Should I use (denser) 13ml soundchek or 16mm fyrcheck?

Please note - I started 4 separate threads at the outset of this adventure. This one - viewtopic.php?f=2&t=17302 - Should I use (denser) 13ml soundchek or 16mm fyrcheck? viewtopic.php?f=2&t=17296 - Triple leaf viewtopic.php?f=2&t=17294 - Please help with options for room within room - And what became my main thread for ongoing discussion - viewtopic.php?f=2&t=17298 Does this count as a 'leaf' Hi there - I'm keeping this separate to my triple-leaf posts as that seems to have been answered really well - thank you! It is clear on this forum that 16mm board is the preferred weight. Over here in Australia we have a 16mm board - called Fyrchek - which is 800kg/m^3 We also have an acoustic product called Soundchek (that is the densest board here) at 900-1000kg/m^3....or 13kg/m2 The price is pretty comparable.... Would someone please like to offer a POV on which would be better? Thank you Peter

Peter, please keep all your posts about your build in one single thread: It helps us moderators (who sometimes have to follow dozens of threads from dozens of different people) to keep things straight about who is doing what, but more important it will also help you many months down the line, when you actually start building and need to find the answer to a question that you know you asked some place, but don't recall where.... Anyway, to answer this one: go with whatever gives you the highest mass at the best prices. If you find stuff that has very high density, then that's OK, but at the same time don't use stuff that is too thin, too flexible, or that has unusual resonant frequency characteristics. Some people even use sheet lead in their builds, which is several TIMES more dense than drywall. But for most people, the issue of cost also comes into play... - Stuart -