All my wall panels and ceiling panels are made from 2" 703. My research showed that was what most people followed. I then mound some white muslin type cloth to tuck around the 703 which helps keep any fibers from floating around, followed by some black like speaker grill material.

It is important the material you use for the wall panels is not reflective or to thick. If you can breath through it and feel your breath come out the other side, it will work.

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85