What sorbothane products did you use to dampen the hard drives?
I bought a sheet of 1/8" sorbothane from McMaster-Carr; I don’t remember the exact dimensions but it was roughly the size of a standard sheet of paper
It’s AMAZING stuff. Truly unparalleled for vibration absorption.
What’s the loudest component in the system?
If in use, definitely the optical drive. If it isn’t in use, the 80mm exhaust fan on the power supply.
About how far away from this do you have to get before you can’t hear it in a quiet room?
It’s partially enclosed in a media shelf, primarily in the rear with sliding doors that stay open when I’m using it. Unfortunately I have to orient it left to right due to the space it needs to fit in, so the fans that SHOULD be facing the rear are facing the “left” which makes a big difference. I have eggcrate foam lined behind it to assist in damping. It’s slightly audible from couch distance, but to give you a baseline-- I can hear the hum of my plasma TV over it. Pretty darn quiet.
What/how many case fans do you have running in there
The two 60mms, severely undervolted using a Zalman Fanmate, and the one 80mm PSU exhaust.
Does the P-M have any thermal failsafe, in case your case fans fail or you get a bit carried away with stepping down the fans?
Yes, it does; Intel always has superior thermal safeguards, so I wouldn’t worry about this. The thing you have to worry about is frying the HDDs, as they are more temperature sensitive than almost anything else inside your PC. Oh yeah, and did I mention they have all your data too?