Methodology
We use a Class 1
Bruel & Kjaer 2250-L G4 sound analyzer equipped with a Type 4955a microphone that features a weighted dynamic range of below 6 dBA and up to 110 dBA. All tests are conducted inside a hemi-anechoic chamber at 25–28 °C ambient, and the test subject is placed a meter away from the sound analyzer.
Output Noise Comparison Graphs
The following graphs show the output noise of the QNAP TVS-472XT and compare it to other NAS units we have tested in the past.