Originally Posted by Trepidati0n
Will fluffy be dense enough though even if you add more? Really would like to know.
Bob knows a bit more about this stuff than I do.
Check out his consolidated list on Absorption Coefficients
. You should be able to get a general idea of how effective a particular product will be at "x" frequency from this list.
Near the bottom of the webpage you will come across this statement:
In all cases if you have less than 4" you use rigid, if you have 8" or more you use fluffy, unless you need rigid for structure.
With that said, stacking 24" x 16" strips of pink fluffy in a brick like structure would probably be the most awesome absorption I've ever heard of.... I mean I don't know of anyone else that has contemplated going 24" deep in pink fluffy! Well, maybe for some bass traps, but never across their front stage (which is what we are talking about in your case, right?)
There are many many others more knowledgeable on the subject (Ethan, LTD02, FOH, Bosso, etc...) and maybe they will weigh in for you?
Or you could cruise over to the Acoustical Treatment Master Thread and start doing some digging. I found this post
regarding thickness and resistance in relation to reflection and transmission that you might find interesting and pertinent to your question.