Output Noise

I use a Class 1 Bruel & Kjaer 2250-L G4 sound analyzer equipped with a Type 4955a microphone that features a dBA-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 from the sound analyzer.


Compared to the AS3304T, the fan is dead silent at low speeds and as noisy at full speed. At medium speeds, the AS1104T's fan is slightly noisier. Given both units use the same fan, an OS update most likely changed the fan-speed profiles.

Output Noise Comparison Graphs

The following graphs show the output noise of the AS1104T and compare it to other units I have tested.