Founded by the head of Jomo Audio, MMR (Metal Magic Research) is a Singaporean IEM brand that has been presenting unprecedentedly unique products along with their new cable brand, Eletech. MMR’s first two releases, Homunculus and Thummim, were just enough to gain a significant amount of interest throughout multiple countries. I was also able to have extensive listening sessions for these two special IEMs, I could tell their sounds were as gorgeous as much as their form factor. Of course, we cannot forget to mention Gae Bolg – the youngest of the line-up that well represents MMR’s house sound signature for a lower price.
While MMR announced an extremely limited edition of Thummim just recently, Thummim is officially discontinued and Balmung has now appeared as the successor to take over the throne. FYI, both Gae Bolg and Balmung first made their appearance to the MMR family as CIEM-only products when the brand just got launched – which soon disappeared to be revamped into their UIEM forms. It was a necessary change since using resin for the housing material would somewhat go against the brand name. Since being reinvented into its official form, Balmung shows significant differences from Thummim in many ways. Today, let us go through the highlights of its sound signature and detailed comparisons against its predecessor and other flagship IEMs.
Earpieces – The Form Factors
Although Balmung uses the same form factor used for Gae Bolg, I’d say Balmung is one of the most beautiful IEMs I have encountered. Balmung uses mirror-polished faceplates with articulated cut-outs and navy backplates with teardrop-shaped, CNC-machined aluminum shells. The faceplate cut-outs reveal its phantasmal concept including the sword shape in the middle, representing the mythological sword called “Balmung”. The blue-silver combination gives Balmung a very luxurious look without overdoing it.
The other side of the earpiece also has a similar but simpler patterning, allowing the faceplates to gain their demanded shine but not leaving the inner side too plain. Nozzles are long enough to compensate for their rather large earpieces and the overall fit is quite comfortable. It is still a large size for those with smaller ears, though most users would not have a problem fitting these into the ears as the ergonomics are further advanced from Homunculus or Thummim. The cable sockets are terminated with non-recessed CIEM 0.78mm 2pin.
Earpieces – The Specs and Balmung Structures
Balmung has a full-BA setup using 4 vented lows, 2 vented mids, 4 mid-highs, and 4 tweeters. Consisting of 12BA drivers in total, MMR has also incorporated proprietary inner chassis and technologies. As mentioned, the transducers used for lows and mids are vented instead of compressing the sound through the transducer’s bore. This allows Balmung to create a wider, fuller, and more natural sound for the lower end. Several manufacturers have also been applying to their recent TOTL IEMs (64Audio, Unique Melody, FIR Audio, etc), however, MMR’s BA ventilation setup is quite interesting as they’ve applied it to lows and mids – while the mentioned brands vented their super tweeters only.
These 12 drivers are infused all in one using the Balmung Acoustic Chamber™ which refers to the proprietary inner chamber specially designed for Balmung, and a 4-way passive EFD (Electro Frequency Division) for efficiently dividing the sonic bands. The concept of the inner chamber shows similarity with Campfire Audio’s Solid-Body™ structure, but MMR’s execution was done more daringly. Balmung uses a wider and longer inner chamber which even has spiral-like waveguides to create its signature sound as well as to correct the phasing differences between the drivers. Such a way of correcting the phase is superior to the traditional tubing method (applying different lengths of tubes to each driver) as the sound is significantly more organic and fuller. For the final touch, Balmung uses an asymmetrical TriBore Waveguide within the inner chamber, allowing these sound reproductions to stay cleanly divided until they reach the tip of the earphone nozzle.
Balmung is the first of the MMR family to come with a dedicated custom-grade cable. Named the Balmung Cable, it is made of 26AWG UPOCC Silver-Plated Copper wires with a 4-braid structure. Cable termination is available in 2.5mm, 3.5mm, and 4.4mm with Y-split and plugs also designed to match Balmung’s design concept. These parts are also made of polished metals and engraved with MMR logos. One thing to note is that the Balmung Cable is terminated with non-recessed 0.78mm 2pin sockets, which offer a seamless cable connection with Balmung but are not compatible with IEMs that use recessed 2pin termination. Any other non-recessed 2pin IEMs are fully compatible, of course.
Sound impressions – Lows
With confidence, Balmung has one of the very best bass performances among all full-BA IEMs ever created. The full-bodied bass punches are well tamed and packed with richness, delivering firm slams without causing bombastic vibes. Lows scale grand and spatial thanks to the vented drivers. However, what’s impressive is that Balmung is an expert in controlling the reverbs for the right amount, letting natural fade-outs happen but preventing muddiness from kicking in. This results in a warm yet pure and clean low-end atmosphere to take place. The general impression of Balmung’s bass presentation is clearly different from traditional tube-based tuning, and in a positive way. The Balmung Acoustic Chamber™ naturally allows the bass to further unleash its potential while still staying under the “boundaries” that MMR has specifically designed. The vented low-end drivers would have certainly gotten the bass to get all loosened up if it wasn’t for the Balmung Acoustic Chamber™, so I could feel this inner chamber system plays a critical role here.
The bass extension may also as a concern for many – but rest assured. As who was formerly an avid basshead user (now I’m more of an all-rounder), the compliment at the beginning of the paragraph has been made also for this reason. Although I’ve been up for dynamic drivers when it comes to bass, Balmung’s lows extend very deep and clean which does not show shortcomings against dynamic drivers. Ultra lows show a nice presence with thick colors.
