RotoSub active noise control

The RotoSub fan solution has an active noise control system built into the fan itself, effectively reducing noise.
No external components is required, the active noise control is contained within the fan itself.

The RotoSub active noise control technology requires no anti-noise speakers.
The fan generates the anti-sound inside the fan itself, in the optimum acoustical position.

Since the RotoSub speaker function behaves as a dipole, the noise and anti-sound will be phase aligned in both directions. This allows for simultaneous attenuation upstream as well as downstream.