DIY HUSH BOX for Home Cinema - Build Technique & WHY mine FAILED TWICE

How I made two Home Theatre Hush Boxes and a look at whether worked in reducing sound levels from my projector into my home cinema.
I didn't mention in the video, but I also used the highest rated acoustic sealant inside the hush box along every join in the plywood and pine structure pieces to try to eliminate any avenue for sound to escape.
In the Hush Box Mark I, part of the weight issue was also that I lined all the inside surfaces (except the back piece) with Mass Loaded Vinyl (approx 3mm thick). That stuff is dense and very heavy itself. I didn't use that in Mark II which cut some weight down.

[@KimmoJaskari]

It's tricky to outdo the projector manufacturer themselves since you still need fans. I might suggest a design that incorporates some of Noctuas 20 cm gigantic silent computer fans or something. For construction material, perhaps 8020 t-slot aluminium, extremely easy to bolt together with fasteners, and for a project like this it could be the lightest thinnest version - 1 inch square diameter, I believe, and it does come in black, with one or more sides flat and more attractive (the parts that are seen on the outside). The good answer would probably be for the projector manufacturers to just build a much larger projector designed to move air quietly with 15 cm or larger fans or something, but many people would probably object to a projector that size instead. Glad my own LS800 UST projector is almost silent when I dial the laser down to 70% or so.... and the noise that remains is up front and not behind my head.

[@KimmoJaskari]

You could also 3D print any necessary ducts, but of course that requires a 3D printer and minimal skill at using a cad program, but even Tinkercad could suffice.