beautifully rendered guitar harmonics throughout, all ringing out clearly against the backdrop of the rest of the music and again highlighting the fine detail in the mix. Smith’s voice is slightly less rich and more breathy here in the opening verses, but kicks into high gear as the song gets going. The rasp in his vocal chords is faint but present in the back of the ear, again giving plenty of texture and emotional grit to the track. The blended backing vocals almost appear to arrive out of thin air, and float around the strong centre image of the lead singer. It’s the sort of presentation that makes you want to close your eyes and drift into the music.

Going digging for some more subtlety in my review playlist, “Coco” by Foy Vance is well rendered. The subtle guitar picks are easy to pick out in the ear, with Vance’s distinctive coffee and whisky soaked growl getting a smooth but not blunted sheen applied by the warmth of the Balmung’s tuning. Playing through another track of his (“Resplendence”), again the piano timbre sounds very convincing, with the guitars playing at both sides of the stage feeling almost ethereal alongside the strong vocal and fat bass line (that upper bass rise at work again), but without being overwhelmed.

Cranking it up a notch and loading some Slash into the playlist, “World On Fire” comes launching out of the IEMs like a Hollywood actor whose wife had just been insulted at an award ceremony. The MMR flagship plays this track out with plenty of bite and chug, and some serious weight in the biting riff that keeps this track moving. The Balmung manages to match the quick-fire speed of the main riff without blending or blurring, but still keeping it all feeling fat rather than lean and crisp. It’s fair to say that the rich analogue tone MMR have gone with here suits electric guitar pretty well, pulling the old JH Audio trick of making things sound “real” and solid. Speed is definitely also a non-issue for the mainly vented armatures MMR have packed in here.

Taking the speed test one notch further, “Holy Wars…” by Megadeth pretty much blisters out of the earpieces, taut and lean but without turning Dave Mustaine’s somewhat thin guitar tone into an instrument of torture. In fact, the Balmung tuning adds a nice sense of weight to this technical thrash track, giving it some body to go along with the speed. Control is exemplary here, with each guitar note stoping and starting on a sixpence. this definitely isn’t an IEM that struggles when tracks get busy. Given the general tonality of the tuning, this wasn’t initially a track I thought would play well with the Balmung, but it can definitely hold its own with uptempo metal.

Focussing on vocals for a minute, Gregg Allman’s voice in the soulful ballad “Song From Adam” from his last album is fully fleshed out and very lifelike in tone, capturing the slightly phlegmatic sound of his cracked and deteriorating vocal chords (this was the last thing he recorded before passing away of throat cancer). It almost feels like he is singing in the same room at some points in the track. The feeling of raw emotion when he tails off and misses two lines of the final chorus is palpable, and highlights the excellent inner resolution of the midrange drivers being used here. It doesn’t distract from the track, just relays all the sonic information that is baked in to the recording without fuss or favour, allowing the listener to take it all in without realising it. The opening acoustic guitars are another example, delicate and shimmering but still sounding incredibly fleshed out and real.

“A Thousand Words” by Seattle muso Myles Kennedy gives another good taste of what the Balmung can do in the mids. The jangling guitars laced through the track sound crystal clear, in sharp contrast to the main guitar line that sits a little fatter and more distorted underneath. Myles Kennedy sounds good here, with a very analogue and rich tone to the voice. It’s a simple mainstream rock track, but the Balmung manages to elevate it to something pretty special – these are definitely tuned for people who enjoy the rockier side of the musical landscape.

Finishing up the midrange test tracks with a little search for sibilance and harshness, “Whiskey And You” by Chris Stapleton always helps me identify raw sounding in-ears. The tone on Stapleton’s voice (and the room echoes) are apparent, sounding velvety but still raw, almost as if the country troubadour was gargling a mouthful of rocks and pouring honey. The notoriously ragged on the ears chorus sounds great on the Balmung, rasping in the ears with plenty of grit but without any unpleasant edges. The tonality of the Balmung actually suits this track superbly, adding a sense of warmth to the otherwise cold and sparse arrangement.

