try booting with the ssd only. if the noise is gone, we should look at the drives, the drive cage and the side panels.
If the noise persist, try cutting of fan by fan and so on until you find the some useful clues where the noise is coming from in the first place.
Okay I did as suggested here and booted with the ssd only with the case fully closed and tightened. Surprisingly the noise did not completely go away. It was still there although far less intense. It was easy to ignore or drown out with a little white/brown noise. Pinching the sidepanels quieted the noise as before.
I will check on the tightness of the screws, very possible I overtightened. I remember being a bit dubious about the drive mounting scheme, and tightening down about as much as I could.
Although I've followed and lurked SPCR for years, I don't consider myself sensitive to computer noise in general; for the past 5 years my case has been an In Win
model that certainly wasn't silent, but any noise it did make could be drowned by a noise maker if needed. It's just that this particular noise is too aggravating.
Can anyone recommend me a particular HDD suspension system? I've got two open 5.25 slots in the case.