Originally posted by the blue1
You'll probably want to use a high pass filter to cut the lows (it passes the highs, see -- which is the same as saying it cuts the lows. It's way easy to slip when talking about these and get that backwards).
Doh, it's just like the x & y axes and the x=0 & the y=0 axes on graphs - always used to get them arse about face as well!