I heard them in the 9.87 system but can not differentiate them from the times I head that system with paper drivers. Their speakers are more specific than the just cone material, of course. I will guess that you will not get a good answer in forums but would get a straight forward answer from Voxativ or their dealers. Voxativ does provide plans for simple baffle construction that would be a big savings over their piano cabinets.
High Efficiency Loudspeakers
The Germany Brand Voxative Made very nice but expensive drivers. Especially very interesting the drivers with wooden cones , If anybody listen loudspeakers or drivers with wooden cones and what you impressions ?