Frequency Plots
I spotted an unusually high noise level with the fan spinning at 60%, so I decided to do an extensive frequency analysis. During this analysis, I found that at 61% speed, the fan’s noise is way higher than expected because of excessive noise at 400 Hz.
20% Fan Speed
- Ignore the 50 Hz noise from the mains grid. The 400 Hz frequency stands out.
50% Fan Speed
- Peak frequency: 400 Hz
60% Fan Speed
- Peak frequency: 400 Hz
61% Fan Speed
- Peak frequency: 400 Hz
62% Fan Speed
- Peak frequency: 400 Hz
63% Fan Speed
- Peak frequency: 400 Hz
70% Fan Speed
- Peak frequency: 500 Hz
75% Fan Speed
- Peak frequency: 400 Hz
99% Fan Speed
- Peak frequency: 400 Hz
100% Fan Speed
- Peak frequency: 400 Hz
Signal Recordings
I have recorded the signals shown above, but please keep in mind that I’ve enabled Automatic Gain Control (AGC) to do so to make it easier for you to reproduce them. The provided recordings are only offered for aural identification purposes.
20% Fan Speed
50% Fan Speed
60% Fan Speed
61% Fan Speed
62% Fan Speed
63% Fan Speed
70% Fan Speed
75% Fan Speed
99% Fan Speed
100% Fan Speed
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