Static and high pitch noise from active PA system

[noblescholar4real1]

Hello everyone,
I have an active PA system that produces static noise when a train, tram or car passes by or when an electric switch is put on in anywhere in the building.
How can I solve this please?

 

[jay32267]

Check your grounds. Check to make sure the all the grounded plugs are good. If there's a turntable....that needs to be grounded.

THEN....check all the outlets and makes sure those are TRULY GROUNDED.

 

[americanaudiophile]

You should check the grounding but you might be picking up RF through the electronics or cables. Ferrite cores on the cables might help.
https://en.wikipedia.org/wiki/Ferrite_bead
https://www.amazon.com/Ferrite-Core-Cord-Noise-Suppressor/dp/B0002MQGEK