Check out my Shapeoko3 enclosure post in the Shapeoko section
It may give you some more ideas.
Mine is 3/4" plywood with 3/8" acrylic windows and it attenuates sound very well. I included sound measurements in the post. I think I even posted a video link to let you hear the difference.
I used acoustical damping caulk in all of the wall joints.
Using some type of soft rubber feet will help prevent transmission of vibrations from the Nomad to the enclosure.