I purchased several large pieces of acoustic foam at a local shop, my plan is to line the enclsoure with it to try and absorb some of the sound. You can see it in the photos, it has an egg crate texture.
I also decided to apply some sound absorbing material directly to the cyclone itself, to try and reduce the noise at its source. I'm using Dynamat, and have it on the upper part of the cylcone. It's nice since it is a peel and stick product, easy to apply.
I bought some acoustic tile, 3/4" thick with a high sound blocking rating, and plan to line the enclosure with it first, the acoustic foam will then go over the acoustic tile.
Lastly, and the thing I think will have the greatest effect, I plan to build an external baffle/muffler, rather just direct exhausting the cylcone.
