DUDE, HANG YOU FANS, DUCT WORK, BALLASTS AND EVERYTHING USING RUBBER BLACK BUNGEES, USE 3" DRYWALL TO MAKE LATCHING POINTS. YOU CAN HEAR A SLIGHT BUZZ FROM A NOISY BALLAST, BUT WALK AWAY FEW FEET CANT HERE IT, BUT WHEN BALLAST IS MOUNTED, THEN FLOOR BOARD VIBRATES, THEN UNCLE FESTER IS PISSED...