I've used Acoustic cotton with my set-up. And it works well. Real good I tell ya..
Made 9 bass traps, which are now ready to be placed in their respective zones. Learn't a lot from Ethan's videos etc..
Just need to find a carpenter to help do it professionally.
They are pretty big, heavy and i want them angeled on the ceiling and corners etc...
Will post pics as and when completed..
Cheers..
Kayo