I have had seven custom pcs to drive me acoustically mad, all mine, every piece altered in some way different than oem (no joke)except for solid state parts like the hdd...
Of course i only learned to doubt everything.
This topic is about heatsink of the box, and some old fashioned pc rules forgotten, especially about the HDD.
Really clamping the hdd down is an absolute must. Today more than ever. the "suspending for silence" theory is like a bungi jump accident waiting to happen...without the case ground an hdd needs to boot (could be pun intended).
I recently added some metal to an already nice box (antec2600) it is the same secc stuff for many electronics. I am glad the antec boxes stuck to a rule of some kind.
Anyway, upon clamping the drives down, a dreaded wah wah bass noise emmitted, and even a case cavity noise (read about here in the 200hz range). I was disappointed. So first thing was to throw the little mouse pad in the bottom of the case to stop cavity noise. That worked. Case is indeed tough enough...
Rather than defy what I know as "rules" for hdds.. if the box is letting it happen, the box isn't tough enough.
So I filled in the 5.25 inch bays back with original metal, by adding some extenders with rivets and making it removable with screws (I could have taken a picture just today as I was finishing it off, but was motivated didn't think of it) drilled holles 1/8th accordingly. As it turns out, one of the nut/screw combos tightened the entire cdrom bay up top.
I added two rivets near the psu ,2.5 years has taken a slight dimply toll at the seams and simply brought it back out again with rivets nicely done, like oem.
The drives were still driving me mad... the whole system is very quiet on 3 fans, max rpm 2376 and its on a duct aiding in acoustics, (reverse cooled). I am not going to give up with crazy silencers. I want rules. I want a tough case. I want on and off, and accidentally kicking it to be no problem.
I took the bezel off again....
added what ended a perfect piece to fit the open floppy spots, and also found that it is flimsy in that area with drives or not, like all my other cases....the irony of putting drives near the open weak area has been just another backwards thought process in the pc world...
I quickly rummaged through some of my junk and found an old cobra cb (fried) and took note that the built in speakers four holes were 120mm, and it was vented for a speaker...and the metal is nearly identical in feel and color as the antec 2600amb...and painted twice, inside out (inside of cover is just like a pc case)
I cut out a square to fill in the whole thing , added four screws....mounted it to case, slid the drive bay back in, noticed it latched tighter...
completely silent drives. I can put my hand on the case and declare it a reduction number unknowable, just that is slient. Side by side, both active, and conquered...
My point here...
do not go against old rules to silence a drive, attack the case by making it stronger, or like I have literally done, take it all aprt slowly to save the good stuff, take it outside, and have a case stomping party.
You will notice, the little hdd is not the acoustic monster it seems to prevail as sometimes, in a proper case to handle the Little HDD.
I remember a wd drive I had some years ago, in a gateway 2000 case, that *had to* be spaced between .25 inch and .5 inch from a solid metal front end, with all four screws attached, and inside a large enough case... or by design.. it would not run at all.
HDD has a powerful energy in relation to a system, grounding by all means is a must do, and it is nothing to notice (if you win). The case is a huge part of the functions, and even aids in clock smoothness by solidly knowing itself is all there at all times, through all layers of pc dynamics..it likes the drive mounted.
I hope to help somebody going mad over this. Blame the case, seriously. As a starter case, antecs are nice, but you may find to have to add some things like I did. Compared to the past. Some of the Antec may as well be golden in pride, even with errors.