MMR Thummim

Slightly Crazy and Truly Unique.

PROS: Truly unique spherical soundstage that is very spacious, powerful signature that oozes musicality, gobs of texture and detail, build quality, surprisingly comfortable, high-end cable, unique leather case.

CONS: Tuning and the angular shell design might not be for everyone, limited accessories, price.


I would like to thank Joseph Mou of MMR for providing me with the MMR Thummim in exchange for my honest opinion. No incentive was given for a favorable review.


  • Triple hybrid with 9 drivers: 1 x bespoke 9.7mm Foster dynamic driver, 2 x Vented Mid (BA), 2 x Highs (BA), 4 x Electrostatic
  • Crossover: 4-Way Passive Electro Frequency Division
  • TriBore Waveguide
  • Eletech Proprietary Internal Litz
  • Frequency response: 10Hz-80kHz
  • Impedance: 35 Ohm
  • Price: US$4,499


Available for Sale from MusicTeck.


Metal Magic Research, or MMR for short, is a brand new company with a familiar face, Joseph Mou, best known as the founder of Jomo Audio. When I first heard about MMR I did not really know what to make of it. Jomo is a more traditional IEM company, but MMR… Metal Magic? That sounds suspiciously like alchemy! Indeed, that is the whole philosophy and theme behind the company. MMR is a collaborative brand where a number of industry veterans have come together to let their brains run wild and to pursue some of the craziest ideas that result from it. A bit like alchemists used to do. You might think that Joseph must have lost his mind, but remember that even the great Sir Isaac Newton could not resist the lure of alchemy. Newton spent many years of his life secretly conducting alchemical experiments in an effort to find the mythical philosopher’s stone. Of course, Newton did end up (temporarily) losing his mind because of mercury poisoning, but I think Joseph prefers to work with other metals.

MMR launched at CanJam Shanghai 2019 with four IEMs in three series. The Metal Series comes with two CIEMs based around balanced armatures only: the 5-driver Gรกe Bolg and the 11-driver Balmung, both named after mythical swords. These will see all metal universal versions launched later in 2020. The Magic Series has the triple hybrid, 4-driver (1 x DD, 1 x BA, 2 x electrostatic) Homunculus, named after the small human being that was created in a laboratory by the 16th-century alchemist Paracelsus (he even published the recipe, but refused to show it in public). The Philosopher’s Stone Series is, as the name implies, the flagship series with the triple hybrid, 9 driver (1 x DD, 4 x BA, 4 x electrostatic) Thummim, named after the objects Urim and Thummim that were part of the breastplate of the prophet Aaron, used for divination and seen by alchemists such as Paracelsus as signifying light and perfection.

If it is all starting to sound a bit far-fetched and over the top, then at least the marketing team have done their job because that looks to be the intention behind it. To advertise the brand’s unconventional philosophy. It seems to me to be a risky strategy, but I always like it when people dare to be different. So now the question becomes… Is Joseph the audio industry’s Nicolas Flamel?


The unboxing experience of the Thummim is a bit mixed in my opinion. These are very expensive IEMs and so it is a bit disappointing to see only the bare necessities included: the IEMs, a cable and a set of tips, all fitted neatly inside a leather case. At this price point I would expect opulence, a filthy decadent over-the-top type of opulence, which sadly isn’t there. What is there, however, has been well thought out and so you are getting quality and something unique.

The outer box will feel familiar to those of us who like a good quality whisky: a sturdy cardboard tube, like the one your favourite bottle of whisky comes in, which is covered with graphics to give off an alchemical vibe. It opens up to show (carefully wrapped in paper) a beautiful leather case shaped like an ancient papyrus scroll. It opens up like it too, with something that feels like unrolling ancient secrets to reveal the philosopher’s stone. There they sit, the Thummim monitors, like two precious stones alongside the Eletech Plato cable and a set of Acoustune tips. All the tools needed for the discerning audiophile to imbue life into their music, and they are darn good quality tools as well. Plato is a very high-end cable, which I reviewed here previously and has become a favourite of mine to pair with the Empire Ears Phantom. The Acoustune tips too are great quality, although I personally usually gravitate towards Final E-tips (not this time, but more on that later). The case is completely unique and something you could easily put on display or set on a desk. If only MMR had put this in a small mahogany chest with a key shaped like something out of the mind of M.C. Escher that once turned released five different locks to open up with a mysterious fog pouring out, golden light permeating through it and that ‘angels singing ahhh‘ sound effect.

Build quality and fit.

In alchemy metal is seen as something that is, in a way, alive because it grows inside the Earth (yes, Newton believed that too, even before he went mad from huffing mercury fumes). The Thummim are of course not grown, but the milling process does transform the titanium into shells that harness the heart of music. The heart in this case being a 3D-printed chassis on which the drivers are installed. This method of construction forgoes the need for sound tubes and provides a very high degree of precision with an accuracy of up to 25 microns to fine-tune the acoustic path from driver to the nozzle. The BA and electrostatic drivers also do not have the traditional port and instead fire straight into the chassis. The BA drivers are from Knowles, the DD driver is from Foster and the electrostatic drivers are from Sonion, which are driven by their new second-generation transformer to improve efficiency. Once the chassis and drivers are installed and connected up with Eletech’s proprietary internal wiring, the lifeless metal becomes the embodiment of musicality. When I first saw the Thummim I also noticed that the nozzles (made from aluminium with chrome coating) are empty and so act like horns, which Joseph explained to me helps to amplify the higher frequencies. The end result is a set of superbly built IEMs that feel very solid, while not being too heavy either.

Images courtesy of MMR

The Thummim of course look crazy and like most other people I had my reservations about their comfort because of all the sharp angles. However, the inside of the shells is actually a lot more comfortable than expected and I had no issues with them. It took me some time to find the right tips, which ended up being the double flange Accoustune tips that MMR included, and once I found those I could use the Thummim all day without the slightest hint of discomfort. Although the fit will vary from person to person, I don’t expect too many problems for most people.

One thing to note is the 4.4mm balanced plug on the Plato cable. When I started using it with my Lotoo PAW6000 I found the fit very tight. So tight in fact that I initially switched to the other Plato I have, a 2.5mm balanced version that I could use with an adapter, and contacted Eric Chong of Eletech to enquire about the tightness. He explained that they have been using a thicker rhodium plating on the 4.4mm plug and that this will wear down over time. They will be looking into reducing the thickness of the plating, but for the current plugs it should be perfectly fine to use, as the plating will wear down and not damage the socket on your source.


Listening was done with the Lotoo PAW6000 from the 4.4mm balanced out without using any EQ settings, as well as some with the Lotoo S1 dongle from my MacBook Pro. (On a side note: Using the S1 in its UAC1 mode, I also had a great time with the Thummim on my PS4.)


Page 2 โ€“ Sound analysis and Aftermarket cables.
Page 3 โ€“ Comparisons and Conclusions.

4 thoughts on “MMR Thummim

  1. Thummim is amazing with classical music provided you use the appropriate cable. In my opinion the Beat Audio Billow 8W clarifies the sound considerably and then the Thummim is by far the best IEM on the market.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s