Have a loud shop vac that you use for a stationary purpose, like sucking up chips off of the shopbot or dust collection for your table saw? This Instructable will show you how to create a sound baffle to minimize some of the noise. By the way, I made it at Techshop!
Step 1: Gather materials, preferably scrap.
This project is meant to be functional rather than beautiful and is done with no budget, so the first order of business was to collect suitable scrap materials. I found 2 pieces of 2" scrap foam, 54" by 30", out by our container, and a few pieces of scrap ply board near the plastics station. (Actually, the availability of properly sized scrap foam was the impetus for this project.)
If you don't happen to have access to a giant pile of scrap or if you want to go out and buy new materials, you can follow this Instructable but make a much nicer looking final product.
2 sheets of 2" foam, 54" by 30", or whatever suits your purpose.
4 pieces of 1/4" or 1/8" ply scrap (owsyp)
About 16' of 1.5" by 0.5" strips of board
Drill with driver bit
(wood glue for the corner supports if you're not lazy like I was)