Glen - Thanks for that link to Jon Sayers' site.
That looks like the best way to line the container !
It gets me to thinking that maybe I should "Stud" wall the whole thing and line it with mineral fibre then face it rather than just putting panels up. I'm quite keen to keep some "air" in the room acoustically but I want to try and gets as uniform a response as possible.
Reflection points need 100 percent absorption, so you don't want any sort of hard board there, perforated or not.
Do you suggest I just line the mineral fibre with acoustically transparent fabric ? Will I not abosorb everything then ?
Are you sure you want a photo ?
It is a rectangular container - just like the one on Sayers' site, lined with plasterboard and with a glass entry door. I would be happy to oblige with a photo if its informative though !!!
thanks for any help