She alive and a noise beast too at full wack.
2.9v - buzzy rumble (like a fridge)
5.1v - rhythmic rumble (like an aquarium pump) - already more air flow that my NB at full speed
6.1v - blade noise + rumble
7.0v - more blade noise + rumble + slight 'woosh' (quiet rumble when held)
7.8v - more blade noise + quiet rumble + slight 'woosh' (rumble just audible when held)
8.7v - more blade noise + quiet rumble + light 'woosh' (no rumble when held)
9.0v - blade noise + slight rumble + woosh + motor 'wine'
9.5v - blade noise + woosh + motor 'wine'
10v - significant blade noise + motor 'wine'
12v - blade noise + motor 'wine'
5.6v is about as noisy as my nb M12-S2 @ 12v but a more annoying type of noise.
having fan on carpeted floor increased noise of 'rumble'
have fan on wooden shelve significaly increased noise of 'rumble'
7.8v is about the same volume as my 460@40%, the intel stock heatsink and M12-S2 fan together.
7.8v will 'overspin' my M12 if alined - it really shifts some air
Above 10v the motor wine is so loud no woosh can be heard.
It don't sound like a delta
All results are fan in the open resting on carpet with my ear 40cm away.
(brackets) are when held - no change to blade/wine/woosh but rumble significatly reduced
Edit: based on martinm210's youtube chanel it's a lot quiter that the 109R1212H1011 - but same type of rumble (low volts) and wine (high volts)