By Andrew Liszewski
If you’ve ever been driven completely mad by the sound of one of your PC’s cooling fans (anyone? no? it’s just me then?) you’ll certainly appreciate the improvements a Swedish company called RotoSub has made to them. While it can’t eliminate the sound of the air rushing through the blades, their R-ANC (Active Noise Control) technology effectively deals with sounds generated by the fan’s mechanical moving parts, which typically are the annoying culprit.
Normally, noise cancelling technologies use a microphone and a separate speaker to generate sound waves that are out-of-phase with the sound being eliminated. And as the two signals combine, they effectively cancel each other out. From what I can tell the R-ANC technology works in a similar fashion, except that instead of a speaker, the noise-cancelling out-of-phase signals are generated by the blades themselves as their ‘angle of attack’ is modulated ever so slightly. The company’s website doesn’t do a great job at explaining how the technology works, but the demonstration in this video below certainly shows it’s effective.
And in case you were wondering, that whole plastic tube setup in the product shot above is just part of their demo system that makes it easier to hear the noises being cancelled. The R-ANC equipped fans will be no different than the fans currently used in desktop computers and other electronics, save for using a touch more electricity in the process.