Yes, that is an option too, but Noctua's fans usually come with Low Noise adapters (basically an in-wire resistor that lowers the voltage to 7V or 5V), so I was thinking maybe trying that one out and seeing if there's a noticable performance loss.
...but it depends a lot also on room temperature and different factors.
Definitely! I'll play around with the setup and see what's the best optimum. Thanks for the input!