2" or 4" thick corner bass traps??

Hello, I have found Roxul RHT40 locally in both 2" and 4" thickness. What would work best for corner bass traps? And what would work best for wall panels? Thanks, Caz

Too easy. The thicker the better. Andre

Even better, if you can afford it - cut the stuff into 2' x 2' x 34" triangles, stack them in the corners to the ceiling - Walls - if you have the room, use 4" spaced off the wall by another 4"... Steve