-- card: 23293 from stack: in
-- bmap block id: 0
-- flags: 0000
-- background id: 3551
-- name: 


-- part contents for background part 3
----- text -----
low-pass filters

-- part contents for background part 4
----- text -----
attenuates frequencies above the cut-off point.

-- part contents for background part 16
----- text -----
177