I think the creator mentioned that the membrane is graphenes. It repel dusts and humidity, and he specifically told me that it does not have dust shield
I wonder on what date that statement was made. I've been discussing drivers a lot with the maker during the past year, including dismissing the dust cover (for much improved dynamics), but he did end up using dust cover membranes.
At least in my Libratum v2 the drivers were protected. They sounded and measured completely neutral, but I wasn't too happy for the small midrange bump it had (though less than the 009). It took me a while to improve the pads so that they start to truly sing, and then they were so good it was incredible, like tears-level good. I didn't want any change to them any more, but unfortunately the diaphragms were the slow charging ones, and also developed an issue, a low volume random static noise. I had to send them back for the v3 stator + diaphragm change, it's being done free of charge, except for shipping. While I am sure they won't have the same problems, but whether will they have the same sound I kind of doubt. The maker claims they are better now. Let's see.
For any case, the rate at which these headphones improved between versions is impressive, the guy definitely knows his science. They already sound very good, somewhere between the Stax 007 and 009. The Libratum 2 was like a more open 007 Mk1, or a 009 without treble issues, but less sensitive than either (less sonic problems as well). The Canorum 2 was more like more open 007 Mk2. The difference between the Libratum and Canorum is similar to the difference between the 007 Mk1 and Mk2. You need very powerful amps with these, and the higher the bias the better (up to 800V).
So the standing question now is how durable and consistent the headphones will be. Only time will tell, but I am sure the maker will take good care of the issues. He is knowledgeable and trustable.
I am definitely thrilled there are new players on the market, the MrSpeakers ES, the Phenomenon headphones, and hopefully more to come. It is also impressive the newcomers catch with the 007/009 sound quality level. I don't think Stax has to fear disruption, but tough competition, yes.