To summarise, the Balmung is an exceptional performer in the midrange, marrying a fat and tonally rich sound with the sort of nuance and clarity you expect from a top end IEM in 2022. The fact it manages to pull off such a soulful and weighty sound while also remaining technical is the real accomplishment for this IEM. To be fair, the tuning won’t suit everyone, as it’s far too warm and far too thick to appeal to lovers of ultra-lean midranges, or the reference tuning crowd. MMR have shot for musicality, and for me, the gamble has definitely paid off.


Treble is a little more laid back than the two ranges underneath, taking a backseat to the mids in both stage location and general amplitude. The Balmung isn’t a blunted or treble-shy IEM by any means, but it sticks to the core tuning choice of warm and musical rather than glittering and airy. If you are looking for CA Andromeda levels of treble sparkle, this probably won’t be the perfect IEM for you. If you prefer your treble clean and weighty, with less emphasis than the mids underneath (spoiler alert – that has always been my core preference), then the Balmung should be a lot further up your alley.

Kicking off the test tracks with another one by Slash, the “Starlight” opening harmonics are pin-sharp and dissonant, as they should be. There is an almost JH Audio sort of analogue tone to proceedings on this track, with a nicely evocative presentation of the vibrato on the guitar at the end of the opening. The vocals are strong, clear and extremely high, but stray away from harshness or sibilance. They do have a slight whiff of piss and vinegar to them rather than being too smoothed over, but that just brings out the character of Kennedy’s unusual falsetto.

Listening to “Chia Mai” by Duel, the opening violin refrain is sharp and crystalline, but still carries a little weight. The warmth from the mids is still present here, with the sound leaning more towards weighty and analogue rather than cold or crisp. The Balmung has plenty of resolving power and isn’t shy in the high end, but compared to the beefy weight and power of the midrange, it definitely starts to take a step back on the stage, pulling back more in line with the sub bass in terms of presence in the mix. The violin and synth swirl around the top end of the sound quite literally, being placed quite high in the stage by the Balmung. This is treble presentation for those who want detail and resolution, but don’t want it emphasised or artificially sharpened.

Firing up some more electronica, “Go” by the Chemical Brothers is suitably swirly in the synth, and the cymbals narrating the track are crisp and oh-so-realistic, but just a pace behind in term of prominence compared to more traditionally v-shaped monitors. The Balmung doesn’t feel “hemmed in” or rolled off when you consider upper extension, but it also doesn’t feel hugely spacious or airy either. Notes fade to immaculate blackness rather than echoing round the rafters of the soundscape – it is almost the sonic equivalent of listening to music in a wide open field as opposed to a large concert hall, as there is much less of a perceived “venue” shaping the treble in your ears.

In summary, the treble tuning MMR have gone for here is highly detailed, very realistic in terms of timbre but quite subdued overall. It plays its part in cementing the rich organic tone the Balmung is shooting for, and resolves detail and space between high notes admirably, but it’s definitely one for aficionados of a warm and solid treble tonality rather than those audiophiles seeking crisp or sparkly high ends.

Soundstage, separation and layering

Imaging prowess is one of the core strengths of the Balmung, with everything being placed in an exact three dimensional position on the stage. The size of the staging helps here, as the larger than average sense of depth and width that the Balmung creates with the stage pushing outside the head in all three directions allows each instrument and its associated room noise and reverb trails plenty of space to breathe without encroaching on anything else.

This could have lead to the Balmung sounding overly clinical or dissected and incoherent, but the gurus at MMR made the wise tuning choice of ensuring the size of the notes (the mental “image” you have of each instrument) is sufficiently large that things never feel lost. The sum total of these choices is an IEM that presents a large and spherical stage with bigger than average notes but stellar placement and separation. For an ostensibly warm and musical sounding monitor, this is a technical achievement that you don’t expect, and not that many IEMs manage to pull off.

