Output Noise
We used a CEM-8852 Sound DB Meter we installed 50 cm away from the NAS for these measurements. Ambient noise in our lab was below 30 dBA while these noise measurements were taken.
Output noise is kept at fairly low levels. If you choose Low Power Mode in the Fan Speed Mode menu, both fans will stop spinning when the system is cool, similar to a semi-passive mode many highly efficienct PSUs utilize nowadays.
Output Noise Comparison Graphs
The following graphs show the DS416j's output noise and compare it to that of other units we have tested in the past.