Frequency Plots P12 Max Black (DBB) vs. White (FDB)
10% Fan Speed
There are notable differences at low frequencies (40 – 80 Hz) at this speed.
25% Fan Speed
The DBB version has a noise spike at 1.25 KHz. Both fans register the same spike also at 80 Hz.
50% Fan Speed
I don’t consider the spikes at 50 Hz since they are low and can be caused by the mains network. The spikes at 160 Hz are almost identical.
75% Fan Speed
The FDB fan has a spike at 80 Hz, which is not present in the DBB model. Both fans have spikes in the 200-250 Hz region.
100% Fan Speed
The spike at 50 Hz is present in both fans, and as expected, there is a lower spike (possibly due to harmonics) at 100 Hz. There is also a notable frequency spike at 250 Hz. In general, both fans have similar frequency plots at full speed.
The differences between the DBB and FDB versions in noise output throughout the frequency range are mostly at low rotation speeds: 10% and 25%. At 50%, the FDB fan has a slightly lower noise output; the difference gets smaller at 75%, and at full speed, both fans have almost identical noise output.
Frequency Plots P12 Max Black (DBB) vs. White (FDB)
10% Fan Speed
25% Fan Speed
The second sample I tested has a notable spike at 80 Hz and another one at 1.25 KHz.
50% Fan Speed
75% Fan Speed
100% Fan Speed
The major differences are at 10% and 25% speeds between the two P12 Max Black fans that I tested.
Signal Recordings
P12 Max White (FDB)
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.
10% Fan Speed
25% Fan Speed
50% Fan Speed
75% Fan Speed
100% Fan Speed
P12 Max Black (DBB)
10% Fan Speed
25% Fan Speed
50% Fan Speed
75% Fan Speed
100% Fan Speed
First of all, many thanks Aris!
Well, I was expecting bigger difference at lower RPMs. In the higher I expected very similar results, as it is, because the main source of noise, which covers other sounds, is created by a moving air mass that radiates a sound wave into the environment. And since the geometry of propeller is the same, there should be no major differences.
This 2nd DBB fan is not so disturbing at 10% (although it’s very near) as the 1st DBB (spike at 5 kHz). However, at 25% it is even more annoying than 1st one because of the harmonics/resonance, which starts between 2nd and 3rd second in the recording.
FDB has much nicer sound at 10% and 25% PWM level.
One note: I have one hypothesis as to why the 1st DBB has higher power consumption than the 2nd. The spike at 5 kHz reminds me of grinding/scraping metal on metal. The bearings may not be sufficiently lubricated, or the tolerance of the bearing balls is not tight enough … but its only a guess 😀
for sure there was something wrong with the first sample, since its peak RPM on the longwin were also off.
The double ball bearing model is gone in the US. Arctic decided to change it to FDB.