10-29-2016, 07:46 PM
It's not electronic. It's like the fan gets back pressure and makes blade noise like propeller airplanes do. It only does it when it's near the perforated metal. It's like there just isn't enough air flow because the perforated metal restricts the air flow. Think of how a small private plane sounds when it warms it's engine. I can't believe these left the factory sounding like this one does. My early SVT is very quiet.