Layering is similarly high-performing, with the Balmung able to stack multiple tracks of guitar or orchestration on top of each other without blurring or blending, allowing the listener to move through the various layers of the mix with ease.

Translating all this into real life listening, “Fill My World” is another fat sounding track, with the guitar harmonics of the intro layering over the beefier and more chugging rhythm track underneath. Layering and separation is exemplary on this track for me, with each different strand of the guitar tracks laying themself out cleanly for the listener’s pleasure.

Going through “S.O.B.” by Nathaniel Rateliff and the Night Sweath, the hand claps that define this track feel unusually three dimensional. The gospel hmm-mmm-mmm-mmm chorus refrain feels raised on the stage and spread left and right compared to the central main vocal, with the percussion cymbal work rattling clearly in the top right of the sound field. It’s fair to say that the Balmung gets the feet tapping and head nodding with its raucous replay and realistic rendering of the imaginary stage space. The finger snaps that start at the 2:21 mark modulate with each snap, picking up all the subtle room reflection, which is something you don’t realise you don’t usually hear on less resolving IEMs until you have with the Balmung.

In summary, the Balmung easily earns its top-tier status here, putting the sound down in a precise but sonically grand fashion all around the listener’s head. To borrow the ubiquitous Campfire Audio slogan, nicely done.

Tip choice

This one is nice and easy: stick with the supplied tips. The Balmung doesn’t have the most generous of load outs when it comes to tips, but that is for a fairly decent reason – the Acoustune tips provided sound better than anything else I’ve tried, from Spiral Dots through Final E-type to the various AZLA Xelastec and Crystal variants, pausing briefly in Mandarine, Campfire Audio and Comply foamie territory. These IEMs are actually fairly unique in that they are the first IEM I’ve come across where I haven’t preferred one of the different flavours of AZLA tips to the “in the box” inclusions.

Being honest, the Balmung aren’t hugely tip dependent anyway, but for me, the included tips give the best balance of richness in the bass and size in the staging. It’s always nice when a brand goes the extra yard and manages to get the pairing right straight out of the box so the end listener doesn’t have to.

Power requirements and synergy

Again, another simple section of the review here. The Balmung are a rich and mid-bass prominent sort of tuning that leans warm, so doubling down with a warm source like the Ibasso DX300 / Amp 11 combo isn’t going to get the best results possible. The Balmung are also very scalable, so feeding them with a mid tier source like the Cayin N3Pro (balanced out) gets a nice sound, but can leaving you feel a little lacking in the finer detail department. Jumping to the Fiio M17, the Balmung starts showing through the additional resolution and clarity across the board that the internal driver setup is capable of.

Some IEMs are tuned with the sort of “artificial” peaks and troughs that imbue perceived detail no matter what you listen with, but the Balmung needs real resolution to be able to pass that sensation on to the end user. In some ways, they are almost too transparent (especially for what is otherwise a pretty coloured sounding in ear monitor). Feed them good clean power married to a pristine signal from a high-performing source and you will get the best out of these pieces of ear-jewellery. Feed them scraps and you won’t be as impressed.

Power wise, they don’t need a lot of juice to get loud – I rarely got over 40 / 120 in medium gain when listening at home on the M17, and they sat at a similar level with the DX300. Jacking up the gain doesn’t really do anything audible to my ears – these are pretty sensitive balanced armature drivers, so they will tell you if your power source is clean, but they don’t drink much of it doing so. These join that rare bracket of top tier IEMs since the adoption of the now-ubiquitous Sonion EST tweeters or rare metal / jewellery related dynamic driver coatings that don’t need a small nuclear power station to get the best out of them.


