Question for Ergo IX builders, how much stuffing and what type did you use? - I'm using a a nylon bulk fiber, a reasonable about but not tightly stuffed. I think James mentioned he used bats, which depending on the type could be quite a lot denser.
I read one data sheet that mentioned 1 lb of acoustic wool per cubic foot of enclosure. That seems a fair amount more than I am currently using, although I never actually weighed it.
Just curious, once I open mine up for the new XO I will experiment a bit and report.