I need to quiet my loud Mac Pro, and I think I can do so without building a sauna. If air can circulate with a quiet fan, while going through a maze of soundproofing, I think it might work, but I have many problems to solve. Has anyone built one of these?
I've worked with commercial ones that cost upwards of $1000 and worked ok. It ran at about 90 degrees with two computers, and you could still hear some noise.
You could build one, but it needs to be pretty thick and have plenty of extra room. I could see it easily costing $200-300 to make a good one.
If it was me, I would put your computer in another room if you can, and spend the money on extension cables. It's a pain sometimes, but it would be dead quiet without compromising on cooling.
I built one for a commercial studio a few years back. We used quarter-sawn cherry veneer plywood, plexiglass, HVAC insulation, Compressed fiberglass and a thermo controlled in-line two-stage fan connected to the HVAC return duct. It was cheaper to build than buy, but not for the faint of heart. Also, temps were high when crunching the computer so we would leave the door open when not absolutely essential.
This option is really only a plan "B"; its much easier and works a lot better to simply put the computer in a climate controlled data room. Most music studios plan for a data room before construction begins (sometimes located in that awkward space produced by an angled rear wall.
e-mail me if you want a copy of my plans. They are very basic and should only be attempted with a working knowledge of carpentry skills.