IMR Acoustics Avalon (c. $1000 before discount, 1xDD 2xBone Conduction 2xEST hybrid)

The IMR Avalon is a tuneable tri-brid IEM, with a single 11mm ADLC coated carbon nanotube driver diaphragm, two bone conduction motors and the aforementioned ubiquitous Sonion dual-EST driver pack. This is complemented by a dual tuning system on the IEM nozzles, giving over 40 different permutations of sound. They are the current “co-flagship” of the IMR Acoustics range, retailing at north of $1000 before any discount is applied.

In terms of construction, the IMR model is a nicely built all-metal shell, which is considerably smaller than the Balmung in dimensions. It certainly isn’t an ugly or chap looking IEM, but compared to the MMR design, it’s fair to say the Avalon isn’t in the same tier aesthetically. In terms of accessories, the IMR model probably takes it over the more expensive monitor, with a more practical transport case, a smaller but nicer looking and feeling leather carry pouch and three included cables in all mainstream connections. They also throw in a hatful of foam and silicone tips. The MMR package is considerably leaner, but feels like they have doubled down on the quality, so you are getting a lot less, but what you are getting is of a slightly higher quality (especially the cable – the IMR cable is sonically decent, but has a braid looser than a daytime American soap opera plot.

Moving straight to the technicalities, the Avalon actually sports a similar levels of detail to the Balmung, which is impressive. It’s slightly outdone in certain areas with a ultra-subtle nuances of a track, but it’s broadly comparable, which is no mean feat. For example, it resolves the shadow vocal in “Hold Back The River” by James Bay slightly less clearly than the Balmung, which pulls more of the backing singer into the foreground.

The IMR model stages as wide and deep as the Balmung (putting both in the upper brackets of capability there), but note size is just slightly smaller on the tri-bird. Vocals just seem to sound “larger” on the Balmung. Room sounds are also slightly less prominent on the Avalon, which has a slightly cooler and more v-shaped tuning with a sweeter and sharper tinge to the vocal. The stage is slightly darker and cleaner on the Balmung.

Tuning wise, using the black base filter (max bass) and blue tip filter (max treble / minimum treble attenuation), the Avalon has a deeper sub bass presence and thicker low end in general, but with less warmth. There is a bigger physical slam on bass drum hits and low end – I’d say there is definitely more bass on the IMR, but no loss in detail between the two IEMs. Cymbals sound more realistic, with better timbre on the Balmung (splitting hairs here). Overall, more similar than different in core tuning, the Balmung sports a more analogue and warmer tonality with a more delicate placement and sense of space around each note, and has the slight edge in resolution of things like texture. The Avalon is not a million miles away technically or sonically, and wins in the areas of bass slam and sheer decibel quantity.

Overall, the Avalon comes out swinging against the Balmung, which given the price differential, is a decent achievement. If you like the ultimate DD sort of textured bass and prefer a cooler and more sweet sounding high end, the Avalon has a lot to recommend it, especially considering the double dose of bone conduction in the mix to provide that loverly 3D staging that BC drivers do so well. If you need something warmer and more akin to an old school tube amp but with ultra-modern technical chops and that subtle resolution that only real top tier monitors can pull off, the Balmung is something to consider if you have the cash to step up.

IMR Dark Matter (c. $750 before discount, 1x DD 1x conduction motor hybrid)

Another “co-flagship” from IMR’s Pro series, which shares an identical loadout of accessories and IEM shell design. This time IMR have included an 11mm DD and an additional 6mm CNT “conduction driver”, which seems to be a little different from the bone conduction motors used in the Avalon model as it is a 6mm dynamic driver design, just utilised internally by the Dark Matter to get the same end effect. This model is a little closer to the Balmung in tuning as it’s more mid forward, but it takes the bass up another notch from the Avalon, as you would expect from the TOTL basshead model of the IMR stable. Again, the DM is tuneable, so far the sake of these comparisons it has been compared using max bass / max treble filters.

The Dark Matter has plenty of detail around the mids and treble, but it’s definitely not as refined or spacious feeling as the Balmung. The DM doesn’t pull as much detail from around each note, although the size of the stage and individual notes is a lot closer between the two.

