We measure from a distance of around 1 meter from the chassis and 4 foot from the ground with our Extech digital sound level meter to mirror a real world situation.
The Asus E35M1-I is completely silent, so this will be a rating of the Thermaltake Armor A60 chassis.
KitGuru noise guide
10dBA – Normal Breathing/Rustling Leaves
20-25dBA – Whisper
30dBA – High Quality Computer fan
40dBA – A Bubbling Brook, or a Refrigerator
50dBA – Normal Conversation
60dBA – Laughter
70dBA – Vacuum Cleaner or Hairdryer
80dBA – City Traffic or a Garbage Disposal
90dBA – Motorcycle or Lawnmower
100dBA – MP3 player at maximum output
110dBA – Orchestra
120dBA – Front row rock concert/Jet Engine
130dBA – Threshold of Pain
140dBA – Military Jet take off/Gunshot (close range)
160dBA – Instant Perforation of eardrum
The system is silent, even at load. The single fan will be inaudible in real world conditions, even with the system reasonably close to the user.