So Stax does its tensioning to get 120Hz to 150Hz. Pretty tomtom drum tight then. That's a useful nugget to note down.
When I was thinking about this, it was really from the point of view of what a drag it might be to disassemble each driver to perform tensioning.
Far better I thought to not give dust a chance to enter - not disturb anything and just turn a little screw or adjuster somewhere.
A lot easier said than done.
Patience is what I need.
btw I am just down the road from you in Kyoto.