Vocals are pushed more forward and emphasised on the Dark Matter, adding an emphasis that sweetens the tone and pushes them almost toward sharpness or sibilance in certain male vocal tracks. Impact and slam in the low end is won hands down by the Dark Matter, which sports the American 11mm ADLC/CNT dynamic driver, but tuned for even more bass output without compromising quality or detailing.

Switching between DM and Balmung, the MMR model almost sounds veiled in the vocals due to the tonality, despite presenting slightly more detail and resolution if you listen critically. Presentation is also more holographic on the Balmung (again, small margins) – “Living On A High Note” by Mavis Staples has the singers and instruments arranged an a more crescent shaped span around the main vocals, with the chorus sitting high and to the sides, with the guitars sitting wider out and lower down height wise. This definitely sounds more compelling and realistic than the comparatively “flatter” and closer soundscape rendition by the DM.

These IEMs are closer in terms of the overall tuning choice than the previous IMR comparison, with the Balmung offering a step up technically in most categories (albeit not a huge one), but giving ground in quantity of bass and getting handily beaten in physicality and raw slam factor. Both are highly musical monitors, and if you value resolution and technicality above all, the price difference becomes apparent. if you are happy with “almost as good” in most categories for about 1/3 of the price at original RRP for both IEMs, the Dark Matter come surprisingly close to the sort of tuning the Balmung is aiming for without compromising things like stage size or imaging.

Jerry Harvey Audio Jolene (c. $1800, 4xDD 8xBA hybrid)

The Jolene is a 12 driver hybrid from the veteran audio designer and industry legend Jerry Harvey, with a quite unusual internal configuration. It relies on 2 opposing 9mm dynamic drivers in a sealed enclosure for the low end, and another two paired dynamics (this time just under 5mm) in a similar D.O.M.E. enclosure overlapping duties for the midrange with one of the uniquitous JH Audio quad-BA packs, which extends up into the lower treble. Another quad-BA pack makes up the high range, giving a pretty unique design. The Jolene also sports JH Audio’s proprietary 7-pin IEM connection and a tuneable bass potentiometer on the cable, allowing you to dial in the bass in a c. 10dB range on both the left and right channels individually. Unlike the other IEMs in the JH Audio range, the Jolene was designed to run with the bass at “fully open” by default, so any impressions below are done with the bass at full whack.

Surprisingly, the Balmung actually sports a bit more overall bass quantity than the Jolene, even with the bass pots fully open. The Jolene bass centres more towards sub than mid in comparison with the Balmung, and has more of a physical grunt to it. The MMR model lacks a little of the visceral impact that the Jolene dual-dynamic drivers can bring, but fills out the low end of the soundscape a little more in terms of overall volume. Listening to something like “Why So Serious?” from The Dark Knight OST, the buildup to the drop at the 3:00 mark sounds cleaner and clearer on the Jolene, but fuller on the Balmung. Similarly, the sub-only heartbeat type murmur that kicks in from around 3:30 sounds more physically “present” and a little more obvious on the Jolene, with the Balmung pushing less air and vibrations at the listener. This is easier to hear on “Go’ by The Chemical Brothers, with the Jolene offering considerably more slam factor to the sub bass breaks on the track. You can’t beat physics in this instance – two dynamic drivers will always move more air than a handful of balanced armatures.

Moving up to mid bass, the Jolene is definitely leaner in quantity than the Balmung. “You’ve Lost That Lovin’ Feelin’” from the Elvis / Royal Philharmonic Orchestra collaboration definitely souds fatter on the Balmung. In terms of detailing, both monitors are definitely flagship tier, but the Balmung souds a little more subtle in terms of showing its resolution here, with the comparatively leaner Jolene mid-bass allowing more of the texture of the notes to come through. The Balmung is also slightly warmer as a result.

