A couple of weeks ago I found myself utterly destitute, so as a birthday present to one of my relatives I decided to attempt to silence their PC - which up until then had emitted a sound not unlike that of a vacuum cleaner with its hose stuck on the carpet.
Utilising various fans I had scrapped over the past few months for 'not sounding quite right' and a cheapo Mercury/Kobian 'Oscar' steel case (http://www.kobian.com/images/pr_ca/pr_ca_au_oscar_b.jpg
) I had scornfully consigned to the cupboard last christmas, I came up with this:
I sprayed the whole chassis, bezel, side panels etc. with matt-black car body paint, then covered every available surface with 1/2" sound-insulating neoprene foam, bent the PSU intake slats... I also jigsawed an 80mm blowhole in the rear face, which I filled with the fan from my antec TP380-sonata:
The two knobs at the top of the picture are potentiometers for control of the rear and PSU(YS-tech 80mm) fans. I jigsawed a 120mm 'suckhole' in the side of the case to blow onto the components - due to my poor workshop skills it also sucked in terms of its likeness to a perfect circle (notice the 3rd variable resistor) ...
The other side of the hole I occupied with a vantec 'stealth', which at its very lowest speed is OK-ish, the black stuff is a dust filter. More neoprene here:
At the front of the case I removed the bezel and covered it with more neoprene. I also partitioned it so incoming air flows directly through these two horrific, jagged, tin-snipped holes. More dust filter material here:
Finally, I had some fun with this elasticated cord from Blacks camping & outdoor, and managed to successfully decouple the HD with a single strand and a cunning thread-pattern:
Don't forget the case feet:
Verdict: It's quiet. Not as quiet as my own machine, but that's not surprising considering how much more money I spent on it. Overall the bill came to ~£20, but I also put my life at risk using that crazy jigsaw without a clamp first time around... main point is that it was appreciated, though the birthday girl subsequently complained about the buzzing noise that was coming from her monitor....