I keep my servers and networking gear in an enclosed, sound insulated rack in my garage. It keeps the noise down, makes it easy to duct the heat outside in the summer-time, and is a setup I’ve been quite happy with over the last number of years.
Unfortunately it seems the old sound foam has gotten to the point in its lifecycle where it starts falling apart if you look at it sideways, so it’s time for a refresh.
I found some inexpensive sound panels through the usual megastore, and after finishing clearing out the old foam, and giving up on getting all the old adhesive off, set to work cutting and fitting the new panels into place, and adhering them with double-sided foam tape.
Subjectively, they seem as quiet as before, but I don’t have any quantitative data. I think they look a lot nicer, and hopefully they hold up well for the next $X number of years.