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
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The output noise is high.
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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And again, the Alphacool Core 4000RPM 120mm is not only 3 times cheaper than the Noctua NF-A12x25 G2 but also better as a radiator fan.