Sound impressions – Mids
Let’s now talk about mids – or the vocals. Mids are slightly pulled towards the front and show good moistness to the texture, not being too dry or damp. Balmung upholds the good crisp that BA drivers typically possess but with noticeably smoother and better refined. It’s a fine example of what high-resolution is, as you get to tune into the details without overwhelming your ears. Though yet, the strongest charm of Balmung is found in its timbre. The sweet creaminess makes the nuance of the vocals somewhat dreamlike or “magical” as the name of the brand suggests. This isn’t done in a way that makes the vocals sound colored, as it has more to do with the chassis tuning and driver setup.
Personally, this sweet and creamy tone is my favorite element from this IEM since it enriches the music while respecting the originality – just like what a pinch of salt and pepper does to a nicely cooked steak. Vocals have a neutral-bright temperature that aligns with the IEM’s smooth nature but could still throw upper-mid airiness. Balmung also forms vivid depth and spatiality to the vocals. Unless you desire a fidelity type of sound that has flatter imaging, Balmung’s immersive tuning will come pleasant to the ears. Mids are sibilant-free and flow without any disharmony in tone.
Sound impressions – Highs, etc.
Since Balmung desires a soothing sound signature, trebles are tamed in terms of intensity but unleash the details required for a flagship IEM. I found it interesting that the trebles are very fine and tamed in a way that EST drivers would typically behave. Highs show accurate, tightly-controlled splashes that are fine in texture. It’s an elegant style of treble because it doesn’t get rough or aggressive in presence yet still manages to keep a distinctive presence in the music. It’s likely not an ideal choice for those looking for highly-boosted treble machines, yet Balmung’s treble just creates a highly homogenous, harmonic sound that allows all details to shine evenly throughout the spectrum. There sure are W-shaped sounds (or a sound that highlights all frequencies) that creates an intense treble presence, but the difference is that such IEMs are prone to sounding over-exaggerated while Balmung remains thoroughly neutral and realistic. The brightness isn’t particularly bright nor dark as it tips towards neutral-dim.
When it comes to the soundstage, Balmung creates one of the largest headrooms I’ve experienced from an IEM. It is similar to the way how Thummim does (further details will be discussed below in the comparison) but with more vastness. The height of the headroom doesn’t reach tall as Thummim’s but a minor difference. Needless to say, separation is spot-on with high accuracy and harmony. The sound details are separated in a smoother way than Thummim. Alongside, Balmung gives velvety tingles more than the crisp bites as Thummim does.
Compared to Gae Bolg
Balmung and Gae Bolg are quite similar in overall tuning. But of course, although Gae Bolg is a fine performer for its competitors, there is a bold gap in performance if we match it up against Balmung. Balmung brings out significantly more details in texture and depth. It’s interesting how Gae Bolg’s fine imaging suddenly sounds dry and one-dimensional once you switch back from Balmung. I’ve found the largest difference to be found in the vocals. Mid-range immersion and liveliness are incomparably better on Balmung. The characteristics of lows and highs are also very similar too but with noticeable gaps in detail retrieval, of course. In all, if Gae Bolg is what offers a good example of what MMR’s house signature is, Balmung shows how far MMR’s house signature could expand in performance. If Gae Bolg’s sound signature suited you well and would like to extend such sound signature to a summit-fi level, Balmung would probably be the best option available.
Compared to Thummim
The most anticipated comparison for Balmung would be Thummim – the discontinued flagship IEM of MMR. Thummim adopts 9 drivers which consist of 1 Foster DD, 4BAs, and 3EST drivers. At first glance, Thummim is overall more vibrant in sound signature and vivid in tonality. Lows have that signature dynamic driver damping. The bass quantity and mass are similar (or roughly the same) to Balmung yet it feels a lot heavier weight and stronger in slam.
Thimmim’s mids highlight more intensity and dynamics, making the vocals sound crisper and tighter. However, Thummim is less refined in texture or has a thicker grain. Balmung’s vocals, on the other hand, spread more evenly and generally sound calmer. the surface also feels smoother and finer in grain. Alongside, Balmung desires a slightly more reference-like sound with a more neutral timbre while Thummim has a thin coat of coloring to its tone. Thummim’s overall sound signature shows masculinity while Balmung is just about neutral. Hence Thummim would vary more in likes and dislikes than Balmung.
While it may be overlooked by pre-existing brands, MMR is immensely loved by many once you get to listen to them. Although I was lured to the two debut models simply due to their unprecedented looks, it wasn’t long for their IEMs to get me fascinated by both – Thummim and Homunculus. Of course, the most impressive one was the Thummim, hence I had to grab one eventually. As an avid fan of the Thummim, it was sad to hear its discontinuation news yet Balmung was born to replenish its disappearance or to even surpass.
Balmung isn’t born only to replace Thummim – but to also introduce noticeably better ergonomics and more reference-based tuning. As you explore more and more IEMs, you eventually realize that things all come down to quality components and tuning skills more than what and how many drivers were used. It still surprises me that a full-BA setup could produce such grand staging and dynamic bass response. If you seek an endgame IEM that produces one of the largest soundstages possible, or a more organic and comfier version of Thummim, I would confidently recommend this one.
One of the largest soundstage
Excellent bass and density reproduction
Custom-grade stock cable with balanced output
Continues the legacy of Thummim with a more organic sound
Not meant for those who seek flatness (although the reference tuning)