Output Noise
I use a Class 1 Bruel & Kjaer 2270 G4 sound analyzer equipped with a Type 4955a microphone with a dBA-weighted dynamic range of below 6 dBA and up to 110 dBA. All tests are conducted inside a hemi-anechoic chamber with a noise floor close to 6 dBA and an ambient temperature of 25–28 °C. The test subject is placed a meter from the sound analyzer.
Full & 70% Speed
Noise output is relatively low, especially at 70% of its maximum speed.
Speed (Percentage) – Noise
I use a different setup to drive the fan for noise measurements, so there might be a difference in the readings of the Longwin machine, especially in the max fan speed reading.
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Why would the white version have a higher noise normalizing RPM than the black version with the same aerodynamic profile? That is, the white version is significantly quieter than the black version?