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MMR Gae Bolg Review – Mythical

Pros –

Gorgeous & comfortable design, Ultra-premium metal build, Well-balanced signature, Rich & organic timbre, Very dynamic bass for a BA earphone, Superb layering and highly immersive imaging

Cons –

Vocals could do with a touch more extension, Not for those craving utmost accuracy

Verdict –

The Gae Bolg is a master craft for those wanting a highly coherent and immersive presentation, bulletproof build quality and visually striking design.

Introduction –

In the years I’ve been reviewing, we’ve seen the market diverge into two streams of thought; one valuing function, the other experience. This can be hard to grasp until one immerses themselves into the niches of the hobby. MMR sit at the pinnacle of immersing the lister in the latter – their direction, design and creativity are truly a masterclass. Similarly, their universal IEMs certainly hold an artisan quality with all-metal build and unique designs and forms. The Gae Bolg is the latest entry to their universal range, utilising the same technologies to realise an all-BA sound. Gae Bolg is positioned as the company’s all-rounder sitting in the attainable but not unreasonable kilo-buck price range and promising a focused and accurate sound; it is a straight-edged IEM that conjures images of precision in line with its inspiration from the legendary lance of Irish mythology.

The Gae Bolg retails for $1199 USD with the stock cable and $1399 for the online exclusive bundle including Eletech Prudence. You can read more about the Gae Bolg and treat yourself to a set here.

Disclaimer –

I would like to thank Joseph from MMR very much for his quick communication and for providing me with the Gae Bolg for the purpose of review. All words are my own and there is no monetary incentive for a positive review. Despite receiving the earphones free of cost, I will attempt to be as objective as possible in my evaluation.

Contents –

Specifications –

  • Drivers: 1x BA Tweeter, 1x Vented BA Mid-High, 1x Ba Mid, 2x Vented Lows
  • Frequency Response: 20Hz – 40kHz
  • Impedance: 25 ohms
  • Noise Isolation: -18dB
  • Crossover: 4-way Electro-Acoustic Frequency Division
  • GB Acoustic Chamber
  • TriBore Waveguide

Behind The Design –


The Gae Bolg implements an advanced 4-way passive electro-frequency division with passive electronic components. This is implemented in conjunction with an RLC filter in band-pass configuration to ensure each driver plays only its intended frequency range.

Gae Bolg Exclusive Acoustic Chamber (GBAC)

As implementing electronic components into the crossover also introduces frequency phase shift, MMR developed a custom acoustic chamber to correct phase and optimise the frequency response. All aspects of the chamber were considered from density of materials, pathway length, consonance, angles and bore in order to achieve the end product.

Unboxing –

Much like their previous works, the Gae Bolg has a tremendously impressive and lavish unboxing experience in-tune with its premium pricing. A matte sleeve adorned with the Irish spear slides away to reveal a hard box with foiled MMR branding. Inside is a velvet piece protecting the earphones and accessories. The box has technical splash art with exploded view of the earphones and text in MMR’s generally charming thematic. The earphones are nestled in a foam inlet with metal branding tag below. A vinyl zippered case is included to house the IEMs and accessories. It feels very high quality with ample internal storage space for a small DAP too. Of note, the Gae Bolg is offered in two versions, lite and full. The Light version comes with a regular OFC braided cable while the online exclusive full version comes with Eltech’s Prudence for an additional $200 USD representing a $50 saving.

Design –

Based on feedback from their hybrid uni designs, MMR redesigned their BA shells to be lighter and more ergonomics whilst retaining a robust all-metal complexion. Gae Bolg takes inspiration from the legendary icon of fiction with its ornate red faceplates popping off a jet-black background and gunmetal body. Once again, MMR’s metalwork is terrific with perfectly even finish and no imperfections visible when pixel peeping my shots.

The shells now take on an aluminium as opposed to titanium construction responsible for the weight savings but make no sacrifice to rigidity or general quality of feel in so doing.  MMR note they are using an irregular sand-blasting process to achieve a rough satin finish and they’ve done so with aplomb, the shells exuding huge texture and tactility. It’s hard not to enjoy the design and craftsmanship on display here and the matching between each of the 3-pieces is exemplary and visually consistent – fitting of a high-end, high-quality product.

I am also a huge fan of MMR’s 0.78mm 2-pin connectors that implement a spring loaded mechanism. This makes them more resistant to wear and less susceptible to loosening over time, so the Gae Bolg is ideal for cable swapping. I have the Lite variant here with standard OFC cable. It’s par for course, with a tight 4-wire square braid, pre-moulded ear guides. The cable is supple and lightweight, with minimal memory and microphonic noise; it is simply easy to live with. The ear guides are somewhat long but offer a stable and comfortable fit regardless. While it is no Eletech cable, it provides a sound wearing and sonic experience.

Fit & Isolation –

This has been a prime focus for MMR and was a common complaint of their former releases. The company even went so far as to redesign the entire shell to be more accommodating of a wider variety of ears. In wear, this appears to be the case, as the Gae Bolg is not nearly as unconventional as the sharp-edged Homunculus or the bulky Thummim. It is rounded and refined with a better nozzle angle promoting a deeper fit and stronger seal. In addition, the more ergonomic shape sits more snugly in the outer ear and, being so smoothly formed, I found it to create no hotspots over extended listening either.

Accordingly, most can expect strong comfort from the Gae Bolg with the right ear tips fitted. Do consider that the shells remain on the large side so they aren’t especially low-profile and those with smaller ears may still struggle here. Still, I found the longer nozzles to uphold a deeper fit and a strong seal was easily achieved. Similarly, the fit was very stable even when out and about, and their dense, fully-sealed construction translates to strong passive noise isolation. These are easily ideal for commute and even air travel with more isolation custom or foam ear tips especially. The Gae Bolg is an ergonomically pleasing and IEM that is much more suitable for everyday use than MMR’s former releases.

Next Page: Measurements, Sound & Source Pairings

2 thoughts on “MMR Gae Bolg Review – Mythical Leave a comment

    • Hey Ivan,

      Sure thing!

      The Gae Bolg and Dorado 2020 are indeed very different beasts. The Dorado is much bassier, the GB more vocal-focused. The Dorado has a lot more slam, impact and texture while the GB has better definition and separation. The midrange is cleaner on the GB, a bit clearer and more forward. Its vocals are more flattered with greater size and presence. The Dorado has a richer midrange voicing and is more articulate, the GB being quite a bit smoother and denser. The Dorado has a crisper, higher energy treble while the GB is a bit more even. Both offer spacious soundstage presentations, the GB has more immersive imaging.

      Hope that helps you out, and have a happy and safe holiday season!



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