The idea was, to use old chieftec server atx case, that was really cheap (ebay), and in my opinion, beats many expensive cases with sound dampening.
Case is made out of very thick steel panels (compared to what is used these days).
What is most important, all panels don't have any ventilation holes, it is all solid steel, both side, bottom and top.
i7 2700k @ 4.8ghz (1.28v) + macho 140mm (TY-140 @ 650rpm)
msi gaming 750ti @ minimum ~900rpm
intel ssd & WD10EZRX on foam
RM750 fan never turns on with this load
Case sits on the floor, last pic only to show how it looks.
I'm really happy with the result, no noise, no coil whine getting through that thick steel case. Also no issues with dust/cleaning, all panels are solid, no mesh, you can easily wipe it (compared to various gimmky ventilation solutions in modern cases).