As mentioned, both are absolute top-tier technically, so either monitor is able to scratch that detail and clarity itch, so it really depends on preference to pull these apart. Jolene provides more audible texture and a leaner, more physical rendition, with the Balmung rendering the low end in a comparatively louder, slightly “fatter” way, giving more weight to bass guitars and synth notes. Both choices work for me in the context of the rest of the respective IEM tunings, so I don’t have a clear favourite.

Mids are slightly more forward on the Balmung, with the Jolene laying a bit further back from the listener when constructing its stage. Both IEMs go for a slightly analogue and romantic “sheen” to the presentation, with the Balmung again providing a slightly fatter sound and more warmth to the stage and the Jolene going for a textured, more physical approach that is leaner in body and colder in tone. There isn’t much to split the models here – detail is pretty much a tie, with the Balmung providing a more “rounded” rendition of tracks like “Three Chords” by Goodbye June compared to the more raw and emotive version replayed by the Jolene.

The only area where there is a notable difference in the mids to me is in terms of timbre and tonality; the Jolene gives guitars and voices a warm glow that is still slightly stylised but at the same time pretty true to life. Guitars and voices sound raw and more importantly real, with the Jolene definitely able to eke out a stronger emotional connection to some of my favourite test tracks.

Treble is where the two models diverge slightly, with the Jolene painting a crisper and more prominent treble note than the more slightly smoother Balmung. Neither model are treble cannons, but the Jolene packs a little extra zip into the hi hats on “Go” by The Chemical Brothers, with the Balmung following a similar theme and sounding more weighted. Given I have the usual hearing for a man in his 40s who has been to plenty of live gigs in my mis-spent youth, I won’t talk too much about treble extension apart from to say that the Jolene “feels” like the more extended of these two in-ears, with no noticeable roll off as the frequencies rise. In comparisons, the Balmung feels more reserved and a little less open here as the Hz keep climbing.

In terms of soundstage, the Jolene feels deeper than the Balmung, with a similar lateral extension. Both IEMs stage on the large to very large side, so again, not a huge amount to discern between them here apart from the relatively flatter spread of instruments on the Balmung, and the smaller instrument size on the Jolene. Imaging is pinpoint precise on both, and separation also operates at a similarly high level. At flagship level it’s usually pretty difficult to pick up glaring differences in technical capability, and these two IEMs are a great example.

Overall, these two IEMs have plenty to recommend them, and very little to definitively separate them either technically or tuning wise. If you prefer a more romantic and thicker sound with more mid-bass, Balmung is the recommendation. If timbre is important to you and you prefer a more textured and slightly cooler sound with more physical grunt and slam, Jolene wins out there. For everything else, either model will suit most genres or musical tastes.

Final thoughts

The Balmung has been a really interesting IEM for me to listen to, and has actually taken me on a bit of a journey. From the initial adjustment period where it didn’t quite blow me away, through a growing appreciation of what it does well to a realisation that a lot of other IEMs just don’t sound as enjoyable in direct comparison. The blend of out and out musicality and colouration alongside the technical refinement is a very difficult combo to find, with the Balmung constantly reminding you of its resolution and capability in tracks you know well but without drawing you out of that enjoyable musical bubble that the best listening experiences provide. It doesn’t quite score a full house for me purely based on cost – it’s not out of step with the current flagship market, and the included accessories are high end, but there is a nagging feeling in my ears that if this was sub $2k then it would be a genuine fixture in the high end recommendation lists.

That said, it’s not an unreserved recommendation for all; it probably leans too warm and thick in its tonality to capture the hearts of every audiophile, and it definitely won’t satisfy the Beyer ice-pick/unmoderated HD800 crowd that crave treble incision over musical precision. MMR have shot squarely at a musical and engaging tuning with a fat, chunky sound, so if you are looking for something that has flagship level technical chops with that sort of sound profile, the Balmung is a very unpublicised but highly polished diamond in the audio weeds. For me, it’s a sound signature I massively enjoy but probably wouldn’t settle with as my daily driver, but would certainly settle down with for some serious musical enjoyment.

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