I was also amazed by the effort that went into making those speakers. The shape of the box, the finish, that phase plug thing etc. Oh and one thing and I just remembered. That top box where the tweeter is mounted is not attached firmly to the rest of the case, there's some play. Not adjustable in position but not glued or bolted to the rest of the case. In comparison, my speakers are a very basic design in most way. Rectangular bass-reflex boxes, both drivers are not flush mounted, no horizontal offset, no chamfered edges, no slanted baffle. The filters are 1st order and impedance equalized (there are 2 PCBs, one on the rear wall and one on a side wall). Not hard to drive. Would I chose them, price no object? Hell no, I've heard much better and not insanely priced. But until I'm sure (where sure means after listening to them in a similar room with my music, not in a dealership where everything is tuned to perfection or at least supposed to be) I want to upgrade I'm staying with these.
Someone said above that if electrolytics are used in the filters they are subject to aging. My friend told me that they use silver wiring, I can't imagine the type of person to use "audiophile" cables inside a speaker opt for electrolytics. Look at pic no 4 here:
https://www.marktplaats.nl/v/audio-tv-en-foto/luidsprekers/m1768910572-mc-systems-m3 There's a Siltech sticker at the back. You can see that we're in mumbo jumbo territory here.
Oh and one more thing. While looking them up I ran across a pic of the M3 where the tweeters are ribbons, not domes. Maybe not a coincidence.
As I said above, to me it sounds like whoever designed the M3s has a very specific taste in music and sound and made them for like people. IMO definitely a niche type of sound which I'm not a fan of.
But IMO we're speculating based on some pics and basic specs. In my native language we like to call this wandering in the fields.
If you run the model on Google images there are so few pics online that it's obvious it's an obscure brand, likely mostly known in The Netherlands. Possibly no distributors outside the country. I'll take a wild guess and say that there aren't any measurements of these speakers. Like I said, way, way too much speculation based on very little info.
Oh and last thing. I believe it's obvious that tweaking them is absolutely out of the question because 1 the resell value in the audiophile market would become zero 2 there's no guarantee it's worth it and my friend doesn't have the inclination and is a busy person.